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34dc7c2f BB |
1 | /* |
2 | * CDDL HEADER START | |
3 | * | |
4 | * The contents of this file are subject to the terms of the | |
5 | * Common Development and Distribution License (the "License"). | |
6 | * You may not use this file except in compliance with the License. | |
7 | * | |
8 | * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE | |
9 | * or http://www.opensolaris.org/os/licensing. | |
10 | * See the License for the specific language governing permissions | |
11 | * and limitations under the License. | |
12 | * | |
13 | * When distributing Covered Code, include this CDDL HEADER in each | |
14 | * file and include the License file at usr/src/OPENSOLARIS.LICENSE. | |
15 | * If applicable, add the following below this CDDL HEADER, with the | |
16 | * fields enclosed by brackets "[]" replaced with your own identifying | |
17 | * information: Portions Copyright [yyyy] [name of copyright owner] | |
18 | * | |
19 | * CDDL HEADER END | |
20 | */ | |
21 | /* | |
428870ff | 22 | * Copyright (c) 2005, 2010, Oracle and/or its affiliates. All rights reserved. |
3541dc6d | 23 | * Copyright 2011 Nexenta Systems, Inc. All rights reserved. |
2e528b49 | 24 | * Copyright (c) 2013 by Delphix. All rights reserved. |
3a17a7a9 | 25 | * Copyright (c) 2013 by Saso Kiselkov. All rights reserved. |
34dc7c2f BB |
26 | */ |
27 | ||
34dc7c2f BB |
28 | /* |
29 | * DVA-based Adjustable Replacement Cache | |
30 | * | |
31 | * While much of the theory of operation used here is | |
32 | * based on the self-tuning, low overhead replacement cache | |
33 | * presented by Megiddo and Modha at FAST 2003, there are some | |
34 | * significant differences: | |
35 | * | |
36 | * 1. The Megiddo and Modha model assumes any page is evictable. | |
37 | * Pages in its cache cannot be "locked" into memory. This makes | |
38 | * the eviction algorithm simple: evict the last page in the list. | |
39 | * This also make the performance characteristics easy to reason | |
40 | * about. Our cache is not so simple. At any given moment, some | |
41 | * subset of the blocks in the cache are un-evictable because we | |
42 | * have handed out a reference to them. Blocks are only evictable | |
43 | * when there are no external references active. This makes | |
44 | * eviction far more problematic: we choose to evict the evictable | |
45 | * blocks that are the "lowest" in the list. | |
46 | * | |
47 | * There are times when it is not possible to evict the requested | |
48 | * space. In these circumstances we are unable to adjust the cache | |
49 | * size. To prevent the cache growing unbounded at these times we | |
50 | * implement a "cache throttle" that slows the flow of new data | |
51 | * into the cache until we can make space available. | |
52 | * | |
53 | * 2. The Megiddo and Modha model assumes a fixed cache size. | |
54 | * Pages are evicted when the cache is full and there is a cache | |
55 | * miss. Our model has a variable sized cache. It grows with | |
56 | * high use, but also tries to react to memory pressure from the | |
57 | * operating system: decreasing its size when system memory is | |
58 | * tight. | |
59 | * | |
60 | * 3. The Megiddo and Modha model assumes a fixed page size. All | |
d3cc8b15 | 61 | * elements of the cache are therefore exactly the same size. So |
34dc7c2f BB |
62 | * when adjusting the cache size following a cache miss, its simply |
63 | * a matter of choosing a single page to evict. In our model, we | |
64 | * have variable sized cache blocks (rangeing from 512 bytes to | |
d3cc8b15 | 65 | * 128K bytes). We therefore choose a set of blocks to evict to make |
34dc7c2f BB |
66 | * space for a cache miss that approximates as closely as possible |
67 | * the space used by the new block. | |
68 | * | |
69 | * See also: "ARC: A Self-Tuning, Low Overhead Replacement Cache" | |
70 | * by N. Megiddo & D. Modha, FAST 2003 | |
71 | */ | |
72 | ||
73 | /* | |
74 | * The locking model: | |
75 | * | |
76 | * A new reference to a cache buffer can be obtained in two | |
77 | * ways: 1) via a hash table lookup using the DVA as a key, | |
78 | * or 2) via one of the ARC lists. The arc_read() interface | |
79 | * uses method 1, while the internal arc algorithms for | |
d3cc8b15 | 80 | * adjusting the cache use method 2. We therefore provide two |
34dc7c2f BB |
81 | * types of locks: 1) the hash table lock array, and 2) the |
82 | * arc list locks. | |
83 | * | |
5c839890 BC |
84 | * Buffers do not have their own mutexes, rather they rely on the |
85 | * hash table mutexes for the bulk of their protection (i.e. most | |
86 | * fields in the arc_buf_hdr_t are protected by these mutexes). | |
34dc7c2f BB |
87 | * |
88 | * buf_hash_find() returns the appropriate mutex (held) when it | |
89 | * locates the requested buffer in the hash table. It returns | |
90 | * NULL for the mutex if the buffer was not in the table. | |
91 | * | |
92 | * buf_hash_remove() expects the appropriate hash mutex to be | |
93 | * already held before it is invoked. | |
94 | * | |
95 | * Each arc state also has a mutex which is used to protect the | |
96 | * buffer list associated with the state. When attempting to | |
97 | * obtain a hash table lock while holding an arc list lock you | |
98 | * must use: mutex_tryenter() to avoid deadlock. Also note that | |
99 | * the active state mutex must be held before the ghost state mutex. | |
100 | * | |
101 | * Arc buffers may have an associated eviction callback function. | |
102 | * This function will be invoked prior to removing the buffer (e.g. | |
103 | * in arc_do_user_evicts()). Note however that the data associated | |
104 | * with the buffer may be evicted prior to the callback. The callback | |
105 | * must be made with *no locks held* (to prevent deadlock). Additionally, | |
106 | * the users of callbacks must ensure that their private data is | |
107 | * protected from simultaneous callbacks from arc_buf_evict() | |
108 | * and arc_do_user_evicts(). | |
109 | * | |
ab26409d BB |
110 | * It as also possible to register a callback which is run when the |
111 | * arc_meta_limit is reached and no buffers can be safely evicted. In | |
112 | * this case the arc user should drop a reference on some arc buffers so | |
113 | * they can be reclaimed and the arc_meta_limit honored. For example, | |
114 | * when using the ZPL each dentry holds a references on a znode. These | |
115 | * dentries must be pruned before the arc buffer holding the znode can | |
116 | * be safely evicted. | |
117 | * | |
34dc7c2f BB |
118 | * Note that the majority of the performance stats are manipulated |
119 | * with atomic operations. | |
120 | * | |
121 | * The L2ARC uses the l2arc_buflist_mtx global mutex for the following: | |
122 | * | |
123 | * - L2ARC buflist creation | |
124 | * - L2ARC buflist eviction | |
125 | * - L2ARC write completion, which walks L2ARC buflists | |
126 | * - ARC header destruction, as it removes from L2ARC buflists | |
127 | * - ARC header release, as it removes from L2ARC buflists | |
128 | */ | |
129 | ||
130 | #include <sys/spa.h> | |
131 | #include <sys/zio.h> | |
3a17a7a9 | 132 | #include <sys/zio_compress.h> |
34dc7c2f BB |
133 | #include <sys/zfs_context.h> |
134 | #include <sys/arc.h> | |
b128c09f | 135 | #include <sys/vdev.h> |
9babb374 | 136 | #include <sys/vdev_impl.h> |
34dc7c2f BB |
137 | #ifdef _KERNEL |
138 | #include <sys/vmsystm.h> | |
139 | #include <vm/anon.h> | |
140 | #include <sys/fs/swapnode.h> | |
ab26409d | 141 | #include <sys/zpl.h> |
34dc7c2f BB |
142 | #endif |
143 | #include <sys/callb.h> | |
144 | #include <sys/kstat.h> | |
570827e1 | 145 | #include <sys/dmu_tx.h> |
428870ff | 146 | #include <zfs_fletcher.h> |
34dc7c2f | 147 | |
498877ba MA |
148 | #ifndef _KERNEL |
149 | /* set with ZFS_DEBUG=watch, to enable watchpoints on frozen buffers */ | |
150 | boolean_t arc_watch = B_FALSE; | |
151 | #endif | |
152 | ||
34dc7c2f BB |
153 | static kmutex_t arc_reclaim_thr_lock; |
154 | static kcondvar_t arc_reclaim_thr_cv; /* used to signal reclaim thr */ | |
155 | static uint8_t arc_thread_exit; | |
156 | ||
ab26409d | 157 | /* number of bytes to prune from caches when at arc_meta_limit is reached */ |
bce45ec9 | 158 | int zfs_arc_meta_prune = 1048576; |
34dc7c2f BB |
159 | |
160 | typedef enum arc_reclaim_strategy { | |
161 | ARC_RECLAIM_AGGR, /* Aggressive reclaim strategy */ | |
162 | ARC_RECLAIM_CONS /* Conservative reclaim strategy */ | |
163 | } arc_reclaim_strategy_t; | |
164 | ||
165 | /* number of seconds before growing cache again */ | |
bce45ec9 | 166 | int zfs_arc_grow_retry = 5; |
34dc7c2f | 167 | |
d164b209 | 168 | /* shift of arc_c for calculating both min and max arc_p */ |
bce45ec9 | 169 | int zfs_arc_p_min_shift = 4; |
d164b209 BB |
170 | |
171 | /* log2(fraction of arc to reclaim) */ | |
bce45ec9 | 172 | int zfs_arc_shrink_shift = 5; |
d164b209 | 173 | |
34dc7c2f BB |
174 | /* |
175 | * minimum lifespan of a prefetch block in clock ticks | |
176 | * (initialized in arc_init()) | |
177 | */ | |
bce45ec9 BB |
178 | int zfs_arc_min_prefetch_lifespan = HZ; |
179 | ||
180 | /* disable arc proactive arc throttle due to low memory */ | |
181 | int zfs_arc_memory_throttle_disable = 1; | |
182 | ||
183 | /* disable duplicate buffer eviction */ | |
184 | int zfs_disable_dup_eviction = 0; | |
34dc7c2f BB |
185 | |
186 | static int arc_dead; | |
187 | ||
bce45ec9 BB |
188 | /* expiration time for arc_no_grow */ |
189 | static clock_t arc_grow_time = 0; | |
190 | ||
b128c09f BB |
191 | /* |
192 | * The arc has filled available memory and has now warmed up. | |
193 | */ | |
194 | static boolean_t arc_warm; | |
195 | ||
34dc7c2f BB |
196 | /* |
197 | * These tunables are for performance analysis. | |
198 | */ | |
c28b2279 BB |
199 | unsigned long zfs_arc_max = 0; |
200 | unsigned long zfs_arc_min = 0; | |
201 | unsigned long zfs_arc_meta_limit = 0; | |
34dc7c2f BB |
202 | |
203 | /* | |
204 | * Note that buffers can be in one of 6 states: | |
205 | * ARC_anon - anonymous (discussed below) | |
206 | * ARC_mru - recently used, currently cached | |
207 | * ARC_mru_ghost - recentely used, no longer in cache | |
208 | * ARC_mfu - frequently used, currently cached | |
209 | * ARC_mfu_ghost - frequently used, no longer in cache | |
210 | * ARC_l2c_only - exists in L2ARC but not other states | |
211 | * When there are no active references to the buffer, they are | |
212 | * are linked onto a list in one of these arc states. These are | |
213 | * the only buffers that can be evicted or deleted. Within each | |
214 | * state there are multiple lists, one for meta-data and one for | |
215 | * non-meta-data. Meta-data (indirect blocks, blocks of dnodes, | |
216 | * etc.) is tracked separately so that it can be managed more | |
217 | * explicitly: favored over data, limited explicitly. | |
218 | * | |
219 | * Anonymous buffers are buffers that are not associated with | |
220 | * a DVA. These are buffers that hold dirty block copies | |
221 | * before they are written to stable storage. By definition, | |
222 | * they are "ref'd" and are considered part of arc_mru | |
223 | * that cannot be freed. Generally, they will aquire a DVA | |
224 | * as they are written and migrate onto the arc_mru list. | |
225 | * | |
226 | * The ARC_l2c_only state is for buffers that are in the second | |
227 | * level ARC but no longer in any of the ARC_m* lists. The second | |
228 | * level ARC itself may also contain buffers that are in any of | |
229 | * the ARC_m* states - meaning that a buffer can exist in two | |
230 | * places. The reason for the ARC_l2c_only state is to keep the | |
231 | * buffer header in the hash table, so that reads that hit the | |
232 | * second level ARC benefit from these fast lookups. | |
233 | */ | |
234 | ||
235 | typedef struct arc_state { | |
236 | list_t arcs_list[ARC_BUFC_NUMTYPES]; /* list of evictable buffers */ | |
237 | uint64_t arcs_lsize[ARC_BUFC_NUMTYPES]; /* amount of evictable data */ | |
238 | uint64_t arcs_size; /* total amount of data in this state */ | |
239 | kmutex_t arcs_mtx; | |
e0b0ca98 | 240 | arc_state_type_t arcs_state; |
34dc7c2f BB |
241 | } arc_state_t; |
242 | ||
243 | /* The 6 states: */ | |
244 | static arc_state_t ARC_anon; | |
245 | static arc_state_t ARC_mru; | |
246 | static arc_state_t ARC_mru_ghost; | |
247 | static arc_state_t ARC_mfu; | |
248 | static arc_state_t ARC_mfu_ghost; | |
249 | static arc_state_t ARC_l2c_only; | |
250 | ||
251 | typedef struct arc_stats { | |
252 | kstat_named_t arcstat_hits; | |
253 | kstat_named_t arcstat_misses; | |
254 | kstat_named_t arcstat_demand_data_hits; | |
255 | kstat_named_t arcstat_demand_data_misses; | |
256 | kstat_named_t arcstat_demand_metadata_hits; | |
257 | kstat_named_t arcstat_demand_metadata_misses; | |
258 | kstat_named_t arcstat_prefetch_data_hits; | |
259 | kstat_named_t arcstat_prefetch_data_misses; | |
260 | kstat_named_t arcstat_prefetch_metadata_hits; | |
261 | kstat_named_t arcstat_prefetch_metadata_misses; | |
262 | kstat_named_t arcstat_mru_hits; | |
263 | kstat_named_t arcstat_mru_ghost_hits; | |
264 | kstat_named_t arcstat_mfu_hits; | |
265 | kstat_named_t arcstat_mfu_ghost_hits; | |
266 | kstat_named_t arcstat_deleted; | |
267 | kstat_named_t arcstat_recycle_miss; | |
e49f1e20 WA |
268 | /* |
269 | * Number of buffers that could not be evicted because the hash lock | |
270 | * was held by another thread. The lock may not necessarily be held | |
271 | * by something using the same buffer, since hash locks are shared | |
272 | * by multiple buffers. | |
273 | */ | |
34dc7c2f | 274 | kstat_named_t arcstat_mutex_miss; |
e49f1e20 WA |
275 | /* |
276 | * Number of buffers skipped because they have I/O in progress, are | |
277 | * indrect prefetch buffers that have not lived long enough, or are | |
278 | * not from the spa we're trying to evict from. | |
279 | */ | |
34dc7c2f | 280 | kstat_named_t arcstat_evict_skip; |
428870ff BB |
281 | kstat_named_t arcstat_evict_l2_cached; |
282 | kstat_named_t arcstat_evict_l2_eligible; | |
283 | kstat_named_t arcstat_evict_l2_ineligible; | |
34dc7c2f BB |
284 | kstat_named_t arcstat_hash_elements; |
285 | kstat_named_t arcstat_hash_elements_max; | |
286 | kstat_named_t arcstat_hash_collisions; | |
287 | kstat_named_t arcstat_hash_chains; | |
288 | kstat_named_t arcstat_hash_chain_max; | |
289 | kstat_named_t arcstat_p; | |
290 | kstat_named_t arcstat_c; | |
291 | kstat_named_t arcstat_c_min; | |
292 | kstat_named_t arcstat_c_max; | |
293 | kstat_named_t arcstat_size; | |
294 | kstat_named_t arcstat_hdr_size; | |
d164b209 BB |
295 | kstat_named_t arcstat_data_size; |
296 | kstat_named_t arcstat_other_size; | |
13be560d BB |
297 | kstat_named_t arcstat_anon_size; |
298 | kstat_named_t arcstat_anon_evict_data; | |
299 | kstat_named_t arcstat_anon_evict_metadata; | |
300 | kstat_named_t arcstat_mru_size; | |
301 | kstat_named_t arcstat_mru_evict_data; | |
302 | kstat_named_t arcstat_mru_evict_metadata; | |
303 | kstat_named_t arcstat_mru_ghost_size; | |
304 | kstat_named_t arcstat_mru_ghost_evict_data; | |
305 | kstat_named_t arcstat_mru_ghost_evict_metadata; | |
306 | kstat_named_t arcstat_mfu_size; | |
307 | kstat_named_t arcstat_mfu_evict_data; | |
308 | kstat_named_t arcstat_mfu_evict_metadata; | |
309 | kstat_named_t arcstat_mfu_ghost_size; | |
310 | kstat_named_t arcstat_mfu_ghost_evict_data; | |
311 | kstat_named_t arcstat_mfu_ghost_evict_metadata; | |
34dc7c2f BB |
312 | kstat_named_t arcstat_l2_hits; |
313 | kstat_named_t arcstat_l2_misses; | |
314 | kstat_named_t arcstat_l2_feeds; | |
315 | kstat_named_t arcstat_l2_rw_clash; | |
d164b209 BB |
316 | kstat_named_t arcstat_l2_read_bytes; |
317 | kstat_named_t arcstat_l2_write_bytes; | |
34dc7c2f BB |
318 | kstat_named_t arcstat_l2_writes_sent; |
319 | kstat_named_t arcstat_l2_writes_done; | |
320 | kstat_named_t arcstat_l2_writes_error; | |
321 | kstat_named_t arcstat_l2_writes_hdr_miss; | |
322 | kstat_named_t arcstat_l2_evict_lock_retry; | |
323 | kstat_named_t arcstat_l2_evict_reading; | |
324 | kstat_named_t arcstat_l2_free_on_write; | |
325 | kstat_named_t arcstat_l2_abort_lowmem; | |
326 | kstat_named_t arcstat_l2_cksum_bad; | |
327 | kstat_named_t arcstat_l2_io_error; | |
328 | kstat_named_t arcstat_l2_size; | |
3a17a7a9 | 329 | kstat_named_t arcstat_l2_asize; |
34dc7c2f | 330 | kstat_named_t arcstat_l2_hdr_size; |
3a17a7a9 SK |
331 | kstat_named_t arcstat_l2_compress_successes; |
332 | kstat_named_t arcstat_l2_compress_zeros; | |
333 | kstat_named_t arcstat_l2_compress_failures; | |
34dc7c2f | 334 | kstat_named_t arcstat_memory_throttle_count; |
1eb5bfa3 GW |
335 | kstat_named_t arcstat_duplicate_buffers; |
336 | kstat_named_t arcstat_duplicate_buffers_size; | |
337 | kstat_named_t arcstat_duplicate_reads; | |
7cb67b45 BB |
338 | kstat_named_t arcstat_memory_direct_count; |
339 | kstat_named_t arcstat_memory_indirect_count; | |
1834f2d8 BB |
340 | kstat_named_t arcstat_no_grow; |
341 | kstat_named_t arcstat_tempreserve; | |
342 | kstat_named_t arcstat_loaned_bytes; | |
ab26409d | 343 | kstat_named_t arcstat_prune; |
1834f2d8 BB |
344 | kstat_named_t arcstat_meta_used; |
345 | kstat_named_t arcstat_meta_limit; | |
346 | kstat_named_t arcstat_meta_max; | |
34dc7c2f BB |
347 | } arc_stats_t; |
348 | ||
349 | static arc_stats_t arc_stats = { | |
350 | { "hits", KSTAT_DATA_UINT64 }, | |
351 | { "misses", KSTAT_DATA_UINT64 }, | |
352 | { "demand_data_hits", KSTAT_DATA_UINT64 }, | |
353 | { "demand_data_misses", KSTAT_DATA_UINT64 }, | |
354 | { "demand_metadata_hits", KSTAT_DATA_UINT64 }, | |
355 | { "demand_metadata_misses", KSTAT_DATA_UINT64 }, | |
356 | { "prefetch_data_hits", KSTAT_DATA_UINT64 }, | |
357 | { "prefetch_data_misses", KSTAT_DATA_UINT64 }, | |
358 | { "prefetch_metadata_hits", KSTAT_DATA_UINT64 }, | |
359 | { "prefetch_metadata_misses", KSTAT_DATA_UINT64 }, | |
360 | { "mru_hits", KSTAT_DATA_UINT64 }, | |
361 | { "mru_ghost_hits", KSTAT_DATA_UINT64 }, | |
362 | { "mfu_hits", KSTAT_DATA_UINT64 }, | |
363 | { "mfu_ghost_hits", KSTAT_DATA_UINT64 }, | |
364 | { "deleted", KSTAT_DATA_UINT64 }, | |
365 | { "recycle_miss", KSTAT_DATA_UINT64 }, | |
366 | { "mutex_miss", KSTAT_DATA_UINT64 }, | |
367 | { "evict_skip", KSTAT_DATA_UINT64 }, | |
428870ff BB |
368 | { "evict_l2_cached", KSTAT_DATA_UINT64 }, |
369 | { "evict_l2_eligible", KSTAT_DATA_UINT64 }, | |
370 | { "evict_l2_ineligible", KSTAT_DATA_UINT64 }, | |
34dc7c2f BB |
371 | { "hash_elements", KSTAT_DATA_UINT64 }, |
372 | { "hash_elements_max", KSTAT_DATA_UINT64 }, | |
373 | { "hash_collisions", KSTAT_DATA_UINT64 }, | |
374 | { "hash_chains", KSTAT_DATA_UINT64 }, | |
375 | { "hash_chain_max", KSTAT_DATA_UINT64 }, | |
376 | { "p", KSTAT_DATA_UINT64 }, | |
377 | { "c", KSTAT_DATA_UINT64 }, | |
378 | { "c_min", KSTAT_DATA_UINT64 }, | |
379 | { "c_max", KSTAT_DATA_UINT64 }, | |
380 | { "size", KSTAT_DATA_UINT64 }, | |
381 | { "hdr_size", KSTAT_DATA_UINT64 }, | |
d164b209 BB |
382 | { "data_size", KSTAT_DATA_UINT64 }, |
383 | { "other_size", KSTAT_DATA_UINT64 }, | |
13be560d BB |
384 | { "anon_size", KSTAT_DATA_UINT64 }, |
385 | { "anon_evict_data", KSTAT_DATA_UINT64 }, | |
386 | { "anon_evict_metadata", KSTAT_DATA_UINT64 }, | |
387 | { "mru_size", KSTAT_DATA_UINT64 }, | |
388 | { "mru_evict_data", KSTAT_DATA_UINT64 }, | |
389 | { "mru_evict_metadata", KSTAT_DATA_UINT64 }, | |
390 | { "mru_ghost_size", KSTAT_DATA_UINT64 }, | |
391 | { "mru_ghost_evict_data", KSTAT_DATA_UINT64 }, | |
392 | { "mru_ghost_evict_metadata", KSTAT_DATA_UINT64 }, | |
393 | { "mfu_size", KSTAT_DATA_UINT64 }, | |
394 | { "mfu_evict_data", KSTAT_DATA_UINT64 }, | |
395 | { "mfu_evict_metadata", KSTAT_DATA_UINT64 }, | |
396 | { "mfu_ghost_size", KSTAT_DATA_UINT64 }, | |
397 | { "mfu_ghost_evict_data", KSTAT_DATA_UINT64 }, | |
398 | { "mfu_ghost_evict_metadata", KSTAT_DATA_UINT64 }, | |
34dc7c2f BB |
399 | { "l2_hits", KSTAT_DATA_UINT64 }, |
400 | { "l2_misses", KSTAT_DATA_UINT64 }, | |
401 | { "l2_feeds", KSTAT_DATA_UINT64 }, | |
402 | { "l2_rw_clash", KSTAT_DATA_UINT64 }, | |
d164b209 BB |
403 | { "l2_read_bytes", KSTAT_DATA_UINT64 }, |
404 | { "l2_write_bytes", KSTAT_DATA_UINT64 }, | |
34dc7c2f BB |
405 | { "l2_writes_sent", KSTAT_DATA_UINT64 }, |
406 | { "l2_writes_done", KSTAT_DATA_UINT64 }, | |
407 | { "l2_writes_error", KSTAT_DATA_UINT64 }, | |
408 | { "l2_writes_hdr_miss", KSTAT_DATA_UINT64 }, | |
409 | { "l2_evict_lock_retry", KSTAT_DATA_UINT64 }, | |
410 | { "l2_evict_reading", KSTAT_DATA_UINT64 }, | |
411 | { "l2_free_on_write", KSTAT_DATA_UINT64 }, | |
412 | { "l2_abort_lowmem", KSTAT_DATA_UINT64 }, | |
413 | { "l2_cksum_bad", KSTAT_DATA_UINT64 }, | |
414 | { "l2_io_error", KSTAT_DATA_UINT64 }, | |
415 | { "l2_size", KSTAT_DATA_UINT64 }, | |
3a17a7a9 | 416 | { "l2_asize", KSTAT_DATA_UINT64 }, |
34dc7c2f | 417 | { "l2_hdr_size", KSTAT_DATA_UINT64 }, |
3a17a7a9 SK |
418 | { "l2_compress_successes", KSTAT_DATA_UINT64 }, |
419 | { "l2_compress_zeros", KSTAT_DATA_UINT64 }, | |
420 | { "l2_compress_failures", KSTAT_DATA_UINT64 }, | |
1834f2d8 | 421 | { "memory_throttle_count", KSTAT_DATA_UINT64 }, |
1eb5bfa3 GW |
422 | { "duplicate_buffers", KSTAT_DATA_UINT64 }, |
423 | { "duplicate_buffers_size", KSTAT_DATA_UINT64 }, | |
424 | { "duplicate_reads", KSTAT_DATA_UINT64 }, | |
7cb67b45 BB |
425 | { "memory_direct_count", KSTAT_DATA_UINT64 }, |
426 | { "memory_indirect_count", KSTAT_DATA_UINT64 }, | |
1834f2d8 BB |
427 | { "arc_no_grow", KSTAT_DATA_UINT64 }, |
428 | { "arc_tempreserve", KSTAT_DATA_UINT64 }, | |
429 | { "arc_loaned_bytes", KSTAT_DATA_UINT64 }, | |
ab26409d | 430 | { "arc_prune", KSTAT_DATA_UINT64 }, |
1834f2d8 BB |
431 | { "arc_meta_used", KSTAT_DATA_UINT64 }, |
432 | { "arc_meta_limit", KSTAT_DATA_UINT64 }, | |
433 | { "arc_meta_max", KSTAT_DATA_UINT64 }, | |
34dc7c2f BB |
434 | }; |
435 | ||
436 | #define ARCSTAT(stat) (arc_stats.stat.value.ui64) | |
437 | ||
438 | #define ARCSTAT_INCR(stat, val) \ | |
d3cc8b15 | 439 | atomic_add_64(&arc_stats.stat.value.ui64, (val)) |
34dc7c2f | 440 | |
428870ff | 441 | #define ARCSTAT_BUMP(stat) ARCSTAT_INCR(stat, 1) |
34dc7c2f BB |
442 | #define ARCSTAT_BUMPDOWN(stat) ARCSTAT_INCR(stat, -1) |
443 | ||
444 | #define ARCSTAT_MAX(stat, val) { \ | |
445 | uint64_t m; \ | |
446 | while ((val) > (m = arc_stats.stat.value.ui64) && \ | |
447 | (m != atomic_cas_64(&arc_stats.stat.value.ui64, m, (val)))) \ | |
448 | continue; \ | |
449 | } | |
450 | ||
451 | #define ARCSTAT_MAXSTAT(stat) \ | |
452 | ARCSTAT_MAX(stat##_max, arc_stats.stat.value.ui64) | |
453 | ||
454 | /* | |
455 | * We define a macro to allow ARC hits/misses to be easily broken down by | |
456 | * two separate conditions, giving a total of four different subtypes for | |
457 | * each of hits and misses (so eight statistics total). | |
458 | */ | |
459 | #define ARCSTAT_CONDSTAT(cond1, stat1, notstat1, cond2, stat2, notstat2, stat) \ | |
460 | if (cond1) { \ | |
461 | if (cond2) { \ | |
462 | ARCSTAT_BUMP(arcstat_##stat1##_##stat2##_##stat); \ | |
463 | } else { \ | |
464 | ARCSTAT_BUMP(arcstat_##stat1##_##notstat2##_##stat); \ | |
465 | } \ | |
466 | } else { \ | |
467 | if (cond2) { \ | |
468 | ARCSTAT_BUMP(arcstat_##notstat1##_##stat2##_##stat); \ | |
469 | } else { \ | |
470 | ARCSTAT_BUMP(arcstat_##notstat1##_##notstat2##_##stat);\ | |
471 | } \ | |
472 | } | |
473 | ||
474 | kstat_t *arc_ksp; | |
428870ff | 475 | static arc_state_t *arc_anon; |
34dc7c2f BB |
476 | static arc_state_t *arc_mru; |
477 | static arc_state_t *arc_mru_ghost; | |
478 | static arc_state_t *arc_mfu; | |
479 | static arc_state_t *arc_mfu_ghost; | |
480 | static arc_state_t *arc_l2c_only; | |
481 | ||
482 | /* | |
483 | * There are several ARC variables that are critical to export as kstats -- | |
484 | * but we don't want to have to grovel around in the kstat whenever we wish to | |
485 | * manipulate them. For these variables, we therefore define them to be in | |
486 | * terms of the statistic variable. This assures that we are not introducing | |
487 | * the possibility of inconsistency by having shadow copies of the variables, | |
488 | * while still allowing the code to be readable. | |
489 | */ | |
490 | #define arc_size ARCSTAT(arcstat_size) /* actual total arc size */ | |
491 | #define arc_p ARCSTAT(arcstat_p) /* target size of MRU */ | |
492 | #define arc_c ARCSTAT(arcstat_c) /* target size of cache */ | |
493 | #define arc_c_min ARCSTAT(arcstat_c_min) /* min target cache size */ | |
494 | #define arc_c_max ARCSTAT(arcstat_c_max) /* max target cache size */ | |
1834f2d8 BB |
495 | #define arc_no_grow ARCSTAT(arcstat_no_grow) |
496 | #define arc_tempreserve ARCSTAT(arcstat_tempreserve) | |
497 | #define arc_loaned_bytes ARCSTAT(arcstat_loaned_bytes) | |
23c0a133 GW |
498 | #define arc_meta_limit ARCSTAT(arcstat_meta_limit) /* max size for metadata */ |
499 | #define arc_meta_used ARCSTAT(arcstat_meta_used) /* size of metadata */ | |
500 | #define arc_meta_max ARCSTAT(arcstat_meta_max) /* max size of metadata */ | |
34dc7c2f | 501 | |
3a17a7a9 SK |
502 | #define L2ARC_IS_VALID_COMPRESS(_c_) \ |
503 | ((_c_) == ZIO_COMPRESS_LZ4 || (_c_) == ZIO_COMPRESS_EMPTY) | |
504 | ||
34dc7c2f BB |
505 | typedef struct l2arc_buf_hdr l2arc_buf_hdr_t; |
506 | ||
507 | typedef struct arc_callback arc_callback_t; | |
508 | ||
509 | struct arc_callback { | |
510 | void *acb_private; | |
511 | arc_done_func_t *acb_done; | |
34dc7c2f BB |
512 | arc_buf_t *acb_buf; |
513 | zio_t *acb_zio_dummy; | |
514 | arc_callback_t *acb_next; | |
515 | }; | |
516 | ||
517 | typedef struct arc_write_callback arc_write_callback_t; | |
518 | ||
519 | struct arc_write_callback { | |
520 | void *awcb_private; | |
521 | arc_done_func_t *awcb_ready; | |
522 | arc_done_func_t *awcb_done; | |
523 | arc_buf_t *awcb_buf; | |
524 | }; | |
525 | ||
526 | struct arc_buf_hdr { | |
527 | /* protected by hash lock */ | |
528 | dva_t b_dva; | |
529 | uint64_t b_birth; | |
530 | uint64_t b_cksum0; | |
531 | ||
532 | kmutex_t b_freeze_lock; | |
533 | zio_cksum_t *b_freeze_cksum; | |
534 | ||
535 | arc_buf_hdr_t *b_hash_next; | |
536 | arc_buf_t *b_buf; | |
537 | uint32_t b_flags; | |
538 | uint32_t b_datacnt; | |
539 | ||
540 | arc_callback_t *b_acb; | |
541 | kcondvar_t b_cv; | |
542 | ||
543 | /* immutable */ | |
544 | arc_buf_contents_t b_type; | |
545 | uint64_t b_size; | |
d164b209 | 546 | uint64_t b_spa; |
34dc7c2f BB |
547 | |
548 | /* protected by arc state mutex */ | |
549 | arc_state_t *b_state; | |
550 | list_node_t b_arc_node; | |
551 | ||
552 | /* updated atomically */ | |
553 | clock_t b_arc_access; | |
e0b0ca98 BB |
554 | uint32_t b_mru_hits; |
555 | uint32_t b_mru_ghost_hits; | |
556 | uint32_t b_mfu_hits; | |
557 | uint32_t b_mfu_ghost_hits; | |
558 | uint32_t b_l2_hits; | |
34dc7c2f BB |
559 | |
560 | /* self protecting */ | |
561 | refcount_t b_refcnt; | |
562 | ||
563 | l2arc_buf_hdr_t *b_l2hdr; | |
564 | list_node_t b_l2node; | |
565 | }; | |
566 | ||
ab26409d BB |
567 | static list_t arc_prune_list; |
568 | static kmutex_t arc_prune_mtx; | |
34dc7c2f BB |
569 | static arc_buf_t *arc_eviction_list; |
570 | static kmutex_t arc_eviction_mtx; | |
571 | static arc_buf_hdr_t arc_eviction_hdr; | |
572 | static void arc_get_data_buf(arc_buf_t *buf); | |
573 | static void arc_access(arc_buf_hdr_t *buf, kmutex_t *hash_lock); | |
574 | static int arc_evict_needed(arc_buf_contents_t type); | |
68121a03 BB |
575 | static void arc_evict_ghost(arc_state_t *state, uint64_t spa, int64_t bytes, |
576 | arc_buf_contents_t type); | |
498877ba | 577 | static void arc_buf_watch(arc_buf_t *buf); |
34dc7c2f | 578 | |
428870ff BB |
579 | static boolean_t l2arc_write_eligible(uint64_t spa_guid, arc_buf_hdr_t *ab); |
580 | ||
34dc7c2f BB |
581 | #define GHOST_STATE(state) \ |
582 | ((state) == arc_mru_ghost || (state) == arc_mfu_ghost || \ | |
583 | (state) == arc_l2c_only) | |
584 | ||
585 | /* | |
586 | * Private ARC flags. These flags are private ARC only flags that will show up | |
587 | * in b_flags in the arc_hdr_buf_t. Some flags are publicly declared, and can | |
588 | * be passed in as arc_flags in things like arc_read. However, these flags | |
589 | * should never be passed and should only be set by ARC code. When adding new | |
590 | * public flags, make sure not to smash the private ones. | |
591 | */ | |
592 | ||
593 | #define ARC_IN_HASH_TABLE (1 << 9) /* this buffer is hashed */ | |
594 | #define ARC_IO_IN_PROGRESS (1 << 10) /* I/O in progress for buf */ | |
595 | #define ARC_IO_ERROR (1 << 11) /* I/O failed for buf */ | |
596 | #define ARC_FREED_IN_READ (1 << 12) /* buf freed while in read */ | |
597 | #define ARC_BUF_AVAILABLE (1 << 13) /* block not in active use */ | |
598 | #define ARC_INDIRECT (1 << 14) /* this is an indirect block */ | |
599 | #define ARC_FREE_IN_PROGRESS (1 << 15) /* hdr about to be freed */ | |
b128c09f BB |
600 | #define ARC_L2_WRITING (1 << 16) /* L2ARC write in progress */ |
601 | #define ARC_L2_EVICTED (1 << 17) /* evicted during I/O */ | |
602 | #define ARC_L2_WRITE_HEAD (1 << 18) /* head of write list */ | |
34dc7c2f BB |
603 | |
604 | #define HDR_IN_HASH_TABLE(hdr) ((hdr)->b_flags & ARC_IN_HASH_TABLE) | |
605 | #define HDR_IO_IN_PROGRESS(hdr) ((hdr)->b_flags & ARC_IO_IN_PROGRESS) | |
606 | #define HDR_IO_ERROR(hdr) ((hdr)->b_flags & ARC_IO_ERROR) | |
d164b209 | 607 | #define HDR_PREFETCH(hdr) ((hdr)->b_flags & ARC_PREFETCH) |
34dc7c2f BB |
608 | #define HDR_FREED_IN_READ(hdr) ((hdr)->b_flags & ARC_FREED_IN_READ) |
609 | #define HDR_BUF_AVAILABLE(hdr) ((hdr)->b_flags & ARC_BUF_AVAILABLE) | |
610 | #define HDR_FREE_IN_PROGRESS(hdr) ((hdr)->b_flags & ARC_FREE_IN_PROGRESS) | |
b128c09f BB |
611 | #define HDR_L2CACHE(hdr) ((hdr)->b_flags & ARC_L2CACHE) |
612 | #define HDR_L2_READING(hdr) ((hdr)->b_flags & ARC_IO_IN_PROGRESS && \ | |
613 | (hdr)->b_l2hdr != NULL) | |
34dc7c2f BB |
614 | #define HDR_L2_WRITING(hdr) ((hdr)->b_flags & ARC_L2_WRITING) |
615 | #define HDR_L2_EVICTED(hdr) ((hdr)->b_flags & ARC_L2_EVICTED) | |
616 | #define HDR_L2_WRITE_HEAD(hdr) ((hdr)->b_flags & ARC_L2_WRITE_HEAD) | |
617 | ||
618 | /* | |
619 | * Other sizes | |
620 | */ | |
621 | ||
622 | #define HDR_SIZE ((int64_t)sizeof (arc_buf_hdr_t)) | |
623 | #define L2HDR_SIZE ((int64_t)sizeof (l2arc_buf_hdr_t)) | |
624 | ||
625 | /* | |
626 | * Hash table routines | |
627 | */ | |
628 | ||
00b46022 BB |
629 | #define HT_LOCK_ALIGN 64 |
630 | #define HT_LOCK_PAD (P2NPHASE(sizeof (kmutex_t), (HT_LOCK_ALIGN))) | |
34dc7c2f BB |
631 | |
632 | struct ht_lock { | |
633 | kmutex_t ht_lock; | |
634 | #ifdef _KERNEL | |
00b46022 | 635 | unsigned char pad[HT_LOCK_PAD]; |
34dc7c2f BB |
636 | #endif |
637 | }; | |
638 | ||
639 | #define BUF_LOCKS 256 | |
640 | typedef struct buf_hash_table { | |
641 | uint64_t ht_mask; | |
642 | arc_buf_hdr_t **ht_table; | |
643 | struct ht_lock ht_locks[BUF_LOCKS]; | |
644 | } buf_hash_table_t; | |
645 | ||
646 | static buf_hash_table_t buf_hash_table; | |
647 | ||
648 | #define BUF_HASH_INDEX(spa, dva, birth) \ | |
649 | (buf_hash(spa, dva, birth) & buf_hash_table.ht_mask) | |
650 | #define BUF_HASH_LOCK_NTRY(idx) (buf_hash_table.ht_locks[idx & (BUF_LOCKS-1)]) | |
651 | #define BUF_HASH_LOCK(idx) (&(BUF_HASH_LOCK_NTRY(idx).ht_lock)) | |
428870ff BB |
652 | #define HDR_LOCK(hdr) \ |
653 | (BUF_HASH_LOCK(BUF_HASH_INDEX(hdr->b_spa, &hdr->b_dva, hdr->b_birth))) | |
34dc7c2f BB |
654 | |
655 | uint64_t zfs_crc64_table[256]; | |
656 | ||
657 | /* | |
658 | * Level 2 ARC | |
659 | */ | |
660 | ||
661 | #define L2ARC_WRITE_SIZE (8 * 1024 * 1024) /* initial write max */ | |
3a17a7a9 SK |
662 | #define L2ARC_HEADROOM 2 /* num of writes */ |
663 | /* | |
664 | * If we discover during ARC scan any buffers to be compressed, we boost | |
665 | * our headroom for the next scanning cycle by this percentage multiple. | |
666 | */ | |
667 | #define L2ARC_HEADROOM_BOOST 200 | |
d164b209 BB |
668 | #define L2ARC_FEED_SECS 1 /* caching interval secs */ |
669 | #define L2ARC_FEED_MIN_MS 200 /* min caching interval ms */ | |
34dc7c2f BB |
670 | |
671 | #define l2arc_writes_sent ARCSTAT(arcstat_l2_writes_sent) | |
672 | #define l2arc_writes_done ARCSTAT(arcstat_l2_writes_done) | |
673 | ||
d3cc8b15 | 674 | /* L2ARC Performance Tunables */ |
abd8610c BB |
675 | unsigned long l2arc_write_max = L2ARC_WRITE_SIZE; /* def max write size */ |
676 | unsigned long l2arc_write_boost = L2ARC_WRITE_SIZE; /* extra warmup write */ | |
677 | unsigned long l2arc_headroom = L2ARC_HEADROOM; /* # of dev writes */ | |
3a17a7a9 | 678 | unsigned long l2arc_headroom_boost = L2ARC_HEADROOM_BOOST; |
abd8610c BB |
679 | unsigned long l2arc_feed_secs = L2ARC_FEED_SECS; /* interval seconds */ |
680 | unsigned long l2arc_feed_min_ms = L2ARC_FEED_MIN_MS; /* min interval msecs */ | |
681 | int l2arc_noprefetch = B_TRUE; /* don't cache prefetch bufs */ | |
3a17a7a9 | 682 | int l2arc_nocompress = B_FALSE; /* don't compress bufs */ |
abd8610c | 683 | int l2arc_feed_again = B_TRUE; /* turbo warmup */ |
c93504f0 | 684 | int l2arc_norw = B_FALSE; /* no reads during writes */ |
34dc7c2f BB |
685 | |
686 | /* | |
687 | * L2ARC Internals | |
688 | */ | |
689 | typedef struct l2arc_dev { | |
690 | vdev_t *l2ad_vdev; /* vdev */ | |
691 | spa_t *l2ad_spa; /* spa */ | |
692 | uint64_t l2ad_hand; /* next write location */ | |
34dc7c2f BB |
693 | uint64_t l2ad_start; /* first addr on device */ |
694 | uint64_t l2ad_end; /* last addr on device */ | |
695 | uint64_t l2ad_evict; /* last addr eviction reached */ | |
696 | boolean_t l2ad_first; /* first sweep through */ | |
d164b209 | 697 | boolean_t l2ad_writing; /* currently writing */ |
34dc7c2f BB |
698 | list_t *l2ad_buflist; /* buffer list */ |
699 | list_node_t l2ad_node; /* device list node */ | |
700 | } l2arc_dev_t; | |
701 | ||
702 | static list_t L2ARC_dev_list; /* device list */ | |
703 | static list_t *l2arc_dev_list; /* device list pointer */ | |
704 | static kmutex_t l2arc_dev_mtx; /* device list mutex */ | |
705 | static l2arc_dev_t *l2arc_dev_last; /* last device used */ | |
706 | static kmutex_t l2arc_buflist_mtx; /* mutex for all buflists */ | |
707 | static list_t L2ARC_free_on_write; /* free after write buf list */ | |
708 | static list_t *l2arc_free_on_write; /* free after write list ptr */ | |
709 | static kmutex_t l2arc_free_on_write_mtx; /* mutex for list */ | |
710 | static uint64_t l2arc_ndev; /* number of devices */ | |
711 | ||
712 | typedef struct l2arc_read_callback { | |
3a17a7a9 SK |
713 | arc_buf_t *l2rcb_buf; /* read buffer */ |
714 | spa_t *l2rcb_spa; /* spa */ | |
715 | blkptr_t l2rcb_bp; /* original blkptr */ | |
716 | zbookmark_t l2rcb_zb; /* original bookmark */ | |
717 | int l2rcb_flags; /* original flags */ | |
718 | enum zio_compress l2rcb_compress; /* applied compress */ | |
34dc7c2f BB |
719 | } l2arc_read_callback_t; |
720 | ||
721 | typedef struct l2arc_write_callback { | |
722 | l2arc_dev_t *l2wcb_dev; /* device info */ | |
723 | arc_buf_hdr_t *l2wcb_head; /* head of write buflist */ | |
724 | } l2arc_write_callback_t; | |
725 | ||
726 | struct l2arc_buf_hdr { | |
727 | /* protected by arc_buf_hdr mutex */ | |
3a17a7a9 SK |
728 | l2arc_dev_t *b_dev; /* L2ARC device */ |
729 | uint64_t b_daddr; /* disk address, offset byte */ | |
730 | /* compression applied to buffer data */ | |
731 | enum zio_compress b_compress; | |
732 | /* real alloc'd buffer size depending on b_compress applied */ | |
e0b0ca98 BB |
733 | uint32_t b_asize; |
734 | uint32_t b_hits; | |
3a17a7a9 SK |
735 | /* temporary buffer holder for in-flight compressed data */ |
736 | void *b_tmp_cdata; | |
34dc7c2f BB |
737 | }; |
738 | ||
739 | typedef struct l2arc_data_free { | |
740 | /* protected by l2arc_free_on_write_mtx */ | |
741 | void *l2df_data; | |
742 | size_t l2df_size; | |
743 | void (*l2df_func)(void *, size_t); | |
744 | list_node_t l2df_list_node; | |
745 | } l2arc_data_free_t; | |
746 | ||
747 | static kmutex_t l2arc_feed_thr_lock; | |
748 | static kcondvar_t l2arc_feed_thr_cv; | |
749 | static uint8_t l2arc_thread_exit; | |
750 | ||
751 | static void l2arc_read_done(zio_t *zio); | |
752 | static void l2arc_hdr_stat_add(void); | |
753 | static void l2arc_hdr_stat_remove(void); | |
754 | ||
3a17a7a9 SK |
755 | static boolean_t l2arc_compress_buf(l2arc_buf_hdr_t *l2hdr); |
756 | static void l2arc_decompress_zio(zio_t *zio, arc_buf_hdr_t *hdr, | |
757 | enum zio_compress c); | |
758 | static void l2arc_release_cdata_buf(arc_buf_hdr_t *ab); | |
759 | ||
34dc7c2f | 760 | static uint64_t |
d164b209 | 761 | buf_hash(uint64_t spa, const dva_t *dva, uint64_t birth) |
34dc7c2f | 762 | { |
34dc7c2f BB |
763 | uint8_t *vdva = (uint8_t *)dva; |
764 | uint64_t crc = -1ULL; | |
765 | int i; | |
766 | ||
767 | ASSERT(zfs_crc64_table[128] == ZFS_CRC64_POLY); | |
768 | ||
769 | for (i = 0; i < sizeof (dva_t); i++) | |
770 | crc = (crc >> 8) ^ zfs_crc64_table[(crc ^ vdva[i]) & 0xFF]; | |
771 | ||
d164b209 | 772 | crc ^= (spa>>8) ^ birth; |
34dc7c2f BB |
773 | |
774 | return (crc); | |
775 | } | |
776 | ||
777 | #define BUF_EMPTY(buf) \ | |
778 | ((buf)->b_dva.dva_word[0] == 0 && \ | |
779 | (buf)->b_dva.dva_word[1] == 0 && \ | |
780 | (buf)->b_birth == 0) | |
781 | ||
782 | #define BUF_EQUAL(spa, dva, birth, buf) \ | |
783 | ((buf)->b_dva.dva_word[0] == (dva)->dva_word[0]) && \ | |
784 | ((buf)->b_dva.dva_word[1] == (dva)->dva_word[1]) && \ | |
785 | ((buf)->b_birth == birth) && ((buf)->b_spa == spa) | |
786 | ||
428870ff BB |
787 | static void |
788 | buf_discard_identity(arc_buf_hdr_t *hdr) | |
789 | { | |
790 | hdr->b_dva.dva_word[0] = 0; | |
791 | hdr->b_dva.dva_word[1] = 0; | |
792 | hdr->b_birth = 0; | |
793 | hdr->b_cksum0 = 0; | |
794 | } | |
795 | ||
34dc7c2f | 796 | static arc_buf_hdr_t * |
d164b209 | 797 | buf_hash_find(uint64_t spa, const dva_t *dva, uint64_t birth, kmutex_t **lockp) |
34dc7c2f BB |
798 | { |
799 | uint64_t idx = BUF_HASH_INDEX(spa, dva, birth); | |
800 | kmutex_t *hash_lock = BUF_HASH_LOCK(idx); | |
801 | arc_buf_hdr_t *buf; | |
802 | ||
803 | mutex_enter(hash_lock); | |
804 | for (buf = buf_hash_table.ht_table[idx]; buf != NULL; | |
805 | buf = buf->b_hash_next) { | |
806 | if (BUF_EQUAL(spa, dva, birth, buf)) { | |
807 | *lockp = hash_lock; | |
808 | return (buf); | |
809 | } | |
810 | } | |
811 | mutex_exit(hash_lock); | |
812 | *lockp = NULL; | |
813 | return (NULL); | |
814 | } | |
815 | ||
816 | /* | |
817 | * Insert an entry into the hash table. If there is already an element | |
818 | * equal to elem in the hash table, then the already existing element | |
819 | * will be returned and the new element will not be inserted. | |
820 | * Otherwise returns NULL. | |
821 | */ | |
822 | static arc_buf_hdr_t * | |
823 | buf_hash_insert(arc_buf_hdr_t *buf, kmutex_t **lockp) | |
824 | { | |
825 | uint64_t idx = BUF_HASH_INDEX(buf->b_spa, &buf->b_dva, buf->b_birth); | |
826 | kmutex_t *hash_lock = BUF_HASH_LOCK(idx); | |
827 | arc_buf_hdr_t *fbuf; | |
828 | uint32_t i; | |
829 | ||
830 | ASSERT(!HDR_IN_HASH_TABLE(buf)); | |
831 | *lockp = hash_lock; | |
832 | mutex_enter(hash_lock); | |
833 | for (fbuf = buf_hash_table.ht_table[idx], i = 0; fbuf != NULL; | |
834 | fbuf = fbuf->b_hash_next, i++) { | |
835 | if (BUF_EQUAL(buf->b_spa, &buf->b_dva, buf->b_birth, fbuf)) | |
836 | return (fbuf); | |
837 | } | |
838 | ||
839 | buf->b_hash_next = buf_hash_table.ht_table[idx]; | |
840 | buf_hash_table.ht_table[idx] = buf; | |
841 | buf->b_flags |= ARC_IN_HASH_TABLE; | |
842 | ||
843 | /* collect some hash table performance data */ | |
844 | if (i > 0) { | |
845 | ARCSTAT_BUMP(arcstat_hash_collisions); | |
846 | if (i == 1) | |
847 | ARCSTAT_BUMP(arcstat_hash_chains); | |
848 | ||
849 | ARCSTAT_MAX(arcstat_hash_chain_max, i); | |
850 | } | |
851 | ||
852 | ARCSTAT_BUMP(arcstat_hash_elements); | |
853 | ARCSTAT_MAXSTAT(arcstat_hash_elements); | |
854 | ||
855 | return (NULL); | |
856 | } | |
857 | ||
858 | static void | |
859 | buf_hash_remove(arc_buf_hdr_t *buf) | |
860 | { | |
861 | arc_buf_hdr_t *fbuf, **bufp; | |
862 | uint64_t idx = BUF_HASH_INDEX(buf->b_spa, &buf->b_dva, buf->b_birth); | |
863 | ||
864 | ASSERT(MUTEX_HELD(BUF_HASH_LOCK(idx))); | |
865 | ASSERT(HDR_IN_HASH_TABLE(buf)); | |
866 | ||
867 | bufp = &buf_hash_table.ht_table[idx]; | |
868 | while ((fbuf = *bufp) != buf) { | |
869 | ASSERT(fbuf != NULL); | |
870 | bufp = &fbuf->b_hash_next; | |
871 | } | |
872 | *bufp = buf->b_hash_next; | |
873 | buf->b_hash_next = NULL; | |
874 | buf->b_flags &= ~ARC_IN_HASH_TABLE; | |
875 | ||
876 | /* collect some hash table performance data */ | |
877 | ARCSTAT_BUMPDOWN(arcstat_hash_elements); | |
878 | ||
879 | if (buf_hash_table.ht_table[idx] && | |
880 | buf_hash_table.ht_table[idx]->b_hash_next == NULL) | |
881 | ARCSTAT_BUMPDOWN(arcstat_hash_chains); | |
882 | } | |
883 | ||
884 | /* | |
885 | * Global data structures and functions for the buf kmem cache. | |
886 | */ | |
887 | static kmem_cache_t *hdr_cache; | |
888 | static kmem_cache_t *buf_cache; | |
889 | ||
890 | static void | |
891 | buf_fini(void) | |
892 | { | |
893 | int i; | |
894 | ||
00b46022 BB |
895 | #if defined(_KERNEL) && defined(HAVE_SPL) |
896 | /* Large allocations which do not require contiguous pages | |
897 | * should be using vmem_free() in the linux kernel */ | |
898 | vmem_free(buf_hash_table.ht_table, | |
899 | (buf_hash_table.ht_mask + 1) * sizeof (void *)); | |
900 | #else | |
34dc7c2f BB |
901 | kmem_free(buf_hash_table.ht_table, |
902 | (buf_hash_table.ht_mask + 1) * sizeof (void *)); | |
00b46022 | 903 | #endif |
34dc7c2f BB |
904 | for (i = 0; i < BUF_LOCKS; i++) |
905 | mutex_destroy(&buf_hash_table.ht_locks[i].ht_lock); | |
906 | kmem_cache_destroy(hdr_cache); | |
907 | kmem_cache_destroy(buf_cache); | |
908 | } | |
909 | ||
910 | /* | |
911 | * Constructor callback - called when the cache is empty | |
912 | * and a new buf is requested. | |
913 | */ | |
914 | /* ARGSUSED */ | |
915 | static int | |
916 | hdr_cons(void *vbuf, void *unused, int kmflag) | |
917 | { | |
918 | arc_buf_hdr_t *buf = vbuf; | |
919 | ||
920 | bzero(buf, sizeof (arc_buf_hdr_t)); | |
921 | refcount_create(&buf->b_refcnt); | |
922 | cv_init(&buf->b_cv, NULL, CV_DEFAULT, NULL); | |
923 | mutex_init(&buf->b_freeze_lock, NULL, MUTEX_DEFAULT, NULL); | |
98f72a53 BB |
924 | list_link_init(&buf->b_arc_node); |
925 | list_link_init(&buf->b_l2node); | |
d164b209 | 926 | arc_space_consume(sizeof (arc_buf_hdr_t), ARC_SPACE_HDRS); |
34dc7c2f | 927 | |
34dc7c2f BB |
928 | return (0); |
929 | } | |
930 | ||
b128c09f BB |
931 | /* ARGSUSED */ |
932 | static int | |
933 | buf_cons(void *vbuf, void *unused, int kmflag) | |
934 | { | |
935 | arc_buf_t *buf = vbuf; | |
936 | ||
937 | bzero(buf, sizeof (arc_buf_t)); | |
428870ff | 938 | mutex_init(&buf->b_evict_lock, NULL, MUTEX_DEFAULT, NULL); |
d164b209 BB |
939 | arc_space_consume(sizeof (arc_buf_t), ARC_SPACE_HDRS); |
940 | ||
b128c09f BB |
941 | return (0); |
942 | } | |
943 | ||
34dc7c2f BB |
944 | /* |
945 | * Destructor callback - called when a cached buf is | |
946 | * no longer required. | |
947 | */ | |
948 | /* ARGSUSED */ | |
949 | static void | |
950 | hdr_dest(void *vbuf, void *unused) | |
951 | { | |
952 | arc_buf_hdr_t *buf = vbuf; | |
953 | ||
428870ff | 954 | ASSERT(BUF_EMPTY(buf)); |
34dc7c2f BB |
955 | refcount_destroy(&buf->b_refcnt); |
956 | cv_destroy(&buf->b_cv); | |
957 | mutex_destroy(&buf->b_freeze_lock); | |
d164b209 | 958 | arc_space_return(sizeof (arc_buf_hdr_t), ARC_SPACE_HDRS); |
34dc7c2f BB |
959 | } |
960 | ||
b128c09f BB |
961 | /* ARGSUSED */ |
962 | static void | |
963 | buf_dest(void *vbuf, void *unused) | |
964 | { | |
965 | arc_buf_t *buf = vbuf; | |
966 | ||
428870ff | 967 | mutex_destroy(&buf->b_evict_lock); |
d164b209 | 968 | arc_space_return(sizeof (arc_buf_t), ARC_SPACE_HDRS); |
b128c09f BB |
969 | } |
970 | ||
34dc7c2f BB |
971 | static void |
972 | buf_init(void) | |
973 | { | |
974 | uint64_t *ct; | |
975 | uint64_t hsize = 1ULL << 12; | |
976 | int i, j; | |
977 | ||
978 | /* | |
979 | * The hash table is big enough to fill all of physical memory | |
980 | * with an average 64K block size. The table will take up | |
981 | * totalmem*sizeof(void*)/64K (eg. 128KB/GB with 8-byte pointers). | |
982 | */ | |
983 | while (hsize * 65536 < physmem * PAGESIZE) | |
984 | hsize <<= 1; | |
985 | retry: | |
986 | buf_hash_table.ht_mask = hsize - 1; | |
00b46022 BB |
987 | #if defined(_KERNEL) && defined(HAVE_SPL) |
988 | /* Large allocations which do not require contiguous pages | |
989 | * should be using vmem_alloc() in the linux kernel */ | |
990 | buf_hash_table.ht_table = | |
991 | vmem_zalloc(hsize * sizeof (void*), KM_SLEEP); | |
992 | #else | |
34dc7c2f BB |
993 | buf_hash_table.ht_table = |
994 | kmem_zalloc(hsize * sizeof (void*), KM_NOSLEEP); | |
00b46022 | 995 | #endif |
34dc7c2f BB |
996 | if (buf_hash_table.ht_table == NULL) { |
997 | ASSERT(hsize > (1ULL << 8)); | |
998 | hsize >>= 1; | |
999 | goto retry; | |
1000 | } | |
1001 | ||
1002 | hdr_cache = kmem_cache_create("arc_buf_hdr_t", sizeof (arc_buf_hdr_t), | |
302f753f | 1003 | 0, hdr_cons, hdr_dest, NULL, NULL, NULL, 0); |
34dc7c2f | 1004 | buf_cache = kmem_cache_create("arc_buf_t", sizeof (arc_buf_t), |
b128c09f | 1005 | 0, buf_cons, buf_dest, NULL, NULL, NULL, 0); |
34dc7c2f BB |
1006 | |
1007 | for (i = 0; i < 256; i++) | |
1008 | for (ct = zfs_crc64_table + i, *ct = i, j = 8; j > 0; j--) | |
1009 | *ct = (*ct >> 1) ^ (-(*ct & 1) & ZFS_CRC64_POLY); | |
1010 | ||
1011 | for (i = 0; i < BUF_LOCKS; i++) { | |
1012 | mutex_init(&buf_hash_table.ht_locks[i].ht_lock, | |
1013 | NULL, MUTEX_DEFAULT, NULL); | |
1014 | } | |
1015 | } | |
1016 | ||
1017 | #define ARC_MINTIME (hz>>4) /* 62 ms */ | |
1018 | ||
1019 | static void | |
1020 | arc_cksum_verify(arc_buf_t *buf) | |
1021 | { | |
1022 | zio_cksum_t zc; | |
1023 | ||
1024 | if (!(zfs_flags & ZFS_DEBUG_MODIFY)) | |
1025 | return; | |
1026 | ||
1027 | mutex_enter(&buf->b_hdr->b_freeze_lock); | |
1028 | if (buf->b_hdr->b_freeze_cksum == NULL || | |
1029 | (buf->b_hdr->b_flags & ARC_IO_ERROR)) { | |
1030 | mutex_exit(&buf->b_hdr->b_freeze_lock); | |
1031 | return; | |
1032 | } | |
1033 | fletcher_2_native(buf->b_data, buf->b_hdr->b_size, &zc); | |
1034 | if (!ZIO_CHECKSUM_EQUAL(*buf->b_hdr->b_freeze_cksum, zc)) | |
1035 | panic("buffer modified while frozen!"); | |
1036 | mutex_exit(&buf->b_hdr->b_freeze_lock); | |
1037 | } | |
1038 | ||
1039 | static int | |
1040 | arc_cksum_equal(arc_buf_t *buf) | |
1041 | { | |
1042 | zio_cksum_t zc; | |
1043 | int equal; | |
1044 | ||
1045 | mutex_enter(&buf->b_hdr->b_freeze_lock); | |
1046 | fletcher_2_native(buf->b_data, buf->b_hdr->b_size, &zc); | |
1047 | equal = ZIO_CHECKSUM_EQUAL(*buf->b_hdr->b_freeze_cksum, zc); | |
1048 | mutex_exit(&buf->b_hdr->b_freeze_lock); | |
1049 | ||
1050 | return (equal); | |
1051 | } | |
1052 | ||
1053 | static void | |
1054 | arc_cksum_compute(arc_buf_t *buf, boolean_t force) | |
1055 | { | |
1056 | if (!force && !(zfs_flags & ZFS_DEBUG_MODIFY)) | |
1057 | return; | |
1058 | ||
1059 | mutex_enter(&buf->b_hdr->b_freeze_lock); | |
1060 | if (buf->b_hdr->b_freeze_cksum != NULL) { | |
1061 | mutex_exit(&buf->b_hdr->b_freeze_lock); | |
1062 | return; | |
1063 | } | |
409dc1a5 PS |
1064 | buf->b_hdr->b_freeze_cksum = kmem_alloc(sizeof (zio_cksum_t), |
1065 | KM_PUSHPAGE); | |
34dc7c2f BB |
1066 | fletcher_2_native(buf->b_data, buf->b_hdr->b_size, |
1067 | buf->b_hdr->b_freeze_cksum); | |
1068 | mutex_exit(&buf->b_hdr->b_freeze_lock); | |
498877ba MA |
1069 | arc_buf_watch(buf); |
1070 | } | |
1071 | ||
1072 | #ifndef _KERNEL | |
1073 | void | |
1074 | arc_buf_sigsegv(int sig, siginfo_t *si, void *unused) | |
1075 | { | |
1076 | panic("Got SIGSEGV at address: 0x%lx\n", (long) si->si_addr); | |
1077 | } | |
1078 | #endif | |
1079 | ||
1080 | /* ARGSUSED */ | |
1081 | static void | |
1082 | arc_buf_unwatch(arc_buf_t *buf) | |
1083 | { | |
1084 | #ifndef _KERNEL | |
1085 | if (arc_watch) { | |
1086 | ASSERT0(mprotect(buf->b_data, buf->b_hdr->b_size, | |
1087 | PROT_READ | PROT_WRITE)); | |
1088 | } | |
1089 | #endif | |
1090 | } | |
1091 | ||
1092 | /* ARGSUSED */ | |
1093 | static void | |
1094 | arc_buf_watch(arc_buf_t *buf) | |
1095 | { | |
1096 | #ifndef _KERNEL | |
1097 | if (arc_watch) | |
1098 | ASSERT0(mprotect(buf->b_data, buf->b_hdr->b_size, PROT_READ)); | |
1099 | #endif | |
34dc7c2f BB |
1100 | } |
1101 | ||
1102 | void | |
1103 | arc_buf_thaw(arc_buf_t *buf) | |
1104 | { | |
1105 | if (zfs_flags & ZFS_DEBUG_MODIFY) { | |
1106 | if (buf->b_hdr->b_state != arc_anon) | |
1107 | panic("modifying non-anon buffer!"); | |
1108 | if (buf->b_hdr->b_flags & ARC_IO_IN_PROGRESS) | |
1109 | panic("modifying buffer while i/o in progress!"); | |
1110 | arc_cksum_verify(buf); | |
1111 | } | |
1112 | ||
1113 | mutex_enter(&buf->b_hdr->b_freeze_lock); | |
1114 | if (buf->b_hdr->b_freeze_cksum != NULL) { | |
1115 | kmem_free(buf->b_hdr->b_freeze_cksum, sizeof (zio_cksum_t)); | |
1116 | buf->b_hdr->b_freeze_cksum = NULL; | |
1117 | } | |
428870ff | 1118 | |
34dc7c2f | 1119 | mutex_exit(&buf->b_hdr->b_freeze_lock); |
498877ba MA |
1120 | |
1121 | arc_buf_unwatch(buf); | |
34dc7c2f BB |
1122 | } |
1123 | ||
1124 | void | |
1125 | arc_buf_freeze(arc_buf_t *buf) | |
1126 | { | |
428870ff BB |
1127 | kmutex_t *hash_lock; |
1128 | ||
34dc7c2f BB |
1129 | if (!(zfs_flags & ZFS_DEBUG_MODIFY)) |
1130 | return; | |
1131 | ||
428870ff BB |
1132 | hash_lock = HDR_LOCK(buf->b_hdr); |
1133 | mutex_enter(hash_lock); | |
1134 | ||
34dc7c2f BB |
1135 | ASSERT(buf->b_hdr->b_freeze_cksum != NULL || |
1136 | buf->b_hdr->b_state == arc_anon); | |
1137 | arc_cksum_compute(buf, B_FALSE); | |
428870ff | 1138 | mutex_exit(hash_lock); |
498877ba | 1139 | |
34dc7c2f BB |
1140 | } |
1141 | ||
1142 | static void | |
1143 | add_reference(arc_buf_hdr_t *ab, kmutex_t *hash_lock, void *tag) | |
1144 | { | |
1145 | ASSERT(MUTEX_HELD(hash_lock)); | |
1146 | ||
1147 | if ((refcount_add(&ab->b_refcnt, tag) == 1) && | |
1148 | (ab->b_state != arc_anon)) { | |
1149 | uint64_t delta = ab->b_size * ab->b_datacnt; | |
1150 | list_t *list = &ab->b_state->arcs_list[ab->b_type]; | |
1151 | uint64_t *size = &ab->b_state->arcs_lsize[ab->b_type]; | |
1152 | ||
1153 | ASSERT(!MUTEX_HELD(&ab->b_state->arcs_mtx)); | |
1154 | mutex_enter(&ab->b_state->arcs_mtx); | |
1155 | ASSERT(list_link_active(&ab->b_arc_node)); | |
1156 | list_remove(list, ab); | |
1157 | if (GHOST_STATE(ab->b_state)) { | |
c99c9001 | 1158 | ASSERT0(ab->b_datacnt); |
34dc7c2f BB |
1159 | ASSERT3P(ab->b_buf, ==, NULL); |
1160 | delta = ab->b_size; | |
1161 | } | |
1162 | ASSERT(delta > 0); | |
1163 | ASSERT3U(*size, >=, delta); | |
1164 | atomic_add_64(size, -delta); | |
1165 | mutex_exit(&ab->b_state->arcs_mtx); | |
b128c09f | 1166 | /* remove the prefetch flag if we get a reference */ |
34dc7c2f BB |
1167 | if (ab->b_flags & ARC_PREFETCH) |
1168 | ab->b_flags &= ~ARC_PREFETCH; | |
1169 | } | |
1170 | } | |
1171 | ||
1172 | static int | |
1173 | remove_reference(arc_buf_hdr_t *ab, kmutex_t *hash_lock, void *tag) | |
1174 | { | |
1175 | int cnt; | |
1176 | arc_state_t *state = ab->b_state; | |
1177 | ||
1178 | ASSERT(state == arc_anon || MUTEX_HELD(hash_lock)); | |
1179 | ASSERT(!GHOST_STATE(state)); | |
1180 | ||
1181 | if (((cnt = refcount_remove(&ab->b_refcnt, tag)) == 0) && | |
1182 | (state != arc_anon)) { | |
1183 | uint64_t *size = &state->arcs_lsize[ab->b_type]; | |
1184 | ||
1185 | ASSERT(!MUTEX_HELD(&state->arcs_mtx)); | |
1186 | mutex_enter(&state->arcs_mtx); | |
1187 | ASSERT(!list_link_active(&ab->b_arc_node)); | |
1188 | list_insert_head(&state->arcs_list[ab->b_type], ab); | |
1189 | ASSERT(ab->b_datacnt > 0); | |
1190 | atomic_add_64(size, ab->b_size * ab->b_datacnt); | |
1191 | mutex_exit(&state->arcs_mtx); | |
1192 | } | |
1193 | return (cnt); | |
1194 | } | |
1195 | ||
e0b0ca98 BB |
1196 | /* |
1197 | * Returns detailed information about a specific arc buffer. When the | |
1198 | * state_index argument is set the function will calculate the arc header | |
1199 | * list position for its arc state. Since this requires a linear traversal | |
1200 | * callers are strongly encourage not to do this. However, it can be helpful | |
1201 | * for targeted analysis so the functionality is provided. | |
1202 | */ | |
1203 | void | |
1204 | arc_buf_info(arc_buf_t *ab, arc_buf_info_t *abi, int state_index) | |
1205 | { | |
1206 | arc_buf_hdr_t *hdr = ab->b_hdr; | |
1207 | arc_state_t *state = hdr->b_state; | |
1208 | ||
1209 | memset(abi, 0, sizeof(arc_buf_info_t)); | |
1210 | abi->abi_flags = hdr->b_flags; | |
1211 | abi->abi_datacnt = hdr->b_datacnt; | |
1212 | abi->abi_state_type = state ? state->arcs_state : ARC_STATE_ANON; | |
1213 | abi->abi_state_contents = hdr->b_type; | |
1214 | abi->abi_state_index = -1; | |
1215 | abi->abi_size = hdr->b_size; | |
1216 | abi->abi_access = hdr->b_arc_access; | |
1217 | abi->abi_mru_hits = hdr->b_mru_hits; | |
1218 | abi->abi_mru_ghost_hits = hdr->b_mru_ghost_hits; | |
1219 | abi->abi_mfu_hits = hdr->b_mfu_hits; | |
1220 | abi->abi_mfu_ghost_hits = hdr->b_mfu_ghost_hits; | |
1221 | abi->abi_holds = refcount_count(&hdr->b_refcnt); | |
1222 | ||
1223 | if (hdr->b_l2hdr) { | |
1224 | abi->abi_l2arc_dattr = hdr->b_l2hdr->b_daddr; | |
1225 | abi->abi_l2arc_asize = hdr->b_l2hdr->b_asize; | |
1226 | abi->abi_l2arc_compress = hdr->b_l2hdr->b_compress; | |
1227 | abi->abi_l2arc_hits = hdr->b_l2hdr->b_hits; | |
1228 | } | |
1229 | ||
1230 | if (state && state_index && list_link_active(&hdr->b_arc_node)) { | |
1231 | list_t *list = &state->arcs_list[hdr->b_type]; | |
1232 | arc_buf_hdr_t *h; | |
1233 | ||
1234 | mutex_enter(&state->arcs_mtx); | |
1235 | for (h = list_head(list); h != NULL; h = list_next(list, h)) { | |
1236 | abi->abi_state_index++; | |
1237 | if (h == hdr) | |
1238 | break; | |
1239 | } | |
1240 | mutex_exit(&state->arcs_mtx); | |
1241 | } | |
1242 | } | |
1243 | ||
34dc7c2f BB |
1244 | /* |
1245 | * Move the supplied buffer to the indicated state. The mutex | |
1246 | * for the buffer must be held by the caller. | |
1247 | */ | |
1248 | static void | |
1249 | arc_change_state(arc_state_t *new_state, arc_buf_hdr_t *ab, kmutex_t *hash_lock) | |
1250 | { | |
1251 | arc_state_t *old_state = ab->b_state; | |
1252 | int64_t refcnt = refcount_count(&ab->b_refcnt); | |
1253 | uint64_t from_delta, to_delta; | |
1254 | ||
1255 | ASSERT(MUTEX_HELD(hash_lock)); | |
1256 | ASSERT(new_state != old_state); | |
1257 | ASSERT(refcnt == 0 || ab->b_datacnt > 0); | |
1258 | ASSERT(ab->b_datacnt == 0 || !GHOST_STATE(new_state)); | |
428870ff | 1259 | ASSERT(ab->b_datacnt <= 1 || old_state != arc_anon); |
34dc7c2f BB |
1260 | |
1261 | from_delta = to_delta = ab->b_datacnt * ab->b_size; | |
1262 | ||
1263 | /* | |
1264 | * If this buffer is evictable, transfer it from the | |
1265 | * old state list to the new state list. | |
1266 | */ | |
1267 | if (refcnt == 0) { | |
1268 | if (old_state != arc_anon) { | |
1269 | int use_mutex = !MUTEX_HELD(&old_state->arcs_mtx); | |
1270 | uint64_t *size = &old_state->arcs_lsize[ab->b_type]; | |
1271 | ||
1272 | if (use_mutex) | |
1273 | mutex_enter(&old_state->arcs_mtx); | |
1274 | ||
1275 | ASSERT(list_link_active(&ab->b_arc_node)); | |
1276 | list_remove(&old_state->arcs_list[ab->b_type], ab); | |
1277 | ||
1278 | /* | |
1279 | * If prefetching out of the ghost cache, | |
428870ff | 1280 | * we will have a non-zero datacnt. |
34dc7c2f BB |
1281 | */ |
1282 | if (GHOST_STATE(old_state) && ab->b_datacnt == 0) { | |
1283 | /* ghost elements have a ghost size */ | |
1284 | ASSERT(ab->b_buf == NULL); | |
1285 | from_delta = ab->b_size; | |
1286 | } | |
1287 | ASSERT3U(*size, >=, from_delta); | |
1288 | atomic_add_64(size, -from_delta); | |
1289 | ||
1290 | if (use_mutex) | |
1291 | mutex_exit(&old_state->arcs_mtx); | |
1292 | } | |
1293 | if (new_state != arc_anon) { | |
1294 | int use_mutex = !MUTEX_HELD(&new_state->arcs_mtx); | |
1295 | uint64_t *size = &new_state->arcs_lsize[ab->b_type]; | |
1296 | ||
1297 | if (use_mutex) | |
1298 | mutex_enter(&new_state->arcs_mtx); | |
1299 | ||
1300 | list_insert_head(&new_state->arcs_list[ab->b_type], ab); | |
1301 | ||
1302 | /* ghost elements have a ghost size */ | |
1303 | if (GHOST_STATE(new_state)) { | |
1304 | ASSERT(ab->b_datacnt == 0); | |
1305 | ASSERT(ab->b_buf == NULL); | |
1306 | to_delta = ab->b_size; | |
1307 | } | |
1308 | atomic_add_64(size, to_delta); | |
1309 | ||
1310 | if (use_mutex) | |
1311 | mutex_exit(&new_state->arcs_mtx); | |
1312 | } | |
1313 | } | |
1314 | ||
1315 | ASSERT(!BUF_EMPTY(ab)); | |
428870ff | 1316 | if (new_state == arc_anon && HDR_IN_HASH_TABLE(ab)) |
34dc7c2f | 1317 | buf_hash_remove(ab); |
34dc7c2f BB |
1318 | |
1319 | /* adjust state sizes */ | |
1320 | if (to_delta) | |
1321 | atomic_add_64(&new_state->arcs_size, to_delta); | |
1322 | if (from_delta) { | |
1323 | ASSERT3U(old_state->arcs_size, >=, from_delta); | |
1324 | atomic_add_64(&old_state->arcs_size, -from_delta); | |
1325 | } | |
1326 | ab->b_state = new_state; | |
1327 | ||
1328 | /* adjust l2arc hdr stats */ | |
1329 | if (new_state == arc_l2c_only) | |
1330 | l2arc_hdr_stat_add(); | |
1331 | else if (old_state == arc_l2c_only) | |
1332 | l2arc_hdr_stat_remove(); | |
1333 | } | |
1334 | ||
1335 | void | |
d164b209 | 1336 | arc_space_consume(uint64_t space, arc_space_type_t type) |
34dc7c2f | 1337 | { |
d164b209 BB |
1338 | ASSERT(type >= 0 && type < ARC_SPACE_NUMTYPES); |
1339 | ||
1340 | switch (type) { | |
e75c13c3 BB |
1341 | default: |
1342 | break; | |
d164b209 BB |
1343 | case ARC_SPACE_DATA: |
1344 | ARCSTAT_INCR(arcstat_data_size, space); | |
1345 | break; | |
1346 | case ARC_SPACE_OTHER: | |
1347 | ARCSTAT_INCR(arcstat_other_size, space); | |
1348 | break; | |
1349 | case ARC_SPACE_HDRS: | |
1350 | ARCSTAT_INCR(arcstat_hdr_size, space); | |
1351 | break; | |
1352 | case ARC_SPACE_L2HDRS: | |
1353 | ARCSTAT_INCR(arcstat_l2_hdr_size, space); | |
1354 | break; | |
1355 | } | |
1356 | ||
23c0a133 | 1357 | ARCSTAT_INCR(arcstat_meta_used, space); |
34dc7c2f BB |
1358 | atomic_add_64(&arc_size, space); |
1359 | } | |
1360 | ||
1361 | void | |
d164b209 | 1362 | arc_space_return(uint64_t space, arc_space_type_t type) |
34dc7c2f | 1363 | { |
d164b209 BB |
1364 | ASSERT(type >= 0 && type < ARC_SPACE_NUMTYPES); |
1365 | ||
1366 | switch (type) { | |
e75c13c3 BB |
1367 | default: |
1368 | break; | |
d164b209 BB |
1369 | case ARC_SPACE_DATA: |
1370 | ARCSTAT_INCR(arcstat_data_size, -space); | |
1371 | break; | |
1372 | case ARC_SPACE_OTHER: | |
1373 | ARCSTAT_INCR(arcstat_other_size, -space); | |
1374 | break; | |
1375 | case ARC_SPACE_HDRS: | |
1376 | ARCSTAT_INCR(arcstat_hdr_size, -space); | |
1377 | break; | |
1378 | case ARC_SPACE_L2HDRS: | |
1379 | ARCSTAT_INCR(arcstat_l2_hdr_size, -space); | |
1380 | break; | |
1381 | } | |
1382 | ||
34dc7c2f BB |
1383 | ASSERT(arc_meta_used >= space); |
1384 | if (arc_meta_max < arc_meta_used) | |
1385 | arc_meta_max = arc_meta_used; | |
23c0a133 | 1386 | ARCSTAT_INCR(arcstat_meta_used, -space); |
34dc7c2f BB |
1387 | ASSERT(arc_size >= space); |
1388 | atomic_add_64(&arc_size, -space); | |
1389 | } | |
1390 | ||
34dc7c2f BB |
1391 | arc_buf_t * |
1392 | arc_buf_alloc(spa_t *spa, int size, void *tag, arc_buf_contents_t type) | |
1393 | { | |
1394 | arc_buf_hdr_t *hdr; | |
1395 | arc_buf_t *buf; | |
1396 | ||
1397 | ASSERT3U(size, >, 0); | |
1398 | hdr = kmem_cache_alloc(hdr_cache, KM_PUSHPAGE); | |
1399 | ASSERT(BUF_EMPTY(hdr)); | |
1400 | hdr->b_size = size; | |
1401 | hdr->b_type = type; | |
3541dc6d | 1402 | hdr->b_spa = spa_load_guid(spa); |
34dc7c2f BB |
1403 | hdr->b_state = arc_anon; |
1404 | hdr->b_arc_access = 0; | |
e0b0ca98 BB |
1405 | hdr->b_mru_hits = 0; |
1406 | hdr->b_mru_ghost_hits = 0; | |
1407 | hdr->b_mfu_hits = 0; | |
1408 | hdr->b_mfu_ghost_hits = 0; | |
1409 | hdr->b_l2_hits = 0; | |
34dc7c2f BB |
1410 | buf = kmem_cache_alloc(buf_cache, KM_PUSHPAGE); |
1411 | buf->b_hdr = hdr; | |
1412 | buf->b_data = NULL; | |
1413 | buf->b_efunc = NULL; | |
1414 | buf->b_private = NULL; | |
1415 | buf->b_next = NULL; | |
1416 | hdr->b_buf = buf; | |
1417 | arc_get_data_buf(buf); | |
1418 | hdr->b_datacnt = 1; | |
1419 | hdr->b_flags = 0; | |
1420 | ASSERT(refcount_is_zero(&hdr->b_refcnt)); | |
1421 | (void) refcount_add(&hdr->b_refcnt, tag); | |
1422 | ||
1423 | return (buf); | |
1424 | } | |
1425 | ||
9babb374 BB |
1426 | static char *arc_onloan_tag = "onloan"; |
1427 | ||
1428 | /* | |
1429 | * Loan out an anonymous arc buffer. Loaned buffers are not counted as in | |
1430 | * flight data by arc_tempreserve_space() until they are "returned". Loaned | |
1431 | * buffers must be returned to the arc before they can be used by the DMU or | |
1432 | * freed. | |
1433 | */ | |
1434 | arc_buf_t * | |
1435 | arc_loan_buf(spa_t *spa, int size) | |
1436 | { | |
1437 | arc_buf_t *buf; | |
1438 | ||
1439 | buf = arc_buf_alloc(spa, size, arc_onloan_tag, ARC_BUFC_DATA); | |
1440 | ||
1441 | atomic_add_64(&arc_loaned_bytes, size); | |
1442 | return (buf); | |
1443 | } | |
1444 | ||
1445 | /* | |
1446 | * Return a loaned arc buffer to the arc. | |
1447 | */ | |
1448 | void | |
1449 | arc_return_buf(arc_buf_t *buf, void *tag) | |
1450 | { | |
1451 | arc_buf_hdr_t *hdr = buf->b_hdr; | |
1452 | ||
9babb374 | 1453 | ASSERT(buf->b_data != NULL); |
428870ff BB |
1454 | (void) refcount_add(&hdr->b_refcnt, tag); |
1455 | (void) refcount_remove(&hdr->b_refcnt, arc_onloan_tag); | |
9babb374 BB |
1456 | |
1457 | atomic_add_64(&arc_loaned_bytes, -hdr->b_size); | |
1458 | } | |
1459 | ||
428870ff BB |
1460 | /* Detach an arc_buf from a dbuf (tag) */ |
1461 | void | |
1462 | arc_loan_inuse_buf(arc_buf_t *buf, void *tag) | |
1463 | { | |
1464 | arc_buf_hdr_t *hdr; | |
1465 | ||
1466 | ASSERT(buf->b_data != NULL); | |
1467 | hdr = buf->b_hdr; | |
1468 | (void) refcount_add(&hdr->b_refcnt, arc_onloan_tag); | |
1469 | (void) refcount_remove(&hdr->b_refcnt, tag); | |
1470 | buf->b_efunc = NULL; | |
1471 | buf->b_private = NULL; | |
1472 | ||
1473 | atomic_add_64(&arc_loaned_bytes, hdr->b_size); | |
1474 | } | |
1475 | ||
34dc7c2f BB |
1476 | static arc_buf_t * |
1477 | arc_buf_clone(arc_buf_t *from) | |
1478 | { | |
1479 | arc_buf_t *buf; | |
1480 | arc_buf_hdr_t *hdr = from->b_hdr; | |
1481 | uint64_t size = hdr->b_size; | |
1482 | ||
428870ff BB |
1483 | ASSERT(hdr->b_state != arc_anon); |
1484 | ||
34dc7c2f BB |
1485 | buf = kmem_cache_alloc(buf_cache, KM_PUSHPAGE); |
1486 | buf->b_hdr = hdr; | |
1487 | buf->b_data = NULL; | |
1488 | buf->b_efunc = NULL; | |
1489 | buf->b_private = NULL; | |
1490 | buf->b_next = hdr->b_buf; | |
1491 | hdr->b_buf = buf; | |
1492 | arc_get_data_buf(buf); | |
1493 | bcopy(from->b_data, buf->b_data, size); | |
1eb5bfa3 GW |
1494 | |
1495 | /* | |
1496 | * This buffer already exists in the arc so create a duplicate | |
1497 | * copy for the caller. If the buffer is associated with user data | |
1498 | * then track the size and number of duplicates. These stats will be | |
1499 | * updated as duplicate buffers are created and destroyed. | |
1500 | */ | |
1501 | if (hdr->b_type == ARC_BUFC_DATA) { | |
1502 | ARCSTAT_BUMP(arcstat_duplicate_buffers); | |
1503 | ARCSTAT_INCR(arcstat_duplicate_buffers_size, size); | |
1504 | } | |
34dc7c2f BB |
1505 | hdr->b_datacnt += 1; |
1506 | return (buf); | |
1507 | } | |
1508 | ||
1509 | void | |
1510 | arc_buf_add_ref(arc_buf_t *buf, void* tag) | |
1511 | { | |
1512 | arc_buf_hdr_t *hdr; | |
1513 | kmutex_t *hash_lock; | |
1514 | ||
1515 | /* | |
b128c09f BB |
1516 | * Check to see if this buffer is evicted. Callers |
1517 | * must verify b_data != NULL to know if the add_ref | |
1518 | * was successful. | |
34dc7c2f | 1519 | */ |
428870ff | 1520 | mutex_enter(&buf->b_evict_lock); |
b128c09f | 1521 | if (buf->b_data == NULL) { |
428870ff | 1522 | mutex_exit(&buf->b_evict_lock); |
34dc7c2f BB |
1523 | return; |
1524 | } | |
428870ff | 1525 | hash_lock = HDR_LOCK(buf->b_hdr); |
34dc7c2f | 1526 | mutex_enter(hash_lock); |
428870ff BB |
1527 | hdr = buf->b_hdr; |
1528 | ASSERT3P(hash_lock, ==, HDR_LOCK(hdr)); | |
1529 | mutex_exit(&buf->b_evict_lock); | |
34dc7c2f | 1530 | |
34dc7c2f BB |
1531 | ASSERT(hdr->b_state == arc_mru || hdr->b_state == arc_mfu); |
1532 | add_reference(hdr, hash_lock, tag); | |
d164b209 | 1533 | DTRACE_PROBE1(arc__hit, arc_buf_hdr_t *, hdr); |
34dc7c2f BB |
1534 | arc_access(hdr, hash_lock); |
1535 | mutex_exit(hash_lock); | |
1536 | ARCSTAT_BUMP(arcstat_hits); | |
1537 | ARCSTAT_CONDSTAT(!(hdr->b_flags & ARC_PREFETCH), | |
1538 | demand, prefetch, hdr->b_type != ARC_BUFC_METADATA, | |
1539 | data, metadata, hits); | |
1540 | } | |
1541 | ||
1542 | /* | |
1543 | * Free the arc data buffer. If it is an l2arc write in progress, | |
1544 | * the buffer is placed on l2arc_free_on_write to be freed later. | |
1545 | */ | |
1546 | static void | |
498877ba | 1547 | arc_buf_data_free(arc_buf_t *buf, void (*free_func)(void *, size_t)) |
34dc7c2f | 1548 | { |
498877ba MA |
1549 | arc_buf_hdr_t *hdr = buf->b_hdr; |
1550 | ||
34dc7c2f BB |
1551 | if (HDR_L2_WRITING(hdr)) { |
1552 | l2arc_data_free_t *df; | |
594b4dd8 | 1553 | df = kmem_alloc(sizeof (l2arc_data_free_t), KM_PUSHPAGE); |
498877ba MA |
1554 | df->l2df_data = buf->b_data; |
1555 | df->l2df_size = hdr->b_size; | |
34dc7c2f BB |
1556 | df->l2df_func = free_func; |
1557 | mutex_enter(&l2arc_free_on_write_mtx); | |
1558 | list_insert_head(l2arc_free_on_write, df); | |
1559 | mutex_exit(&l2arc_free_on_write_mtx); | |
1560 | ARCSTAT_BUMP(arcstat_l2_free_on_write); | |
1561 | } else { | |
498877ba | 1562 | free_func(buf->b_data, hdr->b_size); |
34dc7c2f BB |
1563 | } |
1564 | } | |
1565 | ||
1566 | static void | |
1567 | arc_buf_destroy(arc_buf_t *buf, boolean_t recycle, boolean_t all) | |
1568 | { | |
1569 | arc_buf_t **bufp; | |
1570 | ||
1571 | /* free up data associated with the buf */ | |
1572 | if (buf->b_data) { | |
1573 | arc_state_t *state = buf->b_hdr->b_state; | |
1574 | uint64_t size = buf->b_hdr->b_size; | |
1575 | arc_buf_contents_t type = buf->b_hdr->b_type; | |
1576 | ||
1577 | arc_cksum_verify(buf); | |
498877ba | 1578 | arc_buf_unwatch(buf); |
428870ff | 1579 | |
34dc7c2f BB |
1580 | if (!recycle) { |
1581 | if (type == ARC_BUFC_METADATA) { | |
498877ba | 1582 | arc_buf_data_free(buf, zio_buf_free); |
d164b209 | 1583 | arc_space_return(size, ARC_SPACE_DATA); |
34dc7c2f BB |
1584 | } else { |
1585 | ASSERT(type == ARC_BUFC_DATA); | |
498877ba | 1586 | arc_buf_data_free(buf, zio_data_buf_free); |
d164b209 | 1587 | ARCSTAT_INCR(arcstat_data_size, -size); |
34dc7c2f BB |
1588 | atomic_add_64(&arc_size, -size); |
1589 | } | |
1590 | } | |
1591 | if (list_link_active(&buf->b_hdr->b_arc_node)) { | |
1592 | uint64_t *cnt = &state->arcs_lsize[type]; | |
1593 | ||
1594 | ASSERT(refcount_is_zero(&buf->b_hdr->b_refcnt)); | |
1595 | ASSERT(state != arc_anon); | |
1596 | ||
1597 | ASSERT3U(*cnt, >=, size); | |
1598 | atomic_add_64(cnt, -size); | |
1599 | } | |
1600 | ASSERT3U(state->arcs_size, >=, size); | |
1601 | atomic_add_64(&state->arcs_size, -size); | |
1602 | buf->b_data = NULL; | |
1eb5bfa3 GW |
1603 | |
1604 | /* | |
1605 | * If we're destroying a duplicate buffer make sure | |
1606 | * that the appropriate statistics are updated. | |
1607 | */ | |
1608 | if (buf->b_hdr->b_datacnt > 1 && | |
1609 | buf->b_hdr->b_type == ARC_BUFC_DATA) { | |
1610 | ARCSTAT_BUMPDOWN(arcstat_duplicate_buffers); | |
1611 | ARCSTAT_INCR(arcstat_duplicate_buffers_size, -size); | |
1612 | } | |
34dc7c2f BB |
1613 | ASSERT(buf->b_hdr->b_datacnt > 0); |
1614 | buf->b_hdr->b_datacnt -= 1; | |
1615 | } | |
1616 | ||
1617 | /* only remove the buf if requested */ | |
1618 | if (!all) | |
1619 | return; | |
1620 | ||
1621 | /* remove the buf from the hdr list */ | |
1622 | for (bufp = &buf->b_hdr->b_buf; *bufp != buf; bufp = &(*bufp)->b_next) | |
1623 | continue; | |
1624 | *bufp = buf->b_next; | |
428870ff | 1625 | buf->b_next = NULL; |
34dc7c2f BB |
1626 | |
1627 | ASSERT(buf->b_efunc == NULL); | |
1628 | ||
1629 | /* clean up the buf */ | |
1630 | buf->b_hdr = NULL; | |
1631 | kmem_cache_free(buf_cache, buf); | |
1632 | } | |
1633 | ||
1634 | static void | |
1635 | arc_hdr_destroy(arc_buf_hdr_t *hdr) | |
1636 | { | |
d6320ddb BB |
1637 | l2arc_buf_hdr_t *l2hdr = hdr->b_l2hdr; |
1638 | ||
34dc7c2f BB |
1639 | ASSERT(refcount_is_zero(&hdr->b_refcnt)); |
1640 | ASSERT3P(hdr->b_state, ==, arc_anon); | |
1641 | ASSERT(!HDR_IO_IN_PROGRESS(hdr)); | |
1642 | ||
428870ff BB |
1643 | if (l2hdr != NULL) { |
1644 | boolean_t buflist_held = MUTEX_HELD(&l2arc_buflist_mtx); | |
1645 | /* | |
1646 | * To prevent arc_free() and l2arc_evict() from | |
1647 | * attempting to free the same buffer at the same time, | |
1648 | * a FREE_IN_PROGRESS flag is given to arc_free() to | |
1649 | * give it priority. l2arc_evict() can't destroy this | |
1650 | * header while we are waiting on l2arc_buflist_mtx. | |
1651 | * | |
1652 | * The hdr may be removed from l2ad_buflist before we | |
1653 | * grab l2arc_buflist_mtx, so b_l2hdr is rechecked. | |
1654 | */ | |
1655 | if (!buflist_held) { | |
34dc7c2f | 1656 | mutex_enter(&l2arc_buflist_mtx); |
428870ff | 1657 | l2hdr = hdr->b_l2hdr; |
34dc7c2f | 1658 | } |
428870ff BB |
1659 | |
1660 | if (l2hdr != NULL) { | |
1661 | list_remove(l2hdr->b_dev->l2ad_buflist, hdr); | |
1662 | ARCSTAT_INCR(arcstat_l2_size, -hdr->b_size); | |
3a17a7a9 | 1663 | ARCSTAT_INCR(arcstat_l2_asize, -l2hdr->b_asize); |
428870ff | 1664 | kmem_free(l2hdr, sizeof (l2arc_buf_hdr_t)); |
6e1d7276 | 1665 | arc_space_return(L2HDR_SIZE, ARC_SPACE_L2HDRS); |
428870ff BB |
1666 | if (hdr->b_state == arc_l2c_only) |
1667 | l2arc_hdr_stat_remove(); | |
1668 | hdr->b_l2hdr = NULL; | |
1669 | } | |
1670 | ||
1671 | if (!buflist_held) | |
1672 | mutex_exit(&l2arc_buflist_mtx); | |
34dc7c2f BB |
1673 | } |
1674 | ||
1675 | if (!BUF_EMPTY(hdr)) { | |
1676 | ASSERT(!HDR_IN_HASH_TABLE(hdr)); | |
428870ff | 1677 | buf_discard_identity(hdr); |
34dc7c2f BB |
1678 | } |
1679 | while (hdr->b_buf) { | |
1680 | arc_buf_t *buf = hdr->b_buf; | |
1681 | ||
1682 | if (buf->b_efunc) { | |
1683 | mutex_enter(&arc_eviction_mtx); | |
428870ff | 1684 | mutex_enter(&buf->b_evict_lock); |
34dc7c2f BB |
1685 | ASSERT(buf->b_hdr != NULL); |
1686 | arc_buf_destroy(hdr->b_buf, FALSE, FALSE); | |
1687 | hdr->b_buf = buf->b_next; | |
1688 | buf->b_hdr = &arc_eviction_hdr; | |
1689 | buf->b_next = arc_eviction_list; | |
1690 | arc_eviction_list = buf; | |
428870ff | 1691 | mutex_exit(&buf->b_evict_lock); |
34dc7c2f BB |
1692 | mutex_exit(&arc_eviction_mtx); |
1693 | } else { | |
1694 | arc_buf_destroy(hdr->b_buf, FALSE, TRUE); | |
1695 | } | |
1696 | } | |
1697 | if (hdr->b_freeze_cksum != NULL) { | |
1698 | kmem_free(hdr->b_freeze_cksum, sizeof (zio_cksum_t)); | |
1699 | hdr->b_freeze_cksum = NULL; | |
1700 | } | |
1701 | ||
1702 | ASSERT(!list_link_active(&hdr->b_arc_node)); | |
1703 | ASSERT3P(hdr->b_hash_next, ==, NULL); | |
1704 | ASSERT3P(hdr->b_acb, ==, NULL); | |
1705 | kmem_cache_free(hdr_cache, hdr); | |
1706 | } | |
1707 | ||
1708 | void | |
1709 | arc_buf_free(arc_buf_t *buf, void *tag) | |
1710 | { | |
1711 | arc_buf_hdr_t *hdr = buf->b_hdr; | |
1712 | int hashed = hdr->b_state != arc_anon; | |
1713 | ||
1714 | ASSERT(buf->b_efunc == NULL); | |
1715 | ASSERT(buf->b_data != NULL); | |
1716 | ||
1717 | if (hashed) { | |
1718 | kmutex_t *hash_lock = HDR_LOCK(hdr); | |
1719 | ||
1720 | mutex_enter(hash_lock); | |
428870ff BB |
1721 | hdr = buf->b_hdr; |
1722 | ASSERT3P(hash_lock, ==, HDR_LOCK(hdr)); | |
1723 | ||
34dc7c2f | 1724 | (void) remove_reference(hdr, hash_lock, tag); |
428870ff | 1725 | if (hdr->b_datacnt > 1) { |
34dc7c2f | 1726 | arc_buf_destroy(buf, FALSE, TRUE); |
428870ff BB |
1727 | } else { |
1728 | ASSERT(buf == hdr->b_buf); | |
1729 | ASSERT(buf->b_efunc == NULL); | |
34dc7c2f | 1730 | hdr->b_flags |= ARC_BUF_AVAILABLE; |
428870ff | 1731 | } |
34dc7c2f BB |
1732 | mutex_exit(hash_lock); |
1733 | } else if (HDR_IO_IN_PROGRESS(hdr)) { | |
1734 | int destroy_hdr; | |
1735 | /* | |
1736 | * We are in the middle of an async write. Don't destroy | |
1737 | * this buffer unless the write completes before we finish | |
1738 | * decrementing the reference count. | |
1739 | */ | |
1740 | mutex_enter(&arc_eviction_mtx); | |
1741 | (void) remove_reference(hdr, NULL, tag); | |
1742 | ASSERT(refcount_is_zero(&hdr->b_refcnt)); | |
1743 | destroy_hdr = !HDR_IO_IN_PROGRESS(hdr); | |
1744 | mutex_exit(&arc_eviction_mtx); | |
1745 | if (destroy_hdr) | |
1746 | arc_hdr_destroy(hdr); | |
1747 | } else { | |
428870ff | 1748 | if (remove_reference(hdr, NULL, tag) > 0) |
34dc7c2f | 1749 | arc_buf_destroy(buf, FALSE, TRUE); |
428870ff | 1750 | else |
34dc7c2f | 1751 | arc_hdr_destroy(hdr); |
34dc7c2f BB |
1752 | } |
1753 | } | |
1754 | ||
13fe0198 | 1755 | boolean_t |
34dc7c2f BB |
1756 | arc_buf_remove_ref(arc_buf_t *buf, void* tag) |
1757 | { | |
1758 | arc_buf_hdr_t *hdr = buf->b_hdr; | |
b4f7f105 | 1759 | kmutex_t *hash_lock = NULL; |
13fe0198 | 1760 | boolean_t no_callback = (buf->b_efunc == NULL); |
34dc7c2f BB |
1761 | |
1762 | if (hdr->b_state == arc_anon) { | |
428870ff | 1763 | ASSERT(hdr->b_datacnt == 1); |
34dc7c2f BB |
1764 | arc_buf_free(buf, tag); |
1765 | return (no_callback); | |
1766 | } | |
1767 | ||
b4f7f105 | 1768 | hash_lock = HDR_LOCK(hdr); |
34dc7c2f | 1769 | mutex_enter(hash_lock); |
428870ff BB |
1770 | hdr = buf->b_hdr; |
1771 | ASSERT3P(hash_lock, ==, HDR_LOCK(hdr)); | |
34dc7c2f BB |
1772 | ASSERT(hdr->b_state != arc_anon); |
1773 | ASSERT(buf->b_data != NULL); | |
1774 | ||
1775 | (void) remove_reference(hdr, hash_lock, tag); | |
1776 | if (hdr->b_datacnt > 1) { | |
1777 | if (no_callback) | |
1778 | arc_buf_destroy(buf, FALSE, TRUE); | |
1779 | } else if (no_callback) { | |
1780 | ASSERT(hdr->b_buf == buf && buf->b_next == NULL); | |
428870ff | 1781 | ASSERT(buf->b_efunc == NULL); |
34dc7c2f BB |
1782 | hdr->b_flags |= ARC_BUF_AVAILABLE; |
1783 | } | |
1784 | ASSERT(no_callback || hdr->b_datacnt > 1 || | |
1785 | refcount_is_zero(&hdr->b_refcnt)); | |
1786 | mutex_exit(hash_lock); | |
1787 | return (no_callback); | |
1788 | } | |
1789 | ||
1790 | int | |
1791 | arc_buf_size(arc_buf_t *buf) | |
1792 | { | |
1793 | return (buf->b_hdr->b_size); | |
1794 | } | |
1795 | ||
1eb5bfa3 GW |
1796 | /* |
1797 | * Called from the DMU to determine if the current buffer should be | |
1798 | * evicted. In order to ensure proper locking, the eviction must be initiated | |
1799 | * from the DMU. Return true if the buffer is associated with user data and | |
1800 | * duplicate buffers still exist. | |
1801 | */ | |
1802 | boolean_t | |
1803 | arc_buf_eviction_needed(arc_buf_t *buf) | |
1804 | { | |
1805 | arc_buf_hdr_t *hdr; | |
1806 | boolean_t evict_needed = B_FALSE; | |
1807 | ||
1808 | if (zfs_disable_dup_eviction) | |
1809 | return (B_FALSE); | |
1810 | ||
1811 | mutex_enter(&buf->b_evict_lock); | |
1812 | hdr = buf->b_hdr; | |
1813 | if (hdr == NULL) { | |
1814 | /* | |
1815 | * We are in arc_do_user_evicts(); let that function | |
1816 | * perform the eviction. | |
1817 | */ | |
1818 | ASSERT(buf->b_data == NULL); | |
1819 | mutex_exit(&buf->b_evict_lock); | |
1820 | return (B_FALSE); | |
1821 | } else if (buf->b_data == NULL) { | |
1822 | /* | |
1823 | * We have already been added to the arc eviction list; | |
1824 | * recommend eviction. | |
1825 | */ | |
1826 | ASSERT3P(hdr, ==, &arc_eviction_hdr); | |
1827 | mutex_exit(&buf->b_evict_lock); | |
1828 | return (B_TRUE); | |
1829 | } | |
1830 | ||
1831 | if (hdr->b_datacnt > 1 && hdr->b_type == ARC_BUFC_DATA) | |
1832 | evict_needed = B_TRUE; | |
1833 | ||
1834 | mutex_exit(&buf->b_evict_lock); | |
1835 | return (evict_needed); | |
1836 | } | |
1837 | ||
34dc7c2f BB |
1838 | /* |
1839 | * Evict buffers from list until we've removed the specified number of | |
1840 | * bytes. Move the removed buffers to the appropriate evict state. | |
1841 | * If the recycle flag is set, then attempt to "recycle" a buffer: | |
1842 | * - look for a buffer to evict that is `bytes' long. | |
1843 | * - return the data block from this buffer rather than freeing it. | |
1844 | * This flag is used by callers that are trying to make space for a | |
1845 | * new buffer in a full arc cache. | |
1846 | * | |
1847 | * This function makes a "best effort". It skips over any buffers | |
1848 | * it can't get a hash_lock on, and so may not catch all candidates. | |
1849 | * It may also return without evicting as much space as requested. | |
1850 | */ | |
1851 | static void * | |
d164b209 | 1852 | arc_evict(arc_state_t *state, uint64_t spa, int64_t bytes, boolean_t recycle, |
34dc7c2f BB |
1853 | arc_buf_contents_t type) |
1854 | { | |
1855 | arc_state_t *evicted_state; | |
1856 | uint64_t bytes_evicted = 0, skipped = 0, missed = 0; | |
1857 | arc_buf_hdr_t *ab, *ab_prev = NULL; | |
1858 | list_t *list = &state->arcs_list[type]; | |
1859 | kmutex_t *hash_lock; | |
1860 | boolean_t have_lock; | |
1861 | void *stolen = NULL; | |
1862 | ||
1863 | ASSERT(state == arc_mru || state == arc_mfu); | |
1864 | ||
1865 | evicted_state = (state == arc_mru) ? arc_mru_ghost : arc_mfu_ghost; | |
1866 | ||
1867 | mutex_enter(&state->arcs_mtx); | |
1868 | mutex_enter(&evicted_state->arcs_mtx); | |
1869 | ||
1870 | for (ab = list_tail(list); ab; ab = ab_prev) { | |
1871 | ab_prev = list_prev(list, ab); | |
1872 | /* prefetch buffers have a minimum lifespan */ | |
1873 | if (HDR_IO_IN_PROGRESS(ab) || | |
1874 | (spa && ab->b_spa != spa) || | |
1875 | (ab->b_flags & (ARC_PREFETCH|ARC_INDIRECT) && | |
428870ff | 1876 | ddi_get_lbolt() - ab->b_arc_access < |
bce45ec9 | 1877 | zfs_arc_min_prefetch_lifespan)) { |
34dc7c2f BB |
1878 | skipped++; |
1879 | continue; | |
1880 | } | |
1881 | /* "lookahead" for better eviction candidate */ | |
1882 | if (recycle && ab->b_size != bytes && | |
1883 | ab_prev && ab_prev->b_size == bytes) | |
1884 | continue; | |
1885 | hash_lock = HDR_LOCK(ab); | |
1886 | have_lock = MUTEX_HELD(hash_lock); | |
1887 | if (have_lock || mutex_tryenter(hash_lock)) { | |
c99c9001 | 1888 | ASSERT0(refcount_count(&ab->b_refcnt)); |
34dc7c2f BB |
1889 | ASSERT(ab->b_datacnt > 0); |
1890 | while (ab->b_buf) { | |
1891 | arc_buf_t *buf = ab->b_buf; | |
428870ff | 1892 | if (!mutex_tryenter(&buf->b_evict_lock)) { |
b128c09f BB |
1893 | missed += 1; |
1894 | break; | |
1895 | } | |
34dc7c2f BB |
1896 | if (buf->b_data) { |
1897 | bytes_evicted += ab->b_size; | |
1898 | if (recycle && ab->b_type == type && | |
1899 | ab->b_size == bytes && | |
1900 | !HDR_L2_WRITING(ab)) { | |
1901 | stolen = buf->b_data; | |
1902 | recycle = FALSE; | |
1903 | } | |
1904 | } | |
1905 | if (buf->b_efunc) { | |
1906 | mutex_enter(&arc_eviction_mtx); | |
1907 | arc_buf_destroy(buf, | |
1908 | buf->b_data == stolen, FALSE); | |
1909 | ab->b_buf = buf->b_next; | |
1910 | buf->b_hdr = &arc_eviction_hdr; | |
1911 | buf->b_next = arc_eviction_list; | |
1912 | arc_eviction_list = buf; | |
1913 | mutex_exit(&arc_eviction_mtx); | |
428870ff | 1914 | mutex_exit(&buf->b_evict_lock); |
34dc7c2f | 1915 | } else { |
428870ff | 1916 | mutex_exit(&buf->b_evict_lock); |
34dc7c2f BB |
1917 | arc_buf_destroy(buf, |
1918 | buf->b_data == stolen, TRUE); | |
1919 | } | |
1920 | } | |
428870ff BB |
1921 | |
1922 | if (ab->b_l2hdr) { | |
1923 | ARCSTAT_INCR(arcstat_evict_l2_cached, | |
1924 | ab->b_size); | |
1925 | } else { | |
1926 | if (l2arc_write_eligible(ab->b_spa, ab)) { | |
1927 | ARCSTAT_INCR(arcstat_evict_l2_eligible, | |
1928 | ab->b_size); | |
1929 | } else { | |
1930 | ARCSTAT_INCR( | |
1931 | arcstat_evict_l2_ineligible, | |
1932 | ab->b_size); | |
1933 | } | |
1934 | } | |
1935 | ||
b128c09f BB |
1936 | if (ab->b_datacnt == 0) { |
1937 | arc_change_state(evicted_state, ab, hash_lock); | |
1938 | ASSERT(HDR_IN_HASH_TABLE(ab)); | |
1939 | ab->b_flags |= ARC_IN_HASH_TABLE; | |
1940 | ab->b_flags &= ~ARC_BUF_AVAILABLE; | |
1941 | DTRACE_PROBE1(arc__evict, arc_buf_hdr_t *, ab); | |
1942 | } | |
34dc7c2f BB |
1943 | if (!have_lock) |
1944 | mutex_exit(hash_lock); | |
1945 | if (bytes >= 0 && bytes_evicted >= bytes) | |
1946 | break; | |
1947 | } else { | |
1948 | missed += 1; | |
1949 | } | |
1950 | } | |
1951 | ||
1952 | mutex_exit(&evicted_state->arcs_mtx); | |
1953 | mutex_exit(&state->arcs_mtx); | |
1954 | ||
1955 | if (bytes_evicted < bytes) | |
3f504482 | 1956 | dprintf("only evicted %lld bytes from %x\n", |
34dc7c2f BB |
1957 | (longlong_t)bytes_evicted, state); |
1958 | ||
1959 | if (skipped) | |
1960 | ARCSTAT_INCR(arcstat_evict_skip, skipped); | |
1961 | ||
1962 | if (missed) | |
1963 | ARCSTAT_INCR(arcstat_mutex_miss, missed); | |
1964 | ||
1965 | /* | |
13fe0198 | 1966 | * We have just evicted some data into the ghost state, make |
34dc7c2f BB |
1967 | * sure we also adjust the ghost state size if necessary. |
1968 | */ | |
1969 | if (arc_no_grow && | |
1970 | arc_mru_ghost->arcs_size + arc_mfu_ghost->arcs_size > arc_c) { | |
1971 | int64_t mru_over = arc_anon->arcs_size + arc_mru->arcs_size + | |
1972 | arc_mru_ghost->arcs_size - arc_c; | |
1973 | ||
1974 | if (mru_over > 0 && arc_mru_ghost->arcs_lsize[type] > 0) { | |
1975 | int64_t todelete = | |
1976 | MIN(arc_mru_ghost->arcs_lsize[type], mru_over); | |
68121a03 BB |
1977 | arc_evict_ghost(arc_mru_ghost, 0, todelete, |
1978 | ARC_BUFC_DATA); | |
34dc7c2f BB |
1979 | } else if (arc_mfu_ghost->arcs_lsize[type] > 0) { |
1980 | int64_t todelete = MIN(arc_mfu_ghost->arcs_lsize[type], | |
1981 | arc_mru_ghost->arcs_size + | |
1982 | arc_mfu_ghost->arcs_size - arc_c); | |
68121a03 BB |
1983 | arc_evict_ghost(arc_mfu_ghost, 0, todelete, |
1984 | ARC_BUFC_DATA); | |
34dc7c2f BB |
1985 | } |
1986 | } | |
1987 | ||
1988 | return (stolen); | |
1989 | } | |
1990 | ||
1991 | /* | |
1992 | * Remove buffers from list until we've removed the specified number of | |
1993 | * bytes. Destroy the buffers that are removed. | |
1994 | */ | |
1995 | static void | |
68121a03 BB |
1996 | arc_evict_ghost(arc_state_t *state, uint64_t spa, int64_t bytes, |
1997 | arc_buf_contents_t type) | |
34dc7c2f BB |
1998 | { |
1999 | arc_buf_hdr_t *ab, *ab_prev; | |
2598c001 | 2000 | arc_buf_hdr_t marker; |
68121a03 | 2001 | list_t *list = &state->arcs_list[type]; |
34dc7c2f BB |
2002 | kmutex_t *hash_lock; |
2003 | uint64_t bytes_deleted = 0; | |
2004 | uint64_t bufs_skipped = 0; | |
2005 | ||
2006 | ASSERT(GHOST_STATE(state)); | |
2598c001 | 2007 | bzero(&marker, sizeof(marker)); |
34dc7c2f BB |
2008 | top: |
2009 | mutex_enter(&state->arcs_mtx); | |
2010 | for (ab = list_tail(list); ab; ab = ab_prev) { | |
2011 | ab_prev = list_prev(list, ab); | |
2012 | if (spa && ab->b_spa != spa) | |
2013 | continue; | |
572e2857 BB |
2014 | |
2015 | /* ignore markers */ | |
2016 | if (ab->b_spa == 0) | |
2017 | continue; | |
2018 | ||
34dc7c2f | 2019 | hash_lock = HDR_LOCK(ab); |
428870ff BB |
2020 | /* caller may be trying to modify this buffer, skip it */ |
2021 | if (MUTEX_HELD(hash_lock)) | |
2022 | continue; | |
34dc7c2f BB |
2023 | if (mutex_tryenter(hash_lock)) { |
2024 | ASSERT(!HDR_IO_IN_PROGRESS(ab)); | |
2025 | ASSERT(ab->b_buf == NULL); | |
2026 | ARCSTAT_BUMP(arcstat_deleted); | |
2027 | bytes_deleted += ab->b_size; | |
2028 | ||
2029 | if (ab->b_l2hdr != NULL) { | |
2030 | /* | |
2031 | * This buffer is cached on the 2nd Level ARC; | |
2032 | * don't destroy the header. | |
2033 | */ | |
2034 | arc_change_state(arc_l2c_only, ab, hash_lock); | |
2035 | mutex_exit(hash_lock); | |
2036 | } else { | |
2037 | arc_change_state(arc_anon, ab, hash_lock); | |
2038 | mutex_exit(hash_lock); | |
2039 | arc_hdr_destroy(ab); | |
2040 | } | |
2041 | ||
2042 | DTRACE_PROBE1(arc__delete, arc_buf_hdr_t *, ab); | |
2043 | if (bytes >= 0 && bytes_deleted >= bytes) | |
2044 | break; | |
572e2857 BB |
2045 | } else if (bytes < 0) { |
2046 | /* | |
2047 | * Insert a list marker and then wait for the | |
2048 | * hash lock to become available. Once its | |
2049 | * available, restart from where we left off. | |
2050 | */ | |
2051 | list_insert_after(list, ab, &marker); | |
2052 | mutex_exit(&state->arcs_mtx); | |
2053 | mutex_enter(hash_lock); | |
2054 | mutex_exit(hash_lock); | |
2055 | mutex_enter(&state->arcs_mtx); | |
2056 | ab_prev = list_prev(list, &marker); | |
2057 | list_remove(list, &marker); | |
2058 | } else | |
34dc7c2f | 2059 | bufs_skipped += 1; |
34dc7c2f BB |
2060 | } |
2061 | mutex_exit(&state->arcs_mtx); | |
2062 | ||
2063 | if (list == &state->arcs_list[ARC_BUFC_DATA] && | |
2064 | (bytes < 0 || bytes_deleted < bytes)) { | |
2065 | list = &state->arcs_list[ARC_BUFC_METADATA]; | |
2066 | goto top; | |
2067 | } | |
2068 | ||
2069 | if (bufs_skipped) { | |
2070 | ARCSTAT_INCR(arcstat_mutex_miss, bufs_skipped); | |
2071 | ASSERT(bytes >= 0); | |
2072 | } | |
2073 | ||
2074 | if (bytes_deleted < bytes) | |
3f504482 | 2075 | dprintf("only deleted %lld bytes from %p\n", |
34dc7c2f BB |
2076 | (longlong_t)bytes_deleted, state); |
2077 | } | |
2078 | ||
2079 | static void | |
2080 | arc_adjust(void) | |
2081 | { | |
d164b209 BB |
2082 | int64_t adjustment, delta; |
2083 | ||
2084 | /* | |
2085 | * Adjust MRU size | |
2086 | */ | |
34dc7c2f | 2087 | |
572e2857 BB |
2088 | adjustment = MIN((int64_t)(arc_size - arc_c), |
2089 | (int64_t)(arc_anon->arcs_size + arc_mru->arcs_size + arc_meta_used - | |
2090 | arc_p)); | |
34dc7c2f | 2091 | |
d164b209 BB |
2092 | if (adjustment > 0 && arc_mru->arcs_lsize[ARC_BUFC_DATA] > 0) { |
2093 | delta = MIN(arc_mru->arcs_lsize[ARC_BUFC_DATA], adjustment); | |
b8864a23 | 2094 | (void) arc_evict(arc_mru, 0, delta, FALSE, ARC_BUFC_DATA); |
d164b209 | 2095 | adjustment -= delta; |
34dc7c2f BB |
2096 | } |
2097 | ||
d164b209 BB |
2098 | if (adjustment > 0 && arc_mru->arcs_lsize[ARC_BUFC_METADATA] > 0) { |
2099 | delta = MIN(arc_mru->arcs_lsize[ARC_BUFC_METADATA], adjustment); | |
b8864a23 | 2100 | (void) arc_evict(arc_mru, 0, delta, FALSE, |
34dc7c2f | 2101 | ARC_BUFC_METADATA); |
34dc7c2f BB |
2102 | } |
2103 | ||
d164b209 BB |
2104 | /* |
2105 | * Adjust MFU size | |
2106 | */ | |
34dc7c2f | 2107 | |
d164b209 BB |
2108 | adjustment = arc_size - arc_c; |
2109 | ||
2110 | if (adjustment > 0 && arc_mfu->arcs_lsize[ARC_BUFC_DATA] > 0) { | |
2111 | delta = MIN(adjustment, arc_mfu->arcs_lsize[ARC_BUFC_DATA]); | |
b8864a23 | 2112 | (void) arc_evict(arc_mfu, 0, delta, FALSE, ARC_BUFC_DATA); |
d164b209 | 2113 | adjustment -= delta; |
34dc7c2f BB |
2114 | } |
2115 | ||
d164b209 BB |
2116 | if (adjustment > 0 && arc_mfu->arcs_lsize[ARC_BUFC_METADATA] > 0) { |
2117 | int64_t delta = MIN(adjustment, | |
2118 | arc_mfu->arcs_lsize[ARC_BUFC_METADATA]); | |
b8864a23 | 2119 | (void) arc_evict(arc_mfu, 0, delta, FALSE, |
d164b209 BB |
2120 | ARC_BUFC_METADATA); |
2121 | } | |
34dc7c2f | 2122 | |
d164b209 BB |
2123 | /* |
2124 | * Adjust ghost lists | |
2125 | */ | |
34dc7c2f | 2126 | |
d164b209 BB |
2127 | adjustment = arc_mru->arcs_size + arc_mru_ghost->arcs_size - arc_c; |
2128 | ||
2129 | if (adjustment > 0 && arc_mru_ghost->arcs_size > 0) { | |
2130 | delta = MIN(arc_mru_ghost->arcs_size, adjustment); | |
68121a03 | 2131 | arc_evict_ghost(arc_mru_ghost, 0, delta, ARC_BUFC_DATA); |
d164b209 | 2132 | } |
34dc7c2f | 2133 | |
d164b209 BB |
2134 | adjustment = |
2135 | arc_mru_ghost->arcs_size + arc_mfu_ghost->arcs_size - arc_c; | |
34dc7c2f | 2136 | |
d164b209 BB |
2137 | if (adjustment > 0 && arc_mfu_ghost->arcs_size > 0) { |
2138 | delta = MIN(arc_mfu_ghost->arcs_size, adjustment); | |
68121a03 | 2139 | arc_evict_ghost(arc_mfu_ghost, 0, delta, ARC_BUFC_DATA); |
34dc7c2f BB |
2140 | } |
2141 | } | |
2142 | ||
ab26409d BB |
2143 | /* |
2144 | * Request that arc user drop references so that N bytes can be released | |
2145 | * from the cache. This provides a mechanism to ensure the arc can honor | |
2146 | * the arc_meta_limit and reclaim buffers which are pinned in the cache | |
2147 | * by higher layers. (i.e. the zpl) | |
2148 | */ | |
2149 | static void | |
2150 | arc_do_user_prune(int64_t adjustment) | |
2151 | { | |
2152 | arc_prune_func_t *func; | |
2153 | void *private; | |
2154 | arc_prune_t *cp, *np; | |
2155 | ||
2156 | mutex_enter(&arc_prune_mtx); | |
2157 | ||
2158 | cp = list_head(&arc_prune_list); | |
2159 | while (cp != NULL) { | |
2160 | func = cp->p_pfunc; | |
2161 | private = cp->p_private; | |
2162 | np = list_next(&arc_prune_list, cp); | |
2163 | refcount_add(&cp->p_refcnt, func); | |
2164 | mutex_exit(&arc_prune_mtx); | |
2165 | ||
2166 | if (func != NULL) | |
2167 | func(adjustment, private); | |
2168 | ||
2169 | mutex_enter(&arc_prune_mtx); | |
2170 | ||
2171 | /* User removed prune callback concurrently with execution */ | |
2172 | if (refcount_remove(&cp->p_refcnt, func) == 0) { | |
2173 | ASSERT(!list_link_active(&cp->p_node)); | |
2174 | refcount_destroy(&cp->p_refcnt); | |
2175 | kmem_free(cp, sizeof (*cp)); | |
2176 | } | |
2177 | ||
2178 | cp = np; | |
2179 | } | |
2180 | ||
2181 | ARCSTAT_BUMP(arcstat_prune); | |
2182 | mutex_exit(&arc_prune_mtx); | |
2183 | } | |
2184 | ||
34dc7c2f BB |
2185 | static void |
2186 | arc_do_user_evicts(void) | |
2187 | { | |
2188 | mutex_enter(&arc_eviction_mtx); | |
2189 | while (arc_eviction_list != NULL) { | |
2190 | arc_buf_t *buf = arc_eviction_list; | |
2191 | arc_eviction_list = buf->b_next; | |
428870ff | 2192 | mutex_enter(&buf->b_evict_lock); |
34dc7c2f | 2193 | buf->b_hdr = NULL; |
428870ff | 2194 | mutex_exit(&buf->b_evict_lock); |
34dc7c2f BB |
2195 | mutex_exit(&arc_eviction_mtx); |
2196 | ||
2197 | if (buf->b_efunc != NULL) | |
2198 | VERIFY(buf->b_efunc(buf) == 0); | |
2199 | ||
2200 | buf->b_efunc = NULL; | |
2201 | buf->b_private = NULL; | |
2202 | kmem_cache_free(buf_cache, buf); | |
2203 | mutex_enter(&arc_eviction_mtx); | |
2204 | } | |
2205 | mutex_exit(&arc_eviction_mtx); | |
2206 | } | |
2207 | ||
ab26409d BB |
2208 | /* |
2209 | * Evict only meta data objects from the cache leaving the data objects. | |
2210 | * This is only used to enforce the tunable arc_meta_limit, if we are | |
2211 | * unable to evict enough buffers notify the user via the prune callback. | |
2212 | */ | |
2213 | void | |
2214 | arc_adjust_meta(int64_t adjustment, boolean_t may_prune) | |
2215 | { | |
c273d60d | 2216 | int64_t delta; |
ab26409d BB |
2217 | |
2218 | if (adjustment > 0 && arc_mru->arcs_lsize[ARC_BUFC_METADATA] > 0) { | |
2219 | delta = MIN(arc_mru->arcs_lsize[ARC_BUFC_METADATA], adjustment); | |
2220 | arc_evict(arc_mru, 0, delta, FALSE, ARC_BUFC_METADATA); | |
2221 | adjustment -= delta; | |
2222 | } | |
2223 | ||
2224 | if (adjustment > 0 && arc_mfu->arcs_lsize[ARC_BUFC_METADATA] > 0) { | |
2225 | delta = MIN(arc_mfu->arcs_lsize[ARC_BUFC_METADATA], adjustment); | |
2226 | arc_evict(arc_mfu, 0, delta, FALSE, ARC_BUFC_METADATA); | |
2227 | adjustment -= delta; | |
2228 | } | |
2229 | ||
2230 | if (may_prune && (adjustment > 0) && (arc_meta_used > arc_meta_limit)) | |
bce45ec9 | 2231 | arc_do_user_prune(zfs_arc_meta_prune); |
ab26409d BB |
2232 | } |
2233 | ||
34dc7c2f BB |
2234 | /* |
2235 | * Flush all *evictable* data from the cache for the given spa. | |
2236 | * NOTE: this will not touch "active" (i.e. referenced) data. | |
2237 | */ | |
2238 | void | |
2239 | arc_flush(spa_t *spa) | |
2240 | { | |
d164b209 BB |
2241 | uint64_t guid = 0; |
2242 | ||
2243 | if (spa) | |
3541dc6d | 2244 | guid = spa_load_guid(spa); |
d164b209 | 2245 | |
34dc7c2f | 2246 | while (list_head(&arc_mru->arcs_list[ARC_BUFC_DATA])) { |
d164b209 | 2247 | (void) arc_evict(arc_mru, guid, -1, FALSE, ARC_BUFC_DATA); |
34dc7c2f BB |
2248 | if (spa) |
2249 | break; | |
2250 | } | |
2251 | while (list_head(&arc_mru->arcs_list[ARC_BUFC_METADATA])) { | |
d164b209 | 2252 | (void) arc_evict(arc_mru, guid, -1, FALSE, ARC_BUFC_METADATA); |
34dc7c2f BB |
2253 | if (spa) |
2254 | break; | |
2255 | } | |
2256 | while (list_head(&arc_mfu->arcs_list[ARC_BUFC_DATA])) { | |
d164b209 | 2257 | (void) arc_evict(arc_mfu, guid, -1, FALSE, ARC_BUFC_DATA); |
34dc7c2f BB |
2258 | if (spa) |
2259 | break; | |
2260 | } | |
2261 | while (list_head(&arc_mfu->arcs_list[ARC_BUFC_METADATA])) { | |
d164b209 | 2262 | (void) arc_evict(arc_mfu, guid, -1, FALSE, ARC_BUFC_METADATA); |
34dc7c2f BB |
2263 | if (spa) |
2264 | break; | |
2265 | } | |
2266 | ||
68121a03 BB |
2267 | arc_evict_ghost(arc_mru_ghost, guid, -1, ARC_BUFC_DATA); |
2268 | arc_evict_ghost(arc_mfu_ghost, guid, -1, ARC_BUFC_DATA); | |
34dc7c2f BB |
2269 | |
2270 | mutex_enter(&arc_reclaim_thr_lock); | |
2271 | arc_do_user_evicts(); | |
2272 | mutex_exit(&arc_reclaim_thr_lock); | |
2273 | ASSERT(spa || arc_eviction_list == NULL); | |
2274 | } | |
2275 | ||
34dc7c2f | 2276 | void |
302f753f | 2277 | arc_shrink(uint64_t bytes) |
34dc7c2f BB |
2278 | { |
2279 | if (arc_c > arc_c_min) { | |
2280 | uint64_t to_free; | |
2281 | ||
bce45ec9 | 2282 | to_free = bytes ? bytes : arc_c >> zfs_arc_shrink_shift; |
302f753f | 2283 | |
34dc7c2f BB |
2284 | if (arc_c > arc_c_min + to_free) |
2285 | atomic_add_64(&arc_c, -to_free); | |
2286 | else | |
2287 | arc_c = arc_c_min; | |
2288 | ||
bce45ec9 | 2289 | atomic_add_64(&arc_p, -(arc_p >> zfs_arc_shrink_shift)); |
34dc7c2f BB |
2290 | if (arc_c > arc_size) |
2291 | arc_c = MAX(arc_size, arc_c_min); | |
2292 | if (arc_p > arc_c) | |
2293 | arc_p = (arc_c >> 1); | |
2294 | ASSERT(arc_c >= arc_c_min); | |
2295 | ASSERT((int64_t)arc_p >= 0); | |
2296 | } | |
2297 | ||
2298 | if (arc_size > arc_c) | |
2299 | arc_adjust(); | |
2300 | } | |
2301 | ||
34dc7c2f | 2302 | static void |
302f753f | 2303 | arc_kmem_reap_now(arc_reclaim_strategy_t strat, uint64_t bytes) |
34dc7c2f BB |
2304 | { |
2305 | size_t i; | |
2306 | kmem_cache_t *prev_cache = NULL; | |
2307 | kmem_cache_t *prev_data_cache = NULL; | |
2308 | extern kmem_cache_t *zio_buf_cache[]; | |
2309 | extern kmem_cache_t *zio_data_buf_cache[]; | |
34dc7c2f BB |
2310 | |
2311 | /* | |
2312 | * An aggressive reclamation will shrink the cache size as well as | |
2313 | * reap free buffers from the arc kmem caches. | |
2314 | */ | |
2315 | if (strat == ARC_RECLAIM_AGGR) | |
302f753f | 2316 | arc_shrink(bytes); |
34dc7c2f BB |
2317 | |
2318 | for (i = 0; i < SPA_MAXBLOCKSIZE >> SPA_MINBLOCKSHIFT; i++) { | |
2319 | if (zio_buf_cache[i] != prev_cache) { | |
2320 | prev_cache = zio_buf_cache[i]; | |
2321 | kmem_cache_reap_now(zio_buf_cache[i]); | |
2322 | } | |
2323 | if (zio_data_buf_cache[i] != prev_data_cache) { | |
2324 | prev_data_cache = zio_data_buf_cache[i]; | |
2325 | kmem_cache_reap_now(zio_data_buf_cache[i]); | |
2326 | } | |
2327 | } | |
ab26409d | 2328 | |
34dc7c2f BB |
2329 | kmem_cache_reap_now(buf_cache); |
2330 | kmem_cache_reap_now(hdr_cache); | |
2331 | } | |
2332 | ||
302f753f BB |
2333 | /* |
2334 | * Unlike other ZFS implementations this thread is only responsible for | |
2335 | * adapting the target ARC size on Linux. The responsibility for memory | |
2336 | * reclamation has been entirely delegated to the arc_shrinker_func() | |
2337 | * which is registered with the VM. To reflect this change in behavior | |
2338 | * the arc_reclaim thread has been renamed to arc_adapt. | |
2339 | */ | |
34dc7c2f | 2340 | static void |
302f753f | 2341 | arc_adapt_thread(void) |
34dc7c2f | 2342 | { |
34dc7c2f | 2343 | callb_cpr_t cpr; |
ab26409d | 2344 | int64_t prune; |
34dc7c2f BB |
2345 | |
2346 | CALLB_CPR_INIT(&cpr, &arc_reclaim_thr_lock, callb_generic_cpr, FTAG); | |
2347 | ||
2348 | mutex_enter(&arc_reclaim_thr_lock); | |
2349 | while (arc_thread_exit == 0) { | |
302f753f BB |
2350 | #ifndef _KERNEL |
2351 | arc_reclaim_strategy_t last_reclaim = ARC_RECLAIM_CONS; | |
2352 | ||
2353 | if (spa_get_random(100) == 0) { | |
34dc7c2f BB |
2354 | |
2355 | if (arc_no_grow) { | |
2356 | if (last_reclaim == ARC_RECLAIM_CONS) { | |
2357 | last_reclaim = ARC_RECLAIM_AGGR; | |
2358 | } else { | |
2359 | last_reclaim = ARC_RECLAIM_CONS; | |
2360 | } | |
2361 | } else { | |
2362 | arc_no_grow = TRUE; | |
2363 | last_reclaim = ARC_RECLAIM_AGGR; | |
2364 | membar_producer(); | |
2365 | } | |
2366 | ||
2367 | /* reset the growth delay for every reclaim */ | |
bce45ec9 | 2368 | arc_grow_time = ddi_get_lbolt()+(zfs_arc_grow_retry * hz); |
34dc7c2f | 2369 | |
302f753f | 2370 | arc_kmem_reap_now(last_reclaim, 0); |
b128c09f | 2371 | arc_warm = B_TRUE; |
302f753f BB |
2372 | } |
2373 | #endif /* !_KERNEL */ | |
34dc7c2f | 2374 | |
302f753f BB |
2375 | /* No recent memory pressure allow the ARC to grow. */ |
2376 | if (arc_no_grow && ddi_get_lbolt() >= arc_grow_time) | |
34dc7c2f | 2377 | arc_no_grow = FALSE; |
34dc7c2f | 2378 | |
ab26409d BB |
2379 | /* |
2380 | * Keep meta data usage within limits, arc_shrink() is not | |
2381 | * used to avoid collapsing the arc_c value when only the | |
2382 | * arc_meta_limit is being exceeded. | |
2383 | */ | |
2384 | prune = (int64_t)arc_meta_used - (int64_t)arc_meta_limit; | |
2385 | if (prune > 0) | |
2386 | arc_adjust_meta(prune, B_TRUE); | |
6a8f9b6b | 2387 | |
572e2857 | 2388 | arc_adjust(); |
34dc7c2f BB |
2389 | |
2390 | if (arc_eviction_list != NULL) | |
2391 | arc_do_user_evicts(); | |
2392 | ||
2393 | /* block until needed, or one second, whichever is shorter */ | |
2394 | CALLB_CPR_SAFE_BEGIN(&cpr); | |
5b63b3eb | 2395 | (void) cv_timedwait_interruptible(&arc_reclaim_thr_cv, |
428870ff | 2396 | &arc_reclaim_thr_lock, (ddi_get_lbolt() + hz)); |
34dc7c2f | 2397 | CALLB_CPR_SAFE_END(&cpr, &arc_reclaim_thr_lock); |
bce45ec9 BB |
2398 | |
2399 | ||
2400 | /* Allow the module options to be changed */ | |
2401 | if (zfs_arc_max > 64 << 20 && | |
2402 | zfs_arc_max < physmem * PAGESIZE && | |
2403 | zfs_arc_max != arc_c_max) | |
2404 | arc_c_max = zfs_arc_max; | |
2405 | ||
2406 | if (zfs_arc_min > 0 && | |
2407 | zfs_arc_min < arc_c_max && | |
2408 | zfs_arc_min != arc_c_min) | |
2409 | arc_c_min = zfs_arc_min; | |
2410 | ||
2411 | if (zfs_arc_meta_limit > 0 && | |
2412 | zfs_arc_meta_limit <= arc_c_max && | |
2413 | zfs_arc_meta_limit != arc_meta_limit) | |
2414 | arc_meta_limit = zfs_arc_meta_limit; | |
2415 | ||
2416 | ||
2417 | ||
34dc7c2f BB |
2418 | } |
2419 | ||
2420 | arc_thread_exit = 0; | |
2421 | cv_broadcast(&arc_reclaim_thr_cv); | |
2422 | CALLB_CPR_EXIT(&cpr); /* drops arc_reclaim_thr_lock */ | |
2423 | thread_exit(); | |
2424 | } | |
2425 | ||
7cb67b45 BB |
2426 | #ifdef _KERNEL |
2427 | /* | |
302f753f BB |
2428 | * Determine the amount of memory eligible for eviction contained in the |
2429 | * ARC. All clean data reported by the ghost lists can always be safely | |
2430 | * evicted. Due to arc_c_min, the same does not hold for all clean data | |
2431 | * contained by the regular mru and mfu lists. | |
2432 | * | |
2433 | * In the case of the regular mru and mfu lists, we need to report as | |
2434 | * much clean data as possible, such that evicting that same reported | |
2435 | * data will not bring arc_size below arc_c_min. Thus, in certain | |
2436 | * circumstances, the total amount of clean data in the mru and mfu | |
2437 | * lists might not actually be evictable. | |
2438 | * | |
2439 | * The following two distinct cases are accounted for: | |
2440 | * | |
2441 | * 1. The sum of the amount of dirty data contained by both the mru and | |
2442 | * mfu lists, plus the ARC's other accounting (e.g. the anon list), | |
2443 | * is greater than or equal to arc_c_min. | |
2444 | * (i.e. amount of dirty data >= arc_c_min) | |
2445 | * | |
2446 | * This is the easy case; all clean data contained by the mru and mfu | |
2447 | * lists is evictable. Evicting all clean data can only drop arc_size | |
2448 | * to the amount of dirty data, which is greater than arc_c_min. | |
2449 | * | |
2450 | * 2. The sum of the amount of dirty data contained by both the mru and | |
2451 | * mfu lists, plus the ARC's other accounting (e.g. the anon list), | |
2452 | * is less than arc_c_min. | |
2453 | * (i.e. arc_c_min > amount of dirty data) | |
2454 | * | |
2455 | * 2.1. arc_size is greater than or equal arc_c_min. | |
2456 | * (i.e. arc_size >= arc_c_min > amount of dirty data) | |
2457 | * | |
2458 | * In this case, not all clean data from the regular mru and mfu | |
2459 | * lists is actually evictable; we must leave enough clean data | |
2460 | * to keep arc_size above arc_c_min. Thus, the maximum amount of | |
2461 | * evictable data from the two lists combined, is exactly the | |
2462 | * difference between arc_size and arc_c_min. | |
2463 | * | |
2464 | * 2.2. arc_size is less than arc_c_min | |
2465 | * (i.e. arc_c_min > arc_size > amount of dirty data) | |
2466 | * | |
2467 | * In this case, none of the data contained in the mru and mfu | |
2468 | * lists is evictable, even if it's clean. Since arc_size is | |
2469 | * already below arc_c_min, evicting any more would only | |
2470 | * increase this negative difference. | |
7cb67b45 | 2471 | */ |
302f753f BB |
2472 | static uint64_t |
2473 | arc_evictable_memory(void) { | |
2474 | uint64_t arc_clean = | |
2475 | arc_mru->arcs_lsize[ARC_BUFC_DATA] + | |
2476 | arc_mru->arcs_lsize[ARC_BUFC_METADATA] + | |
2477 | arc_mfu->arcs_lsize[ARC_BUFC_DATA] + | |
2478 | arc_mfu->arcs_lsize[ARC_BUFC_METADATA]; | |
2479 | uint64_t ghost_clean = | |
2480 | arc_mru_ghost->arcs_lsize[ARC_BUFC_DATA] + | |
2481 | arc_mru_ghost->arcs_lsize[ARC_BUFC_METADATA] + | |
2482 | arc_mfu_ghost->arcs_lsize[ARC_BUFC_DATA] + | |
2483 | arc_mfu_ghost->arcs_lsize[ARC_BUFC_METADATA]; | |
2484 | uint64_t arc_dirty = MAX((int64_t)arc_size - (int64_t)arc_clean, 0); | |
2485 | ||
2486 | if (arc_dirty >= arc_c_min) | |
2487 | return (ghost_clean + arc_clean); | |
2488 | ||
2489 | return (ghost_clean + MAX((int64_t)arc_size - (int64_t)arc_c_min, 0)); | |
2490 | } | |
2491 | ||
7e7baeca BB |
2492 | static int |
2493 | __arc_shrinker_func(struct shrinker *shrink, struct shrink_control *sc) | |
7cb67b45 | 2494 | { |
302f753f | 2495 | uint64_t pages; |
7cb67b45 | 2496 | |
302f753f BB |
2497 | /* The arc is considered warm once reclaim has occurred */ |
2498 | if (unlikely(arc_warm == B_FALSE)) | |
2499 | arc_warm = B_TRUE; | |
7cb67b45 | 2500 | |
302f753f BB |
2501 | /* Return the potential number of reclaimable pages */ |
2502 | pages = btop(arc_evictable_memory()); | |
2503 | if (sc->nr_to_scan == 0) | |
2504 | return (pages); | |
3fd70ee6 BB |
2505 | |
2506 | /* Not allowed to perform filesystem reclaim */ | |
7e7baeca | 2507 | if (!(sc->gfp_mask & __GFP_FS)) |
3fd70ee6 BB |
2508 | return (-1); |
2509 | ||
7cb67b45 BB |
2510 | /* Reclaim in progress */ |
2511 | if (mutex_tryenter(&arc_reclaim_thr_lock) == 0) | |
2512 | return (-1); | |
2513 | ||
302f753f BB |
2514 | /* |
2515 | * Evict the requested number of pages by shrinking arc_c the | |
2516 | * requested amount. If there is nothing left to evict just | |
2517 | * reap whatever we can from the various arc slabs. | |
2518 | */ | |
2519 | if (pages > 0) { | |
2520 | arc_kmem_reap_now(ARC_RECLAIM_AGGR, ptob(sc->nr_to_scan)); | |
302f753f BB |
2521 | } else { |
2522 | arc_kmem_reap_now(ARC_RECLAIM_CONS, ptob(sc->nr_to_scan)); | |
302f753f BB |
2523 | } |
2524 | ||
2525 | /* | |
2526 | * When direct reclaim is observed it usually indicates a rapid | |
2527 | * increase in memory pressure. This occurs because the kswapd | |
2528 | * threads were unable to asynchronously keep enough free memory | |
2529 | * available. In this case set arc_no_grow to briefly pause arc | |
2530 | * growth to avoid compounding the memory pressure. | |
2531 | */ | |
7cb67b45 | 2532 | if (current_is_kswapd()) { |
302f753f | 2533 | ARCSTAT_BUMP(arcstat_memory_indirect_count); |
7cb67b45 | 2534 | } else { |
302f753f | 2535 | arc_no_grow = B_TRUE; |
bce45ec9 | 2536 | arc_grow_time = ddi_get_lbolt() + (zfs_arc_grow_retry * hz); |
302f753f | 2537 | ARCSTAT_BUMP(arcstat_memory_direct_count); |
7cb67b45 BB |
2538 | } |
2539 | ||
7cb67b45 BB |
2540 | mutex_exit(&arc_reclaim_thr_lock); |
2541 | ||
c11a12bc | 2542 | return (-1); |
7cb67b45 | 2543 | } |
7e7baeca | 2544 | SPL_SHRINKER_CALLBACK_WRAPPER(arc_shrinker_func); |
7cb67b45 BB |
2545 | |
2546 | SPL_SHRINKER_DECLARE(arc_shrinker, arc_shrinker_func, DEFAULT_SEEKS); | |
2547 | #endif /* _KERNEL */ | |
2548 | ||
34dc7c2f BB |
2549 | /* |
2550 | * Adapt arc info given the number of bytes we are trying to add and | |
2551 | * the state that we are comming from. This function is only called | |
2552 | * when we are adding new content to the cache. | |
2553 | */ | |
2554 | static void | |
2555 | arc_adapt(int bytes, arc_state_t *state) | |
2556 | { | |
2557 | int mult; | |
bce45ec9 | 2558 | uint64_t arc_p_min = (arc_c >> zfs_arc_p_min_shift); |
34dc7c2f BB |
2559 | |
2560 | if (state == arc_l2c_only) | |
2561 | return; | |
2562 | ||
2563 | ASSERT(bytes > 0); | |
2564 | /* | |
2565 | * Adapt the target size of the MRU list: | |
2566 | * - if we just hit in the MRU ghost list, then increase | |
2567 | * the target size of the MRU list. | |
2568 | * - if we just hit in the MFU ghost list, then increase | |
2569 | * the target size of the MFU list by decreasing the | |
2570 | * target size of the MRU list. | |
2571 | */ | |
2572 | if (state == arc_mru_ghost) { | |
2573 | mult = ((arc_mru_ghost->arcs_size >= arc_mfu_ghost->arcs_size) ? | |
2574 | 1 : (arc_mfu_ghost->arcs_size/arc_mru_ghost->arcs_size)); | |
572e2857 | 2575 | mult = MIN(mult, 10); /* avoid wild arc_p adjustment */ |
34dc7c2f | 2576 | |
d164b209 | 2577 | arc_p = MIN(arc_c - arc_p_min, arc_p + bytes * mult); |
34dc7c2f | 2578 | } else if (state == arc_mfu_ghost) { |
d164b209 BB |
2579 | uint64_t delta; |
2580 | ||
34dc7c2f BB |
2581 | mult = ((arc_mfu_ghost->arcs_size >= arc_mru_ghost->arcs_size) ? |
2582 | 1 : (arc_mru_ghost->arcs_size/arc_mfu_ghost->arcs_size)); | |
572e2857 | 2583 | mult = MIN(mult, 10); |
34dc7c2f | 2584 | |
d164b209 BB |
2585 | delta = MIN(bytes * mult, arc_p); |
2586 | arc_p = MAX(arc_p_min, arc_p - delta); | |
34dc7c2f BB |
2587 | } |
2588 | ASSERT((int64_t)arc_p >= 0); | |
2589 | ||
34dc7c2f BB |
2590 | if (arc_no_grow) |
2591 | return; | |
2592 | ||
2593 | if (arc_c >= arc_c_max) | |
2594 | return; | |
2595 | ||
2596 | /* | |
2597 | * If we're within (2 * maxblocksize) bytes of the target | |
2598 | * cache size, increment the target cache size | |
2599 | */ | |
2600 | if (arc_size > arc_c - (2ULL << SPA_MAXBLOCKSHIFT)) { | |
2601 | atomic_add_64(&arc_c, (int64_t)bytes); | |
2602 | if (arc_c > arc_c_max) | |
2603 | arc_c = arc_c_max; | |
2604 | else if (state == arc_anon) | |
2605 | atomic_add_64(&arc_p, (int64_t)bytes); | |
2606 | if (arc_p > arc_c) | |
2607 | arc_p = arc_c; | |
2608 | } | |
2609 | ASSERT((int64_t)arc_p >= 0); | |
2610 | } | |
2611 | ||
2612 | /* | |
2613 | * Check if the cache has reached its limits and eviction is required | |
2614 | * prior to insert. | |
2615 | */ | |
2616 | static int | |
2617 | arc_evict_needed(arc_buf_contents_t type) | |
2618 | { | |
2619 | if (type == ARC_BUFC_METADATA && arc_meta_used >= arc_meta_limit) | |
2620 | return (1); | |
2621 | ||
302f753f | 2622 | if (arc_no_grow) |
34dc7c2f BB |
2623 | return (1); |
2624 | ||
2625 | return (arc_size > arc_c); | |
2626 | } | |
2627 | ||
2628 | /* | |
2629 | * The buffer, supplied as the first argument, needs a data block. | |
2630 | * So, if we are at cache max, determine which cache should be victimized. | |
2631 | * We have the following cases: | |
2632 | * | |
2633 | * 1. Insert for MRU, p > sizeof(arc_anon + arc_mru) -> | |
2634 | * In this situation if we're out of space, but the resident size of the MFU is | |
2635 | * under the limit, victimize the MFU cache to satisfy this insertion request. | |
2636 | * | |
2637 | * 2. Insert for MRU, p <= sizeof(arc_anon + arc_mru) -> | |
2638 | * Here, we've used up all of the available space for the MRU, so we need to | |
2639 | * evict from our own cache instead. Evict from the set of resident MRU | |
2640 | * entries. | |
2641 | * | |
2642 | * 3. Insert for MFU (c - p) > sizeof(arc_mfu) -> | |
2643 | * c minus p represents the MFU space in the cache, since p is the size of the | |
2644 | * cache that is dedicated to the MRU. In this situation there's still space on | |
2645 | * the MFU side, so the MRU side needs to be victimized. | |
2646 | * | |
2647 | * 4. Insert for MFU (c - p) < sizeof(arc_mfu) -> | |
2648 | * MFU's resident set is consuming more space than it has been allotted. In | |
2649 | * this situation, we must victimize our own cache, the MFU, for this insertion. | |
2650 | */ | |
2651 | static void | |
2652 | arc_get_data_buf(arc_buf_t *buf) | |
2653 | { | |
2654 | arc_state_t *state = buf->b_hdr->b_state; | |
2655 | uint64_t size = buf->b_hdr->b_size; | |
2656 | arc_buf_contents_t type = buf->b_hdr->b_type; | |
2657 | ||
2658 | arc_adapt(size, state); | |
2659 | ||
2660 | /* | |
2661 | * We have not yet reached cache maximum size, | |
2662 | * just allocate a new buffer. | |
2663 | */ | |
2664 | if (!arc_evict_needed(type)) { | |
2665 | if (type == ARC_BUFC_METADATA) { | |
2666 | buf->b_data = zio_buf_alloc(size); | |
d164b209 | 2667 | arc_space_consume(size, ARC_SPACE_DATA); |
34dc7c2f BB |
2668 | } else { |
2669 | ASSERT(type == ARC_BUFC_DATA); | |
2670 | buf->b_data = zio_data_buf_alloc(size); | |
d164b209 | 2671 | ARCSTAT_INCR(arcstat_data_size, size); |
34dc7c2f BB |
2672 | atomic_add_64(&arc_size, size); |
2673 | } | |
2674 | goto out; | |
2675 | } | |
2676 | ||
2677 | /* | |
2678 | * If we are prefetching from the mfu ghost list, this buffer | |
2679 | * will end up on the mru list; so steal space from there. | |
2680 | */ | |
2681 | if (state == arc_mfu_ghost) | |
2682 | state = buf->b_hdr->b_flags & ARC_PREFETCH ? arc_mru : arc_mfu; | |
2683 | else if (state == arc_mru_ghost) | |
2684 | state = arc_mru; | |
2685 | ||
2686 | if (state == arc_mru || state == arc_anon) { | |
2687 | uint64_t mru_used = arc_anon->arcs_size + arc_mru->arcs_size; | |
d164b209 | 2688 | state = (arc_mfu->arcs_lsize[type] >= size && |
34dc7c2f BB |
2689 | arc_p > mru_used) ? arc_mfu : arc_mru; |
2690 | } else { | |
2691 | /* MFU cases */ | |
2692 | uint64_t mfu_space = arc_c - arc_p; | |
d164b209 | 2693 | state = (arc_mru->arcs_lsize[type] >= size && |
34dc7c2f BB |
2694 | mfu_space > arc_mfu->arcs_size) ? arc_mru : arc_mfu; |
2695 | } | |
ab26409d | 2696 | |
b8864a23 | 2697 | if ((buf->b_data = arc_evict(state, 0, size, TRUE, type)) == NULL) { |
34dc7c2f BB |
2698 | if (type == ARC_BUFC_METADATA) { |
2699 | buf->b_data = zio_buf_alloc(size); | |
d164b209 | 2700 | arc_space_consume(size, ARC_SPACE_DATA); |
ab26409d BB |
2701 | |
2702 | /* | |
2703 | * If we are unable to recycle an existing meta buffer | |
2704 | * signal the reclaim thread. It will notify users | |
2705 | * via the prune callback to drop references. The | |
2706 | * prune callback in run in the context of the reclaim | |
2707 | * thread to avoid deadlocking on the hash_lock. | |
2708 | */ | |
2709 | cv_signal(&arc_reclaim_thr_cv); | |
34dc7c2f BB |
2710 | } else { |
2711 | ASSERT(type == ARC_BUFC_DATA); | |
2712 | buf->b_data = zio_data_buf_alloc(size); | |
d164b209 | 2713 | ARCSTAT_INCR(arcstat_data_size, size); |
34dc7c2f BB |
2714 | atomic_add_64(&arc_size, size); |
2715 | } | |
ab26409d | 2716 | |
34dc7c2f BB |
2717 | ARCSTAT_BUMP(arcstat_recycle_miss); |
2718 | } | |
2719 | ASSERT(buf->b_data != NULL); | |
2720 | out: | |
2721 | /* | |
2722 | * Update the state size. Note that ghost states have a | |
2723 | * "ghost size" and so don't need to be updated. | |
2724 | */ | |
2725 | if (!GHOST_STATE(buf->b_hdr->b_state)) { | |
2726 | arc_buf_hdr_t *hdr = buf->b_hdr; | |
2727 | ||
2728 | atomic_add_64(&hdr->b_state->arcs_size, size); | |
2729 | if (list_link_active(&hdr->b_arc_node)) { | |
2730 | ASSERT(refcount_is_zero(&hdr->b_refcnt)); | |
2731 | atomic_add_64(&hdr->b_state->arcs_lsize[type], size); | |
2732 | } | |
2733 | /* | |
2734 | * If we are growing the cache, and we are adding anonymous | |
2735 | * data, and we have outgrown arc_p, update arc_p | |
2736 | */ | |
2737 | if (arc_size < arc_c && hdr->b_state == arc_anon && | |
2738 | arc_anon->arcs_size + arc_mru->arcs_size > arc_p) | |
2739 | arc_p = MIN(arc_c, arc_p + size); | |
2740 | } | |
2741 | } | |
2742 | ||
2743 | /* | |
2744 | * This routine is called whenever a buffer is accessed. | |
2745 | * NOTE: the hash lock is dropped in this function. | |
2746 | */ | |
2747 | static void | |
2748 | arc_access(arc_buf_hdr_t *buf, kmutex_t *hash_lock) | |
2749 | { | |
428870ff BB |
2750 | clock_t now; |
2751 | ||
34dc7c2f BB |
2752 | ASSERT(MUTEX_HELD(hash_lock)); |
2753 | ||
2754 | if (buf->b_state == arc_anon) { | |
2755 | /* | |
2756 | * This buffer is not in the cache, and does not | |
2757 | * appear in our "ghost" list. Add the new buffer | |
2758 | * to the MRU state. | |
2759 | */ | |
2760 | ||
2761 | ASSERT(buf->b_arc_access == 0); | |
428870ff | 2762 | buf->b_arc_access = ddi_get_lbolt(); |
34dc7c2f BB |
2763 | DTRACE_PROBE1(new_state__mru, arc_buf_hdr_t *, buf); |
2764 | arc_change_state(arc_mru, buf, hash_lock); | |
2765 | ||
2766 | } else if (buf->b_state == arc_mru) { | |
428870ff BB |
2767 | now = ddi_get_lbolt(); |
2768 | ||
34dc7c2f BB |
2769 | /* |
2770 | * If this buffer is here because of a prefetch, then either: | |
2771 | * - clear the flag if this is a "referencing" read | |
2772 | * (any subsequent access will bump this into the MFU state). | |
2773 | * or | |
2774 | * - move the buffer to the head of the list if this is | |
2775 | * another prefetch (to make it less likely to be evicted). | |
2776 | */ | |
2777 | if ((buf->b_flags & ARC_PREFETCH) != 0) { | |
2778 | if (refcount_count(&buf->b_refcnt) == 0) { | |
2779 | ASSERT(list_link_active(&buf->b_arc_node)); | |
2780 | } else { | |
2781 | buf->b_flags &= ~ARC_PREFETCH; | |
e0b0ca98 | 2782 | atomic_inc_32(&buf->b_mru_hits); |
34dc7c2f BB |
2783 | ARCSTAT_BUMP(arcstat_mru_hits); |
2784 | } | |
428870ff | 2785 | buf->b_arc_access = now; |
34dc7c2f BB |
2786 | return; |
2787 | } | |
2788 | ||
2789 | /* | |
2790 | * This buffer has been "accessed" only once so far, | |
2791 | * but it is still in the cache. Move it to the MFU | |
2792 | * state. | |
2793 | */ | |
428870ff | 2794 | if (now > buf->b_arc_access + ARC_MINTIME) { |
34dc7c2f BB |
2795 | /* |
2796 | * More than 125ms have passed since we | |
2797 | * instantiated this buffer. Move it to the | |
2798 | * most frequently used state. | |
2799 | */ | |
428870ff | 2800 | buf->b_arc_access = now; |
34dc7c2f BB |
2801 | DTRACE_PROBE1(new_state__mfu, arc_buf_hdr_t *, buf); |
2802 | arc_change_state(arc_mfu, buf, hash_lock); | |
2803 | } | |
e0b0ca98 | 2804 | atomic_inc_32(&buf->b_mru_hits); |
34dc7c2f BB |
2805 | ARCSTAT_BUMP(arcstat_mru_hits); |
2806 | } else if (buf->b_state == arc_mru_ghost) { | |
2807 | arc_state_t *new_state; | |
2808 | /* | |
2809 | * This buffer has been "accessed" recently, but | |
2810 | * was evicted from the cache. Move it to the | |
2811 | * MFU state. | |
2812 | */ | |
2813 | ||
2814 | if (buf->b_flags & ARC_PREFETCH) { | |
2815 | new_state = arc_mru; | |
2816 | if (refcount_count(&buf->b_refcnt) > 0) | |
2817 | buf->b_flags &= ~ARC_PREFETCH; | |
2818 | DTRACE_PROBE1(new_state__mru, arc_buf_hdr_t *, buf); | |
2819 | } else { | |
2820 | new_state = arc_mfu; | |
2821 | DTRACE_PROBE1(new_state__mfu, arc_buf_hdr_t *, buf); | |
2822 | } | |
2823 | ||
428870ff | 2824 | buf->b_arc_access = ddi_get_lbolt(); |
34dc7c2f BB |
2825 | arc_change_state(new_state, buf, hash_lock); |
2826 | ||
e0b0ca98 | 2827 | atomic_inc_32(&buf->b_mru_ghost_hits); |
34dc7c2f BB |
2828 | ARCSTAT_BUMP(arcstat_mru_ghost_hits); |
2829 | } else if (buf->b_state == arc_mfu) { | |
2830 | /* | |
2831 | * This buffer has been accessed more than once and is | |
2832 | * still in the cache. Keep it in the MFU state. | |
2833 | * | |
2834 | * NOTE: an add_reference() that occurred when we did | |
2835 | * the arc_read() will have kicked this off the list. | |
2836 | * If it was a prefetch, we will explicitly move it to | |
2837 | * the head of the list now. | |
2838 | */ | |
2839 | if ((buf->b_flags & ARC_PREFETCH) != 0) { | |
2840 | ASSERT(refcount_count(&buf->b_refcnt) == 0); | |
2841 | ASSERT(list_link_active(&buf->b_arc_node)); | |
2842 | } | |
e0b0ca98 | 2843 | atomic_inc_32(&buf->b_mfu_hits); |
34dc7c2f | 2844 | ARCSTAT_BUMP(arcstat_mfu_hits); |
428870ff | 2845 | buf->b_arc_access = ddi_get_lbolt(); |
34dc7c2f BB |
2846 | } else if (buf->b_state == arc_mfu_ghost) { |
2847 | arc_state_t *new_state = arc_mfu; | |
2848 | /* | |
2849 | * This buffer has been accessed more than once but has | |
2850 | * been evicted from the cache. Move it back to the | |
2851 | * MFU state. | |
2852 | */ | |
2853 | ||
2854 | if (buf->b_flags & ARC_PREFETCH) { | |
2855 | /* | |
2856 | * This is a prefetch access... | |
2857 | * move this block back to the MRU state. | |
2858 | */ | |
c99c9001 | 2859 | ASSERT0(refcount_count(&buf->b_refcnt)); |
34dc7c2f BB |
2860 | new_state = arc_mru; |
2861 | } | |
2862 | ||
428870ff | 2863 | buf->b_arc_access = ddi_get_lbolt(); |
34dc7c2f BB |
2864 | DTRACE_PROBE1(new_state__mfu, arc_buf_hdr_t *, buf); |
2865 | arc_change_state(new_state, buf, hash_lock); | |
2866 | ||
e0b0ca98 | 2867 | atomic_inc_32(&buf->b_mfu_ghost_hits); |
34dc7c2f BB |
2868 | ARCSTAT_BUMP(arcstat_mfu_ghost_hits); |
2869 | } else if (buf->b_state == arc_l2c_only) { | |
2870 | /* | |
2871 | * This buffer is on the 2nd Level ARC. | |
2872 | */ | |
2873 | ||
428870ff | 2874 | buf->b_arc_access = ddi_get_lbolt(); |
34dc7c2f BB |
2875 | DTRACE_PROBE1(new_state__mfu, arc_buf_hdr_t *, buf); |
2876 | arc_change_state(arc_mfu, buf, hash_lock); | |
2877 | } else { | |
2878 | ASSERT(!"invalid arc state"); | |
2879 | } | |
2880 | } | |
2881 | ||
2882 | /* a generic arc_done_func_t which you can use */ | |
2883 | /* ARGSUSED */ | |
2884 | void | |
2885 | arc_bcopy_func(zio_t *zio, arc_buf_t *buf, void *arg) | |
2886 | { | |
428870ff BB |
2887 | if (zio == NULL || zio->io_error == 0) |
2888 | bcopy(buf->b_data, arg, buf->b_hdr->b_size); | |
13fe0198 | 2889 | VERIFY(arc_buf_remove_ref(buf, arg)); |
34dc7c2f BB |
2890 | } |
2891 | ||
2892 | /* a generic arc_done_func_t */ | |
2893 | void | |
2894 | arc_getbuf_func(zio_t *zio, arc_buf_t *buf, void *arg) | |
2895 | { | |
2896 | arc_buf_t **bufp = arg; | |
2897 | if (zio && zio->io_error) { | |
13fe0198 | 2898 | VERIFY(arc_buf_remove_ref(buf, arg)); |
34dc7c2f BB |
2899 | *bufp = NULL; |
2900 | } else { | |
2901 | *bufp = buf; | |
428870ff | 2902 | ASSERT(buf->b_data); |
34dc7c2f BB |
2903 | } |
2904 | } | |
2905 | ||
2906 | static void | |
2907 | arc_read_done(zio_t *zio) | |
2908 | { | |
2909 | arc_buf_hdr_t *hdr, *found; | |
2910 | arc_buf_t *buf; | |
2911 | arc_buf_t *abuf; /* buffer we're assigning to callback */ | |
2912 | kmutex_t *hash_lock; | |
2913 | arc_callback_t *callback_list, *acb; | |
2914 | int freeable = FALSE; | |
2915 | ||
2916 | buf = zio->io_private; | |
2917 | hdr = buf->b_hdr; | |
2918 | ||
2919 | /* | |
2920 | * The hdr was inserted into hash-table and removed from lists | |
2921 | * prior to starting I/O. We should find this header, since | |
2922 | * it's in the hash table, and it should be legit since it's | |
2923 | * not possible to evict it during the I/O. The only possible | |
2924 | * reason for it not to be found is if we were freed during the | |
2925 | * read. | |
2926 | */ | |
d164b209 | 2927 | found = buf_hash_find(hdr->b_spa, &hdr->b_dva, hdr->b_birth, |
34dc7c2f BB |
2928 | &hash_lock); |
2929 | ||
2930 | ASSERT((found == NULL && HDR_FREED_IN_READ(hdr) && hash_lock == NULL) || | |
2931 | (found == hdr && DVA_EQUAL(&hdr->b_dva, BP_IDENTITY(zio->io_bp))) || | |
2932 | (found == hdr && HDR_L2_READING(hdr))); | |
2933 | ||
b128c09f | 2934 | hdr->b_flags &= ~ARC_L2_EVICTED; |
34dc7c2f | 2935 | if (l2arc_noprefetch && (hdr->b_flags & ARC_PREFETCH)) |
b128c09f | 2936 | hdr->b_flags &= ~ARC_L2CACHE; |
34dc7c2f BB |
2937 | |
2938 | /* byteswap if necessary */ | |
2939 | callback_list = hdr->b_acb; | |
2940 | ASSERT(callback_list != NULL); | |
428870ff | 2941 | if (BP_SHOULD_BYTESWAP(zio->io_bp) && zio->io_error == 0) { |
9ae529ec CS |
2942 | dmu_object_byteswap_t bswap = |
2943 | DMU_OT_BYTESWAP(BP_GET_TYPE(zio->io_bp)); | |
b01615d5 RY |
2944 | if (BP_GET_LEVEL(zio->io_bp) > 0) |
2945 | byteswap_uint64_array(buf->b_data, hdr->b_size); | |
2946 | else | |
2947 | dmu_ot_byteswap[bswap].ob_func(buf->b_data, hdr->b_size); | |
b128c09f | 2948 | } |
34dc7c2f BB |
2949 | |
2950 | arc_cksum_compute(buf, B_FALSE); | |
498877ba | 2951 | arc_buf_watch(buf); |
34dc7c2f | 2952 | |
428870ff BB |
2953 | if (hash_lock && zio->io_error == 0 && hdr->b_state == arc_anon) { |
2954 | /* | |
2955 | * Only call arc_access on anonymous buffers. This is because | |
2956 | * if we've issued an I/O for an evicted buffer, we've already | |
2957 | * called arc_access (to prevent any simultaneous readers from | |
2958 | * getting confused). | |
2959 | */ | |
2960 | arc_access(hdr, hash_lock); | |
2961 | } | |
2962 | ||
34dc7c2f BB |
2963 | /* create copies of the data buffer for the callers */ |
2964 | abuf = buf; | |
2965 | for (acb = callback_list; acb; acb = acb->acb_next) { | |
2966 | if (acb->acb_done) { | |
1eb5bfa3 GW |
2967 | if (abuf == NULL) { |
2968 | ARCSTAT_BUMP(arcstat_duplicate_reads); | |
34dc7c2f | 2969 | abuf = arc_buf_clone(buf); |
1eb5bfa3 | 2970 | } |
34dc7c2f BB |
2971 | acb->acb_buf = abuf; |
2972 | abuf = NULL; | |
2973 | } | |
2974 | } | |
2975 | hdr->b_acb = NULL; | |
2976 | hdr->b_flags &= ~ARC_IO_IN_PROGRESS; | |
2977 | ASSERT(!HDR_BUF_AVAILABLE(hdr)); | |
428870ff BB |
2978 | if (abuf == buf) { |
2979 | ASSERT(buf->b_efunc == NULL); | |
2980 | ASSERT(hdr->b_datacnt == 1); | |
34dc7c2f | 2981 | hdr->b_flags |= ARC_BUF_AVAILABLE; |
428870ff | 2982 | } |
34dc7c2f BB |
2983 | |
2984 | ASSERT(refcount_is_zero(&hdr->b_refcnt) || callback_list != NULL); | |
2985 | ||
2986 | if (zio->io_error != 0) { | |
2987 | hdr->b_flags |= ARC_IO_ERROR; | |
2988 | if (hdr->b_state != arc_anon) | |
2989 | arc_change_state(arc_anon, hdr, hash_lock); | |
2990 | if (HDR_IN_HASH_TABLE(hdr)) | |
2991 | buf_hash_remove(hdr); | |
2992 | freeable = refcount_is_zero(&hdr->b_refcnt); | |
34dc7c2f BB |
2993 | } |
2994 | ||
2995 | /* | |
2996 | * Broadcast before we drop the hash_lock to avoid the possibility | |
2997 | * that the hdr (and hence the cv) might be freed before we get to | |
2998 | * the cv_broadcast(). | |
2999 | */ | |
3000 | cv_broadcast(&hdr->b_cv); | |
3001 | ||
3002 | if (hash_lock) { | |
34dc7c2f BB |
3003 | mutex_exit(hash_lock); |
3004 | } else { | |
3005 | /* | |
3006 | * This block was freed while we waited for the read to | |
3007 | * complete. It has been removed from the hash table and | |
3008 | * moved to the anonymous state (so that it won't show up | |
3009 | * in the cache). | |
3010 | */ | |
3011 | ASSERT3P(hdr->b_state, ==, arc_anon); | |
3012 | freeable = refcount_is_zero(&hdr->b_refcnt); | |
3013 | } | |
3014 | ||
3015 | /* execute each callback and free its structure */ | |
3016 | while ((acb = callback_list) != NULL) { | |
3017 | if (acb->acb_done) | |
3018 | acb->acb_done(zio, acb->acb_buf, acb->acb_private); | |
3019 | ||
3020 | if (acb->acb_zio_dummy != NULL) { | |
3021 | acb->acb_zio_dummy->io_error = zio->io_error; | |
3022 | zio_nowait(acb->acb_zio_dummy); | |
3023 | } | |
3024 | ||
3025 | callback_list = acb->acb_next; | |
3026 | kmem_free(acb, sizeof (arc_callback_t)); | |
3027 | } | |
3028 | ||
3029 | if (freeable) | |
3030 | arc_hdr_destroy(hdr); | |
3031 | } | |
3032 | ||
3033 | /* | |
5c839890 | 3034 | * "Read" the block at the specified DVA (in bp) via the |
34dc7c2f BB |
3035 | * cache. If the block is found in the cache, invoke the provided |
3036 | * callback immediately and return. Note that the `zio' parameter | |
3037 | * in the callback will be NULL in this case, since no IO was | |
3038 | * required. If the block is not in the cache pass the read request | |
3039 | * on to the spa with a substitute callback function, so that the | |
3040 | * requested block will be added to the cache. | |
3041 | * | |
3042 | * If a read request arrives for a block that has a read in-progress, | |
3043 | * either wait for the in-progress read to complete (and return the | |
3044 | * results); or, if this is a read with a "done" func, add a record | |
3045 | * to the read to invoke the "done" func when the read completes, | |
3046 | * and return; or just return. | |
3047 | * | |
3048 | * arc_read_done() will invoke all the requested "done" functions | |
3049 | * for readers of this block. | |
3050 | */ | |
3051 | int | |
294f6806 GW |
3052 | arc_read(zio_t *pio, spa_t *spa, const blkptr_t *bp, arc_done_func_t *done, |
3053 | void *private, int priority, int zio_flags, uint32_t *arc_flags, | |
3054 | const zbookmark_t *zb) | |
34dc7c2f BB |
3055 | { |
3056 | arc_buf_hdr_t *hdr; | |
d4ed6673 | 3057 | arc_buf_t *buf = NULL; |
34dc7c2f BB |
3058 | kmutex_t *hash_lock; |
3059 | zio_t *rzio; | |
3541dc6d | 3060 | uint64_t guid = spa_load_guid(spa); |
1421c891 | 3061 | int rc = 0; |
34dc7c2f BB |
3062 | |
3063 | top: | |
428870ff BB |
3064 | hdr = buf_hash_find(guid, BP_IDENTITY(bp), BP_PHYSICAL_BIRTH(bp), |
3065 | &hash_lock); | |
34dc7c2f BB |
3066 | if (hdr && hdr->b_datacnt > 0) { |
3067 | ||
3068 | *arc_flags |= ARC_CACHED; | |
3069 | ||
3070 | if (HDR_IO_IN_PROGRESS(hdr)) { | |
3071 | ||
3072 | if (*arc_flags & ARC_WAIT) { | |
3073 | cv_wait(&hdr->b_cv, hash_lock); | |
3074 | mutex_exit(hash_lock); | |
3075 | goto top; | |
3076 | } | |
3077 | ASSERT(*arc_flags & ARC_NOWAIT); | |
3078 | ||
3079 | if (done) { | |
3080 | arc_callback_t *acb = NULL; | |
3081 | ||
3082 | acb = kmem_zalloc(sizeof (arc_callback_t), | |
691f6ac4 | 3083 | KM_PUSHPAGE); |
34dc7c2f BB |
3084 | acb->acb_done = done; |
3085 | acb->acb_private = private; | |
34dc7c2f BB |
3086 | if (pio != NULL) |
3087 | acb->acb_zio_dummy = zio_null(pio, | |
d164b209 | 3088 | spa, NULL, NULL, NULL, zio_flags); |
34dc7c2f BB |
3089 | |
3090 | ASSERT(acb->acb_done != NULL); | |
3091 | acb->acb_next = hdr->b_acb; | |
3092 | hdr->b_acb = acb; | |
3093 | add_reference(hdr, hash_lock, private); | |
3094 | mutex_exit(hash_lock); | |
1421c891 | 3095 | goto out; |
34dc7c2f BB |
3096 | } |
3097 | mutex_exit(hash_lock); | |
1421c891 | 3098 | goto out; |
34dc7c2f BB |
3099 | } |
3100 | ||
3101 | ASSERT(hdr->b_state == arc_mru || hdr->b_state == arc_mfu); | |
3102 | ||
3103 | if (done) { | |
3104 | add_reference(hdr, hash_lock, private); | |
3105 | /* | |
3106 | * If this block is already in use, create a new | |
3107 | * copy of the data so that we will be guaranteed | |
3108 | * that arc_release() will always succeed. | |
3109 | */ | |
3110 | buf = hdr->b_buf; | |
3111 | ASSERT(buf); | |
3112 | ASSERT(buf->b_data); | |
3113 | if (HDR_BUF_AVAILABLE(hdr)) { | |
3114 | ASSERT(buf->b_efunc == NULL); | |
3115 | hdr->b_flags &= ~ARC_BUF_AVAILABLE; | |
3116 | } else { | |
3117 | buf = arc_buf_clone(buf); | |
3118 | } | |
428870ff | 3119 | |
34dc7c2f BB |
3120 | } else if (*arc_flags & ARC_PREFETCH && |
3121 | refcount_count(&hdr->b_refcnt) == 0) { | |
3122 | hdr->b_flags |= ARC_PREFETCH; | |
3123 | } | |
3124 | DTRACE_PROBE1(arc__hit, arc_buf_hdr_t *, hdr); | |
3125 | arc_access(hdr, hash_lock); | |
b128c09f BB |
3126 | if (*arc_flags & ARC_L2CACHE) |
3127 | hdr->b_flags |= ARC_L2CACHE; | |
3a17a7a9 SK |
3128 | if (*arc_flags & ARC_L2COMPRESS) |
3129 | hdr->b_flags |= ARC_L2COMPRESS; | |
34dc7c2f BB |
3130 | mutex_exit(hash_lock); |
3131 | ARCSTAT_BUMP(arcstat_hits); | |
3132 | ARCSTAT_CONDSTAT(!(hdr->b_flags & ARC_PREFETCH), | |
3133 | demand, prefetch, hdr->b_type != ARC_BUFC_METADATA, | |
3134 | data, metadata, hits); | |
3135 | ||
3136 | if (done) | |
3137 | done(NULL, buf, private); | |
3138 | } else { | |
3139 | uint64_t size = BP_GET_LSIZE(bp); | |
3140 | arc_callback_t *acb; | |
b128c09f | 3141 | vdev_t *vd = NULL; |
a117a6d6 | 3142 | uint64_t addr = 0; |
d164b209 | 3143 | boolean_t devw = B_FALSE; |
34dc7c2f BB |
3144 | |
3145 | if (hdr == NULL) { | |
3146 | /* this block is not in the cache */ | |
3147 | arc_buf_hdr_t *exists; | |
3148 | arc_buf_contents_t type = BP_GET_BUFC_TYPE(bp); | |
3149 | buf = arc_buf_alloc(spa, size, private, type); | |
3150 | hdr = buf->b_hdr; | |
3151 | hdr->b_dva = *BP_IDENTITY(bp); | |
428870ff | 3152 | hdr->b_birth = BP_PHYSICAL_BIRTH(bp); |
34dc7c2f BB |
3153 | hdr->b_cksum0 = bp->blk_cksum.zc_word[0]; |
3154 | exists = buf_hash_insert(hdr, &hash_lock); | |
3155 | if (exists) { | |
3156 | /* somebody beat us to the hash insert */ | |
3157 | mutex_exit(hash_lock); | |
428870ff | 3158 | buf_discard_identity(hdr); |
34dc7c2f BB |
3159 | (void) arc_buf_remove_ref(buf, private); |
3160 | goto top; /* restart the IO request */ | |
3161 | } | |
3162 | /* if this is a prefetch, we don't have a reference */ | |
3163 | if (*arc_flags & ARC_PREFETCH) { | |
3164 | (void) remove_reference(hdr, hash_lock, | |
3165 | private); | |
3166 | hdr->b_flags |= ARC_PREFETCH; | |
3167 | } | |
b128c09f BB |
3168 | if (*arc_flags & ARC_L2CACHE) |
3169 | hdr->b_flags |= ARC_L2CACHE; | |
3a17a7a9 SK |
3170 | if (*arc_flags & ARC_L2COMPRESS) |
3171 | hdr->b_flags |= ARC_L2COMPRESS; | |
34dc7c2f BB |
3172 | if (BP_GET_LEVEL(bp) > 0) |
3173 | hdr->b_flags |= ARC_INDIRECT; | |
3174 | } else { | |
3175 | /* this block is in the ghost cache */ | |
3176 | ASSERT(GHOST_STATE(hdr->b_state)); | |
3177 | ASSERT(!HDR_IO_IN_PROGRESS(hdr)); | |
c99c9001 | 3178 | ASSERT0(refcount_count(&hdr->b_refcnt)); |
34dc7c2f BB |
3179 | ASSERT(hdr->b_buf == NULL); |
3180 | ||
3181 | /* if this is a prefetch, we don't have a reference */ | |
3182 | if (*arc_flags & ARC_PREFETCH) | |
3183 | hdr->b_flags |= ARC_PREFETCH; | |
3184 | else | |
3185 | add_reference(hdr, hash_lock, private); | |
b128c09f BB |
3186 | if (*arc_flags & ARC_L2CACHE) |
3187 | hdr->b_flags |= ARC_L2CACHE; | |
3a17a7a9 SK |
3188 | if (*arc_flags & ARC_L2COMPRESS) |
3189 | hdr->b_flags |= ARC_L2COMPRESS; | |
34dc7c2f BB |
3190 | buf = kmem_cache_alloc(buf_cache, KM_PUSHPAGE); |
3191 | buf->b_hdr = hdr; | |
3192 | buf->b_data = NULL; | |
3193 | buf->b_efunc = NULL; | |
3194 | buf->b_private = NULL; | |
3195 | buf->b_next = NULL; | |
3196 | hdr->b_buf = buf; | |
34dc7c2f BB |
3197 | ASSERT(hdr->b_datacnt == 0); |
3198 | hdr->b_datacnt = 1; | |
428870ff BB |
3199 | arc_get_data_buf(buf); |
3200 | arc_access(hdr, hash_lock); | |
34dc7c2f BB |
3201 | } |
3202 | ||
428870ff BB |
3203 | ASSERT(!GHOST_STATE(hdr->b_state)); |
3204 | ||
691f6ac4 | 3205 | acb = kmem_zalloc(sizeof (arc_callback_t), KM_PUSHPAGE); |
34dc7c2f BB |
3206 | acb->acb_done = done; |
3207 | acb->acb_private = private; | |
34dc7c2f BB |
3208 | |
3209 | ASSERT(hdr->b_acb == NULL); | |
3210 | hdr->b_acb = acb; | |
3211 | hdr->b_flags |= ARC_IO_IN_PROGRESS; | |
3212 | ||
b128c09f BB |
3213 | if (HDR_L2CACHE(hdr) && hdr->b_l2hdr != NULL && |
3214 | (vd = hdr->b_l2hdr->b_dev->l2ad_vdev) != NULL) { | |
d164b209 | 3215 | devw = hdr->b_l2hdr->b_dev->l2ad_writing; |
b128c09f BB |
3216 | addr = hdr->b_l2hdr->b_daddr; |
3217 | /* | |
3218 | * Lock out device removal. | |
3219 | */ | |
3220 | if (vdev_is_dead(vd) || | |
3221 | !spa_config_tryenter(spa, SCL_L2ARC, vd, RW_READER)) | |
3222 | vd = NULL; | |
3223 | } | |
3224 | ||
3225 | mutex_exit(hash_lock); | |
3226 | ||
e49f1e20 WA |
3227 | /* |
3228 | * At this point, we have a level 1 cache miss. Try again in | |
3229 | * L2ARC if possible. | |
3230 | */ | |
34dc7c2f | 3231 | ASSERT3U(hdr->b_size, ==, size); |
428870ff BB |
3232 | DTRACE_PROBE4(arc__miss, arc_buf_hdr_t *, hdr, blkptr_t *, bp, |
3233 | uint64_t, size, zbookmark_t *, zb); | |
34dc7c2f BB |
3234 | ARCSTAT_BUMP(arcstat_misses); |
3235 | ARCSTAT_CONDSTAT(!(hdr->b_flags & ARC_PREFETCH), | |
3236 | demand, prefetch, hdr->b_type != ARC_BUFC_METADATA, | |
3237 | data, metadata, misses); | |
3238 | ||
d164b209 | 3239 | if (vd != NULL && l2arc_ndev != 0 && !(l2arc_norw && devw)) { |
34dc7c2f BB |
3240 | /* |
3241 | * Read from the L2ARC if the following are true: | |
b128c09f BB |
3242 | * 1. The L2ARC vdev was previously cached. |
3243 | * 2. This buffer still has L2ARC metadata. | |
3244 | * 3. This buffer isn't currently writing to the L2ARC. | |
3245 | * 4. The L2ARC entry wasn't evicted, which may | |
3246 | * also have invalidated the vdev. | |
d164b209 | 3247 | * 5. This isn't prefetch and l2arc_noprefetch is set. |
34dc7c2f | 3248 | */ |
b128c09f | 3249 | if (hdr->b_l2hdr != NULL && |
d164b209 BB |
3250 | !HDR_L2_WRITING(hdr) && !HDR_L2_EVICTED(hdr) && |
3251 | !(l2arc_noprefetch && HDR_PREFETCH(hdr))) { | |
34dc7c2f BB |
3252 | l2arc_read_callback_t *cb; |
3253 | ||
3254 | DTRACE_PROBE1(l2arc__hit, arc_buf_hdr_t *, hdr); | |
3255 | ARCSTAT_BUMP(arcstat_l2_hits); | |
e0b0ca98 | 3256 | atomic_inc_32(&hdr->b_l2hdr->b_hits); |
34dc7c2f | 3257 | |
34dc7c2f | 3258 | cb = kmem_zalloc(sizeof (l2arc_read_callback_t), |
691f6ac4 | 3259 | KM_PUSHPAGE); |
34dc7c2f BB |
3260 | cb->l2rcb_buf = buf; |
3261 | cb->l2rcb_spa = spa; | |
3262 | cb->l2rcb_bp = *bp; | |
3263 | cb->l2rcb_zb = *zb; | |
b128c09f | 3264 | cb->l2rcb_flags = zio_flags; |
3a17a7a9 | 3265 | cb->l2rcb_compress = hdr->b_l2hdr->b_compress; |
34dc7c2f | 3266 | |
a117a6d6 GW |
3267 | ASSERT(addr >= VDEV_LABEL_START_SIZE && |
3268 | addr + size < vd->vdev_psize - | |
3269 | VDEV_LABEL_END_SIZE); | |
3270 | ||
34dc7c2f | 3271 | /* |
b128c09f BB |
3272 | * l2arc read. The SCL_L2ARC lock will be |
3273 | * released by l2arc_read_done(). | |
3a17a7a9 SK |
3274 | * Issue a null zio if the underlying buffer |
3275 | * was squashed to zero size by compression. | |
34dc7c2f | 3276 | */ |
3a17a7a9 SK |
3277 | if (hdr->b_l2hdr->b_compress == |
3278 | ZIO_COMPRESS_EMPTY) { | |
3279 | rzio = zio_null(pio, spa, vd, | |
3280 | l2arc_read_done, cb, | |
3281 | zio_flags | ZIO_FLAG_DONT_CACHE | | |
3282 | ZIO_FLAG_CANFAIL | | |
3283 | ZIO_FLAG_DONT_PROPAGATE | | |
3284 | ZIO_FLAG_DONT_RETRY); | |
3285 | } else { | |
3286 | rzio = zio_read_phys(pio, vd, addr, | |
3287 | hdr->b_l2hdr->b_asize, | |
3288 | buf->b_data, ZIO_CHECKSUM_OFF, | |
3289 | l2arc_read_done, cb, priority, | |
3290 | zio_flags | ZIO_FLAG_DONT_CACHE | | |
3291 | ZIO_FLAG_CANFAIL | | |
3292 | ZIO_FLAG_DONT_PROPAGATE | | |
3293 | ZIO_FLAG_DONT_RETRY, B_FALSE); | |
3294 | } | |
34dc7c2f BB |
3295 | DTRACE_PROBE2(l2arc__read, vdev_t *, vd, |
3296 | zio_t *, rzio); | |
3a17a7a9 SK |
3297 | ARCSTAT_INCR(arcstat_l2_read_bytes, |
3298 | hdr->b_l2hdr->b_asize); | |
34dc7c2f | 3299 | |
b128c09f BB |
3300 | if (*arc_flags & ARC_NOWAIT) { |
3301 | zio_nowait(rzio); | |
1421c891 | 3302 | goto out; |
b128c09f | 3303 | } |
34dc7c2f | 3304 | |
b128c09f BB |
3305 | ASSERT(*arc_flags & ARC_WAIT); |
3306 | if (zio_wait(rzio) == 0) | |
1421c891 | 3307 | goto out; |
b128c09f BB |
3308 | |
3309 | /* l2arc read error; goto zio_read() */ | |
34dc7c2f BB |
3310 | } else { |
3311 | DTRACE_PROBE1(l2arc__miss, | |
3312 | arc_buf_hdr_t *, hdr); | |
3313 | ARCSTAT_BUMP(arcstat_l2_misses); | |
3314 | if (HDR_L2_WRITING(hdr)) | |
3315 | ARCSTAT_BUMP(arcstat_l2_rw_clash); | |
b128c09f | 3316 | spa_config_exit(spa, SCL_L2ARC, vd); |
34dc7c2f | 3317 | } |
d164b209 BB |
3318 | } else { |
3319 | if (vd != NULL) | |
3320 | spa_config_exit(spa, SCL_L2ARC, vd); | |
3321 | if (l2arc_ndev != 0) { | |
3322 | DTRACE_PROBE1(l2arc__miss, | |
3323 | arc_buf_hdr_t *, hdr); | |
3324 | ARCSTAT_BUMP(arcstat_l2_misses); | |
3325 | } | |
34dc7c2f | 3326 | } |
34dc7c2f BB |
3327 | |
3328 | rzio = zio_read(pio, spa, bp, buf->b_data, size, | |
b128c09f | 3329 | arc_read_done, buf, priority, zio_flags, zb); |
34dc7c2f | 3330 | |
1421c891 PS |
3331 | if (*arc_flags & ARC_WAIT) { |
3332 | rc = zio_wait(rzio); | |
3333 | goto out; | |
3334 | } | |
34dc7c2f BB |
3335 | |
3336 | ASSERT(*arc_flags & ARC_NOWAIT); | |
3337 | zio_nowait(rzio); | |
3338 | } | |
1421c891 PS |
3339 | |
3340 | out: | |
3341 | spa_read_history_add(spa, zb, *arc_flags); | |
3342 | return (rc); | |
34dc7c2f BB |
3343 | } |
3344 | ||
ab26409d BB |
3345 | arc_prune_t * |
3346 | arc_add_prune_callback(arc_prune_func_t *func, void *private) | |
3347 | { | |
3348 | arc_prune_t *p; | |
3349 | ||
3350 | p = kmem_alloc(sizeof(*p), KM_SLEEP); | |
3351 | p->p_pfunc = func; | |
3352 | p->p_private = private; | |
3353 | list_link_init(&p->p_node); | |
3354 | refcount_create(&p->p_refcnt); | |
3355 | ||
3356 | mutex_enter(&arc_prune_mtx); | |
3357 | refcount_add(&p->p_refcnt, &arc_prune_list); | |
3358 | list_insert_head(&arc_prune_list, p); | |
3359 | mutex_exit(&arc_prune_mtx); | |
3360 | ||
3361 | return (p); | |
3362 | } | |
3363 | ||
3364 | void | |
3365 | arc_remove_prune_callback(arc_prune_t *p) | |
3366 | { | |
3367 | mutex_enter(&arc_prune_mtx); | |
3368 | list_remove(&arc_prune_list, p); | |
3369 | if (refcount_remove(&p->p_refcnt, &arc_prune_list) == 0) { | |
3370 | refcount_destroy(&p->p_refcnt); | |
3371 | kmem_free(p, sizeof (*p)); | |
3372 | } | |
3373 | mutex_exit(&arc_prune_mtx); | |
3374 | } | |
3375 | ||
34dc7c2f BB |
3376 | void |
3377 | arc_set_callback(arc_buf_t *buf, arc_evict_func_t *func, void *private) | |
3378 | { | |
3379 | ASSERT(buf->b_hdr != NULL); | |
3380 | ASSERT(buf->b_hdr->b_state != arc_anon); | |
3381 | ASSERT(!refcount_is_zero(&buf->b_hdr->b_refcnt) || func == NULL); | |
428870ff BB |
3382 | ASSERT(buf->b_efunc == NULL); |
3383 | ASSERT(!HDR_BUF_AVAILABLE(buf->b_hdr)); | |
3384 | ||
34dc7c2f BB |
3385 | buf->b_efunc = func; |
3386 | buf->b_private = private; | |
3387 | } | |
3388 | ||
df4474f9 MA |
3389 | /* |
3390 | * Notify the arc that a block was freed, and thus will never be used again. | |
3391 | */ | |
3392 | void | |
3393 | arc_freed(spa_t *spa, const blkptr_t *bp) | |
3394 | { | |
3395 | arc_buf_hdr_t *hdr; | |
3396 | kmutex_t *hash_lock; | |
3397 | uint64_t guid = spa_load_guid(spa); | |
3398 | ||
3399 | hdr = buf_hash_find(guid, BP_IDENTITY(bp), BP_PHYSICAL_BIRTH(bp), | |
3400 | &hash_lock); | |
3401 | if (hdr == NULL) | |
3402 | return; | |
3403 | if (HDR_BUF_AVAILABLE(hdr)) { | |
3404 | arc_buf_t *buf = hdr->b_buf; | |
3405 | add_reference(hdr, hash_lock, FTAG); | |
3406 | hdr->b_flags &= ~ARC_BUF_AVAILABLE; | |
3407 | mutex_exit(hash_lock); | |
3408 | ||
3409 | arc_release(buf, FTAG); | |
3410 | (void) arc_buf_remove_ref(buf, FTAG); | |
3411 | } else { | |
3412 | mutex_exit(hash_lock); | |
3413 | } | |
3414 | ||
3415 | } | |
3416 | ||
34dc7c2f BB |
3417 | /* |
3418 | * This is used by the DMU to let the ARC know that a buffer is | |
3419 | * being evicted, so the ARC should clean up. If this arc buf | |
3420 | * is not yet in the evicted state, it will be put there. | |
3421 | */ | |
3422 | int | |
3423 | arc_buf_evict(arc_buf_t *buf) | |
3424 | { | |
3425 | arc_buf_hdr_t *hdr; | |
3426 | kmutex_t *hash_lock; | |
3427 | arc_buf_t **bufp; | |
3428 | ||
428870ff | 3429 | mutex_enter(&buf->b_evict_lock); |
34dc7c2f BB |
3430 | hdr = buf->b_hdr; |
3431 | if (hdr == NULL) { | |
3432 | /* | |
3433 | * We are in arc_do_user_evicts(). | |
3434 | */ | |
3435 | ASSERT(buf->b_data == NULL); | |
428870ff | 3436 | mutex_exit(&buf->b_evict_lock); |
34dc7c2f | 3437 | return (0); |
b128c09f BB |
3438 | } else if (buf->b_data == NULL) { |
3439 | arc_buf_t copy = *buf; /* structure assignment */ | |
34dc7c2f | 3440 | /* |
b128c09f BB |
3441 | * We are on the eviction list; process this buffer now |
3442 | * but let arc_do_user_evicts() do the reaping. | |
34dc7c2f | 3443 | */ |
b128c09f | 3444 | buf->b_efunc = NULL; |
428870ff | 3445 | mutex_exit(&buf->b_evict_lock); |
b128c09f BB |
3446 | VERIFY(copy.b_efunc(©) == 0); |
3447 | return (1); | |
34dc7c2f | 3448 | } |
b128c09f BB |
3449 | hash_lock = HDR_LOCK(hdr); |
3450 | mutex_enter(hash_lock); | |
428870ff BB |
3451 | hdr = buf->b_hdr; |
3452 | ASSERT3P(hash_lock, ==, HDR_LOCK(hdr)); | |
34dc7c2f | 3453 | |
34dc7c2f BB |
3454 | ASSERT3U(refcount_count(&hdr->b_refcnt), <, hdr->b_datacnt); |
3455 | ASSERT(hdr->b_state == arc_mru || hdr->b_state == arc_mfu); | |
3456 | ||
3457 | /* | |
3458 | * Pull this buffer off of the hdr | |
3459 | */ | |
3460 | bufp = &hdr->b_buf; | |
3461 | while (*bufp != buf) | |
3462 | bufp = &(*bufp)->b_next; | |
3463 | *bufp = buf->b_next; | |
3464 | ||
3465 | ASSERT(buf->b_data != NULL); | |
3466 | arc_buf_destroy(buf, FALSE, FALSE); | |
3467 | ||
3468 | if (hdr->b_datacnt == 0) { | |
3469 | arc_state_t *old_state = hdr->b_state; | |
3470 | arc_state_t *evicted_state; | |
3471 | ||
428870ff | 3472 | ASSERT(hdr->b_buf == NULL); |
34dc7c2f BB |
3473 | ASSERT(refcount_is_zero(&hdr->b_refcnt)); |
3474 | ||
3475 | evicted_state = | |
3476 | (old_state == arc_mru) ? arc_mru_ghost : arc_mfu_ghost; | |
3477 | ||
3478 | mutex_enter(&old_state->arcs_mtx); | |
3479 | mutex_enter(&evicted_state->arcs_mtx); | |
3480 | ||
3481 | arc_change_state(evicted_state, hdr, hash_lock); | |
3482 | ASSERT(HDR_IN_HASH_TABLE(hdr)); | |
3483 | hdr->b_flags |= ARC_IN_HASH_TABLE; | |
3484 | hdr->b_flags &= ~ARC_BUF_AVAILABLE; | |
3485 | ||
3486 | mutex_exit(&evicted_state->arcs_mtx); | |
3487 | mutex_exit(&old_state->arcs_mtx); | |
3488 | } | |
3489 | mutex_exit(hash_lock); | |
428870ff | 3490 | mutex_exit(&buf->b_evict_lock); |
34dc7c2f BB |
3491 | |
3492 | VERIFY(buf->b_efunc(buf) == 0); | |
3493 | buf->b_efunc = NULL; | |
3494 | buf->b_private = NULL; | |
3495 | buf->b_hdr = NULL; | |
428870ff | 3496 | buf->b_next = NULL; |
34dc7c2f BB |
3497 | kmem_cache_free(buf_cache, buf); |
3498 | return (1); | |
3499 | } | |
3500 | ||
3501 | /* | |
e49f1e20 WA |
3502 | * Release this buffer from the cache, making it an anonymous buffer. This |
3503 | * must be done after a read and prior to modifying the buffer contents. | |
34dc7c2f | 3504 | * If the buffer has more than one reference, we must make |
b128c09f | 3505 | * a new hdr for the buffer. |
34dc7c2f BB |
3506 | */ |
3507 | void | |
3508 | arc_release(arc_buf_t *buf, void *tag) | |
3509 | { | |
b128c09f | 3510 | arc_buf_hdr_t *hdr; |
428870ff | 3511 | kmutex_t *hash_lock = NULL; |
b128c09f | 3512 | l2arc_buf_hdr_t *l2hdr; |
d4ed6673 | 3513 | uint64_t buf_size = 0; |
34dc7c2f | 3514 | |
428870ff BB |
3515 | /* |
3516 | * It would be nice to assert that if it's DMU metadata (level > | |
3517 | * 0 || it's the dnode file), then it must be syncing context. | |
3518 | * But we don't know that information at this level. | |
3519 | */ | |
3520 | ||
3521 | mutex_enter(&buf->b_evict_lock); | |
b128c09f BB |
3522 | hdr = buf->b_hdr; |
3523 | ||
34dc7c2f BB |
3524 | /* this buffer is not on any list */ |
3525 | ASSERT(refcount_count(&hdr->b_refcnt) > 0); | |
3526 | ||
3527 | if (hdr->b_state == arc_anon) { | |
3528 | /* this buffer is already released */ | |
34dc7c2f | 3529 | ASSERT(buf->b_efunc == NULL); |
9babb374 BB |
3530 | } else { |
3531 | hash_lock = HDR_LOCK(hdr); | |
3532 | mutex_enter(hash_lock); | |
428870ff BB |
3533 | hdr = buf->b_hdr; |
3534 | ASSERT3P(hash_lock, ==, HDR_LOCK(hdr)); | |
34dc7c2f BB |
3535 | } |
3536 | ||
b128c09f BB |
3537 | l2hdr = hdr->b_l2hdr; |
3538 | if (l2hdr) { | |
3539 | mutex_enter(&l2arc_buflist_mtx); | |
3540 | hdr->b_l2hdr = NULL; | |
b128c09f | 3541 | } |
a117a6d6 | 3542 | buf_size = hdr->b_size; |
b128c09f | 3543 | |
34dc7c2f BB |
3544 | /* |
3545 | * Do we have more than one buf? | |
3546 | */ | |
b128c09f | 3547 | if (hdr->b_datacnt > 1) { |
34dc7c2f BB |
3548 | arc_buf_hdr_t *nhdr; |
3549 | arc_buf_t **bufp; | |
3550 | uint64_t blksz = hdr->b_size; | |
d164b209 | 3551 | uint64_t spa = hdr->b_spa; |
34dc7c2f BB |
3552 | arc_buf_contents_t type = hdr->b_type; |
3553 | uint32_t flags = hdr->b_flags; | |
3554 | ||
b128c09f | 3555 | ASSERT(hdr->b_buf != buf || buf->b_next != NULL); |
34dc7c2f | 3556 | /* |
428870ff BB |
3557 | * Pull the data off of this hdr and attach it to |
3558 | * a new anonymous hdr. | |
34dc7c2f BB |
3559 | */ |
3560 | (void) remove_reference(hdr, hash_lock, tag); | |
3561 | bufp = &hdr->b_buf; | |
3562 | while (*bufp != buf) | |
3563 | bufp = &(*bufp)->b_next; | |
428870ff | 3564 | *bufp = buf->b_next; |
34dc7c2f BB |
3565 | buf->b_next = NULL; |
3566 | ||
3567 | ASSERT3U(hdr->b_state->arcs_size, >=, hdr->b_size); | |
3568 | atomic_add_64(&hdr->b_state->arcs_size, -hdr->b_size); | |
3569 | if (refcount_is_zero(&hdr->b_refcnt)) { | |
3570 | uint64_t *size = &hdr->b_state->arcs_lsize[hdr->b_type]; | |
3571 | ASSERT3U(*size, >=, hdr->b_size); | |
3572 | atomic_add_64(size, -hdr->b_size); | |
3573 | } | |
1eb5bfa3 GW |
3574 | |
3575 | /* | |
3576 | * We're releasing a duplicate user data buffer, update | |
3577 | * our statistics accordingly. | |
3578 | */ | |
3579 | if (hdr->b_type == ARC_BUFC_DATA) { | |
3580 | ARCSTAT_BUMPDOWN(arcstat_duplicate_buffers); | |
3581 | ARCSTAT_INCR(arcstat_duplicate_buffers_size, | |
3582 | -hdr->b_size); | |
3583 | } | |
34dc7c2f | 3584 | hdr->b_datacnt -= 1; |
34dc7c2f | 3585 | arc_cksum_verify(buf); |
498877ba | 3586 | arc_buf_unwatch(buf); |
34dc7c2f BB |
3587 | |
3588 | mutex_exit(hash_lock); | |
3589 | ||
3590 | nhdr = kmem_cache_alloc(hdr_cache, KM_PUSHPAGE); | |
3591 | nhdr->b_size = blksz; | |
3592 | nhdr->b_spa = spa; | |
3593 | nhdr->b_type = type; | |
3594 | nhdr->b_buf = buf; | |
3595 | nhdr->b_state = arc_anon; | |
3596 | nhdr->b_arc_access = 0; | |
e0b0ca98 BB |
3597 | nhdr->b_mru_hits = 0; |
3598 | nhdr->b_mru_ghost_hits = 0; | |
3599 | nhdr->b_mfu_hits = 0; | |
3600 | nhdr->b_mfu_ghost_hits = 0; | |
3601 | nhdr->b_l2_hits = 0; | |
34dc7c2f BB |
3602 | nhdr->b_flags = flags & ARC_L2_WRITING; |
3603 | nhdr->b_l2hdr = NULL; | |
3604 | nhdr->b_datacnt = 1; | |
3605 | nhdr->b_freeze_cksum = NULL; | |
3606 | (void) refcount_add(&nhdr->b_refcnt, tag); | |
3607 | buf->b_hdr = nhdr; | |
428870ff | 3608 | mutex_exit(&buf->b_evict_lock); |
34dc7c2f BB |
3609 | atomic_add_64(&arc_anon->arcs_size, blksz); |
3610 | } else { | |
428870ff | 3611 | mutex_exit(&buf->b_evict_lock); |
34dc7c2f BB |
3612 | ASSERT(refcount_count(&hdr->b_refcnt) == 1); |
3613 | ASSERT(!list_link_active(&hdr->b_arc_node)); | |
3614 | ASSERT(!HDR_IO_IN_PROGRESS(hdr)); | |
428870ff BB |
3615 | if (hdr->b_state != arc_anon) |
3616 | arc_change_state(arc_anon, hdr, hash_lock); | |
34dc7c2f | 3617 | hdr->b_arc_access = 0; |
e0b0ca98 BB |
3618 | hdr->b_mru_hits = 0; |
3619 | hdr->b_mru_ghost_hits = 0; | |
3620 | hdr->b_mfu_hits = 0; | |
3621 | hdr->b_mfu_ghost_hits = 0; | |
3622 | hdr->b_l2_hits = 0; | |
428870ff BB |
3623 | if (hash_lock) |
3624 | mutex_exit(hash_lock); | |
34dc7c2f | 3625 | |
428870ff | 3626 | buf_discard_identity(hdr); |
34dc7c2f BB |
3627 | arc_buf_thaw(buf); |
3628 | } | |
3629 | buf->b_efunc = NULL; | |
3630 | buf->b_private = NULL; | |
3631 | ||
3632 | if (l2hdr) { | |
3a17a7a9 | 3633 | ARCSTAT_INCR(arcstat_l2_asize, -l2hdr->b_asize); |
34dc7c2f BB |
3634 | list_remove(l2hdr->b_dev->l2ad_buflist, hdr); |
3635 | kmem_free(l2hdr, sizeof (l2arc_buf_hdr_t)); | |
6e1d7276 | 3636 | arc_space_return(L2HDR_SIZE, ARC_SPACE_L2HDRS); |
34dc7c2f | 3637 | ARCSTAT_INCR(arcstat_l2_size, -buf_size); |
34dc7c2f | 3638 | mutex_exit(&l2arc_buflist_mtx); |
b128c09f | 3639 | } |
34dc7c2f BB |
3640 | } |
3641 | ||
3642 | int | |
3643 | arc_released(arc_buf_t *buf) | |
3644 | { | |
b128c09f BB |
3645 | int released; |
3646 | ||
428870ff | 3647 | mutex_enter(&buf->b_evict_lock); |
b128c09f | 3648 | released = (buf->b_data != NULL && buf->b_hdr->b_state == arc_anon); |
428870ff | 3649 | mutex_exit(&buf->b_evict_lock); |
b128c09f | 3650 | return (released); |
34dc7c2f BB |
3651 | } |
3652 | ||
3653 | int | |
3654 | arc_has_callback(arc_buf_t *buf) | |
3655 | { | |
b128c09f BB |
3656 | int callback; |
3657 | ||
428870ff | 3658 | mutex_enter(&buf->b_evict_lock); |
b128c09f | 3659 | callback = (buf->b_efunc != NULL); |
428870ff | 3660 | mutex_exit(&buf->b_evict_lock); |
b128c09f | 3661 | return (callback); |
34dc7c2f BB |
3662 | } |
3663 | ||
3664 | #ifdef ZFS_DEBUG | |
3665 | int | |
3666 | arc_referenced(arc_buf_t *buf) | |
3667 | { | |
b128c09f BB |
3668 | int referenced; |
3669 | ||
428870ff | 3670 | mutex_enter(&buf->b_evict_lock); |
b128c09f | 3671 | referenced = (refcount_count(&buf->b_hdr->b_refcnt)); |
428870ff | 3672 | mutex_exit(&buf->b_evict_lock); |
b128c09f | 3673 | return (referenced); |
34dc7c2f BB |
3674 | } |
3675 | #endif | |
3676 | ||
3677 | static void | |
3678 | arc_write_ready(zio_t *zio) | |
3679 | { | |
3680 | arc_write_callback_t *callback = zio->io_private; | |
3681 | arc_buf_t *buf = callback->awcb_buf; | |
3682 | arc_buf_hdr_t *hdr = buf->b_hdr; | |
3683 | ||
b128c09f BB |
3684 | ASSERT(!refcount_is_zero(&buf->b_hdr->b_refcnt)); |
3685 | callback->awcb_ready(zio, buf, callback->awcb_private); | |
3686 | ||
34dc7c2f BB |
3687 | /* |
3688 | * If the IO is already in progress, then this is a re-write | |
b128c09f BB |
3689 | * attempt, so we need to thaw and re-compute the cksum. |
3690 | * It is the responsibility of the callback to handle the | |
3691 | * accounting for any re-write attempt. | |
34dc7c2f BB |
3692 | */ |
3693 | if (HDR_IO_IN_PROGRESS(hdr)) { | |
34dc7c2f BB |
3694 | mutex_enter(&hdr->b_freeze_lock); |
3695 | if (hdr->b_freeze_cksum != NULL) { | |
3696 | kmem_free(hdr->b_freeze_cksum, sizeof (zio_cksum_t)); | |
3697 | hdr->b_freeze_cksum = NULL; | |
3698 | } | |
3699 | mutex_exit(&hdr->b_freeze_lock); | |
3700 | } | |
3701 | arc_cksum_compute(buf, B_FALSE); | |
3702 | hdr->b_flags |= ARC_IO_IN_PROGRESS; | |
3703 | } | |
3704 | ||
3705 | static void | |
3706 | arc_write_done(zio_t *zio) | |
3707 | { | |
3708 | arc_write_callback_t *callback = zio->io_private; | |
3709 | arc_buf_t *buf = callback->awcb_buf; | |
3710 | arc_buf_hdr_t *hdr = buf->b_hdr; | |
3711 | ||
428870ff BB |
3712 | ASSERT(hdr->b_acb == NULL); |
3713 | ||
3714 | if (zio->io_error == 0) { | |
3715 | hdr->b_dva = *BP_IDENTITY(zio->io_bp); | |
3716 | hdr->b_birth = BP_PHYSICAL_BIRTH(zio->io_bp); | |
3717 | hdr->b_cksum0 = zio->io_bp->blk_cksum.zc_word[0]; | |
3718 | } else { | |
3719 | ASSERT(BUF_EMPTY(hdr)); | |
3720 | } | |
34dc7c2f | 3721 | |
34dc7c2f BB |
3722 | /* |
3723 | * If the block to be written was all-zero, we may have | |
3724 | * compressed it away. In this case no write was performed | |
428870ff BB |
3725 | * so there will be no dva/birth/checksum. The buffer must |
3726 | * therefore remain anonymous (and uncached). | |
34dc7c2f BB |
3727 | */ |
3728 | if (!BUF_EMPTY(hdr)) { | |
3729 | arc_buf_hdr_t *exists; | |
3730 | kmutex_t *hash_lock; | |
3731 | ||
428870ff BB |
3732 | ASSERT(zio->io_error == 0); |
3733 | ||
34dc7c2f BB |
3734 | arc_cksum_verify(buf); |
3735 | ||
3736 | exists = buf_hash_insert(hdr, &hash_lock); | |
3737 | if (exists) { | |
3738 | /* | |
3739 | * This can only happen if we overwrite for | |
3740 | * sync-to-convergence, because we remove | |
3741 | * buffers from the hash table when we arc_free(). | |
3742 | */ | |
428870ff BB |
3743 | if (zio->io_flags & ZIO_FLAG_IO_REWRITE) { |
3744 | if (!BP_EQUAL(&zio->io_bp_orig, zio->io_bp)) | |
3745 | panic("bad overwrite, hdr=%p exists=%p", | |
3746 | (void *)hdr, (void *)exists); | |
3747 | ASSERT(refcount_is_zero(&exists->b_refcnt)); | |
3748 | arc_change_state(arc_anon, exists, hash_lock); | |
3749 | mutex_exit(hash_lock); | |
3750 | arc_hdr_destroy(exists); | |
3751 | exists = buf_hash_insert(hdr, &hash_lock); | |
3752 | ASSERT3P(exists, ==, NULL); | |
03c6040b GW |
3753 | } else if (zio->io_flags & ZIO_FLAG_NOPWRITE) { |
3754 | /* nopwrite */ | |
3755 | ASSERT(zio->io_prop.zp_nopwrite); | |
3756 | if (!BP_EQUAL(&zio->io_bp_orig, zio->io_bp)) | |
3757 | panic("bad nopwrite, hdr=%p exists=%p", | |
3758 | (void *)hdr, (void *)exists); | |
428870ff BB |
3759 | } else { |
3760 | /* Dedup */ | |
3761 | ASSERT(hdr->b_datacnt == 1); | |
3762 | ASSERT(hdr->b_state == arc_anon); | |
3763 | ASSERT(BP_GET_DEDUP(zio->io_bp)); | |
3764 | ASSERT(BP_GET_LEVEL(zio->io_bp) == 0); | |
3765 | } | |
34dc7c2f BB |
3766 | } |
3767 | hdr->b_flags &= ~ARC_IO_IN_PROGRESS; | |
b128c09f | 3768 | /* if it's not anon, we are doing a scrub */ |
428870ff | 3769 | if (!exists && hdr->b_state == arc_anon) |
b128c09f | 3770 | arc_access(hdr, hash_lock); |
34dc7c2f | 3771 | mutex_exit(hash_lock); |
34dc7c2f BB |
3772 | } else { |
3773 | hdr->b_flags &= ~ARC_IO_IN_PROGRESS; | |
3774 | } | |
3775 | ||
428870ff BB |
3776 | ASSERT(!refcount_is_zero(&hdr->b_refcnt)); |
3777 | callback->awcb_done(zio, buf, callback->awcb_private); | |
34dc7c2f BB |
3778 | |
3779 | kmem_free(callback, sizeof (arc_write_callback_t)); | |
3780 | } | |
3781 | ||
3782 | zio_t * | |
428870ff | 3783 | arc_write(zio_t *pio, spa_t *spa, uint64_t txg, |
3a17a7a9 SK |
3784 | blkptr_t *bp, arc_buf_t *buf, boolean_t l2arc, boolean_t l2arc_compress, |
3785 | const zio_prop_t *zp, arc_done_func_t *ready, arc_done_func_t *done, | |
3786 | void *private, int priority, int zio_flags, const zbookmark_t *zb) | |
34dc7c2f BB |
3787 | { |
3788 | arc_buf_hdr_t *hdr = buf->b_hdr; | |
3789 | arc_write_callback_t *callback; | |
b128c09f | 3790 | zio_t *zio; |
34dc7c2f | 3791 | |
b128c09f | 3792 | ASSERT(ready != NULL); |
428870ff | 3793 | ASSERT(done != NULL); |
34dc7c2f BB |
3794 | ASSERT(!HDR_IO_ERROR(hdr)); |
3795 | ASSERT((hdr->b_flags & ARC_IO_IN_PROGRESS) == 0); | |
428870ff | 3796 | ASSERT(hdr->b_acb == NULL); |
b128c09f BB |
3797 | if (l2arc) |
3798 | hdr->b_flags |= ARC_L2CACHE; | |
3a17a7a9 SK |
3799 | if (l2arc_compress) |
3800 | hdr->b_flags |= ARC_L2COMPRESS; | |
b8d06fca | 3801 | callback = kmem_zalloc(sizeof (arc_write_callback_t), KM_PUSHPAGE); |
34dc7c2f BB |
3802 | callback->awcb_ready = ready; |
3803 | callback->awcb_done = done; | |
3804 | callback->awcb_private = private; | |
3805 | callback->awcb_buf = buf; | |
b128c09f | 3806 | |
428870ff | 3807 | zio = zio_write(pio, spa, txg, bp, buf->b_data, hdr->b_size, zp, |
b128c09f | 3808 | arc_write_ready, arc_write_done, callback, priority, zio_flags, zb); |
34dc7c2f BB |
3809 | |
3810 | return (zio); | |
3811 | } | |
3812 | ||
34dc7c2f | 3813 | static int |
9babb374 | 3814 | arc_memory_throttle(uint64_t reserve, uint64_t inflight_data, uint64_t txg) |
34dc7c2f BB |
3815 | { |
3816 | #ifdef _KERNEL | |
302f753f | 3817 | uint64_t available_memory; |
34dc7c2f | 3818 | |
0c5493d4 BB |
3819 | if (zfs_arc_memory_throttle_disable) |
3820 | return (0); | |
3821 | ||
302f753f BB |
3822 | /* Easily reclaimable memory (free + inactive + arc-evictable) */ |
3823 | available_memory = ptob(spl_kmem_availrmem()) + arc_evictable_memory(); | |
34dc7c2f | 3824 | |
302f753f | 3825 | if (available_memory <= zfs_write_limit_max) { |
34dc7c2f | 3826 | ARCSTAT_INCR(arcstat_memory_throttle_count, 1); |
570827e1 | 3827 | DMU_TX_STAT_BUMP(dmu_tx_memory_reclaim); |
2e528b49 | 3828 | return (SET_ERROR(EAGAIN)); |
34dc7c2f | 3829 | } |
34dc7c2f BB |
3830 | |
3831 | if (inflight_data > available_memory / 4) { | |
3832 | ARCSTAT_INCR(arcstat_memory_throttle_count, 1); | |
570827e1 | 3833 | DMU_TX_STAT_BUMP(dmu_tx_memory_inflight); |
34dc7c2f BB |
3834 | return (ERESTART); |
3835 | } | |
3836 | #endif | |
3837 | return (0); | |
3838 | } | |
3839 | ||
3840 | void | |
3841 | arc_tempreserve_clear(uint64_t reserve) | |
3842 | { | |
3843 | atomic_add_64(&arc_tempreserve, -reserve); | |
3844 | ASSERT((int64_t)arc_tempreserve >= 0); | |
3845 | } | |
3846 | ||
3847 | int | |
3848 | arc_tempreserve_space(uint64_t reserve, uint64_t txg) | |
3849 | { | |
3850 | int error; | |
9babb374 | 3851 | uint64_t anon_size; |
34dc7c2f BB |
3852 | |
3853 | #ifdef ZFS_DEBUG | |
3854 | /* | |
3855 | * Once in a while, fail for no reason. Everything should cope. | |
3856 | */ | |
3857 | if (spa_get_random(10000) == 0) { | |
3858 | dprintf("forcing random failure\n"); | |
3859 | return (ERESTART); | |
3860 | } | |
3861 | #endif | |
3862 | if (reserve > arc_c/4 && !arc_no_grow) | |
3863 | arc_c = MIN(arc_c_max, reserve * 4); | |
570827e1 BB |
3864 | if (reserve > arc_c) { |
3865 | DMU_TX_STAT_BUMP(dmu_tx_memory_reserve); | |
2e528b49 | 3866 | return (SET_ERROR(ENOMEM)); |
570827e1 | 3867 | } |
34dc7c2f | 3868 | |
9babb374 BB |
3869 | /* |
3870 | * Don't count loaned bufs as in flight dirty data to prevent long | |
3871 | * network delays from blocking transactions that are ready to be | |
3872 | * assigned to a txg. | |
3873 | */ | |
3874 | anon_size = MAX((int64_t)(arc_anon->arcs_size - arc_loaned_bytes), 0); | |
3875 | ||
34dc7c2f BB |
3876 | /* |
3877 | * Writes will, almost always, require additional memory allocations | |
d3cc8b15 | 3878 | * in order to compress/encrypt/etc the data. We therefore need to |
34dc7c2f BB |
3879 | * make sure that there is sufficient available memory for this. |
3880 | */ | |
c65aa5b2 | 3881 | if ((error = arc_memory_throttle(reserve, anon_size, txg))) |
34dc7c2f BB |
3882 | return (error); |
3883 | ||
3884 | /* | |
3885 | * Throttle writes when the amount of dirty data in the cache | |
3886 | * gets too large. We try to keep the cache less than half full | |
3887 | * of dirty blocks so that our sync times don't grow too large. | |
3888 | * Note: if two requests come in concurrently, we might let them | |
3889 | * both succeed, when one of them should fail. Not a huge deal. | |
3890 | */ | |
9babb374 BB |
3891 | |
3892 | if (reserve + arc_tempreserve + anon_size > arc_c / 2 && | |
3893 | anon_size > arc_c / 4) { | |
34dc7c2f BB |
3894 | dprintf("failing, arc_tempreserve=%lluK anon_meta=%lluK " |
3895 | "anon_data=%lluK tempreserve=%lluK arc_c=%lluK\n", | |
3896 | arc_tempreserve>>10, | |
3897 | arc_anon->arcs_lsize[ARC_BUFC_METADATA]>>10, | |
3898 | arc_anon->arcs_lsize[ARC_BUFC_DATA]>>10, | |
3899 | reserve>>10, arc_c>>10); | |
570827e1 | 3900 | DMU_TX_STAT_BUMP(dmu_tx_dirty_throttle); |
2e528b49 | 3901 | return (SET_ERROR(ERESTART)); |
34dc7c2f BB |
3902 | } |
3903 | atomic_add_64(&arc_tempreserve, reserve); | |
3904 | return (0); | |
3905 | } | |
3906 | ||
13be560d BB |
3907 | static void |
3908 | arc_kstat_update_state(arc_state_t *state, kstat_named_t *size, | |
3909 | kstat_named_t *evict_data, kstat_named_t *evict_metadata) | |
3910 | { | |
3911 | size->value.ui64 = state->arcs_size; | |
3912 | evict_data->value.ui64 = state->arcs_lsize[ARC_BUFC_DATA]; | |
3913 | evict_metadata->value.ui64 = state->arcs_lsize[ARC_BUFC_METADATA]; | |
3914 | } | |
3915 | ||
3916 | static int | |
3917 | arc_kstat_update(kstat_t *ksp, int rw) | |
3918 | { | |
3919 | arc_stats_t *as = ksp->ks_data; | |
3920 | ||
3921 | if (rw == KSTAT_WRITE) { | |
2e528b49 | 3922 | return (SET_ERROR(EACCES)); |
13be560d BB |
3923 | } else { |
3924 | arc_kstat_update_state(arc_anon, | |
3925 | &as->arcstat_anon_size, | |
3926 | &as->arcstat_anon_evict_data, | |
3927 | &as->arcstat_anon_evict_metadata); | |
3928 | arc_kstat_update_state(arc_mru, | |
3929 | &as->arcstat_mru_size, | |
3930 | &as->arcstat_mru_evict_data, | |
3931 | &as->arcstat_mru_evict_metadata); | |
3932 | arc_kstat_update_state(arc_mru_ghost, | |
3933 | &as->arcstat_mru_ghost_size, | |
3934 | &as->arcstat_mru_ghost_evict_data, | |
3935 | &as->arcstat_mru_ghost_evict_metadata); | |
3936 | arc_kstat_update_state(arc_mfu, | |
3937 | &as->arcstat_mfu_size, | |
3938 | &as->arcstat_mfu_evict_data, | |
3939 | &as->arcstat_mfu_evict_metadata); | |
fc41c640 | 3940 | arc_kstat_update_state(arc_mfu_ghost, |
13be560d BB |
3941 | &as->arcstat_mfu_ghost_size, |
3942 | &as->arcstat_mfu_ghost_evict_data, | |
3943 | &as->arcstat_mfu_ghost_evict_metadata); | |
3944 | } | |
3945 | ||
3946 | return (0); | |
3947 | } | |
3948 | ||
34dc7c2f BB |
3949 | void |
3950 | arc_init(void) | |
3951 | { | |
3952 | mutex_init(&arc_reclaim_thr_lock, NULL, MUTEX_DEFAULT, NULL); | |
3953 | cv_init(&arc_reclaim_thr_cv, NULL, CV_DEFAULT, NULL); | |
3954 | ||
3955 | /* Convert seconds to clock ticks */ | |
bce45ec9 | 3956 | zfs_arc_min_prefetch_lifespan = 1 * hz; |
34dc7c2f BB |
3957 | |
3958 | /* Start out with 1/8 of all memory */ | |
3959 | arc_c = physmem * PAGESIZE / 8; | |
3960 | ||
3961 | #ifdef _KERNEL | |
3962 | /* | |
3963 | * On architectures where the physical memory can be larger | |
3964 | * than the addressable space (intel in 32-bit mode), we may | |
3965 | * need to limit the cache to 1/8 of VM size. | |
3966 | */ | |
3967 | arc_c = MIN(arc_c, vmem_size(heap_arena, VMEM_ALLOC | VMEM_FREE) / 8); | |
7cb67b45 BB |
3968 | /* |
3969 | * Register a shrinker to support synchronous (direct) memory | |
3970 | * reclaim from the arc. This is done to prevent kswapd from | |
3971 | * swapping out pages when it is preferable to shrink the arc. | |
3972 | */ | |
3973 | spl_register_shrinker(&arc_shrinker); | |
34dc7c2f BB |
3974 | #endif |
3975 | ||
3976 | /* set min cache to 1/32 of all memory, or 64MB, whichever is more */ | |
3977 | arc_c_min = MAX(arc_c / 4, 64<<20); | |
518b4876 | 3978 | /* set max to 1/2 of all memory */ |
23bdb07d | 3979 | arc_c_max = MAX(arc_c * 4, arc_c_max); |
34dc7c2f BB |
3980 | |
3981 | /* | |
3982 | * Allow the tunables to override our calculations if they are | |
3983 | * reasonable (ie. over 64MB) | |
3984 | */ | |
3985 | if (zfs_arc_max > 64<<20 && zfs_arc_max < physmem * PAGESIZE) | |
3986 | arc_c_max = zfs_arc_max; | |
3987 | if (zfs_arc_min > 64<<20 && zfs_arc_min <= arc_c_max) | |
3988 | arc_c_min = zfs_arc_min; | |
3989 | ||
3990 | arc_c = arc_c_max; | |
3991 | arc_p = (arc_c >> 1); | |
3992 | ||
3993 | /* limit meta-data to 1/4 of the arc capacity */ | |
3994 | arc_meta_limit = arc_c_max / 4; | |
1834f2d8 | 3995 | arc_meta_max = 0; |
34dc7c2f BB |
3996 | |
3997 | /* Allow the tunable to override if it is reasonable */ | |
3998 | if (zfs_arc_meta_limit > 0 && zfs_arc_meta_limit <= arc_c_max) | |
3999 | arc_meta_limit = zfs_arc_meta_limit; | |
4000 | ||
4001 | if (arc_c_min < arc_meta_limit / 2 && zfs_arc_min == 0) | |
4002 | arc_c_min = arc_meta_limit / 2; | |
4003 | ||
4004 | /* if kmem_flags are set, lets try to use less memory */ | |
4005 | if (kmem_debugging()) | |
4006 | arc_c = arc_c / 2; | |
4007 | if (arc_c < arc_c_min) | |
4008 | arc_c = arc_c_min; | |
4009 | ||
4010 | arc_anon = &ARC_anon; | |
4011 | arc_mru = &ARC_mru; | |
4012 | arc_mru_ghost = &ARC_mru_ghost; | |
4013 | arc_mfu = &ARC_mfu; | |
4014 | arc_mfu_ghost = &ARC_mfu_ghost; | |
4015 | arc_l2c_only = &ARC_l2c_only; | |
4016 | arc_size = 0; | |
4017 | ||
4018 | mutex_init(&arc_anon->arcs_mtx, NULL, MUTEX_DEFAULT, NULL); | |
4019 | mutex_init(&arc_mru->arcs_mtx, NULL, MUTEX_DEFAULT, NULL); | |
4020 | mutex_init(&arc_mru_ghost->arcs_mtx, NULL, MUTEX_DEFAULT, NULL); | |
4021 | mutex_init(&arc_mfu->arcs_mtx, NULL, MUTEX_DEFAULT, NULL); | |
4022 | mutex_init(&arc_mfu_ghost->arcs_mtx, NULL, MUTEX_DEFAULT, NULL); | |
4023 | mutex_init(&arc_l2c_only->arcs_mtx, NULL, MUTEX_DEFAULT, NULL); | |
4024 | ||
4025 | list_create(&arc_mru->arcs_list[ARC_BUFC_METADATA], | |
4026 | sizeof (arc_buf_hdr_t), offsetof(arc_buf_hdr_t, b_arc_node)); | |
4027 | list_create(&arc_mru->arcs_list[ARC_BUFC_DATA], | |
4028 | sizeof (arc_buf_hdr_t), offsetof(arc_buf_hdr_t, b_arc_node)); | |
4029 | list_create(&arc_mru_ghost->arcs_list[ARC_BUFC_METADATA], | |
4030 | sizeof (arc_buf_hdr_t), offsetof(arc_buf_hdr_t, b_arc_node)); | |
4031 | list_create(&arc_mru_ghost->arcs_list[ARC_BUFC_DATA], | |
4032 | sizeof (arc_buf_hdr_t), offsetof(arc_buf_hdr_t, b_arc_node)); | |
4033 | list_create(&arc_mfu->arcs_list[ARC_BUFC_METADATA], | |
4034 | sizeof (arc_buf_hdr_t), offsetof(arc_buf_hdr_t, b_arc_node)); | |
4035 | list_create(&arc_mfu->arcs_list[ARC_BUFC_DATA], | |
4036 | sizeof (arc_buf_hdr_t), offsetof(arc_buf_hdr_t, b_arc_node)); | |
4037 | list_create(&arc_mfu_ghost->arcs_list[ARC_BUFC_METADATA], | |
4038 | sizeof (arc_buf_hdr_t), offsetof(arc_buf_hdr_t, b_arc_node)); | |
4039 | list_create(&arc_mfu_ghost->arcs_list[ARC_BUFC_DATA], | |
4040 | sizeof (arc_buf_hdr_t), offsetof(arc_buf_hdr_t, b_arc_node)); | |
4041 | list_create(&arc_l2c_only->arcs_list[ARC_BUFC_METADATA], | |
4042 | sizeof (arc_buf_hdr_t), offsetof(arc_buf_hdr_t, b_arc_node)); | |
4043 | list_create(&arc_l2c_only->arcs_list[ARC_BUFC_DATA], | |
4044 | sizeof (arc_buf_hdr_t), offsetof(arc_buf_hdr_t, b_arc_node)); | |
4045 | ||
e0b0ca98 BB |
4046 | arc_anon->arcs_state = ARC_STATE_ANON; |
4047 | arc_mru->arcs_state = ARC_STATE_MRU; | |
4048 | arc_mru_ghost->arcs_state = ARC_STATE_MRU_GHOST; | |
4049 | arc_mfu->arcs_state = ARC_STATE_MFU; | |
4050 | arc_mfu_ghost->arcs_state = ARC_STATE_MFU_GHOST; | |
4051 | arc_l2c_only->arcs_state = ARC_STATE_L2C_ONLY; | |
4052 | ||
34dc7c2f BB |
4053 | buf_init(); |
4054 | ||
4055 | arc_thread_exit = 0; | |
ab26409d BB |
4056 | list_create(&arc_prune_list, sizeof (arc_prune_t), |
4057 | offsetof(arc_prune_t, p_node)); | |
34dc7c2f | 4058 | arc_eviction_list = NULL; |
ab26409d | 4059 | mutex_init(&arc_prune_mtx, NULL, MUTEX_DEFAULT, NULL); |
34dc7c2f BB |
4060 | mutex_init(&arc_eviction_mtx, NULL, MUTEX_DEFAULT, NULL); |
4061 | bzero(&arc_eviction_hdr, sizeof (arc_buf_hdr_t)); | |
4062 | ||
4063 | arc_ksp = kstat_create("zfs", 0, "arcstats", "misc", KSTAT_TYPE_NAMED, | |
4064 | sizeof (arc_stats) / sizeof (kstat_named_t), KSTAT_FLAG_VIRTUAL); | |
4065 | ||
4066 | if (arc_ksp != NULL) { | |
4067 | arc_ksp->ks_data = &arc_stats; | |
13be560d | 4068 | arc_ksp->ks_update = arc_kstat_update; |
34dc7c2f BB |
4069 | kstat_install(arc_ksp); |
4070 | } | |
4071 | ||
302f753f | 4072 | (void) thread_create(NULL, 0, arc_adapt_thread, NULL, 0, &p0, |
34dc7c2f BB |
4073 | TS_RUN, minclsyspri); |
4074 | ||
4075 | arc_dead = FALSE; | |
b128c09f | 4076 | arc_warm = B_FALSE; |
34dc7c2f BB |
4077 | |
4078 | if (zfs_write_limit_max == 0) | |
b128c09f | 4079 | zfs_write_limit_max = ptob(physmem) >> zfs_write_limit_shift; |
34dc7c2f BB |
4080 | else |
4081 | zfs_write_limit_shift = 0; | |
b128c09f | 4082 | mutex_init(&zfs_write_limit_lock, NULL, MUTEX_DEFAULT, NULL); |
34dc7c2f BB |
4083 | } |
4084 | ||
4085 | void | |
4086 | arc_fini(void) | |
4087 | { | |
ab26409d BB |
4088 | arc_prune_t *p; |
4089 | ||
34dc7c2f | 4090 | mutex_enter(&arc_reclaim_thr_lock); |
7cb67b45 BB |
4091 | #ifdef _KERNEL |
4092 | spl_unregister_shrinker(&arc_shrinker); | |
4093 | #endif /* _KERNEL */ | |
4094 | ||
34dc7c2f BB |
4095 | arc_thread_exit = 1; |
4096 | while (arc_thread_exit != 0) | |
4097 | cv_wait(&arc_reclaim_thr_cv, &arc_reclaim_thr_lock); | |
4098 | mutex_exit(&arc_reclaim_thr_lock); | |
4099 | ||
4100 | arc_flush(NULL); | |
4101 | ||
4102 | arc_dead = TRUE; | |
4103 | ||
4104 | if (arc_ksp != NULL) { | |
4105 | kstat_delete(arc_ksp); | |
4106 | arc_ksp = NULL; | |
4107 | } | |
4108 | ||
ab26409d BB |
4109 | mutex_enter(&arc_prune_mtx); |
4110 | while ((p = list_head(&arc_prune_list)) != NULL) { | |
4111 | list_remove(&arc_prune_list, p); | |
4112 | refcount_remove(&p->p_refcnt, &arc_prune_list); | |
4113 | refcount_destroy(&p->p_refcnt); | |
4114 | kmem_free(p, sizeof (*p)); | |
4115 | } | |
4116 | mutex_exit(&arc_prune_mtx); | |
4117 | ||
4118 | list_destroy(&arc_prune_list); | |
4119 | mutex_destroy(&arc_prune_mtx); | |
34dc7c2f BB |
4120 | mutex_destroy(&arc_eviction_mtx); |
4121 | mutex_destroy(&arc_reclaim_thr_lock); | |
4122 | cv_destroy(&arc_reclaim_thr_cv); | |
4123 | ||
4124 | list_destroy(&arc_mru->arcs_list[ARC_BUFC_METADATA]); | |
4125 | list_destroy(&arc_mru_ghost->arcs_list[ARC_BUFC_METADATA]); | |
4126 | list_destroy(&arc_mfu->arcs_list[ARC_BUFC_METADATA]); | |
4127 | list_destroy(&arc_mfu_ghost->arcs_list[ARC_BUFC_METADATA]); | |
4128 | list_destroy(&arc_mru->arcs_list[ARC_BUFC_DATA]); | |
4129 | list_destroy(&arc_mru_ghost->arcs_list[ARC_BUFC_DATA]); | |
4130 | list_destroy(&arc_mfu->arcs_list[ARC_BUFC_DATA]); | |
4131 | list_destroy(&arc_mfu_ghost->arcs_list[ARC_BUFC_DATA]); | |
4132 | ||
4133 | mutex_destroy(&arc_anon->arcs_mtx); | |
4134 | mutex_destroy(&arc_mru->arcs_mtx); | |
4135 | mutex_destroy(&arc_mru_ghost->arcs_mtx); | |
4136 | mutex_destroy(&arc_mfu->arcs_mtx); | |
4137 | mutex_destroy(&arc_mfu_ghost->arcs_mtx); | |
fb5f0bc8 | 4138 | mutex_destroy(&arc_l2c_only->arcs_mtx); |
34dc7c2f | 4139 | |
b128c09f BB |
4140 | mutex_destroy(&zfs_write_limit_lock); |
4141 | ||
34dc7c2f | 4142 | buf_fini(); |
9babb374 BB |
4143 | |
4144 | ASSERT(arc_loaned_bytes == 0); | |
34dc7c2f BB |
4145 | } |
4146 | ||
4147 | /* | |
4148 | * Level 2 ARC | |
4149 | * | |
4150 | * The level 2 ARC (L2ARC) is a cache layer in-between main memory and disk. | |
4151 | * It uses dedicated storage devices to hold cached data, which are populated | |
4152 | * using large infrequent writes. The main role of this cache is to boost | |
4153 | * the performance of random read workloads. The intended L2ARC devices | |
4154 | * include short-stroked disks, solid state disks, and other media with | |
4155 | * substantially faster read latency than disk. | |
4156 | * | |
4157 | * +-----------------------+ | |
4158 | * | ARC | | |
4159 | * +-----------------------+ | |
4160 | * | ^ ^ | |
4161 | * | | | | |
4162 | * l2arc_feed_thread() arc_read() | |
4163 | * | | | | |
4164 | * | l2arc read | | |
4165 | * V | | | |
4166 | * +---------------+ | | |
4167 | * | L2ARC | | | |
4168 | * +---------------+ | | |
4169 | * | ^ | | |
4170 | * l2arc_write() | | | |
4171 | * | | | | |
4172 | * V | | | |
4173 | * +-------+ +-------+ | |
4174 | * | vdev | | vdev | | |
4175 | * | cache | | cache | | |
4176 | * +-------+ +-------+ | |
4177 | * +=========+ .-----. | |
4178 | * : L2ARC : |-_____-| | |
4179 | * : devices : | Disks | | |
4180 | * +=========+ `-_____-' | |
4181 | * | |
4182 | * Read requests are satisfied from the following sources, in order: | |
4183 | * | |
4184 | * 1) ARC | |
4185 | * 2) vdev cache of L2ARC devices | |
4186 | * 3) L2ARC devices | |
4187 | * 4) vdev cache of disks | |
4188 | * 5) disks | |
4189 | * | |
4190 | * Some L2ARC device types exhibit extremely slow write performance. | |
4191 | * To accommodate for this there are some significant differences between | |
4192 | * the L2ARC and traditional cache design: | |
4193 | * | |
4194 | * 1. There is no eviction path from the ARC to the L2ARC. Evictions from | |
4195 | * the ARC behave as usual, freeing buffers and placing headers on ghost | |
4196 | * lists. The ARC does not send buffers to the L2ARC during eviction as | |
4197 | * this would add inflated write latencies for all ARC memory pressure. | |
4198 | * | |
4199 | * 2. The L2ARC attempts to cache data from the ARC before it is evicted. | |
4200 | * It does this by periodically scanning buffers from the eviction-end of | |
4201 | * the MFU and MRU ARC lists, copying them to the L2ARC devices if they are | |
3a17a7a9 SK |
4202 | * not already there. It scans until a headroom of buffers is satisfied, |
4203 | * which itself is a buffer for ARC eviction. If a compressible buffer is | |
4204 | * found during scanning and selected for writing to an L2ARC device, we | |
4205 | * temporarily boost scanning headroom during the next scan cycle to make | |
4206 | * sure we adapt to compression effects (which might significantly reduce | |
4207 | * the data volume we write to L2ARC). The thread that does this is | |
34dc7c2f BB |
4208 | * l2arc_feed_thread(), illustrated below; example sizes are included to |
4209 | * provide a better sense of ratio than this diagram: | |
4210 | * | |
4211 | * head --> tail | |
4212 | * +---------------------+----------+ | |
4213 | * ARC_mfu |:::::#:::::::::::::::|o#o###o###|-->. # already on L2ARC | |
4214 | * +---------------------+----------+ | o L2ARC eligible | |
4215 | * ARC_mru |:#:::::::::::::::::::|#o#ooo####|-->| : ARC buffer | |
4216 | * +---------------------+----------+ | | |
4217 | * 15.9 Gbytes ^ 32 Mbytes | | |
4218 | * headroom | | |
4219 | * l2arc_feed_thread() | |
4220 | * | | |
4221 | * l2arc write hand <--[oooo]--' | |
4222 | * | 8 Mbyte | |
4223 | * | write max | |
4224 | * V | |
4225 | * +==============================+ | |
4226 | * L2ARC dev |####|#|###|###| |####| ... | | |
4227 | * +==============================+ | |
4228 | * 32 Gbytes | |
4229 | * | |
4230 | * 3. If an ARC buffer is copied to the L2ARC but then hit instead of | |
4231 | * evicted, then the L2ARC has cached a buffer much sooner than it probably | |
4232 | * needed to, potentially wasting L2ARC device bandwidth and storage. It is | |
4233 | * safe to say that this is an uncommon case, since buffers at the end of | |
4234 | * the ARC lists have moved there due to inactivity. | |
4235 | * | |
4236 | * 4. If the ARC evicts faster than the L2ARC can maintain a headroom, | |
4237 | * then the L2ARC simply misses copying some buffers. This serves as a | |
4238 | * pressure valve to prevent heavy read workloads from both stalling the ARC | |
4239 | * with waits and clogging the L2ARC with writes. This also helps prevent | |
4240 | * the potential for the L2ARC to churn if it attempts to cache content too | |
4241 | * quickly, such as during backups of the entire pool. | |
4242 | * | |
b128c09f BB |
4243 | * 5. After system boot and before the ARC has filled main memory, there are |
4244 | * no evictions from the ARC and so the tails of the ARC_mfu and ARC_mru | |
4245 | * lists can remain mostly static. Instead of searching from tail of these | |
4246 | * lists as pictured, the l2arc_feed_thread() will search from the list heads | |
4247 | * for eligible buffers, greatly increasing its chance of finding them. | |
4248 | * | |
4249 | * The L2ARC device write speed is also boosted during this time so that | |
4250 | * the L2ARC warms up faster. Since there have been no ARC evictions yet, | |
4251 | * there are no L2ARC reads, and no fear of degrading read performance | |
4252 | * through increased writes. | |
4253 | * | |
4254 | * 6. Writes to the L2ARC devices are grouped and sent in-sequence, so that | |
34dc7c2f BB |
4255 | * the vdev queue can aggregate them into larger and fewer writes. Each |
4256 | * device is written to in a rotor fashion, sweeping writes through | |
4257 | * available space then repeating. | |
4258 | * | |
b128c09f | 4259 | * 7. The L2ARC does not store dirty content. It never needs to flush |
34dc7c2f BB |
4260 | * write buffers back to disk based storage. |
4261 | * | |
b128c09f | 4262 | * 8. If an ARC buffer is written (and dirtied) which also exists in the |
34dc7c2f BB |
4263 | * L2ARC, the now stale L2ARC buffer is immediately dropped. |
4264 | * | |
4265 | * The performance of the L2ARC can be tweaked by a number of tunables, which | |
4266 | * may be necessary for different workloads: | |
4267 | * | |
4268 | * l2arc_write_max max write bytes per interval | |
b128c09f | 4269 | * l2arc_write_boost extra write bytes during device warmup |
34dc7c2f | 4270 | * l2arc_noprefetch skip caching prefetched buffers |
3a17a7a9 | 4271 | * l2arc_nocompress skip compressing buffers |
34dc7c2f | 4272 | * l2arc_headroom number of max device writes to precache |
3a17a7a9 SK |
4273 | * l2arc_headroom_boost when we find compressed buffers during ARC |
4274 | * scanning, we multiply headroom by this | |
4275 | * percentage factor for the next scan cycle, | |
4276 | * since more compressed buffers are likely to | |
4277 | * be present | |
34dc7c2f BB |
4278 | * l2arc_feed_secs seconds between L2ARC writing |
4279 | * | |
4280 | * Tunables may be removed or added as future performance improvements are | |
4281 | * integrated, and also may become zpool properties. | |
d164b209 BB |
4282 | * |
4283 | * There are three key functions that control how the L2ARC warms up: | |
4284 | * | |
4285 | * l2arc_write_eligible() check if a buffer is eligible to cache | |
4286 | * l2arc_write_size() calculate how much to write | |
4287 | * l2arc_write_interval() calculate sleep delay between writes | |
4288 | * | |
4289 | * These three functions determine what to write, how much, and how quickly | |
4290 | * to send writes. | |
34dc7c2f BB |
4291 | */ |
4292 | ||
d164b209 BB |
4293 | static boolean_t |
4294 | l2arc_write_eligible(uint64_t spa_guid, arc_buf_hdr_t *ab) | |
4295 | { | |
4296 | /* | |
4297 | * A buffer is *not* eligible for the L2ARC if it: | |
4298 | * 1. belongs to a different spa. | |
428870ff BB |
4299 | * 2. is already cached on the L2ARC. |
4300 | * 3. has an I/O in progress (it may be an incomplete read). | |
4301 | * 4. is flagged not eligible (zfs property). | |
d164b209 | 4302 | */ |
428870ff | 4303 | if (ab->b_spa != spa_guid || ab->b_l2hdr != NULL || |
d164b209 BB |
4304 | HDR_IO_IN_PROGRESS(ab) || !HDR_L2CACHE(ab)) |
4305 | return (B_FALSE); | |
4306 | ||
4307 | return (B_TRUE); | |
4308 | } | |
4309 | ||
4310 | static uint64_t | |
3a17a7a9 | 4311 | l2arc_write_size(void) |
d164b209 BB |
4312 | { |
4313 | uint64_t size; | |
4314 | ||
3a17a7a9 SK |
4315 | /* |
4316 | * Make sure our globals have meaningful values in case the user | |
4317 | * altered them. | |
4318 | */ | |
4319 | size = l2arc_write_max; | |
4320 | if (size == 0) { | |
4321 | cmn_err(CE_NOTE, "Bad value for l2arc_write_max, value must " | |
4322 | "be greater than zero, resetting it to the default (%d)", | |
4323 | L2ARC_WRITE_SIZE); | |
4324 | size = l2arc_write_max = L2ARC_WRITE_SIZE; | |
4325 | } | |
d164b209 BB |
4326 | |
4327 | if (arc_warm == B_FALSE) | |
3a17a7a9 | 4328 | size += l2arc_write_boost; |
d164b209 BB |
4329 | |
4330 | return (size); | |
4331 | ||
4332 | } | |
4333 | ||
4334 | static clock_t | |
4335 | l2arc_write_interval(clock_t began, uint64_t wanted, uint64_t wrote) | |
4336 | { | |
428870ff | 4337 | clock_t interval, next, now; |
d164b209 BB |
4338 | |
4339 | /* | |
4340 | * If the ARC lists are busy, increase our write rate; if the | |
4341 | * lists are stale, idle back. This is achieved by checking | |
4342 | * how much we previously wrote - if it was more than half of | |
4343 | * what we wanted, schedule the next write much sooner. | |
4344 | */ | |
4345 | if (l2arc_feed_again && wrote > (wanted / 2)) | |
4346 | interval = (hz * l2arc_feed_min_ms) / 1000; | |
4347 | else | |
4348 | interval = hz * l2arc_feed_secs; | |
4349 | ||
428870ff BB |
4350 | now = ddi_get_lbolt(); |
4351 | next = MAX(now, MIN(now + interval, began + interval)); | |
d164b209 BB |
4352 | |
4353 | return (next); | |
4354 | } | |
4355 | ||
34dc7c2f BB |
4356 | static void |
4357 | l2arc_hdr_stat_add(void) | |
4358 | { | |
6e1d7276 | 4359 | ARCSTAT_INCR(arcstat_l2_hdr_size, HDR_SIZE); |
34dc7c2f BB |
4360 | ARCSTAT_INCR(arcstat_hdr_size, -HDR_SIZE); |
4361 | } | |
4362 | ||
4363 | static void | |
4364 | l2arc_hdr_stat_remove(void) | |
4365 | { | |
6e1d7276 | 4366 | ARCSTAT_INCR(arcstat_l2_hdr_size, -HDR_SIZE); |
34dc7c2f BB |
4367 | ARCSTAT_INCR(arcstat_hdr_size, HDR_SIZE); |
4368 | } | |
4369 | ||
4370 | /* | |
4371 | * Cycle through L2ARC devices. This is how L2ARC load balances. | |
b128c09f | 4372 | * If a device is returned, this also returns holding the spa config lock. |
34dc7c2f BB |
4373 | */ |
4374 | static l2arc_dev_t * | |
4375 | l2arc_dev_get_next(void) | |
4376 | { | |
b128c09f | 4377 | l2arc_dev_t *first, *next = NULL; |
34dc7c2f | 4378 | |
b128c09f BB |
4379 | /* |
4380 | * Lock out the removal of spas (spa_namespace_lock), then removal | |
4381 | * of cache devices (l2arc_dev_mtx). Once a device has been selected, | |
4382 | * both locks will be dropped and a spa config lock held instead. | |
4383 | */ | |
4384 | mutex_enter(&spa_namespace_lock); | |
4385 | mutex_enter(&l2arc_dev_mtx); | |
4386 | ||
4387 | /* if there are no vdevs, there is nothing to do */ | |
4388 | if (l2arc_ndev == 0) | |
4389 | goto out; | |
4390 | ||
4391 | first = NULL; | |
4392 | next = l2arc_dev_last; | |
4393 | do { | |
4394 | /* loop around the list looking for a non-faulted vdev */ | |
4395 | if (next == NULL) { | |
34dc7c2f | 4396 | next = list_head(l2arc_dev_list); |
b128c09f BB |
4397 | } else { |
4398 | next = list_next(l2arc_dev_list, next); | |
4399 | if (next == NULL) | |
4400 | next = list_head(l2arc_dev_list); | |
4401 | } | |
4402 | ||
4403 | /* if we have come back to the start, bail out */ | |
4404 | if (first == NULL) | |
4405 | first = next; | |
4406 | else if (next == first) | |
4407 | break; | |
4408 | ||
4409 | } while (vdev_is_dead(next->l2ad_vdev)); | |
4410 | ||
4411 | /* if we were unable to find any usable vdevs, return NULL */ | |
4412 | if (vdev_is_dead(next->l2ad_vdev)) | |
4413 | next = NULL; | |
34dc7c2f BB |
4414 | |
4415 | l2arc_dev_last = next; | |
4416 | ||
b128c09f BB |
4417 | out: |
4418 | mutex_exit(&l2arc_dev_mtx); | |
4419 | ||
4420 | /* | |
4421 | * Grab the config lock to prevent the 'next' device from being | |
4422 | * removed while we are writing to it. | |
4423 | */ | |
4424 | if (next != NULL) | |
4425 | spa_config_enter(next->l2ad_spa, SCL_L2ARC, next, RW_READER); | |
4426 | mutex_exit(&spa_namespace_lock); | |
4427 | ||
34dc7c2f BB |
4428 | return (next); |
4429 | } | |
4430 | ||
b128c09f BB |
4431 | /* |
4432 | * Free buffers that were tagged for destruction. | |
4433 | */ | |
4434 | static void | |
0bc8fd78 | 4435 | l2arc_do_free_on_write(void) |
b128c09f BB |
4436 | { |
4437 | list_t *buflist; | |
4438 | l2arc_data_free_t *df, *df_prev; | |
4439 | ||
4440 | mutex_enter(&l2arc_free_on_write_mtx); | |
4441 | buflist = l2arc_free_on_write; | |
4442 | ||
4443 | for (df = list_tail(buflist); df; df = df_prev) { | |
4444 | df_prev = list_prev(buflist, df); | |
4445 | ASSERT(df->l2df_data != NULL); | |
4446 | ASSERT(df->l2df_func != NULL); | |
4447 | df->l2df_func(df->l2df_data, df->l2df_size); | |
4448 | list_remove(buflist, df); | |
4449 | kmem_free(df, sizeof (l2arc_data_free_t)); | |
4450 | } | |
4451 | ||
4452 | mutex_exit(&l2arc_free_on_write_mtx); | |
4453 | } | |
4454 | ||
34dc7c2f BB |
4455 | /* |
4456 | * A write to a cache device has completed. Update all headers to allow | |
4457 | * reads from these buffers to begin. | |
4458 | */ | |
4459 | static void | |
4460 | l2arc_write_done(zio_t *zio) | |
4461 | { | |
4462 | l2arc_write_callback_t *cb; | |
4463 | l2arc_dev_t *dev; | |
4464 | list_t *buflist; | |
34dc7c2f | 4465 | arc_buf_hdr_t *head, *ab, *ab_prev; |
b128c09f | 4466 | l2arc_buf_hdr_t *abl2; |
34dc7c2f BB |
4467 | kmutex_t *hash_lock; |
4468 | ||
4469 | cb = zio->io_private; | |
4470 | ASSERT(cb != NULL); | |
4471 | dev = cb->l2wcb_dev; | |
4472 | ASSERT(dev != NULL); | |
4473 | head = cb->l2wcb_head; | |
4474 | ASSERT(head != NULL); | |
4475 | buflist = dev->l2ad_buflist; | |
4476 | ASSERT(buflist != NULL); | |
4477 | DTRACE_PROBE2(l2arc__iodone, zio_t *, zio, | |
4478 | l2arc_write_callback_t *, cb); | |
4479 | ||
4480 | if (zio->io_error != 0) | |
4481 | ARCSTAT_BUMP(arcstat_l2_writes_error); | |
4482 | ||
4483 | mutex_enter(&l2arc_buflist_mtx); | |
4484 | ||
4485 | /* | |
4486 | * All writes completed, or an error was hit. | |
4487 | */ | |
4488 | for (ab = list_prev(buflist, head); ab; ab = ab_prev) { | |
4489 | ab_prev = list_prev(buflist, ab); | |
4490 | ||
4491 | hash_lock = HDR_LOCK(ab); | |
4492 | if (!mutex_tryenter(hash_lock)) { | |
4493 | /* | |
4494 | * This buffer misses out. It may be in a stage | |
4495 | * of eviction. Its ARC_L2_WRITING flag will be | |
4496 | * left set, denying reads to this buffer. | |
4497 | */ | |
4498 | ARCSTAT_BUMP(arcstat_l2_writes_hdr_miss); | |
4499 | continue; | |
4500 | } | |
4501 | ||
3a17a7a9 SK |
4502 | abl2 = ab->b_l2hdr; |
4503 | ||
4504 | /* | |
4505 | * Release the temporary compressed buffer as soon as possible. | |
4506 | */ | |
4507 | if (abl2->b_compress != ZIO_COMPRESS_OFF) | |
4508 | l2arc_release_cdata_buf(ab); | |
4509 | ||
34dc7c2f BB |
4510 | if (zio->io_error != 0) { |
4511 | /* | |
b128c09f | 4512 | * Error - drop L2ARC entry. |
34dc7c2f | 4513 | */ |
b128c09f | 4514 | list_remove(buflist, ab); |
3a17a7a9 | 4515 | ARCSTAT_INCR(arcstat_l2_asize, -abl2->b_asize); |
34dc7c2f | 4516 | ab->b_l2hdr = NULL; |
b128c09f | 4517 | kmem_free(abl2, sizeof (l2arc_buf_hdr_t)); |
6e1d7276 | 4518 | arc_space_return(L2HDR_SIZE, ARC_SPACE_L2HDRS); |
b128c09f | 4519 | ARCSTAT_INCR(arcstat_l2_size, -ab->b_size); |
34dc7c2f BB |
4520 | } |
4521 | ||
4522 | /* | |
4523 | * Allow ARC to begin reads to this L2ARC entry. | |
4524 | */ | |
4525 | ab->b_flags &= ~ARC_L2_WRITING; | |
4526 | ||
4527 | mutex_exit(hash_lock); | |
4528 | } | |
4529 | ||
4530 | atomic_inc_64(&l2arc_writes_done); | |
4531 | list_remove(buflist, head); | |
4532 | kmem_cache_free(hdr_cache, head); | |
4533 | mutex_exit(&l2arc_buflist_mtx); | |
4534 | ||
b128c09f | 4535 | l2arc_do_free_on_write(); |
34dc7c2f BB |
4536 | |
4537 | kmem_free(cb, sizeof (l2arc_write_callback_t)); | |
4538 | } | |
4539 | ||
4540 | /* | |
4541 | * A read to a cache device completed. Validate buffer contents before | |
4542 | * handing over to the regular ARC routines. | |
4543 | */ | |
4544 | static void | |
4545 | l2arc_read_done(zio_t *zio) | |
4546 | { | |
4547 | l2arc_read_callback_t *cb; | |
4548 | arc_buf_hdr_t *hdr; | |
4549 | arc_buf_t *buf; | |
34dc7c2f | 4550 | kmutex_t *hash_lock; |
b128c09f BB |
4551 | int equal; |
4552 | ||
4553 | ASSERT(zio->io_vd != NULL); | |
4554 | ASSERT(zio->io_flags & ZIO_FLAG_DONT_PROPAGATE); | |
4555 | ||
4556 | spa_config_exit(zio->io_spa, SCL_L2ARC, zio->io_vd); | |
34dc7c2f BB |
4557 | |
4558 | cb = zio->io_private; | |
4559 | ASSERT(cb != NULL); | |
4560 | buf = cb->l2rcb_buf; | |
4561 | ASSERT(buf != NULL); | |
34dc7c2f | 4562 | |
428870ff | 4563 | hash_lock = HDR_LOCK(buf->b_hdr); |
34dc7c2f | 4564 | mutex_enter(hash_lock); |
428870ff BB |
4565 | hdr = buf->b_hdr; |
4566 | ASSERT3P(hash_lock, ==, HDR_LOCK(hdr)); | |
34dc7c2f | 4567 | |
3a17a7a9 SK |
4568 | /* |
4569 | * If the buffer was compressed, decompress it first. | |
4570 | */ | |
4571 | if (cb->l2rcb_compress != ZIO_COMPRESS_OFF) | |
4572 | l2arc_decompress_zio(zio, hdr, cb->l2rcb_compress); | |
4573 | ASSERT(zio->io_data != NULL); | |
4574 | ||
34dc7c2f BB |
4575 | /* |
4576 | * Check this survived the L2ARC journey. | |
4577 | */ | |
4578 | equal = arc_cksum_equal(buf); | |
4579 | if (equal && zio->io_error == 0 && !HDR_L2_EVICTED(hdr)) { | |
4580 | mutex_exit(hash_lock); | |
4581 | zio->io_private = buf; | |
b128c09f BB |
4582 | zio->io_bp_copy = cb->l2rcb_bp; /* XXX fix in L2ARC 2.0 */ |
4583 | zio->io_bp = &zio->io_bp_copy; /* XXX fix in L2ARC 2.0 */ | |
34dc7c2f BB |
4584 | arc_read_done(zio); |
4585 | } else { | |
4586 | mutex_exit(hash_lock); | |
4587 | /* | |
4588 | * Buffer didn't survive caching. Increment stats and | |
4589 | * reissue to the original storage device. | |
4590 | */ | |
b128c09f | 4591 | if (zio->io_error != 0) { |
34dc7c2f | 4592 | ARCSTAT_BUMP(arcstat_l2_io_error); |
b128c09f | 4593 | } else { |
2e528b49 | 4594 | zio->io_error = SET_ERROR(EIO); |
b128c09f | 4595 | } |
34dc7c2f BB |
4596 | if (!equal) |
4597 | ARCSTAT_BUMP(arcstat_l2_cksum_bad); | |
4598 | ||
34dc7c2f | 4599 | /* |
b128c09f BB |
4600 | * If there's no waiter, issue an async i/o to the primary |
4601 | * storage now. If there *is* a waiter, the caller must | |
4602 | * issue the i/o in a context where it's OK to block. | |
34dc7c2f | 4603 | */ |
d164b209 BB |
4604 | if (zio->io_waiter == NULL) { |
4605 | zio_t *pio = zio_unique_parent(zio); | |
4606 | ||
4607 | ASSERT(!pio || pio->io_child_type == ZIO_CHILD_LOGICAL); | |
4608 | ||
4609 | zio_nowait(zio_read(pio, cb->l2rcb_spa, &cb->l2rcb_bp, | |
b128c09f BB |
4610 | buf->b_data, zio->io_size, arc_read_done, buf, |
4611 | zio->io_priority, cb->l2rcb_flags, &cb->l2rcb_zb)); | |
d164b209 | 4612 | } |
34dc7c2f BB |
4613 | } |
4614 | ||
4615 | kmem_free(cb, sizeof (l2arc_read_callback_t)); | |
4616 | } | |
4617 | ||
4618 | /* | |
4619 | * This is the list priority from which the L2ARC will search for pages to | |
4620 | * cache. This is used within loops (0..3) to cycle through lists in the | |
4621 | * desired order. This order can have a significant effect on cache | |
4622 | * performance. | |
4623 | * | |
4624 | * Currently the metadata lists are hit first, MFU then MRU, followed by | |
4625 | * the data lists. This function returns a locked list, and also returns | |
4626 | * the lock pointer. | |
4627 | */ | |
4628 | static list_t * | |
4629 | l2arc_list_locked(int list_num, kmutex_t **lock) | |
4630 | { | |
d4ed6673 | 4631 | list_t *list = NULL; |
34dc7c2f BB |
4632 | |
4633 | ASSERT(list_num >= 0 && list_num <= 3); | |
4634 | ||
4635 | switch (list_num) { | |
4636 | case 0: | |
4637 | list = &arc_mfu->arcs_list[ARC_BUFC_METADATA]; | |
4638 | *lock = &arc_mfu->arcs_mtx; | |
4639 | break; | |
4640 | case 1: | |
4641 | list = &arc_mru->arcs_list[ARC_BUFC_METADATA]; | |
4642 | *lock = &arc_mru->arcs_mtx; | |
4643 | break; | |
4644 | case 2: | |
4645 | list = &arc_mfu->arcs_list[ARC_BUFC_DATA]; | |
4646 | *lock = &arc_mfu->arcs_mtx; | |
4647 | break; | |
4648 | case 3: | |
4649 | list = &arc_mru->arcs_list[ARC_BUFC_DATA]; | |
4650 | *lock = &arc_mru->arcs_mtx; | |
4651 | break; | |
4652 | } | |
4653 | ||
4654 | ASSERT(!(MUTEX_HELD(*lock))); | |
4655 | mutex_enter(*lock); | |
4656 | return (list); | |
4657 | } | |
4658 | ||
4659 | /* | |
4660 | * Evict buffers from the device write hand to the distance specified in | |
4661 | * bytes. This distance may span populated buffers, it may span nothing. | |
4662 | * This is clearing a region on the L2ARC device ready for writing. | |
4663 | * If the 'all' boolean is set, every buffer is evicted. | |
4664 | */ | |
4665 | static void | |
4666 | l2arc_evict(l2arc_dev_t *dev, uint64_t distance, boolean_t all) | |
4667 | { | |
4668 | list_t *buflist; | |
4669 | l2arc_buf_hdr_t *abl2; | |
4670 | arc_buf_hdr_t *ab, *ab_prev; | |
4671 | kmutex_t *hash_lock; | |
4672 | uint64_t taddr; | |
4673 | ||
34dc7c2f BB |
4674 | buflist = dev->l2ad_buflist; |
4675 | ||
4676 | if (buflist == NULL) | |
4677 | return; | |
4678 | ||
4679 | if (!all && dev->l2ad_first) { | |
4680 | /* | |
4681 | * This is the first sweep through the device. There is | |
4682 | * nothing to evict. | |
4683 | */ | |
4684 | return; | |
4685 | } | |
4686 | ||
b128c09f | 4687 | if (dev->l2ad_hand >= (dev->l2ad_end - (2 * distance))) { |
34dc7c2f BB |
4688 | /* |
4689 | * When nearing the end of the device, evict to the end | |
4690 | * before the device write hand jumps to the start. | |
4691 | */ | |
4692 | taddr = dev->l2ad_end; | |
4693 | } else { | |
4694 | taddr = dev->l2ad_hand + distance; | |
4695 | } | |
4696 | DTRACE_PROBE4(l2arc__evict, l2arc_dev_t *, dev, list_t *, buflist, | |
4697 | uint64_t, taddr, boolean_t, all); | |
4698 | ||
4699 | top: | |
4700 | mutex_enter(&l2arc_buflist_mtx); | |
4701 | for (ab = list_tail(buflist); ab; ab = ab_prev) { | |
4702 | ab_prev = list_prev(buflist, ab); | |
4703 | ||
4704 | hash_lock = HDR_LOCK(ab); | |
4705 | if (!mutex_tryenter(hash_lock)) { | |
4706 | /* | |
4707 | * Missed the hash lock. Retry. | |
4708 | */ | |
4709 | ARCSTAT_BUMP(arcstat_l2_evict_lock_retry); | |
4710 | mutex_exit(&l2arc_buflist_mtx); | |
4711 | mutex_enter(hash_lock); | |
4712 | mutex_exit(hash_lock); | |
4713 | goto top; | |
4714 | } | |
4715 | ||
4716 | if (HDR_L2_WRITE_HEAD(ab)) { | |
4717 | /* | |
4718 | * We hit a write head node. Leave it for | |
4719 | * l2arc_write_done(). | |
4720 | */ | |
4721 | list_remove(buflist, ab); | |
4722 | mutex_exit(hash_lock); | |
4723 | continue; | |
4724 | } | |
4725 | ||
4726 | if (!all && ab->b_l2hdr != NULL && | |
4727 | (ab->b_l2hdr->b_daddr > taddr || | |
4728 | ab->b_l2hdr->b_daddr < dev->l2ad_hand)) { | |
4729 | /* | |
4730 | * We've evicted to the target address, | |
4731 | * or the end of the device. | |
4732 | */ | |
4733 | mutex_exit(hash_lock); | |
4734 | break; | |
4735 | } | |
4736 | ||
4737 | if (HDR_FREE_IN_PROGRESS(ab)) { | |
4738 | /* | |
4739 | * Already on the path to destruction. | |
4740 | */ | |
4741 | mutex_exit(hash_lock); | |
4742 | continue; | |
4743 | } | |
4744 | ||
4745 | if (ab->b_state == arc_l2c_only) { | |
4746 | ASSERT(!HDR_L2_READING(ab)); | |
4747 | /* | |
4748 | * This doesn't exist in the ARC. Destroy. | |
4749 | * arc_hdr_destroy() will call list_remove() | |
4750 | * and decrement arcstat_l2_size. | |
4751 | */ | |
4752 | arc_change_state(arc_anon, ab, hash_lock); | |
4753 | arc_hdr_destroy(ab); | |
4754 | } else { | |
b128c09f BB |
4755 | /* |
4756 | * Invalidate issued or about to be issued | |
4757 | * reads, since we may be about to write | |
4758 | * over this location. | |
4759 | */ | |
4760 | if (HDR_L2_READING(ab)) { | |
4761 | ARCSTAT_BUMP(arcstat_l2_evict_reading); | |
4762 | ab->b_flags |= ARC_L2_EVICTED; | |
4763 | } | |
4764 | ||
34dc7c2f BB |
4765 | /* |
4766 | * Tell ARC this no longer exists in L2ARC. | |
4767 | */ | |
4768 | if (ab->b_l2hdr != NULL) { | |
4769 | abl2 = ab->b_l2hdr; | |
3a17a7a9 | 4770 | ARCSTAT_INCR(arcstat_l2_asize, -abl2->b_asize); |
34dc7c2f BB |
4771 | ab->b_l2hdr = NULL; |
4772 | kmem_free(abl2, sizeof (l2arc_buf_hdr_t)); | |
6e1d7276 | 4773 | arc_space_return(L2HDR_SIZE, ARC_SPACE_L2HDRS); |
34dc7c2f BB |
4774 | ARCSTAT_INCR(arcstat_l2_size, -ab->b_size); |
4775 | } | |
4776 | list_remove(buflist, ab); | |
4777 | ||
4778 | /* | |
4779 | * This may have been leftover after a | |
4780 | * failed write. | |
4781 | */ | |
4782 | ab->b_flags &= ~ARC_L2_WRITING; | |
34dc7c2f BB |
4783 | } |
4784 | mutex_exit(hash_lock); | |
4785 | } | |
4786 | mutex_exit(&l2arc_buflist_mtx); | |
4787 | ||
428870ff | 4788 | vdev_space_update(dev->l2ad_vdev, -(taddr - dev->l2ad_evict), 0, 0); |
34dc7c2f BB |
4789 | dev->l2ad_evict = taddr; |
4790 | } | |
4791 | ||
4792 | /* | |
4793 | * Find and write ARC buffers to the L2ARC device. | |
4794 | * | |
4795 | * An ARC_L2_WRITING flag is set so that the L2ARC buffers are not valid | |
4796 | * for reading until they have completed writing. | |
3a17a7a9 SK |
4797 | * The headroom_boost is an in-out parameter used to maintain headroom boost |
4798 | * state between calls to this function. | |
4799 | * | |
4800 | * Returns the number of bytes actually written (which may be smaller than | |
4801 | * the delta by which the device hand has changed due to alignment). | |
34dc7c2f | 4802 | */ |
d164b209 | 4803 | static uint64_t |
3a17a7a9 SK |
4804 | l2arc_write_buffers(spa_t *spa, l2arc_dev_t *dev, uint64_t target_sz, |
4805 | boolean_t *headroom_boost) | |
34dc7c2f BB |
4806 | { |
4807 | arc_buf_hdr_t *ab, *ab_prev, *head; | |
34dc7c2f | 4808 | list_t *list; |
3a17a7a9 SK |
4809 | uint64_t write_asize, write_psize, write_sz, headroom, |
4810 | buf_compress_minsz; | |
34dc7c2f | 4811 | void *buf_data; |
3a17a7a9 SK |
4812 | kmutex_t *list_lock = NULL; |
4813 | boolean_t full; | |
34dc7c2f BB |
4814 | l2arc_write_callback_t *cb; |
4815 | zio_t *pio, *wzio; | |
3541dc6d | 4816 | uint64_t guid = spa_load_guid(spa); |
d6320ddb | 4817 | int try; |
3a17a7a9 | 4818 | const boolean_t do_headroom_boost = *headroom_boost; |
34dc7c2f | 4819 | |
34dc7c2f BB |
4820 | ASSERT(dev->l2ad_vdev != NULL); |
4821 | ||
3a17a7a9 SK |
4822 | /* Lower the flag now, we might want to raise it again later. */ |
4823 | *headroom_boost = B_FALSE; | |
4824 | ||
34dc7c2f | 4825 | pio = NULL; |
3a17a7a9 | 4826 | write_sz = write_asize = write_psize = 0; |
34dc7c2f BB |
4827 | full = B_FALSE; |
4828 | head = kmem_cache_alloc(hdr_cache, KM_PUSHPAGE); | |
4829 | head->b_flags |= ARC_L2_WRITE_HEAD; | |
4830 | ||
3a17a7a9 SK |
4831 | /* |
4832 | * We will want to try to compress buffers that are at least 2x the | |
4833 | * device sector size. | |
4834 | */ | |
4835 | buf_compress_minsz = 2 << dev->l2ad_vdev->vdev_ashift; | |
4836 | ||
34dc7c2f BB |
4837 | /* |
4838 | * Copy buffers for L2ARC writing. | |
4839 | */ | |
4840 | mutex_enter(&l2arc_buflist_mtx); | |
d6320ddb | 4841 | for (try = 0; try <= 3; try++) { |
3a17a7a9 SK |
4842 | uint64_t passed_sz = 0; |
4843 | ||
34dc7c2f | 4844 | list = l2arc_list_locked(try, &list_lock); |
34dc7c2f | 4845 | |
b128c09f BB |
4846 | /* |
4847 | * L2ARC fast warmup. | |
4848 | * | |
4849 | * Until the ARC is warm and starts to evict, read from the | |
4850 | * head of the ARC lists rather than the tail. | |
4851 | */ | |
b128c09f BB |
4852 | if (arc_warm == B_FALSE) |
4853 | ab = list_head(list); | |
4854 | else | |
4855 | ab = list_tail(list); | |
4856 | ||
3a17a7a9 SK |
4857 | headroom = target_sz * l2arc_headroom; |
4858 | if (do_headroom_boost) | |
4859 | headroom = (headroom * l2arc_headroom_boost) / 100; | |
4860 | ||
b128c09f | 4861 | for (; ab; ab = ab_prev) { |
3a17a7a9 SK |
4862 | l2arc_buf_hdr_t *l2hdr; |
4863 | kmutex_t *hash_lock; | |
4864 | uint64_t buf_sz; | |
4865 | ||
b128c09f BB |
4866 | if (arc_warm == B_FALSE) |
4867 | ab_prev = list_next(list, ab); | |
4868 | else | |
4869 | ab_prev = list_prev(list, ab); | |
34dc7c2f BB |
4870 | |
4871 | hash_lock = HDR_LOCK(ab); | |
3a17a7a9 | 4872 | if (!mutex_tryenter(hash_lock)) { |
34dc7c2f BB |
4873 | /* |
4874 | * Skip this buffer rather than waiting. | |
4875 | */ | |
4876 | continue; | |
4877 | } | |
4878 | ||
4879 | passed_sz += ab->b_size; | |
4880 | if (passed_sz > headroom) { | |
4881 | /* | |
4882 | * Searched too far. | |
4883 | */ | |
4884 | mutex_exit(hash_lock); | |
4885 | break; | |
4886 | } | |
4887 | ||
d164b209 | 4888 | if (!l2arc_write_eligible(guid, ab)) { |
34dc7c2f BB |
4889 | mutex_exit(hash_lock); |
4890 | continue; | |
4891 | } | |
4892 | ||
4893 | if ((write_sz + ab->b_size) > target_sz) { | |
4894 | full = B_TRUE; | |
4895 | mutex_exit(hash_lock); | |
4896 | break; | |
4897 | } | |
4898 | ||
34dc7c2f BB |
4899 | if (pio == NULL) { |
4900 | /* | |
4901 | * Insert a dummy header on the buflist so | |
4902 | * l2arc_write_done() can find where the | |
4903 | * write buffers begin without searching. | |
4904 | */ | |
4905 | list_insert_head(dev->l2ad_buflist, head); | |
4906 | ||
409dc1a5 PS |
4907 | cb = kmem_alloc(sizeof (l2arc_write_callback_t), |
4908 | KM_PUSHPAGE); | |
34dc7c2f BB |
4909 | cb->l2wcb_dev = dev; |
4910 | cb->l2wcb_head = head; | |
4911 | pio = zio_root(spa, l2arc_write_done, cb, | |
4912 | ZIO_FLAG_CANFAIL); | |
4913 | } | |
4914 | ||
4915 | /* | |
4916 | * Create and add a new L2ARC header. | |
4917 | */ | |
3a17a7a9 SK |
4918 | l2hdr = kmem_zalloc(sizeof (l2arc_buf_hdr_t), |
4919 | KM_PUSHPAGE); | |
4920 | l2hdr->b_dev = dev; | |
6e1d7276 | 4921 | arc_space_consume(L2HDR_SIZE, ARC_SPACE_L2HDRS); |
34dc7c2f BB |
4922 | |
4923 | ab->b_flags |= ARC_L2_WRITING; | |
3a17a7a9 SK |
4924 | |
4925 | /* | |
4926 | * Temporarily stash the data buffer in b_tmp_cdata. | |
4927 | * The subsequent write step will pick it up from | |
4928 | * there. This is because can't access ab->b_buf | |
4929 | * without holding the hash_lock, which we in turn | |
4930 | * can't access without holding the ARC list locks | |
4931 | * (which we want to avoid during compression/writing) | |
4932 | */ | |
4933 | l2hdr->b_compress = ZIO_COMPRESS_OFF; | |
4934 | l2hdr->b_asize = ab->b_size; | |
4935 | l2hdr->b_tmp_cdata = ab->b_buf->b_data; | |
e0b0ca98 | 4936 | l2hdr->b_hits = 0; |
3a17a7a9 | 4937 | |
34dc7c2f | 4938 | buf_sz = ab->b_size; |
3a17a7a9 SK |
4939 | ab->b_l2hdr = l2hdr; |
4940 | ||
4941 | list_insert_head(dev->l2ad_buflist, ab); | |
34dc7c2f BB |
4942 | |
4943 | /* | |
4944 | * Compute and store the buffer cksum before | |
4945 | * writing. On debug the cksum is verified first. | |
4946 | */ | |
4947 | arc_cksum_verify(ab->b_buf); | |
4948 | arc_cksum_compute(ab->b_buf, B_TRUE); | |
4949 | ||
4950 | mutex_exit(hash_lock); | |
4951 | ||
3a17a7a9 SK |
4952 | write_sz += buf_sz; |
4953 | } | |
4954 | ||
4955 | mutex_exit(list_lock); | |
4956 | ||
4957 | if (full == B_TRUE) | |
4958 | break; | |
4959 | } | |
4960 | ||
4961 | /* No buffers selected for writing? */ | |
4962 | if (pio == NULL) { | |
4963 | ASSERT0(write_sz); | |
4964 | mutex_exit(&l2arc_buflist_mtx); | |
4965 | kmem_cache_free(hdr_cache, head); | |
4966 | return (0); | |
4967 | } | |
4968 | ||
4969 | /* | |
4970 | * Now start writing the buffers. We're starting at the write head | |
4971 | * and work backwards, retracing the course of the buffer selector | |
4972 | * loop above. | |
4973 | */ | |
4974 | for (ab = list_prev(dev->l2ad_buflist, head); ab; | |
4975 | ab = list_prev(dev->l2ad_buflist, ab)) { | |
4976 | l2arc_buf_hdr_t *l2hdr; | |
4977 | uint64_t buf_sz; | |
4978 | ||
4979 | /* | |
4980 | * We shouldn't need to lock the buffer here, since we flagged | |
4981 | * it as ARC_L2_WRITING in the previous step, but we must take | |
4982 | * care to only access its L2 cache parameters. In particular, | |
4983 | * ab->b_buf may be invalid by now due to ARC eviction. | |
4984 | */ | |
4985 | l2hdr = ab->b_l2hdr; | |
4986 | l2hdr->b_daddr = dev->l2ad_hand; | |
4987 | ||
4988 | if (!l2arc_nocompress && (ab->b_flags & ARC_L2COMPRESS) && | |
4989 | l2hdr->b_asize >= buf_compress_minsz) { | |
4990 | if (l2arc_compress_buf(l2hdr)) { | |
4991 | /* | |
4992 | * If compression succeeded, enable headroom | |
4993 | * boost on the next scan cycle. | |
4994 | */ | |
4995 | *headroom_boost = B_TRUE; | |
4996 | } | |
4997 | } | |
4998 | ||
4999 | /* | |
5000 | * Pick up the buffer data we had previously stashed away | |
5001 | * (and now potentially also compressed). | |
5002 | */ | |
5003 | buf_data = l2hdr->b_tmp_cdata; | |
5004 | buf_sz = l2hdr->b_asize; | |
5005 | ||
5006 | /* Compression may have squashed the buffer to zero length. */ | |
5007 | if (buf_sz != 0) { | |
5008 | uint64_t buf_p_sz; | |
5009 | ||
34dc7c2f BB |
5010 | wzio = zio_write_phys(pio, dev->l2ad_vdev, |
5011 | dev->l2ad_hand, buf_sz, buf_data, ZIO_CHECKSUM_OFF, | |
5012 | NULL, NULL, ZIO_PRIORITY_ASYNC_WRITE, | |
5013 | ZIO_FLAG_CANFAIL, B_FALSE); | |
5014 | ||
5015 | DTRACE_PROBE2(l2arc__write, vdev_t *, dev->l2ad_vdev, | |
5016 | zio_t *, wzio); | |
5017 | (void) zio_nowait(wzio); | |
5018 | ||
3a17a7a9 | 5019 | write_asize += buf_sz; |
b128c09f BB |
5020 | /* |
5021 | * Keep the clock hand suitably device-aligned. | |
5022 | */ | |
3a17a7a9 SK |
5023 | buf_p_sz = vdev_psize_to_asize(dev->l2ad_vdev, buf_sz); |
5024 | write_psize += buf_p_sz; | |
5025 | dev->l2ad_hand += buf_p_sz; | |
34dc7c2f | 5026 | } |
34dc7c2f | 5027 | } |
34dc7c2f | 5028 | |
3a17a7a9 | 5029 | mutex_exit(&l2arc_buflist_mtx); |
34dc7c2f | 5030 | |
3a17a7a9 | 5031 | ASSERT3U(write_asize, <=, target_sz); |
34dc7c2f | 5032 | ARCSTAT_BUMP(arcstat_l2_writes_sent); |
3a17a7a9 | 5033 | ARCSTAT_INCR(arcstat_l2_write_bytes, write_asize); |
34dc7c2f | 5034 | ARCSTAT_INCR(arcstat_l2_size, write_sz); |
3a17a7a9 SK |
5035 | ARCSTAT_INCR(arcstat_l2_asize, write_asize); |
5036 | vdev_space_update(dev->l2ad_vdev, write_psize, 0, 0); | |
34dc7c2f BB |
5037 | |
5038 | /* | |
5039 | * Bump device hand to the device start if it is approaching the end. | |
5040 | * l2arc_evict() will already have evicted ahead for this case. | |
5041 | */ | |
b128c09f | 5042 | if (dev->l2ad_hand >= (dev->l2ad_end - target_sz)) { |
428870ff BB |
5043 | vdev_space_update(dev->l2ad_vdev, |
5044 | dev->l2ad_end - dev->l2ad_hand, 0, 0); | |
34dc7c2f BB |
5045 | dev->l2ad_hand = dev->l2ad_start; |
5046 | dev->l2ad_evict = dev->l2ad_start; | |
5047 | dev->l2ad_first = B_FALSE; | |
5048 | } | |
5049 | ||
d164b209 | 5050 | dev->l2ad_writing = B_TRUE; |
34dc7c2f | 5051 | (void) zio_wait(pio); |
d164b209 BB |
5052 | dev->l2ad_writing = B_FALSE; |
5053 | ||
3a17a7a9 SK |
5054 | return (write_asize); |
5055 | } | |
5056 | ||
5057 | /* | |
5058 | * Compresses an L2ARC buffer. | |
5059 | * The data to be compressed must be prefilled in l2hdr->b_tmp_cdata and its | |
5060 | * size in l2hdr->b_asize. This routine tries to compress the data and | |
5061 | * depending on the compression result there are three possible outcomes: | |
5062 | * *) The buffer was incompressible. The original l2hdr contents were left | |
5063 | * untouched and are ready for writing to an L2 device. | |
5064 | * *) The buffer was all-zeros, so there is no need to write it to an L2 | |
5065 | * device. To indicate this situation b_tmp_cdata is NULL'ed, b_asize is | |
5066 | * set to zero and b_compress is set to ZIO_COMPRESS_EMPTY. | |
5067 | * *) Compression succeeded and b_tmp_cdata was replaced with a temporary | |
5068 | * data buffer which holds the compressed data to be written, and b_asize | |
5069 | * tells us how much data there is. b_compress is set to the appropriate | |
5070 | * compression algorithm. Once writing is done, invoke | |
5071 | * l2arc_release_cdata_buf on this l2hdr to free this temporary buffer. | |
5072 | * | |
5073 | * Returns B_TRUE if compression succeeded, or B_FALSE if it didn't (the | |
5074 | * buffer was incompressible). | |
5075 | */ | |
5076 | static boolean_t | |
5077 | l2arc_compress_buf(l2arc_buf_hdr_t *l2hdr) | |
5078 | { | |
5079 | void *cdata; | |
5080 | size_t csize, len; | |
5081 | ||
5082 | ASSERT(l2hdr->b_compress == ZIO_COMPRESS_OFF); | |
5083 | ASSERT(l2hdr->b_tmp_cdata != NULL); | |
5084 | ||
5085 | len = l2hdr->b_asize; | |
5086 | cdata = zio_data_buf_alloc(len); | |
5087 | csize = zio_compress_data(ZIO_COMPRESS_LZ4, l2hdr->b_tmp_cdata, | |
5088 | cdata, l2hdr->b_asize); | |
5089 | ||
5090 | if (csize == 0) { | |
5091 | /* zero block, indicate that there's nothing to write */ | |
5092 | zio_data_buf_free(cdata, len); | |
5093 | l2hdr->b_compress = ZIO_COMPRESS_EMPTY; | |
5094 | l2hdr->b_asize = 0; | |
5095 | l2hdr->b_tmp_cdata = NULL; | |
5096 | ARCSTAT_BUMP(arcstat_l2_compress_zeros); | |
5097 | return (B_TRUE); | |
5098 | } else if (csize > 0 && csize < len) { | |
5099 | /* | |
5100 | * Compression succeeded, we'll keep the cdata around for | |
5101 | * writing and release it afterwards. | |
5102 | */ | |
5103 | l2hdr->b_compress = ZIO_COMPRESS_LZ4; | |
5104 | l2hdr->b_asize = csize; | |
5105 | l2hdr->b_tmp_cdata = cdata; | |
5106 | ARCSTAT_BUMP(arcstat_l2_compress_successes); | |
5107 | return (B_TRUE); | |
5108 | } else { | |
5109 | /* | |
5110 | * Compression failed, release the compressed buffer. | |
5111 | * l2hdr will be left unmodified. | |
5112 | */ | |
5113 | zio_data_buf_free(cdata, len); | |
5114 | ARCSTAT_BUMP(arcstat_l2_compress_failures); | |
5115 | return (B_FALSE); | |
5116 | } | |
5117 | } | |
5118 | ||
5119 | /* | |
5120 | * Decompresses a zio read back from an l2arc device. On success, the | |
5121 | * underlying zio's io_data buffer is overwritten by the uncompressed | |
5122 | * version. On decompression error (corrupt compressed stream), the | |
5123 | * zio->io_error value is set to signal an I/O error. | |
5124 | * | |
5125 | * Please note that the compressed data stream is not checksummed, so | |
5126 | * if the underlying device is experiencing data corruption, we may feed | |
5127 | * corrupt data to the decompressor, so the decompressor needs to be | |
5128 | * able to handle this situation (LZ4 does). | |
5129 | */ | |
5130 | static void | |
5131 | l2arc_decompress_zio(zio_t *zio, arc_buf_hdr_t *hdr, enum zio_compress c) | |
5132 | { | |
5133 | uint64_t csize; | |
5134 | void *cdata; | |
5135 | ||
5136 | ASSERT(L2ARC_IS_VALID_COMPRESS(c)); | |
5137 | ||
5138 | if (zio->io_error != 0) { | |
5139 | /* | |
5140 | * An io error has occured, just restore the original io | |
5141 | * size in preparation for a main pool read. | |
5142 | */ | |
5143 | zio->io_orig_size = zio->io_size = hdr->b_size; | |
5144 | return; | |
5145 | } | |
5146 | ||
5147 | if (c == ZIO_COMPRESS_EMPTY) { | |
5148 | /* | |
5149 | * An empty buffer results in a null zio, which means we | |
5150 | * need to fill its io_data after we're done restoring the | |
5151 | * buffer's contents. | |
5152 | */ | |
5153 | ASSERT(hdr->b_buf != NULL); | |
5154 | bzero(hdr->b_buf->b_data, hdr->b_size); | |
5155 | zio->io_data = zio->io_orig_data = hdr->b_buf->b_data; | |
5156 | } else { | |
5157 | ASSERT(zio->io_data != NULL); | |
5158 | /* | |
5159 | * We copy the compressed data from the start of the arc buffer | |
5160 | * (the zio_read will have pulled in only what we need, the | |
5161 | * rest is garbage which we will overwrite at decompression) | |
5162 | * and then decompress back to the ARC data buffer. This way we | |
5163 | * can minimize copying by simply decompressing back over the | |
5164 | * original compressed data (rather than decompressing to an | |
5165 | * aux buffer and then copying back the uncompressed buffer, | |
5166 | * which is likely to be much larger). | |
5167 | */ | |
5168 | csize = zio->io_size; | |
5169 | cdata = zio_data_buf_alloc(csize); | |
5170 | bcopy(zio->io_data, cdata, csize); | |
5171 | if (zio_decompress_data(c, cdata, zio->io_data, csize, | |
5172 | hdr->b_size) != 0) | |
2e528b49 | 5173 | zio->io_error = SET_ERROR(EIO); |
3a17a7a9 SK |
5174 | zio_data_buf_free(cdata, csize); |
5175 | } | |
5176 | ||
5177 | /* Restore the expected uncompressed IO size. */ | |
5178 | zio->io_orig_size = zio->io_size = hdr->b_size; | |
5179 | } | |
5180 | ||
5181 | /* | |
5182 | * Releases the temporary b_tmp_cdata buffer in an l2arc header structure. | |
5183 | * This buffer serves as a temporary holder of compressed data while | |
5184 | * the buffer entry is being written to an l2arc device. Once that is | |
5185 | * done, we can dispose of it. | |
5186 | */ | |
5187 | static void | |
5188 | l2arc_release_cdata_buf(arc_buf_hdr_t *ab) | |
5189 | { | |
5190 | l2arc_buf_hdr_t *l2hdr = ab->b_l2hdr; | |
5191 | ||
5192 | if (l2hdr->b_compress == ZIO_COMPRESS_LZ4) { | |
5193 | /* | |
5194 | * If the data was compressed, then we've allocated a | |
5195 | * temporary buffer for it, so now we need to release it. | |
5196 | */ | |
5197 | ASSERT(l2hdr->b_tmp_cdata != NULL); | |
5198 | zio_data_buf_free(l2hdr->b_tmp_cdata, ab->b_size); | |
5199 | } | |
5200 | l2hdr->b_tmp_cdata = NULL; | |
34dc7c2f BB |
5201 | } |
5202 | ||
5203 | /* | |
5204 | * This thread feeds the L2ARC at regular intervals. This is the beating | |
5205 | * heart of the L2ARC. | |
5206 | */ | |
5207 | static void | |
5208 | l2arc_feed_thread(void) | |
5209 | { | |
5210 | callb_cpr_t cpr; | |
5211 | l2arc_dev_t *dev; | |
5212 | spa_t *spa; | |
d164b209 | 5213 | uint64_t size, wrote; |
428870ff | 5214 | clock_t begin, next = ddi_get_lbolt(); |
3a17a7a9 | 5215 | boolean_t headroom_boost = B_FALSE; |
34dc7c2f BB |
5216 | |
5217 | CALLB_CPR_INIT(&cpr, &l2arc_feed_thr_lock, callb_generic_cpr, FTAG); | |
5218 | ||
5219 | mutex_enter(&l2arc_feed_thr_lock); | |
5220 | ||
5221 | while (l2arc_thread_exit == 0) { | |
34dc7c2f | 5222 | CALLB_CPR_SAFE_BEGIN(&cpr); |
5b63b3eb BB |
5223 | (void) cv_timedwait_interruptible(&l2arc_feed_thr_cv, |
5224 | &l2arc_feed_thr_lock, next); | |
34dc7c2f | 5225 | CALLB_CPR_SAFE_END(&cpr, &l2arc_feed_thr_lock); |
428870ff | 5226 | next = ddi_get_lbolt() + hz; |
34dc7c2f BB |
5227 | |
5228 | /* | |
b128c09f | 5229 | * Quick check for L2ARC devices. |
34dc7c2f BB |
5230 | */ |
5231 | mutex_enter(&l2arc_dev_mtx); | |
5232 | if (l2arc_ndev == 0) { | |
5233 | mutex_exit(&l2arc_dev_mtx); | |
5234 | continue; | |
5235 | } | |
b128c09f | 5236 | mutex_exit(&l2arc_dev_mtx); |
428870ff | 5237 | begin = ddi_get_lbolt(); |
34dc7c2f BB |
5238 | |
5239 | /* | |
b128c09f BB |
5240 | * This selects the next l2arc device to write to, and in |
5241 | * doing so the next spa to feed from: dev->l2ad_spa. This | |
5242 | * will return NULL if there are now no l2arc devices or if | |
5243 | * they are all faulted. | |
5244 | * | |
5245 | * If a device is returned, its spa's config lock is also | |
5246 | * held to prevent device removal. l2arc_dev_get_next() | |
5247 | * will grab and release l2arc_dev_mtx. | |
34dc7c2f | 5248 | */ |
b128c09f | 5249 | if ((dev = l2arc_dev_get_next()) == NULL) |
34dc7c2f | 5250 | continue; |
b128c09f BB |
5251 | |
5252 | spa = dev->l2ad_spa; | |
5253 | ASSERT(spa != NULL); | |
34dc7c2f | 5254 | |
572e2857 BB |
5255 | /* |
5256 | * If the pool is read-only then force the feed thread to | |
5257 | * sleep a little longer. | |
5258 | */ | |
5259 | if (!spa_writeable(spa)) { | |
5260 | next = ddi_get_lbolt() + 5 * l2arc_feed_secs * hz; | |
5261 | spa_config_exit(spa, SCL_L2ARC, dev); | |
5262 | continue; | |
5263 | } | |
5264 | ||
34dc7c2f | 5265 | /* |
b128c09f | 5266 | * Avoid contributing to memory pressure. |
34dc7c2f | 5267 | */ |
302f753f | 5268 | if (arc_no_grow) { |
b128c09f BB |
5269 | ARCSTAT_BUMP(arcstat_l2_abort_lowmem); |
5270 | spa_config_exit(spa, SCL_L2ARC, dev); | |
34dc7c2f BB |
5271 | continue; |
5272 | } | |
b128c09f | 5273 | |
34dc7c2f BB |
5274 | ARCSTAT_BUMP(arcstat_l2_feeds); |
5275 | ||
3a17a7a9 | 5276 | size = l2arc_write_size(); |
b128c09f | 5277 | |
34dc7c2f BB |
5278 | /* |
5279 | * Evict L2ARC buffers that will be overwritten. | |
5280 | */ | |
b128c09f | 5281 | l2arc_evict(dev, size, B_FALSE); |
34dc7c2f BB |
5282 | |
5283 | /* | |
5284 | * Write ARC buffers. | |
5285 | */ | |
3a17a7a9 | 5286 | wrote = l2arc_write_buffers(spa, dev, size, &headroom_boost); |
d164b209 BB |
5287 | |
5288 | /* | |
5289 | * Calculate interval between writes. | |
5290 | */ | |
5291 | next = l2arc_write_interval(begin, size, wrote); | |
b128c09f | 5292 | spa_config_exit(spa, SCL_L2ARC, dev); |
34dc7c2f BB |
5293 | } |
5294 | ||
5295 | l2arc_thread_exit = 0; | |
5296 | cv_broadcast(&l2arc_feed_thr_cv); | |
5297 | CALLB_CPR_EXIT(&cpr); /* drops l2arc_feed_thr_lock */ | |
5298 | thread_exit(); | |
5299 | } | |
5300 | ||
b128c09f BB |
5301 | boolean_t |
5302 | l2arc_vdev_present(vdev_t *vd) | |
5303 | { | |
5304 | l2arc_dev_t *dev; | |
5305 | ||
5306 | mutex_enter(&l2arc_dev_mtx); | |
5307 | for (dev = list_head(l2arc_dev_list); dev != NULL; | |
5308 | dev = list_next(l2arc_dev_list, dev)) { | |
5309 | if (dev->l2ad_vdev == vd) | |
5310 | break; | |
5311 | } | |
5312 | mutex_exit(&l2arc_dev_mtx); | |
5313 | ||
5314 | return (dev != NULL); | |
5315 | } | |
5316 | ||
34dc7c2f BB |
5317 | /* |
5318 | * Add a vdev for use by the L2ARC. By this point the spa has already | |
5319 | * validated the vdev and opened it. | |
5320 | */ | |
5321 | void | |
9babb374 | 5322 | l2arc_add_vdev(spa_t *spa, vdev_t *vd) |
34dc7c2f BB |
5323 | { |
5324 | l2arc_dev_t *adddev; | |
5325 | ||
b128c09f BB |
5326 | ASSERT(!l2arc_vdev_present(vd)); |
5327 | ||
34dc7c2f BB |
5328 | /* |
5329 | * Create a new l2arc device entry. | |
5330 | */ | |
5331 | adddev = kmem_zalloc(sizeof (l2arc_dev_t), KM_SLEEP); | |
5332 | adddev->l2ad_spa = spa; | |
5333 | adddev->l2ad_vdev = vd; | |
9babb374 BB |
5334 | adddev->l2ad_start = VDEV_LABEL_START_SIZE; |
5335 | adddev->l2ad_end = VDEV_LABEL_START_SIZE + vdev_get_min_asize(vd); | |
34dc7c2f BB |
5336 | adddev->l2ad_hand = adddev->l2ad_start; |
5337 | adddev->l2ad_evict = adddev->l2ad_start; | |
5338 | adddev->l2ad_first = B_TRUE; | |
d164b209 | 5339 | adddev->l2ad_writing = B_FALSE; |
98f72a53 | 5340 | list_link_init(&adddev->l2ad_node); |
34dc7c2f BB |
5341 | |
5342 | /* | |
5343 | * This is a list of all ARC buffers that are still valid on the | |
5344 | * device. | |
5345 | */ | |
5346 | adddev->l2ad_buflist = kmem_zalloc(sizeof (list_t), KM_SLEEP); | |
5347 | list_create(adddev->l2ad_buflist, sizeof (arc_buf_hdr_t), | |
5348 | offsetof(arc_buf_hdr_t, b_l2node)); | |
5349 | ||
428870ff | 5350 | vdev_space_update(vd, 0, 0, adddev->l2ad_end - adddev->l2ad_hand); |
34dc7c2f BB |
5351 | |
5352 | /* | |
5353 | * Add device to global list | |
5354 | */ | |
5355 | mutex_enter(&l2arc_dev_mtx); | |
5356 | list_insert_head(l2arc_dev_list, adddev); | |
5357 | atomic_inc_64(&l2arc_ndev); | |
5358 | mutex_exit(&l2arc_dev_mtx); | |
5359 | } | |
5360 | ||
5361 | /* | |
5362 | * Remove a vdev from the L2ARC. | |
5363 | */ | |
5364 | void | |
5365 | l2arc_remove_vdev(vdev_t *vd) | |
5366 | { | |
5367 | l2arc_dev_t *dev, *nextdev, *remdev = NULL; | |
5368 | ||
34dc7c2f BB |
5369 | /* |
5370 | * Find the device by vdev | |
5371 | */ | |
5372 | mutex_enter(&l2arc_dev_mtx); | |
5373 | for (dev = list_head(l2arc_dev_list); dev; dev = nextdev) { | |
5374 | nextdev = list_next(l2arc_dev_list, dev); | |
5375 | if (vd == dev->l2ad_vdev) { | |
5376 | remdev = dev; | |
5377 | break; | |
5378 | } | |
5379 | } | |
5380 | ASSERT(remdev != NULL); | |
5381 | ||
5382 | /* | |
5383 | * Remove device from global list | |
5384 | */ | |
5385 | list_remove(l2arc_dev_list, remdev); | |
5386 | l2arc_dev_last = NULL; /* may have been invalidated */ | |
b128c09f BB |
5387 | atomic_dec_64(&l2arc_ndev); |
5388 | mutex_exit(&l2arc_dev_mtx); | |
34dc7c2f BB |
5389 | |
5390 | /* | |
5391 | * Clear all buflists and ARC references. L2ARC device flush. | |
5392 | */ | |
5393 | l2arc_evict(remdev, 0, B_TRUE); | |
5394 | list_destroy(remdev->l2ad_buflist); | |
5395 | kmem_free(remdev->l2ad_buflist, sizeof (list_t)); | |
5396 | kmem_free(remdev, sizeof (l2arc_dev_t)); | |
34dc7c2f BB |
5397 | } |
5398 | ||
5399 | void | |
b128c09f | 5400 | l2arc_init(void) |
34dc7c2f BB |
5401 | { |
5402 | l2arc_thread_exit = 0; | |
5403 | l2arc_ndev = 0; | |
5404 | l2arc_writes_sent = 0; | |
5405 | l2arc_writes_done = 0; | |
5406 | ||
5407 | mutex_init(&l2arc_feed_thr_lock, NULL, MUTEX_DEFAULT, NULL); | |
5408 | cv_init(&l2arc_feed_thr_cv, NULL, CV_DEFAULT, NULL); | |
5409 | mutex_init(&l2arc_dev_mtx, NULL, MUTEX_DEFAULT, NULL); | |
5410 | mutex_init(&l2arc_buflist_mtx, NULL, MUTEX_DEFAULT, NULL); | |
5411 | mutex_init(&l2arc_free_on_write_mtx, NULL, MUTEX_DEFAULT, NULL); | |
5412 | ||
5413 | l2arc_dev_list = &L2ARC_dev_list; | |
5414 | l2arc_free_on_write = &L2ARC_free_on_write; | |
5415 | list_create(l2arc_dev_list, sizeof (l2arc_dev_t), | |
5416 | offsetof(l2arc_dev_t, l2ad_node)); | |
5417 | list_create(l2arc_free_on_write, sizeof (l2arc_data_free_t), | |
5418 | offsetof(l2arc_data_free_t, l2df_list_node)); | |
34dc7c2f BB |
5419 | } |
5420 | ||
5421 | void | |
b128c09f | 5422 | l2arc_fini(void) |
34dc7c2f | 5423 | { |
b128c09f BB |
5424 | /* |
5425 | * This is called from dmu_fini(), which is called from spa_fini(); | |
5426 | * Because of this, we can assume that all l2arc devices have | |
5427 | * already been removed when the pools themselves were removed. | |
5428 | */ | |
5429 | ||
5430 | l2arc_do_free_on_write(); | |
34dc7c2f BB |
5431 | |
5432 | mutex_destroy(&l2arc_feed_thr_lock); | |
5433 | cv_destroy(&l2arc_feed_thr_cv); | |
5434 | mutex_destroy(&l2arc_dev_mtx); | |
5435 | mutex_destroy(&l2arc_buflist_mtx); | |
5436 | mutex_destroy(&l2arc_free_on_write_mtx); | |
5437 | ||
5438 | list_destroy(l2arc_dev_list); | |
5439 | list_destroy(l2arc_free_on_write); | |
5440 | } | |
b128c09f BB |
5441 | |
5442 | void | |
5443 | l2arc_start(void) | |
5444 | { | |
fb5f0bc8 | 5445 | if (!(spa_mode_global & FWRITE)) |
b128c09f BB |
5446 | return; |
5447 | ||
5448 | (void) thread_create(NULL, 0, l2arc_feed_thread, NULL, 0, &p0, | |
5449 | TS_RUN, minclsyspri); | |
5450 | } | |
5451 | ||
5452 | void | |
5453 | l2arc_stop(void) | |
5454 | { | |
fb5f0bc8 | 5455 | if (!(spa_mode_global & FWRITE)) |
b128c09f BB |
5456 | return; |
5457 | ||
5458 | mutex_enter(&l2arc_feed_thr_lock); | |
5459 | cv_signal(&l2arc_feed_thr_cv); /* kick thread out of startup */ | |
5460 | l2arc_thread_exit = 1; | |
5461 | while (l2arc_thread_exit != 0) | |
5462 | cv_wait(&l2arc_feed_thr_cv, &l2arc_feed_thr_lock); | |
5463 | mutex_exit(&l2arc_feed_thr_lock); | |
5464 | } | |
c28b2279 BB |
5465 | |
5466 | #if defined(_KERNEL) && defined(HAVE_SPL) | |
5467 | EXPORT_SYMBOL(arc_read); | |
5468 | EXPORT_SYMBOL(arc_buf_remove_ref); | |
e0b0ca98 | 5469 | EXPORT_SYMBOL(arc_buf_info); |
c28b2279 | 5470 | EXPORT_SYMBOL(arc_getbuf_func); |
ab26409d BB |
5471 | EXPORT_SYMBOL(arc_add_prune_callback); |
5472 | EXPORT_SYMBOL(arc_remove_prune_callback); | |
c28b2279 | 5473 | |
bce45ec9 | 5474 | module_param(zfs_arc_min, ulong, 0644); |
c409e464 | 5475 | MODULE_PARM_DESC(zfs_arc_min, "Min arc size"); |
c28b2279 | 5476 | |
bce45ec9 | 5477 | module_param(zfs_arc_max, ulong, 0644); |
c409e464 | 5478 | MODULE_PARM_DESC(zfs_arc_max, "Max arc size"); |
c28b2279 | 5479 | |
bce45ec9 | 5480 | module_param(zfs_arc_meta_limit, ulong, 0644); |
c28b2279 | 5481 | MODULE_PARM_DESC(zfs_arc_meta_limit, "Meta limit for arc size"); |
6a8f9b6b | 5482 | |
bce45ec9 | 5483 | module_param(zfs_arc_meta_prune, int, 0644); |
ab26409d | 5484 | MODULE_PARM_DESC(zfs_arc_meta_prune, "Bytes of meta data to prune"); |
c409e464 | 5485 | |
bce45ec9 | 5486 | module_param(zfs_arc_grow_retry, int, 0644); |
c409e464 BB |
5487 | MODULE_PARM_DESC(zfs_arc_grow_retry, "Seconds before growing arc size"); |
5488 | ||
bce45ec9 | 5489 | module_param(zfs_arc_shrink_shift, int, 0644); |
c409e464 BB |
5490 | MODULE_PARM_DESC(zfs_arc_shrink_shift, "log2(fraction of arc to reclaim)"); |
5491 | ||
bce45ec9 | 5492 | module_param(zfs_arc_p_min_shift, int, 0644); |
c409e464 BB |
5493 | MODULE_PARM_DESC(zfs_arc_p_min_shift, "arc_c shift to calc min/max arc_p"); |
5494 | ||
1f7c30df BB |
5495 | module_param(zfs_disable_dup_eviction, int, 0644); |
5496 | MODULE_PARM_DESC(zfs_disable_dup_eviction, "disable duplicate buffer eviction"); | |
5497 | ||
0c5493d4 BB |
5498 | module_param(zfs_arc_memory_throttle_disable, int, 0644); |
5499 | MODULE_PARM_DESC(zfs_arc_memory_throttle_disable, "disable memory throttle"); | |
5500 | ||
bce45ec9 BB |
5501 | module_param(zfs_arc_min_prefetch_lifespan, int, 0644); |
5502 | MODULE_PARM_DESC(zfs_arc_min_prefetch_lifespan, "Min life of prefetch block"); | |
5503 | ||
5504 | module_param(l2arc_write_max, ulong, 0644); | |
abd8610c BB |
5505 | MODULE_PARM_DESC(l2arc_write_max, "Max write bytes per interval"); |
5506 | ||
bce45ec9 | 5507 | module_param(l2arc_write_boost, ulong, 0644); |
abd8610c BB |
5508 | MODULE_PARM_DESC(l2arc_write_boost, "Extra write bytes during device warmup"); |
5509 | ||
bce45ec9 | 5510 | module_param(l2arc_headroom, ulong, 0644); |
abd8610c BB |
5511 | MODULE_PARM_DESC(l2arc_headroom, "Number of max device writes to precache"); |
5512 | ||
3a17a7a9 SK |
5513 | module_param(l2arc_headroom_boost, ulong, 0644); |
5514 | MODULE_PARM_DESC(l2arc_headroom_boost, "Compressed l2arc_headroom multiplier"); | |
5515 | ||
bce45ec9 | 5516 | module_param(l2arc_feed_secs, ulong, 0644); |
abd8610c BB |
5517 | MODULE_PARM_DESC(l2arc_feed_secs, "Seconds between L2ARC writing"); |
5518 | ||
bce45ec9 | 5519 | module_param(l2arc_feed_min_ms, ulong, 0644); |
abd8610c BB |
5520 | MODULE_PARM_DESC(l2arc_feed_min_ms, "Min feed interval in milliseconds"); |
5521 | ||
bce45ec9 | 5522 | module_param(l2arc_noprefetch, int, 0644); |
abd8610c BB |
5523 | MODULE_PARM_DESC(l2arc_noprefetch, "Skip caching prefetched buffers"); |
5524 | ||
3a17a7a9 SK |
5525 | module_param(l2arc_nocompress, int, 0644); |
5526 | MODULE_PARM_DESC(l2arc_nocompress, "Skip compressing L2ARC buffers"); | |
5527 | ||
bce45ec9 | 5528 | module_param(l2arc_feed_again, int, 0644); |
abd8610c BB |
5529 | MODULE_PARM_DESC(l2arc_feed_again, "Turbo L2ARC warmup"); |
5530 | ||
bce45ec9 | 5531 | module_param(l2arc_norw, int, 0644); |
abd8610c BB |
5532 | MODULE_PARM_DESC(l2arc_norw, "No reads during writes"); |
5533 | ||
c28b2279 | 5534 | #endif |