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Commit | Line | Data |
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1da177e4 | 1 | /* |
1da177e4 LT |
2 | * CFQ, or complete fairness queueing, disk scheduler. |
3 | * | |
4 | * Based on ideas from a previously unfinished io | |
5 | * scheduler (round robin per-process disk scheduling) and Andrea Arcangeli. | |
6 | * | |
0fe23479 | 7 | * Copyright (C) 2003 Jens Axboe <axboe@kernel.dk> |
1da177e4 | 8 | */ |
1da177e4 | 9 | #include <linux/module.h> |
5a0e3ad6 | 10 | #include <linux/slab.h> |
1cc9be68 AV |
11 | #include <linux/blkdev.h> |
12 | #include <linux/elevator.h> | |
ad5ebd2f | 13 | #include <linux/jiffies.h> |
1da177e4 | 14 | #include <linux/rbtree.h> |
22e2c507 | 15 | #include <linux/ioprio.h> |
7b679138 | 16 | #include <linux/blktrace_api.h> |
eea8f41c | 17 | #include <linux/blk-cgroup.h> |
6e736be7 | 18 | #include "blk.h" |
1da177e4 LT |
19 | |
20 | /* | |
21 | * tunables | |
22 | */ | |
fe094d98 | 23 | /* max queue in one round of service */ |
abc3c744 | 24 | static const int cfq_quantum = 8; |
64100099 | 25 | static const int cfq_fifo_expire[2] = { HZ / 4, HZ / 8 }; |
fe094d98 JA |
26 | /* maximum backwards seek, in KiB */ |
27 | static const int cfq_back_max = 16 * 1024; | |
28 | /* penalty of a backwards seek */ | |
29 | static const int cfq_back_penalty = 2; | |
64100099 | 30 | static const int cfq_slice_sync = HZ / 10; |
3b18152c | 31 | static int cfq_slice_async = HZ / 25; |
64100099 | 32 | static const int cfq_slice_async_rq = 2; |
caaa5f9f | 33 | static int cfq_slice_idle = HZ / 125; |
80bdf0c7 | 34 | static int cfq_group_idle = HZ / 125; |
5db5d642 CZ |
35 | static const int cfq_target_latency = HZ * 3/10; /* 300 ms */ |
36 | static const int cfq_hist_divisor = 4; | |
22e2c507 | 37 | |
d9e7620e | 38 | /* |
0871714e | 39 | * offset from end of service tree |
d9e7620e | 40 | */ |
0871714e | 41 | #define CFQ_IDLE_DELAY (HZ / 5) |
d9e7620e JA |
42 | |
43 | /* | |
44 | * below this threshold, we consider thinktime immediate | |
45 | */ | |
46 | #define CFQ_MIN_TT (2) | |
47 | ||
22e2c507 | 48 | #define CFQ_SLICE_SCALE (5) |
45333d5a | 49 | #define CFQ_HW_QUEUE_MIN (5) |
25bc6b07 | 50 | #define CFQ_SERVICE_SHIFT 12 |
22e2c507 | 51 | |
3dde36dd | 52 | #define CFQQ_SEEK_THR (sector_t)(8 * 100) |
e9ce335d | 53 | #define CFQQ_CLOSE_THR (sector_t)(8 * 1024) |
41647e7a | 54 | #define CFQQ_SECT_THR_NONROT (sector_t)(2 * 32) |
3dde36dd | 55 | #define CFQQ_SEEKY(cfqq) (hweight32(cfqq->seek_history) > 32/8) |
ae54abed | 56 | |
a612fddf TH |
57 | #define RQ_CIC(rq) icq_to_cic((rq)->elv.icq) |
58 | #define RQ_CFQQ(rq) (struct cfq_queue *) ((rq)->elv.priv[0]) | |
59 | #define RQ_CFQG(rq) (struct cfq_group *) ((rq)->elv.priv[1]) | |
1da177e4 | 60 | |
e18b890b | 61 | static struct kmem_cache *cfq_pool; |
1da177e4 | 62 | |
22e2c507 JA |
63 | #define CFQ_PRIO_LISTS IOPRIO_BE_NR |
64 | #define cfq_class_idle(cfqq) ((cfqq)->ioprio_class == IOPRIO_CLASS_IDLE) | |
22e2c507 JA |
65 | #define cfq_class_rt(cfqq) ((cfqq)->ioprio_class == IOPRIO_CLASS_RT) |
66 | ||
206dc69b | 67 | #define sample_valid(samples) ((samples) > 80) |
1fa8f6d6 | 68 | #define rb_entry_cfqg(node) rb_entry((node), struct cfq_group, rb_node) |
206dc69b | 69 | |
e48453c3 AA |
70 | /* blkio-related constants */ |
71 | #define CFQ_WEIGHT_MIN 10 | |
72 | #define CFQ_WEIGHT_MAX 1000 | |
73 | #define CFQ_WEIGHT_DEFAULT 500 | |
74 | ||
c5869807 TH |
75 | struct cfq_ttime { |
76 | unsigned long last_end_request; | |
77 | ||
78 | unsigned long ttime_total; | |
79 | unsigned long ttime_samples; | |
80 | unsigned long ttime_mean; | |
81 | }; | |
82 | ||
cc09e299 JA |
83 | /* |
84 | * Most of our rbtree usage is for sorting with min extraction, so | |
85 | * if we cache the leftmost node we don't have to walk down the tree | |
86 | * to find it. Idea borrowed from Ingo Molnars CFS scheduler. We should | |
87 | * move this into the elevator for the rq sorting as well. | |
88 | */ | |
89 | struct cfq_rb_root { | |
90 | struct rb_root rb; | |
91 | struct rb_node *left; | |
aa6f6a3d | 92 | unsigned count; |
1fa8f6d6 | 93 | u64 min_vdisktime; |
f5f2b6ce | 94 | struct cfq_ttime ttime; |
cc09e299 | 95 | }; |
f5f2b6ce SL |
96 | #define CFQ_RB_ROOT (struct cfq_rb_root) { .rb = RB_ROOT, \ |
97 | .ttime = {.last_end_request = jiffies,},} | |
cc09e299 | 98 | |
6118b70b JA |
99 | /* |
100 | * Per process-grouping structure | |
101 | */ | |
102 | struct cfq_queue { | |
103 | /* reference count */ | |
30d7b944 | 104 | int ref; |
6118b70b JA |
105 | /* various state flags, see below */ |
106 | unsigned int flags; | |
107 | /* parent cfq_data */ | |
108 | struct cfq_data *cfqd; | |
109 | /* service_tree member */ | |
110 | struct rb_node rb_node; | |
111 | /* service_tree key */ | |
112 | unsigned long rb_key; | |
113 | /* prio tree member */ | |
114 | struct rb_node p_node; | |
115 | /* prio tree root we belong to, if any */ | |
116 | struct rb_root *p_root; | |
117 | /* sorted list of pending requests */ | |
118 | struct rb_root sort_list; | |
119 | /* if fifo isn't expired, next request to serve */ | |
120 | struct request *next_rq; | |
121 | /* requests queued in sort_list */ | |
122 | int queued[2]; | |
123 | /* currently allocated requests */ | |
124 | int allocated[2]; | |
125 | /* fifo list of requests in sort_list */ | |
126 | struct list_head fifo; | |
127 | ||
dae739eb VG |
128 | /* time when queue got scheduled in to dispatch first request. */ |
129 | unsigned long dispatch_start; | |
f75edf2d | 130 | unsigned int allocated_slice; |
c4081ba5 | 131 | unsigned int slice_dispatch; |
dae739eb VG |
132 | /* time when first request from queue completed and slice started. */ |
133 | unsigned long slice_start; | |
6118b70b JA |
134 | unsigned long slice_end; |
135 | long slice_resid; | |
6118b70b | 136 | |
65299a3b CH |
137 | /* pending priority requests */ |
138 | int prio_pending; | |
6118b70b JA |
139 | /* number of requests that are on the dispatch list or inside driver */ |
140 | int dispatched; | |
141 | ||
142 | /* io prio of this group */ | |
143 | unsigned short ioprio, org_ioprio; | |
4aede84b | 144 | unsigned short ioprio_class; |
6118b70b | 145 | |
c4081ba5 RK |
146 | pid_t pid; |
147 | ||
3dde36dd | 148 | u32 seek_history; |
b2c18e1e JM |
149 | sector_t last_request_pos; |
150 | ||
aa6f6a3d | 151 | struct cfq_rb_root *service_tree; |
df5fe3e8 | 152 | struct cfq_queue *new_cfqq; |
cdb16e8f | 153 | struct cfq_group *cfqg; |
c4e7893e VG |
154 | /* Number of sectors dispatched from queue in single dispatch round */ |
155 | unsigned long nr_sectors; | |
6118b70b JA |
156 | }; |
157 | ||
c0324a02 | 158 | /* |
718eee05 | 159 | * First index in the service_trees. |
c0324a02 CZ |
160 | * IDLE is handled separately, so it has negative index |
161 | */ | |
3bf10fea | 162 | enum wl_class_t { |
c0324a02 | 163 | BE_WORKLOAD = 0, |
615f0259 VG |
164 | RT_WORKLOAD = 1, |
165 | IDLE_WORKLOAD = 2, | |
b4627321 | 166 | CFQ_PRIO_NR, |
c0324a02 CZ |
167 | }; |
168 | ||
718eee05 CZ |
169 | /* |
170 | * Second index in the service_trees. | |
171 | */ | |
172 | enum wl_type_t { | |
173 | ASYNC_WORKLOAD = 0, | |
174 | SYNC_NOIDLE_WORKLOAD = 1, | |
175 | SYNC_WORKLOAD = 2 | |
176 | }; | |
177 | ||
155fead9 TH |
178 | struct cfqg_stats { |
179 | #ifdef CONFIG_CFQ_GROUP_IOSCHED | |
155fead9 TH |
180 | /* number of ios merged */ |
181 | struct blkg_rwstat merged; | |
182 | /* total time spent on device in ns, may not be accurate w/ queueing */ | |
183 | struct blkg_rwstat service_time; | |
184 | /* total time spent waiting in scheduler queue in ns */ | |
185 | struct blkg_rwstat wait_time; | |
186 | /* number of IOs queued up */ | |
187 | struct blkg_rwstat queued; | |
155fead9 TH |
188 | /* total disk time and nr sectors dispatched by this group */ |
189 | struct blkg_stat time; | |
190 | #ifdef CONFIG_DEBUG_BLK_CGROUP | |
191 | /* time not charged to this cgroup */ | |
192 | struct blkg_stat unaccounted_time; | |
193 | /* sum of number of ios queued across all samples */ | |
194 | struct blkg_stat avg_queue_size_sum; | |
195 | /* count of samples taken for average */ | |
196 | struct blkg_stat avg_queue_size_samples; | |
197 | /* how many times this group has been removed from service tree */ | |
198 | struct blkg_stat dequeue; | |
199 | /* total time spent waiting for it to be assigned a timeslice. */ | |
200 | struct blkg_stat group_wait_time; | |
3c798398 | 201 | /* time spent idling for this blkcg_gq */ |
155fead9 TH |
202 | struct blkg_stat idle_time; |
203 | /* total time with empty current active q with other requests queued */ | |
204 | struct blkg_stat empty_time; | |
205 | /* fields after this shouldn't be cleared on stat reset */ | |
206 | uint64_t start_group_wait_time; | |
207 | uint64_t start_idle_time; | |
208 | uint64_t start_empty_time; | |
209 | uint16_t flags; | |
210 | #endif /* CONFIG_DEBUG_BLK_CGROUP */ | |
211 | #endif /* CONFIG_CFQ_GROUP_IOSCHED */ | |
212 | }; | |
213 | ||
e48453c3 AA |
214 | /* Per-cgroup data */ |
215 | struct cfq_group_data { | |
216 | /* must be the first member */ | |
81437648 | 217 | struct blkcg_policy_data cpd; |
e48453c3 AA |
218 | |
219 | unsigned int weight; | |
220 | unsigned int leaf_weight; | |
221 | }; | |
222 | ||
cdb16e8f VG |
223 | /* This is per cgroup per device grouping structure */ |
224 | struct cfq_group { | |
f95a04af TH |
225 | /* must be the first member */ |
226 | struct blkg_policy_data pd; | |
227 | ||
1fa8f6d6 VG |
228 | /* group service_tree member */ |
229 | struct rb_node rb_node; | |
230 | ||
231 | /* group service_tree key */ | |
232 | u64 vdisktime; | |
e71357e1 | 233 | |
7918ffb5 TH |
234 | /* |
235 | * The number of active cfqgs and sum of their weights under this | |
236 | * cfqg. This covers this cfqg's leaf_weight and all children's | |
237 | * weights, but does not cover weights of further descendants. | |
238 | * | |
239 | * If a cfqg is on the service tree, it's active. An active cfqg | |
240 | * also activates its parent and contributes to the children_weight | |
241 | * of the parent. | |
242 | */ | |
243 | int nr_active; | |
244 | unsigned int children_weight; | |
245 | ||
1d3650f7 TH |
246 | /* |
247 | * vfraction is the fraction of vdisktime that the tasks in this | |
248 | * cfqg are entitled to. This is determined by compounding the | |
249 | * ratios walking up from this cfqg to the root. | |
250 | * | |
251 | * It is in fixed point w/ CFQ_SERVICE_SHIFT and the sum of all | |
252 | * vfractions on a service tree is approximately 1. The sum may | |
253 | * deviate a bit due to rounding errors and fluctuations caused by | |
254 | * cfqgs entering and leaving the service tree. | |
255 | */ | |
256 | unsigned int vfraction; | |
257 | ||
e71357e1 TH |
258 | /* |
259 | * There are two weights - (internal) weight is the weight of this | |
260 | * cfqg against the sibling cfqgs. leaf_weight is the wight of | |
261 | * this cfqg against the child cfqgs. For the root cfqg, both | |
262 | * weights are kept in sync for backward compatibility. | |
263 | */ | |
25bc6b07 | 264 | unsigned int weight; |
8184f93e | 265 | unsigned int new_weight; |
3381cb8d | 266 | unsigned int dev_weight; |
1fa8f6d6 | 267 | |
e71357e1 TH |
268 | unsigned int leaf_weight; |
269 | unsigned int new_leaf_weight; | |
270 | unsigned int dev_leaf_weight; | |
271 | ||
1fa8f6d6 VG |
272 | /* number of cfqq currently on this group */ |
273 | int nr_cfqq; | |
274 | ||
cdb16e8f | 275 | /* |
4495a7d4 | 276 | * Per group busy queues average. Useful for workload slice calc. We |
b4627321 VG |
277 | * create the array for each prio class but at run time it is used |
278 | * only for RT and BE class and slot for IDLE class remains unused. | |
279 | * This is primarily done to avoid confusion and a gcc warning. | |
280 | */ | |
281 | unsigned int busy_queues_avg[CFQ_PRIO_NR]; | |
282 | /* | |
283 | * rr lists of queues with requests. We maintain service trees for | |
284 | * RT and BE classes. These trees are subdivided in subclasses | |
285 | * of SYNC, SYNC_NOIDLE and ASYNC based on workload type. For IDLE | |
286 | * class there is no subclassification and all the cfq queues go on | |
287 | * a single tree service_tree_idle. | |
cdb16e8f VG |
288 | * Counts are embedded in the cfq_rb_root |
289 | */ | |
290 | struct cfq_rb_root service_trees[2][3]; | |
291 | struct cfq_rb_root service_tree_idle; | |
dae739eb | 292 | |
4d2ceea4 VG |
293 | unsigned long saved_wl_slice; |
294 | enum wl_type_t saved_wl_type; | |
295 | enum wl_class_t saved_wl_class; | |
4eef3049 | 296 | |
80bdf0c7 VG |
297 | /* number of requests that are on the dispatch list or inside driver */ |
298 | int dispatched; | |
7700fc4f | 299 | struct cfq_ttime ttime; |
0b39920b | 300 | struct cfqg_stats stats; /* stats for this cfqg */ |
60a83707 TH |
301 | |
302 | /* async queue for each priority case */ | |
303 | struct cfq_queue *async_cfqq[2][IOPRIO_BE_NR]; | |
304 | struct cfq_queue *async_idle_cfqq; | |
305 | ||
cdb16e8f | 306 | }; |
718eee05 | 307 | |
c5869807 TH |
308 | struct cfq_io_cq { |
309 | struct io_cq icq; /* must be the first member */ | |
310 | struct cfq_queue *cfqq[2]; | |
311 | struct cfq_ttime ttime; | |
598971bf TH |
312 | int ioprio; /* the current ioprio */ |
313 | #ifdef CONFIG_CFQ_GROUP_IOSCHED | |
f4da8072 | 314 | uint64_t blkcg_serial_nr; /* the current blkcg serial */ |
598971bf | 315 | #endif |
c5869807 TH |
316 | }; |
317 | ||
22e2c507 JA |
318 | /* |
319 | * Per block device queue structure | |
320 | */ | |
1da177e4 | 321 | struct cfq_data { |
165125e1 | 322 | struct request_queue *queue; |
1fa8f6d6 VG |
323 | /* Root service tree for cfq_groups */ |
324 | struct cfq_rb_root grp_service_tree; | |
f51b802c | 325 | struct cfq_group *root_group; |
22e2c507 | 326 | |
c0324a02 CZ |
327 | /* |
328 | * The priority currently being served | |
22e2c507 | 329 | */ |
4d2ceea4 VG |
330 | enum wl_class_t serving_wl_class; |
331 | enum wl_type_t serving_wl_type; | |
718eee05 | 332 | unsigned long workload_expires; |
cdb16e8f | 333 | struct cfq_group *serving_group; |
a36e71f9 JA |
334 | |
335 | /* | |
336 | * Each priority tree is sorted by next_request position. These | |
337 | * trees are used when determining if two or more queues are | |
338 | * interleaving requests (see cfq_close_cooperator). | |
339 | */ | |
340 | struct rb_root prio_trees[CFQ_PRIO_LISTS]; | |
341 | ||
22e2c507 | 342 | unsigned int busy_queues; |
ef8a41df | 343 | unsigned int busy_sync_queues; |
22e2c507 | 344 | |
53c583d2 CZ |
345 | int rq_in_driver; |
346 | int rq_in_flight[2]; | |
45333d5a AC |
347 | |
348 | /* | |
349 | * queue-depth detection | |
350 | */ | |
351 | int rq_queued; | |
25776e35 | 352 | int hw_tag; |
e459dd08 CZ |
353 | /* |
354 | * hw_tag can be | |
355 | * -1 => indeterminate, (cfq will behave as if NCQ is present, to allow better detection) | |
356 | * 1 => NCQ is present (hw_tag_est_depth is the estimated max depth) | |
357 | * 0 => no NCQ | |
358 | */ | |
359 | int hw_tag_est_depth; | |
360 | unsigned int hw_tag_samples; | |
1da177e4 | 361 | |
22e2c507 JA |
362 | /* |
363 | * idle window management | |
364 | */ | |
365 | struct timer_list idle_slice_timer; | |
23e018a1 | 366 | struct work_struct unplug_work; |
1da177e4 | 367 | |
22e2c507 | 368 | struct cfq_queue *active_queue; |
c5869807 | 369 | struct cfq_io_cq *active_cic; |
22e2c507 | 370 | |
6d048f53 | 371 | sector_t last_position; |
1da177e4 | 372 | |
1da177e4 LT |
373 | /* |
374 | * tunables, see top of file | |
375 | */ | |
376 | unsigned int cfq_quantum; | |
22e2c507 | 377 | unsigned int cfq_fifo_expire[2]; |
1da177e4 LT |
378 | unsigned int cfq_back_penalty; |
379 | unsigned int cfq_back_max; | |
22e2c507 JA |
380 | unsigned int cfq_slice[2]; |
381 | unsigned int cfq_slice_async_rq; | |
382 | unsigned int cfq_slice_idle; | |
80bdf0c7 | 383 | unsigned int cfq_group_idle; |
963b72fc | 384 | unsigned int cfq_latency; |
5bf14c07 | 385 | unsigned int cfq_target_latency; |
d9ff4187 | 386 | |
6118b70b JA |
387 | /* |
388 | * Fallback dummy cfqq for extreme OOM conditions | |
389 | */ | |
390 | struct cfq_queue oom_cfqq; | |
365722bb | 391 | |
573412b2 | 392 | unsigned long last_delayed_sync; |
1da177e4 LT |
393 | }; |
394 | ||
25fb5169 | 395 | static struct cfq_group *cfq_get_next_cfqg(struct cfq_data *cfqd); |
60a83707 | 396 | static void cfq_put_queue(struct cfq_queue *cfqq); |
25fb5169 | 397 | |
34b98d03 | 398 | static struct cfq_rb_root *st_for(struct cfq_group *cfqg, |
3bf10fea | 399 | enum wl_class_t class, |
65b32a57 | 400 | enum wl_type_t type) |
c0324a02 | 401 | { |
1fa8f6d6 VG |
402 | if (!cfqg) |
403 | return NULL; | |
404 | ||
3bf10fea | 405 | if (class == IDLE_WORKLOAD) |
cdb16e8f | 406 | return &cfqg->service_tree_idle; |
c0324a02 | 407 | |
3bf10fea | 408 | return &cfqg->service_trees[class][type]; |
c0324a02 CZ |
409 | } |
410 | ||
3b18152c | 411 | enum cfqq_state_flags { |
b0b8d749 JA |
412 | CFQ_CFQQ_FLAG_on_rr = 0, /* on round-robin busy list */ |
413 | CFQ_CFQQ_FLAG_wait_request, /* waiting for a request */ | |
b029195d | 414 | CFQ_CFQQ_FLAG_must_dispatch, /* must be allowed a dispatch */ |
b0b8d749 | 415 | CFQ_CFQQ_FLAG_must_alloc_slice, /* per-slice must_alloc flag */ |
b0b8d749 JA |
416 | CFQ_CFQQ_FLAG_fifo_expire, /* FIFO checked in this slice */ |
417 | CFQ_CFQQ_FLAG_idle_window, /* slice idling enabled */ | |
418 | CFQ_CFQQ_FLAG_prio_changed, /* task priority has changed */ | |
44f7c160 | 419 | CFQ_CFQQ_FLAG_slice_new, /* no requests dispatched in slice */ |
91fac317 | 420 | CFQ_CFQQ_FLAG_sync, /* synchronous queue */ |
b3b6d040 | 421 | CFQ_CFQQ_FLAG_coop, /* cfqq is shared */ |
ae54abed | 422 | CFQ_CFQQ_FLAG_split_coop, /* shared cfqq will be splitted */ |
76280aff | 423 | CFQ_CFQQ_FLAG_deep, /* sync cfqq experienced large depth */ |
f75edf2d | 424 | CFQ_CFQQ_FLAG_wait_busy, /* Waiting for next request */ |
3b18152c JA |
425 | }; |
426 | ||
427 | #define CFQ_CFQQ_FNS(name) \ | |
428 | static inline void cfq_mark_cfqq_##name(struct cfq_queue *cfqq) \ | |
429 | { \ | |
fe094d98 | 430 | (cfqq)->flags |= (1 << CFQ_CFQQ_FLAG_##name); \ |
3b18152c JA |
431 | } \ |
432 | static inline void cfq_clear_cfqq_##name(struct cfq_queue *cfqq) \ | |
433 | { \ | |
fe094d98 | 434 | (cfqq)->flags &= ~(1 << CFQ_CFQQ_FLAG_##name); \ |
3b18152c JA |
435 | } \ |
436 | static inline int cfq_cfqq_##name(const struct cfq_queue *cfqq) \ | |
437 | { \ | |
fe094d98 | 438 | return ((cfqq)->flags & (1 << CFQ_CFQQ_FLAG_##name)) != 0; \ |
3b18152c JA |
439 | } |
440 | ||
441 | CFQ_CFQQ_FNS(on_rr); | |
442 | CFQ_CFQQ_FNS(wait_request); | |
b029195d | 443 | CFQ_CFQQ_FNS(must_dispatch); |
3b18152c | 444 | CFQ_CFQQ_FNS(must_alloc_slice); |
3b18152c JA |
445 | CFQ_CFQQ_FNS(fifo_expire); |
446 | CFQ_CFQQ_FNS(idle_window); | |
447 | CFQ_CFQQ_FNS(prio_changed); | |
44f7c160 | 448 | CFQ_CFQQ_FNS(slice_new); |
91fac317 | 449 | CFQ_CFQQ_FNS(sync); |
a36e71f9 | 450 | CFQ_CFQQ_FNS(coop); |
ae54abed | 451 | CFQ_CFQQ_FNS(split_coop); |
76280aff | 452 | CFQ_CFQQ_FNS(deep); |
f75edf2d | 453 | CFQ_CFQQ_FNS(wait_busy); |
3b18152c JA |
454 | #undef CFQ_CFQQ_FNS |
455 | ||
629ed0b1 | 456 | #if defined(CONFIG_CFQ_GROUP_IOSCHED) && defined(CONFIG_DEBUG_BLK_CGROUP) |
2ce4d50f | 457 | |
155fead9 TH |
458 | /* cfqg stats flags */ |
459 | enum cfqg_stats_flags { | |
460 | CFQG_stats_waiting = 0, | |
461 | CFQG_stats_idling, | |
462 | CFQG_stats_empty, | |
629ed0b1 TH |
463 | }; |
464 | ||
155fead9 TH |
465 | #define CFQG_FLAG_FNS(name) \ |
466 | static inline void cfqg_stats_mark_##name(struct cfqg_stats *stats) \ | |
629ed0b1 | 467 | { \ |
155fead9 | 468 | stats->flags |= (1 << CFQG_stats_##name); \ |
629ed0b1 | 469 | } \ |
155fead9 | 470 | static inline void cfqg_stats_clear_##name(struct cfqg_stats *stats) \ |
629ed0b1 | 471 | { \ |
155fead9 | 472 | stats->flags &= ~(1 << CFQG_stats_##name); \ |
629ed0b1 | 473 | } \ |
155fead9 | 474 | static inline int cfqg_stats_##name(struct cfqg_stats *stats) \ |
629ed0b1 | 475 | { \ |
155fead9 | 476 | return (stats->flags & (1 << CFQG_stats_##name)) != 0; \ |
629ed0b1 TH |
477 | } \ |
478 | ||
155fead9 TH |
479 | CFQG_FLAG_FNS(waiting) |
480 | CFQG_FLAG_FNS(idling) | |
481 | CFQG_FLAG_FNS(empty) | |
482 | #undef CFQG_FLAG_FNS | |
629ed0b1 TH |
483 | |
484 | /* This should be called with the queue_lock held. */ | |
155fead9 | 485 | static void cfqg_stats_update_group_wait_time(struct cfqg_stats *stats) |
629ed0b1 TH |
486 | { |
487 | unsigned long long now; | |
488 | ||
155fead9 | 489 | if (!cfqg_stats_waiting(stats)) |
629ed0b1 TH |
490 | return; |
491 | ||
492 | now = sched_clock(); | |
493 | if (time_after64(now, stats->start_group_wait_time)) | |
494 | blkg_stat_add(&stats->group_wait_time, | |
495 | now - stats->start_group_wait_time); | |
155fead9 | 496 | cfqg_stats_clear_waiting(stats); |
629ed0b1 TH |
497 | } |
498 | ||
499 | /* This should be called with the queue_lock held. */ | |
155fead9 TH |
500 | static void cfqg_stats_set_start_group_wait_time(struct cfq_group *cfqg, |
501 | struct cfq_group *curr_cfqg) | |
629ed0b1 | 502 | { |
155fead9 | 503 | struct cfqg_stats *stats = &cfqg->stats; |
629ed0b1 | 504 | |
155fead9 | 505 | if (cfqg_stats_waiting(stats)) |
629ed0b1 | 506 | return; |
155fead9 | 507 | if (cfqg == curr_cfqg) |
629ed0b1 | 508 | return; |
155fead9 TH |
509 | stats->start_group_wait_time = sched_clock(); |
510 | cfqg_stats_mark_waiting(stats); | |
629ed0b1 TH |
511 | } |
512 | ||
513 | /* This should be called with the queue_lock held. */ | |
155fead9 | 514 | static void cfqg_stats_end_empty_time(struct cfqg_stats *stats) |
629ed0b1 TH |
515 | { |
516 | unsigned long long now; | |
517 | ||
155fead9 | 518 | if (!cfqg_stats_empty(stats)) |
629ed0b1 TH |
519 | return; |
520 | ||
521 | now = sched_clock(); | |
522 | if (time_after64(now, stats->start_empty_time)) | |
523 | blkg_stat_add(&stats->empty_time, | |
524 | now - stats->start_empty_time); | |
155fead9 | 525 | cfqg_stats_clear_empty(stats); |
629ed0b1 TH |
526 | } |
527 | ||
155fead9 | 528 | static void cfqg_stats_update_dequeue(struct cfq_group *cfqg) |
629ed0b1 | 529 | { |
155fead9 | 530 | blkg_stat_add(&cfqg->stats.dequeue, 1); |
629ed0b1 TH |
531 | } |
532 | ||
155fead9 | 533 | static void cfqg_stats_set_start_empty_time(struct cfq_group *cfqg) |
629ed0b1 | 534 | { |
155fead9 | 535 | struct cfqg_stats *stats = &cfqg->stats; |
629ed0b1 | 536 | |
4d5e80a7 | 537 | if (blkg_rwstat_total(&stats->queued)) |
629ed0b1 TH |
538 | return; |
539 | ||
540 | /* | |
541 | * group is already marked empty. This can happen if cfqq got new | |
542 | * request in parent group and moved to this group while being added | |
543 | * to service tree. Just ignore the event and move on. | |
544 | */ | |
155fead9 | 545 | if (cfqg_stats_empty(stats)) |
629ed0b1 TH |
546 | return; |
547 | ||
548 | stats->start_empty_time = sched_clock(); | |
155fead9 | 549 | cfqg_stats_mark_empty(stats); |
629ed0b1 TH |
550 | } |
551 | ||
155fead9 | 552 | static void cfqg_stats_update_idle_time(struct cfq_group *cfqg) |
629ed0b1 | 553 | { |
155fead9 | 554 | struct cfqg_stats *stats = &cfqg->stats; |
629ed0b1 | 555 | |
155fead9 | 556 | if (cfqg_stats_idling(stats)) { |
629ed0b1 TH |
557 | unsigned long long now = sched_clock(); |
558 | ||
559 | if (time_after64(now, stats->start_idle_time)) | |
560 | blkg_stat_add(&stats->idle_time, | |
561 | now - stats->start_idle_time); | |
155fead9 | 562 | cfqg_stats_clear_idling(stats); |
629ed0b1 TH |
563 | } |
564 | } | |
565 | ||
155fead9 | 566 | static void cfqg_stats_set_start_idle_time(struct cfq_group *cfqg) |
629ed0b1 | 567 | { |
155fead9 | 568 | struct cfqg_stats *stats = &cfqg->stats; |
629ed0b1 | 569 | |
155fead9 | 570 | BUG_ON(cfqg_stats_idling(stats)); |
629ed0b1 TH |
571 | |
572 | stats->start_idle_time = sched_clock(); | |
155fead9 | 573 | cfqg_stats_mark_idling(stats); |
629ed0b1 TH |
574 | } |
575 | ||
155fead9 | 576 | static void cfqg_stats_update_avg_queue_size(struct cfq_group *cfqg) |
629ed0b1 | 577 | { |
155fead9 | 578 | struct cfqg_stats *stats = &cfqg->stats; |
629ed0b1 TH |
579 | |
580 | blkg_stat_add(&stats->avg_queue_size_sum, | |
4d5e80a7 | 581 | blkg_rwstat_total(&stats->queued)); |
629ed0b1 | 582 | blkg_stat_add(&stats->avg_queue_size_samples, 1); |
155fead9 | 583 | cfqg_stats_update_group_wait_time(stats); |
629ed0b1 TH |
584 | } |
585 | ||
586 | #else /* CONFIG_CFQ_GROUP_IOSCHED && CONFIG_DEBUG_BLK_CGROUP */ | |
587 | ||
f48ec1d7 TH |
588 | static inline void cfqg_stats_set_start_group_wait_time(struct cfq_group *cfqg, struct cfq_group *curr_cfqg) { } |
589 | static inline void cfqg_stats_end_empty_time(struct cfqg_stats *stats) { } | |
590 | static inline void cfqg_stats_update_dequeue(struct cfq_group *cfqg) { } | |
591 | static inline void cfqg_stats_set_start_empty_time(struct cfq_group *cfqg) { } | |
592 | static inline void cfqg_stats_update_idle_time(struct cfq_group *cfqg) { } | |
593 | static inline void cfqg_stats_set_start_idle_time(struct cfq_group *cfqg) { } | |
594 | static inline void cfqg_stats_update_avg_queue_size(struct cfq_group *cfqg) { } | |
629ed0b1 TH |
595 | |
596 | #endif /* CONFIG_CFQ_GROUP_IOSCHED && CONFIG_DEBUG_BLK_CGROUP */ | |
597 | ||
598 | #ifdef CONFIG_CFQ_GROUP_IOSCHED | |
2ce4d50f | 599 | |
4ceab71b JA |
600 | static inline struct cfq_group *pd_to_cfqg(struct blkg_policy_data *pd) |
601 | { | |
602 | return pd ? container_of(pd, struct cfq_group, pd) : NULL; | |
603 | } | |
604 | ||
605 | static struct cfq_group_data | |
606 | *cpd_to_cfqgd(struct blkcg_policy_data *cpd) | |
607 | { | |
81437648 | 608 | return cpd ? container_of(cpd, struct cfq_group_data, cpd) : NULL; |
4ceab71b JA |
609 | } |
610 | ||
611 | static inline struct blkcg_gq *cfqg_to_blkg(struct cfq_group *cfqg) | |
612 | { | |
613 | return pd_to_blkg(&cfqg->pd); | |
614 | } | |
615 | ||
ffea73fc TH |
616 | static struct blkcg_policy blkcg_policy_cfq; |
617 | ||
618 | static inline struct cfq_group *blkg_to_cfqg(struct blkcg_gq *blkg) | |
619 | { | |
620 | return pd_to_cfqg(blkg_to_pd(blkg, &blkcg_policy_cfq)); | |
621 | } | |
622 | ||
e48453c3 AA |
623 | static struct cfq_group_data *blkcg_to_cfqgd(struct blkcg *blkcg) |
624 | { | |
625 | return cpd_to_cfqgd(blkcg_to_cpd(blkcg, &blkcg_policy_cfq)); | |
626 | } | |
627 | ||
d02f7aa8 | 628 | static inline struct cfq_group *cfqg_parent(struct cfq_group *cfqg) |
7918ffb5 | 629 | { |
d02f7aa8 | 630 | struct blkcg_gq *pblkg = cfqg_to_blkg(cfqg)->parent; |
7918ffb5 | 631 | |
d02f7aa8 | 632 | return pblkg ? blkg_to_cfqg(pblkg) : NULL; |
7918ffb5 TH |
633 | } |
634 | ||
eb7d8c07 TH |
635 | static inline void cfqg_get(struct cfq_group *cfqg) |
636 | { | |
637 | return blkg_get(cfqg_to_blkg(cfqg)); | |
638 | } | |
639 | ||
640 | static inline void cfqg_put(struct cfq_group *cfqg) | |
641 | { | |
642 | return blkg_put(cfqg_to_blkg(cfqg)); | |
643 | } | |
644 | ||
54e7ed12 TH |
645 | #define cfq_log_cfqq(cfqd, cfqq, fmt, args...) do { \ |
646 | char __pbuf[128]; \ | |
647 | \ | |
648 | blkg_path(cfqg_to_blkg((cfqq)->cfqg), __pbuf, sizeof(__pbuf)); \ | |
b226e5c4 VG |
649 | blk_add_trace_msg((cfqd)->queue, "cfq%d%c%c %s " fmt, (cfqq)->pid, \ |
650 | cfq_cfqq_sync((cfqq)) ? 'S' : 'A', \ | |
651 | cfqq_type((cfqq)) == SYNC_NOIDLE_WORKLOAD ? 'N' : ' ',\ | |
54e7ed12 TH |
652 | __pbuf, ##args); \ |
653 | } while (0) | |
654 | ||
655 | #define cfq_log_cfqg(cfqd, cfqg, fmt, args...) do { \ | |
656 | char __pbuf[128]; \ | |
657 | \ | |
658 | blkg_path(cfqg_to_blkg(cfqg), __pbuf, sizeof(__pbuf)); \ | |
659 | blk_add_trace_msg((cfqd)->queue, "%s " fmt, __pbuf, ##args); \ | |
660 | } while (0) | |
2868ef7b | 661 | |
155fead9 TH |
662 | static inline void cfqg_stats_update_io_add(struct cfq_group *cfqg, |
663 | struct cfq_group *curr_cfqg, int rw) | |
2ce4d50f | 664 | { |
155fead9 TH |
665 | blkg_rwstat_add(&cfqg->stats.queued, rw, 1); |
666 | cfqg_stats_end_empty_time(&cfqg->stats); | |
667 | cfqg_stats_set_start_group_wait_time(cfqg, curr_cfqg); | |
2ce4d50f TH |
668 | } |
669 | ||
155fead9 TH |
670 | static inline void cfqg_stats_update_timeslice_used(struct cfq_group *cfqg, |
671 | unsigned long time, unsigned long unaccounted_time) | |
2ce4d50f | 672 | { |
155fead9 | 673 | blkg_stat_add(&cfqg->stats.time, time); |
629ed0b1 | 674 | #ifdef CONFIG_DEBUG_BLK_CGROUP |
155fead9 | 675 | blkg_stat_add(&cfqg->stats.unaccounted_time, unaccounted_time); |
629ed0b1 | 676 | #endif |
2ce4d50f TH |
677 | } |
678 | ||
155fead9 | 679 | static inline void cfqg_stats_update_io_remove(struct cfq_group *cfqg, int rw) |
2ce4d50f | 680 | { |
155fead9 | 681 | blkg_rwstat_add(&cfqg->stats.queued, rw, -1); |
2ce4d50f TH |
682 | } |
683 | ||
155fead9 | 684 | static inline void cfqg_stats_update_io_merged(struct cfq_group *cfqg, int rw) |
2ce4d50f | 685 | { |
155fead9 | 686 | blkg_rwstat_add(&cfqg->stats.merged, rw, 1); |
2ce4d50f TH |
687 | } |
688 | ||
155fead9 TH |
689 | static inline void cfqg_stats_update_completion(struct cfq_group *cfqg, |
690 | uint64_t start_time, uint64_t io_start_time, int rw) | |
2ce4d50f | 691 | { |
155fead9 | 692 | struct cfqg_stats *stats = &cfqg->stats; |
629ed0b1 | 693 | unsigned long long now = sched_clock(); |
629ed0b1 TH |
694 | |
695 | if (time_after64(now, io_start_time)) | |
696 | blkg_rwstat_add(&stats->service_time, rw, now - io_start_time); | |
697 | if (time_after64(io_start_time, start_time)) | |
698 | blkg_rwstat_add(&stats->wait_time, rw, | |
699 | io_start_time - start_time); | |
2ce4d50f TH |
700 | } |
701 | ||
689665af TH |
702 | /* @stats = 0 */ |
703 | static void cfqg_stats_reset(struct cfqg_stats *stats) | |
155fead9 | 704 | { |
155fead9 | 705 | /* queued stats shouldn't be cleared */ |
155fead9 TH |
706 | blkg_rwstat_reset(&stats->merged); |
707 | blkg_rwstat_reset(&stats->service_time); | |
708 | blkg_rwstat_reset(&stats->wait_time); | |
709 | blkg_stat_reset(&stats->time); | |
710 | #ifdef CONFIG_DEBUG_BLK_CGROUP | |
711 | blkg_stat_reset(&stats->unaccounted_time); | |
712 | blkg_stat_reset(&stats->avg_queue_size_sum); | |
713 | blkg_stat_reset(&stats->avg_queue_size_samples); | |
714 | blkg_stat_reset(&stats->dequeue); | |
715 | blkg_stat_reset(&stats->group_wait_time); | |
716 | blkg_stat_reset(&stats->idle_time); | |
717 | blkg_stat_reset(&stats->empty_time); | |
718 | #endif | |
719 | } | |
720 | ||
0b39920b | 721 | /* @to += @from */ |
e6269c44 | 722 | static void cfqg_stats_add_aux(struct cfqg_stats *to, struct cfqg_stats *from) |
0b39920b TH |
723 | { |
724 | /* queued stats shouldn't be cleared */ | |
e6269c44 TH |
725 | blkg_rwstat_add_aux(&to->merged, &from->merged); |
726 | blkg_rwstat_add_aux(&to->service_time, &from->service_time); | |
727 | blkg_rwstat_add_aux(&to->wait_time, &from->wait_time); | |
728 | blkg_stat_add_aux(&from->time, &from->time); | |
0b39920b | 729 | #ifdef CONFIG_DEBUG_BLK_CGROUP |
e6269c44 TH |
730 | blkg_stat_add_aux(&to->unaccounted_time, &from->unaccounted_time); |
731 | blkg_stat_add_aux(&to->avg_queue_size_sum, &from->avg_queue_size_sum); | |
732 | blkg_stat_add_aux(&to->avg_queue_size_samples, &from->avg_queue_size_samples); | |
733 | blkg_stat_add_aux(&to->dequeue, &from->dequeue); | |
734 | blkg_stat_add_aux(&to->group_wait_time, &from->group_wait_time); | |
735 | blkg_stat_add_aux(&to->idle_time, &from->idle_time); | |
736 | blkg_stat_add_aux(&to->empty_time, &from->empty_time); | |
0b39920b TH |
737 | #endif |
738 | } | |
739 | ||
740 | /* | |
e6269c44 | 741 | * Transfer @cfqg's stats to its parent's aux counts so that the ancestors' |
0b39920b TH |
742 | * recursive stats can still account for the amount used by this cfqg after |
743 | * it's gone. | |
744 | */ | |
745 | static void cfqg_stats_xfer_dead(struct cfq_group *cfqg) | |
746 | { | |
747 | struct cfq_group *parent = cfqg_parent(cfqg); | |
748 | ||
749 | lockdep_assert_held(cfqg_to_blkg(cfqg)->q->queue_lock); | |
750 | ||
751 | if (unlikely(!parent)) | |
752 | return; | |
753 | ||
e6269c44 | 754 | cfqg_stats_add_aux(&parent->stats, &cfqg->stats); |
0b39920b | 755 | cfqg_stats_reset(&cfqg->stats); |
0b39920b TH |
756 | } |
757 | ||
eb7d8c07 TH |
758 | #else /* CONFIG_CFQ_GROUP_IOSCHED */ |
759 | ||
d02f7aa8 | 760 | static inline struct cfq_group *cfqg_parent(struct cfq_group *cfqg) { return NULL; } |
eb7d8c07 TH |
761 | static inline void cfqg_get(struct cfq_group *cfqg) { } |
762 | static inline void cfqg_put(struct cfq_group *cfqg) { } | |
763 | ||
7b679138 | 764 | #define cfq_log_cfqq(cfqd, cfqq, fmt, args...) \ |
b226e5c4 VG |
765 | blk_add_trace_msg((cfqd)->queue, "cfq%d%c%c " fmt, (cfqq)->pid, \ |
766 | cfq_cfqq_sync((cfqq)) ? 'S' : 'A', \ | |
767 | cfqq_type((cfqq)) == SYNC_NOIDLE_WORKLOAD ? 'N' : ' ',\ | |
768 | ##args) | |
4495a7d4 | 769 | #define cfq_log_cfqg(cfqd, cfqg, fmt, args...) do {} while (0) |
eb7d8c07 | 770 | |
155fead9 TH |
771 | static inline void cfqg_stats_update_io_add(struct cfq_group *cfqg, |
772 | struct cfq_group *curr_cfqg, int rw) { } | |
773 | static inline void cfqg_stats_update_timeslice_used(struct cfq_group *cfqg, | |
774 | unsigned long time, unsigned long unaccounted_time) { } | |
775 | static inline void cfqg_stats_update_io_remove(struct cfq_group *cfqg, int rw) { } | |
776 | static inline void cfqg_stats_update_io_merged(struct cfq_group *cfqg, int rw) { } | |
155fead9 TH |
777 | static inline void cfqg_stats_update_completion(struct cfq_group *cfqg, |
778 | uint64_t start_time, uint64_t io_start_time, int rw) { } | |
2ce4d50f | 779 | |
eb7d8c07 TH |
780 | #endif /* CONFIG_CFQ_GROUP_IOSCHED */ |
781 | ||
7b679138 JA |
782 | #define cfq_log(cfqd, fmt, args...) \ |
783 | blk_add_trace_msg((cfqd)->queue, "cfq " fmt, ##args) | |
784 | ||
615f0259 VG |
785 | /* Traverses through cfq group service trees */ |
786 | #define for_each_cfqg_st(cfqg, i, j, st) \ | |
787 | for (i = 0; i <= IDLE_WORKLOAD; i++) \ | |
788 | for (j = 0, st = i < IDLE_WORKLOAD ? &cfqg->service_trees[i][j]\ | |
789 | : &cfqg->service_tree_idle; \ | |
790 | (i < IDLE_WORKLOAD && j <= SYNC_WORKLOAD) || \ | |
791 | (i == IDLE_WORKLOAD && j == 0); \ | |
792 | j++, st = i < IDLE_WORKLOAD ? \ | |
793 | &cfqg->service_trees[i][j]: NULL) \ | |
794 | ||
f5f2b6ce SL |
795 | static inline bool cfq_io_thinktime_big(struct cfq_data *cfqd, |
796 | struct cfq_ttime *ttime, bool group_idle) | |
797 | { | |
798 | unsigned long slice; | |
799 | if (!sample_valid(ttime->ttime_samples)) | |
800 | return false; | |
801 | if (group_idle) | |
802 | slice = cfqd->cfq_group_idle; | |
803 | else | |
804 | slice = cfqd->cfq_slice_idle; | |
805 | return ttime->ttime_mean > slice; | |
806 | } | |
615f0259 | 807 | |
02b35081 VG |
808 | static inline bool iops_mode(struct cfq_data *cfqd) |
809 | { | |
810 | /* | |
811 | * If we are not idling on queues and it is a NCQ drive, parallel | |
812 | * execution of requests is on and measuring time is not possible | |
813 | * in most of the cases until and unless we drive shallower queue | |
814 | * depths and that becomes a performance bottleneck. In such cases | |
815 | * switch to start providing fairness in terms of number of IOs. | |
816 | */ | |
817 | if (!cfqd->cfq_slice_idle && cfqd->hw_tag) | |
818 | return true; | |
819 | else | |
820 | return false; | |
821 | } | |
822 | ||
3bf10fea | 823 | static inline enum wl_class_t cfqq_class(struct cfq_queue *cfqq) |
c0324a02 CZ |
824 | { |
825 | if (cfq_class_idle(cfqq)) | |
826 | return IDLE_WORKLOAD; | |
827 | if (cfq_class_rt(cfqq)) | |
828 | return RT_WORKLOAD; | |
829 | return BE_WORKLOAD; | |
830 | } | |
831 | ||
718eee05 CZ |
832 | |
833 | static enum wl_type_t cfqq_type(struct cfq_queue *cfqq) | |
834 | { | |
835 | if (!cfq_cfqq_sync(cfqq)) | |
836 | return ASYNC_WORKLOAD; | |
837 | if (!cfq_cfqq_idle_window(cfqq)) | |
838 | return SYNC_NOIDLE_WORKLOAD; | |
839 | return SYNC_WORKLOAD; | |
840 | } | |
841 | ||
3bf10fea | 842 | static inline int cfq_group_busy_queues_wl(enum wl_class_t wl_class, |
58ff82f3 VG |
843 | struct cfq_data *cfqd, |
844 | struct cfq_group *cfqg) | |
c0324a02 | 845 | { |
3bf10fea | 846 | if (wl_class == IDLE_WORKLOAD) |
cdb16e8f | 847 | return cfqg->service_tree_idle.count; |
c0324a02 | 848 | |
34b98d03 VG |
849 | return cfqg->service_trees[wl_class][ASYNC_WORKLOAD].count + |
850 | cfqg->service_trees[wl_class][SYNC_NOIDLE_WORKLOAD].count + | |
851 | cfqg->service_trees[wl_class][SYNC_WORKLOAD].count; | |
c0324a02 CZ |
852 | } |
853 | ||
f26bd1f0 VG |
854 | static inline int cfqg_busy_async_queues(struct cfq_data *cfqd, |
855 | struct cfq_group *cfqg) | |
856 | { | |
34b98d03 VG |
857 | return cfqg->service_trees[RT_WORKLOAD][ASYNC_WORKLOAD].count + |
858 | cfqg->service_trees[BE_WORKLOAD][ASYNC_WORKLOAD].count; | |
f26bd1f0 VG |
859 | } |
860 | ||
165125e1 | 861 | static void cfq_dispatch_insert(struct request_queue *, struct request *); |
4f85cb96 | 862 | static struct cfq_queue *cfq_get_queue(struct cfq_data *cfqd, bool is_sync, |
2da8de0b | 863 | struct cfq_io_cq *cic, struct bio *bio); |
91fac317 | 864 | |
c5869807 TH |
865 | static inline struct cfq_io_cq *icq_to_cic(struct io_cq *icq) |
866 | { | |
867 | /* cic->icq is the first member, %NULL will convert to %NULL */ | |
868 | return container_of(icq, struct cfq_io_cq, icq); | |
869 | } | |
870 | ||
47fdd4ca TH |
871 | static inline struct cfq_io_cq *cfq_cic_lookup(struct cfq_data *cfqd, |
872 | struct io_context *ioc) | |
873 | { | |
874 | if (ioc) | |
875 | return icq_to_cic(ioc_lookup_icq(ioc, cfqd->queue)); | |
876 | return NULL; | |
877 | } | |
878 | ||
c5869807 | 879 | static inline struct cfq_queue *cic_to_cfqq(struct cfq_io_cq *cic, bool is_sync) |
91fac317 | 880 | { |
a6151c3a | 881 | return cic->cfqq[is_sync]; |
91fac317 VT |
882 | } |
883 | ||
c5869807 TH |
884 | static inline void cic_set_cfqq(struct cfq_io_cq *cic, struct cfq_queue *cfqq, |
885 | bool is_sync) | |
91fac317 | 886 | { |
a6151c3a | 887 | cic->cfqq[is_sync] = cfqq; |
91fac317 VT |
888 | } |
889 | ||
c5869807 | 890 | static inline struct cfq_data *cic_to_cfqd(struct cfq_io_cq *cic) |
bca4b914 | 891 | { |
c5869807 | 892 | return cic->icq.q->elevator->elevator_data; |
bca4b914 KK |
893 | } |
894 | ||
91fac317 VT |
895 | /* |
896 | * We regard a request as SYNC, if it's either a read or has the SYNC bit | |
897 | * set (in which case it could also be direct WRITE). | |
898 | */ | |
a6151c3a | 899 | static inline bool cfq_bio_sync(struct bio *bio) |
91fac317 | 900 | { |
7b6d91da | 901 | return bio_data_dir(bio) == READ || (bio->bi_rw & REQ_SYNC); |
91fac317 | 902 | } |
1da177e4 | 903 | |
99f95e52 AM |
904 | /* |
905 | * scheduler run of queue, if there are requests pending and no one in the | |
906 | * driver that will restart queueing | |
907 | */ | |
23e018a1 | 908 | static inline void cfq_schedule_dispatch(struct cfq_data *cfqd) |
99f95e52 | 909 | { |
7b679138 JA |
910 | if (cfqd->busy_queues) { |
911 | cfq_log(cfqd, "schedule dispatch"); | |
59c3d45e | 912 | kblockd_schedule_work(&cfqd->unplug_work); |
7b679138 | 913 | } |
99f95e52 AM |
914 | } |
915 | ||
44f7c160 JA |
916 | /* |
917 | * Scale schedule slice based on io priority. Use the sync time slice only | |
918 | * if a queue is marked sync and has sync io queued. A sync queue with async | |
919 | * io only, should not get full sync slice length. | |
920 | */ | |
a6151c3a | 921 | static inline int cfq_prio_slice(struct cfq_data *cfqd, bool sync, |
d9e7620e | 922 | unsigned short prio) |
44f7c160 | 923 | { |
d9e7620e | 924 | const int base_slice = cfqd->cfq_slice[sync]; |
44f7c160 | 925 | |
d9e7620e JA |
926 | WARN_ON(prio >= IOPRIO_BE_NR); |
927 | ||
928 | return base_slice + (base_slice/CFQ_SLICE_SCALE * (4 - prio)); | |
929 | } | |
44f7c160 | 930 | |
d9e7620e JA |
931 | static inline int |
932 | cfq_prio_to_slice(struct cfq_data *cfqd, struct cfq_queue *cfqq) | |
933 | { | |
934 | return cfq_prio_slice(cfqd, cfq_cfqq_sync(cfqq), cfqq->ioprio); | |
44f7c160 JA |
935 | } |
936 | ||
1d3650f7 TH |
937 | /** |
938 | * cfqg_scale_charge - scale disk time charge according to cfqg weight | |
939 | * @charge: disk time being charged | |
940 | * @vfraction: vfraction of the cfqg, fixed point w/ CFQ_SERVICE_SHIFT | |
941 | * | |
942 | * Scale @charge according to @vfraction, which is in range (0, 1]. The | |
943 | * scaling is inversely proportional. | |
944 | * | |
945 | * scaled = charge / vfraction | |
946 | * | |
947 | * The result is also in fixed point w/ CFQ_SERVICE_SHIFT. | |
948 | */ | |
949 | static inline u64 cfqg_scale_charge(unsigned long charge, | |
950 | unsigned int vfraction) | |
25bc6b07 | 951 | { |
1d3650f7 | 952 | u64 c = charge << CFQ_SERVICE_SHIFT; /* make it fixed point */ |
25bc6b07 | 953 | |
1d3650f7 TH |
954 | /* charge / vfraction */ |
955 | c <<= CFQ_SERVICE_SHIFT; | |
956 | do_div(c, vfraction); | |
957 | return c; | |
25bc6b07 VG |
958 | } |
959 | ||
960 | static inline u64 max_vdisktime(u64 min_vdisktime, u64 vdisktime) | |
961 | { | |
962 | s64 delta = (s64)(vdisktime - min_vdisktime); | |
963 | if (delta > 0) | |
964 | min_vdisktime = vdisktime; | |
965 | ||
966 | return min_vdisktime; | |
967 | } | |
968 | ||
969 | static inline u64 min_vdisktime(u64 min_vdisktime, u64 vdisktime) | |
970 | { | |
971 | s64 delta = (s64)(vdisktime - min_vdisktime); | |
972 | if (delta < 0) | |
973 | min_vdisktime = vdisktime; | |
974 | ||
975 | return min_vdisktime; | |
976 | } | |
977 | ||
978 | static void update_min_vdisktime(struct cfq_rb_root *st) | |
979 | { | |
25bc6b07 VG |
980 | struct cfq_group *cfqg; |
981 | ||
25bc6b07 VG |
982 | if (st->left) { |
983 | cfqg = rb_entry_cfqg(st->left); | |
a6032710 GJ |
984 | st->min_vdisktime = max_vdisktime(st->min_vdisktime, |
985 | cfqg->vdisktime); | |
25bc6b07 | 986 | } |
25bc6b07 VG |
987 | } |
988 | ||
5db5d642 CZ |
989 | /* |
990 | * get averaged number of queues of RT/BE priority. | |
991 | * average is updated, with a formula that gives more weight to higher numbers, | |
992 | * to quickly follows sudden increases and decrease slowly | |
993 | */ | |
994 | ||
58ff82f3 VG |
995 | static inline unsigned cfq_group_get_avg_queues(struct cfq_data *cfqd, |
996 | struct cfq_group *cfqg, bool rt) | |
5869619c | 997 | { |
5db5d642 CZ |
998 | unsigned min_q, max_q; |
999 | unsigned mult = cfq_hist_divisor - 1; | |
1000 | unsigned round = cfq_hist_divisor / 2; | |
58ff82f3 | 1001 | unsigned busy = cfq_group_busy_queues_wl(rt, cfqd, cfqg); |
5db5d642 | 1002 | |
58ff82f3 VG |
1003 | min_q = min(cfqg->busy_queues_avg[rt], busy); |
1004 | max_q = max(cfqg->busy_queues_avg[rt], busy); | |
1005 | cfqg->busy_queues_avg[rt] = (mult * max_q + min_q + round) / | |
5db5d642 | 1006 | cfq_hist_divisor; |
58ff82f3 VG |
1007 | return cfqg->busy_queues_avg[rt]; |
1008 | } | |
1009 | ||
1010 | static inline unsigned | |
1011 | cfq_group_slice(struct cfq_data *cfqd, struct cfq_group *cfqg) | |
1012 | { | |
41cad6ab | 1013 | return cfqd->cfq_target_latency * cfqg->vfraction >> CFQ_SERVICE_SHIFT; |
5db5d642 CZ |
1014 | } |
1015 | ||
c553f8e3 | 1016 | static inline unsigned |
ba5bd520 | 1017 | cfq_scaled_cfqq_slice(struct cfq_data *cfqd, struct cfq_queue *cfqq) |
44f7c160 | 1018 | { |
5db5d642 CZ |
1019 | unsigned slice = cfq_prio_to_slice(cfqd, cfqq); |
1020 | if (cfqd->cfq_latency) { | |
58ff82f3 VG |
1021 | /* |
1022 | * interested queues (we consider only the ones with the same | |
1023 | * priority class in the cfq group) | |
1024 | */ | |
1025 | unsigned iq = cfq_group_get_avg_queues(cfqd, cfqq->cfqg, | |
1026 | cfq_class_rt(cfqq)); | |
5db5d642 CZ |
1027 | unsigned sync_slice = cfqd->cfq_slice[1]; |
1028 | unsigned expect_latency = sync_slice * iq; | |
58ff82f3 VG |
1029 | unsigned group_slice = cfq_group_slice(cfqd, cfqq->cfqg); |
1030 | ||
1031 | if (expect_latency > group_slice) { | |
5db5d642 CZ |
1032 | unsigned base_low_slice = 2 * cfqd->cfq_slice_idle; |
1033 | /* scale low_slice according to IO priority | |
1034 | * and sync vs async */ | |
1035 | unsigned low_slice = | |
1036 | min(slice, base_low_slice * slice / sync_slice); | |
1037 | /* the adapted slice value is scaled to fit all iqs | |
1038 | * into the target latency */ | |
58ff82f3 | 1039 | slice = max(slice * group_slice / expect_latency, |
5db5d642 CZ |
1040 | low_slice); |
1041 | } | |
1042 | } | |
c553f8e3 SL |
1043 | return slice; |
1044 | } | |
1045 | ||
1046 | static inline void | |
1047 | cfq_set_prio_slice(struct cfq_data *cfqd, struct cfq_queue *cfqq) | |
1048 | { | |
ba5bd520 | 1049 | unsigned slice = cfq_scaled_cfqq_slice(cfqd, cfqq); |
c553f8e3 | 1050 | |
dae739eb | 1051 | cfqq->slice_start = jiffies; |
5db5d642 | 1052 | cfqq->slice_end = jiffies + slice; |
f75edf2d | 1053 | cfqq->allocated_slice = slice; |
7b679138 | 1054 | cfq_log_cfqq(cfqd, cfqq, "set_slice=%lu", cfqq->slice_end - jiffies); |
44f7c160 JA |
1055 | } |
1056 | ||
1057 | /* | |
1058 | * We need to wrap this check in cfq_cfqq_slice_new(), since ->slice_end | |
1059 | * isn't valid until the first request from the dispatch is activated | |
1060 | * and the slice time set. | |
1061 | */ | |
a6151c3a | 1062 | static inline bool cfq_slice_used(struct cfq_queue *cfqq) |
44f7c160 JA |
1063 | { |
1064 | if (cfq_cfqq_slice_new(cfqq)) | |
c1e44756 | 1065 | return false; |
44f7c160 | 1066 | if (time_before(jiffies, cfqq->slice_end)) |
c1e44756 | 1067 | return false; |
44f7c160 | 1068 | |
c1e44756 | 1069 | return true; |
44f7c160 JA |
1070 | } |
1071 | ||
1da177e4 | 1072 | /* |
5e705374 | 1073 | * Lifted from AS - choose which of rq1 and rq2 that is best served now. |
1da177e4 | 1074 | * We choose the request that is closest to the head right now. Distance |
e8a99053 | 1075 | * behind the head is penalized and only allowed to a certain extent. |
1da177e4 | 1076 | */ |
5e705374 | 1077 | static struct request * |
cf7c25cf | 1078 | cfq_choose_req(struct cfq_data *cfqd, struct request *rq1, struct request *rq2, sector_t last) |
1da177e4 | 1079 | { |
cf7c25cf | 1080 | sector_t s1, s2, d1 = 0, d2 = 0; |
1da177e4 | 1081 | unsigned long back_max; |
e8a99053 AM |
1082 | #define CFQ_RQ1_WRAP 0x01 /* request 1 wraps */ |
1083 | #define CFQ_RQ2_WRAP 0x02 /* request 2 wraps */ | |
1084 | unsigned wrap = 0; /* bit mask: requests behind the disk head? */ | |
1da177e4 | 1085 | |
5e705374 JA |
1086 | if (rq1 == NULL || rq1 == rq2) |
1087 | return rq2; | |
1088 | if (rq2 == NULL) | |
1089 | return rq1; | |
9c2c38a1 | 1090 | |
229836bd NK |
1091 | if (rq_is_sync(rq1) != rq_is_sync(rq2)) |
1092 | return rq_is_sync(rq1) ? rq1 : rq2; | |
1093 | ||
65299a3b CH |
1094 | if ((rq1->cmd_flags ^ rq2->cmd_flags) & REQ_PRIO) |
1095 | return rq1->cmd_flags & REQ_PRIO ? rq1 : rq2; | |
b53d1ed7 | 1096 | |
83096ebf TH |
1097 | s1 = blk_rq_pos(rq1); |
1098 | s2 = blk_rq_pos(rq2); | |
1da177e4 | 1099 | |
1da177e4 LT |
1100 | /* |
1101 | * by definition, 1KiB is 2 sectors | |
1102 | */ | |
1103 | back_max = cfqd->cfq_back_max * 2; | |
1104 | ||
1105 | /* | |
1106 | * Strict one way elevator _except_ in the case where we allow | |
1107 | * short backward seeks which are biased as twice the cost of a | |
1108 | * similar forward seek. | |
1109 | */ | |
1110 | if (s1 >= last) | |
1111 | d1 = s1 - last; | |
1112 | else if (s1 + back_max >= last) | |
1113 | d1 = (last - s1) * cfqd->cfq_back_penalty; | |
1114 | else | |
e8a99053 | 1115 | wrap |= CFQ_RQ1_WRAP; |
1da177e4 LT |
1116 | |
1117 | if (s2 >= last) | |
1118 | d2 = s2 - last; | |
1119 | else if (s2 + back_max >= last) | |
1120 | d2 = (last - s2) * cfqd->cfq_back_penalty; | |
1121 | else | |
e8a99053 | 1122 | wrap |= CFQ_RQ2_WRAP; |
1da177e4 LT |
1123 | |
1124 | /* Found required data */ | |
e8a99053 AM |
1125 | |
1126 | /* | |
1127 | * By doing switch() on the bit mask "wrap" we avoid having to | |
1128 | * check two variables for all permutations: --> faster! | |
1129 | */ | |
1130 | switch (wrap) { | |
5e705374 | 1131 | case 0: /* common case for CFQ: rq1 and rq2 not wrapped */ |
e8a99053 | 1132 | if (d1 < d2) |
5e705374 | 1133 | return rq1; |
e8a99053 | 1134 | else if (d2 < d1) |
5e705374 | 1135 | return rq2; |
e8a99053 AM |
1136 | else { |
1137 | if (s1 >= s2) | |
5e705374 | 1138 | return rq1; |
e8a99053 | 1139 | else |
5e705374 | 1140 | return rq2; |
e8a99053 | 1141 | } |
1da177e4 | 1142 | |
e8a99053 | 1143 | case CFQ_RQ2_WRAP: |
5e705374 | 1144 | return rq1; |
e8a99053 | 1145 | case CFQ_RQ1_WRAP: |
5e705374 JA |
1146 | return rq2; |
1147 | case (CFQ_RQ1_WRAP|CFQ_RQ2_WRAP): /* both rqs wrapped */ | |
e8a99053 AM |
1148 | default: |
1149 | /* | |
1150 | * Since both rqs are wrapped, | |
1151 | * start with the one that's further behind head | |
1152 | * (--> only *one* back seek required), | |
1153 | * since back seek takes more time than forward. | |
1154 | */ | |
1155 | if (s1 <= s2) | |
5e705374 | 1156 | return rq1; |
1da177e4 | 1157 | else |
5e705374 | 1158 | return rq2; |
1da177e4 LT |
1159 | } |
1160 | } | |
1161 | ||
498d3aa2 JA |
1162 | /* |
1163 | * The below is leftmost cache rbtree addon | |
1164 | */ | |
0871714e | 1165 | static struct cfq_queue *cfq_rb_first(struct cfq_rb_root *root) |
cc09e299 | 1166 | { |
615f0259 VG |
1167 | /* Service tree is empty */ |
1168 | if (!root->count) | |
1169 | return NULL; | |
1170 | ||
cc09e299 JA |
1171 | if (!root->left) |
1172 | root->left = rb_first(&root->rb); | |
1173 | ||
0871714e JA |
1174 | if (root->left) |
1175 | return rb_entry(root->left, struct cfq_queue, rb_node); | |
1176 | ||
1177 | return NULL; | |
cc09e299 JA |
1178 | } |
1179 | ||
1fa8f6d6 VG |
1180 | static struct cfq_group *cfq_rb_first_group(struct cfq_rb_root *root) |
1181 | { | |
1182 | if (!root->left) | |
1183 | root->left = rb_first(&root->rb); | |
1184 | ||
1185 | if (root->left) | |
1186 | return rb_entry_cfqg(root->left); | |
1187 | ||
1188 | return NULL; | |
1189 | } | |
1190 | ||
a36e71f9 JA |
1191 | static void rb_erase_init(struct rb_node *n, struct rb_root *root) |
1192 | { | |
1193 | rb_erase(n, root); | |
1194 | RB_CLEAR_NODE(n); | |
1195 | } | |
1196 | ||
cc09e299 JA |
1197 | static void cfq_rb_erase(struct rb_node *n, struct cfq_rb_root *root) |
1198 | { | |
1199 | if (root->left == n) | |
1200 | root->left = NULL; | |
a36e71f9 | 1201 | rb_erase_init(n, &root->rb); |
aa6f6a3d | 1202 | --root->count; |
cc09e299 JA |
1203 | } |
1204 | ||
1da177e4 LT |
1205 | /* |
1206 | * would be nice to take fifo expire time into account as well | |
1207 | */ | |
5e705374 JA |
1208 | static struct request * |
1209 | cfq_find_next_rq(struct cfq_data *cfqd, struct cfq_queue *cfqq, | |
1210 | struct request *last) | |
1da177e4 | 1211 | { |
21183b07 JA |
1212 | struct rb_node *rbnext = rb_next(&last->rb_node); |
1213 | struct rb_node *rbprev = rb_prev(&last->rb_node); | |
5e705374 | 1214 | struct request *next = NULL, *prev = NULL; |
1da177e4 | 1215 | |
21183b07 | 1216 | BUG_ON(RB_EMPTY_NODE(&last->rb_node)); |
1da177e4 LT |
1217 | |
1218 | if (rbprev) | |
5e705374 | 1219 | prev = rb_entry_rq(rbprev); |
1da177e4 | 1220 | |
21183b07 | 1221 | if (rbnext) |
5e705374 | 1222 | next = rb_entry_rq(rbnext); |
21183b07 JA |
1223 | else { |
1224 | rbnext = rb_first(&cfqq->sort_list); | |
1225 | if (rbnext && rbnext != &last->rb_node) | |
5e705374 | 1226 | next = rb_entry_rq(rbnext); |
21183b07 | 1227 | } |
1da177e4 | 1228 | |
cf7c25cf | 1229 | return cfq_choose_req(cfqd, next, prev, blk_rq_pos(last)); |
1da177e4 LT |
1230 | } |
1231 | ||
d9e7620e JA |
1232 | static unsigned long cfq_slice_offset(struct cfq_data *cfqd, |
1233 | struct cfq_queue *cfqq) | |
1da177e4 | 1234 | { |
d9e7620e JA |
1235 | /* |
1236 | * just an approximation, should be ok. | |
1237 | */ | |
cdb16e8f | 1238 | return (cfqq->cfqg->nr_cfqq - 1) * (cfq_prio_slice(cfqd, 1, 0) - |
464191c6 | 1239 | cfq_prio_slice(cfqd, cfq_cfqq_sync(cfqq), cfqq->ioprio)); |
d9e7620e JA |
1240 | } |
1241 | ||
1fa8f6d6 VG |
1242 | static inline s64 |
1243 | cfqg_key(struct cfq_rb_root *st, struct cfq_group *cfqg) | |
1244 | { | |
1245 | return cfqg->vdisktime - st->min_vdisktime; | |
1246 | } | |
1247 | ||
1248 | static void | |
1249 | __cfq_group_service_tree_add(struct cfq_rb_root *st, struct cfq_group *cfqg) | |
1250 | { | |
1251 | struct rb_node **node = &st->rb.rb_node; | |
1252 | struct rb_node *parent = NULL; | |
1253 | struct cfq_group *__cfqg; | |
1254 | s64 key = cfqg_key(st, cfqg); | |
1255 | int left = 1; | |
1256 | ||
1257 | while (*node != NULL) { | |
1258 | parent = *node; | |
1259 | __cfqg = rb_entry_cfqg(parent); | |
1260 | ||
1261 | if (key < cfqg_key(st, __cfqg)) | |
1262 | node = &parent->rb_left; | |
1263 | else { | |
1264 | node = &parent->rb_right; | |
1265 | left = 0; | |
1266 | } | |
1267 | } | |
1268 | ||
1269 | if (left) | |
1270 | st->left = &cfqg->rb_node; | |
1271 | ||
1272 | rb_link_node(&cfqg->rb_node, parent, node); | |
1273 | rb_insert_color(&cfqg->rb_node, &st->rb); | |
1274 | } | |
1275 | ||
7b5af5cf TM |
1276 | /* |
1277 | * This has to be called only on activation of cfqg | |
1278 | */ | |
1fa8f6d6 | 1279 | static void |
8184f93e JT |
1280 | cfq_update_group_weight(struct cfq_group *cfqg) |
1281 | { | |
3381cb8d | 1282 | if (cfqg->new_weight) { |
8184f93e | 1283 | cfqg->weight = cfqg->new_weight; |
3381cb8d | 1284 | cfqg->new_weight = 0; |
8184f93e | 1285 | } |
e15693ef TM |
1286 | } |
1287 | ||
1288 | static void | |
1289 | cfq_update_group_leaf_weight(struct cfq_group *cfqg) | |
1290 | { | |
1291 | BUG_ON(!RB_EMPTY_NODE(&cfqg->rb_node)); | |
e71357e1 TH |
1292 | |
1293 | if (cfqg->new_leaf_weight) { | |
1294 | cfqg->leaf_weight = cfqg->new_leaf_weight; | |
1295 | cfqg->new_leaf_weight = 0; | |
1296 | } | |
8184f93e JT |
1297 | } |
1298 | ||
1299 | static void | |
1300 | cfq_group_service_tree_add(struct cfq_rb_root *st, struct cfq_group *cfqg) | |
1301 | { | |
1d3650f7 | 1302 | unsigned int vfr = 1 << CFQ_SERVICE_SHIFT; /* start with 1 */ |
7918ffb5 | 1303 | struct cfq_group *pos = cfqg; |
1d3650f7 | 1304 | struct cfq_group *parent; |
7918ffb5 TH |
1305 | bool propagate; |
1306 | ||
1307 | /* add to the service tree */ | |
8184f93e JT |
1308 | BUG_ON(!RB_EMPTY_NODE(&cfqg->rb_node)); |
1309 | ||
7b5af5cf TM |
1310 | /* |
1311 | * Update leaf_weight. We cannot update weight at this point | |
1312 | * because cfqg might already have been activated and is | |
1313 | * contributing its current weight to the parent's child_weight. | |
1314 | */ | |
e15693ef | 1315 | cfq_update_group_leaf_weight(cfqg); |
8184f93e | 1316 | __cfq_group_service_tree_add(st, cfqg); |
7918ffb5 TH |
1317 | |
1318 | /* | |
1d3650f7 TH |
1319 | * Activate @cfqg and calculate the portion of vfraction @cfqg is |
1320 | * entitled to. vfraction is calculated by walking the tree | |
1321 | * towards the root calculating the fraction it has at each level. | |
1322 | * The compounded ratio is how much vfraction @cfqg owns. | |
1323 | * | |
1324 | * Start with the proportion tasks in this cfqg has against active | |
1325 | * children cfqgs - its leaf_weight against children_weight. | |
7918ffb5 TH |
1326 | */ |
1327 | propagate = !pos->nr_active++; | |
1328 | pos->children_weight += pos->leaf_weight; | |
1d3650f7 | 1329 | vfr = vfr * pos->leaf_weight / pos->children_weight; |
7918ffb5 | 1330 | |
1d3650f7 TH |
1331 | /* |
1332 | * Compound ->weight walking up the tree. Both activation and | |
1333 | * vfraction calculation are done in the same loop. Propagation | |
1334 | * stops once an already activated node is met. vfraction | |
1335 | * calculation should always continue to the root. | |
1336 | */ | |
d02f7aa8 | 1337 | while ((parent = cfqg_parent(pos))) { |
1d3650f7 | 1338 | if (propagate) { |
e15693ef | 1339 | cfq_update_group_weight(pos); |
1d3650f7 TH |
1340 | propagate = !parent->nr_active++; |
1341 | parent->children_weight += pos->weight; | |
1342 | } | |
1343 | vfr = vfr * pos->weight / parent->children_weight; | |
7918ffb5 TH |
1344 | pos = parent; |
1345 | } | |
1d3650f7 TH |
1346 | |
1347 | cfqg->vfraction = max_t(unsigned, vfr, 1); | |
8184f93e JT |
1348 | } |
1349 | ||
1350 | static void | |
1351 | cfq_group_notify_queue_add(struct cfq_data *cfqd, struct cfq_group *cfqg) | |
1fa8f6d6 VG |
1352 | { |
1353 | struct cfq_rb_root *st = &cfqd->grp_service_tree; | |
1354 | struct cfq_group *__cfqg; | |
1355 | struct rb_node *n; | |
1356 | ||
1357 | cfqg->nr_cfqq++; | |
760701bf | 1358 | if (!RB_EMPTY_NODE(&cfqg->rb_node)) |
1fa8f6d6 VG |
1359 | return; |
1360 | ||
1361 | /* | |
1362 | * Currently put the group at the end. Later implement something | |
1363 | * so that groups get lesser vtime based on their weights, so that | |
25985edc | 1364 | * if group does not loose all if it was not continuously backlogged. |
1fa8f6d6 VG |
1365 | */ |
1366 | n = rb_last(&st->rb); | |
1367 | if (n) { | |
1368 | __cfqg = rb_entry_cfqg(n); | |
1369 | cfqg->vdisktime = __cfqg->vdisktime + CFQ_IDLE_DELAY; | |
1370 | } else | |
1371 | cfqg->vdisktime = st->min_vdisktime; | |
8184f93e JT |
1372 | cfq_group_service_tree_add(st, cfqg); |
1373 | } | |
1fa8f6d6 | 1374 | |
8184f93e JT |
1375 | static void |
1376 | cfq_group_service_tree_del(struct cfq_rb_root *st, struct cfq_group *cfqg) | |
1377 | { | |
7918ffb5 TH |
1378 | struct cfq_group *pos = cfqg; |
1379 | bool propagate; | |
1380 | ||
1381 | /* | |
1382 | * Undo activation from cfq_group_service_tree_add(). Deactivate | |
1383 | * @cfqg and propagate deactivation upwards. | |
1384 | */ | |
1385 | propagate = !--pos->nr_active; | |
1386 | pos->children_weight -= pos->leaf_weight; | |
1387 | ||
1388 | while (propagate) { | |
d02f7aa8 | 1389 | struct cfq_group *parent = cfqg_parent(pos); |
7918ffb5 TH |
1390 | |
1391 | /* @pos has 0 nr_active at this point */ | |
1392 | WARN_ON_ONCE(pos->children_weight); | |
1d3650f7 | 1393 | pos->vfraction = 0; |
7918ffb5 TH |
1394 | |
1395 | if (!parent) | |
1396 | break; | |
1397 | ||
1398 | propagate = !--parent->nr_active; | |
1399 | parent->children_weight -= pos->weight; | |
1400 | pos = parent; | |
1401 | } | |
1402 | ||
1403 | /* remove from the service tree */ | |
8184f93e JT |
1404 | if (!RB_EMPTY_NODE(&cfqg->rb_node)) |
1405 | cfq_rb_erase(&cfqg->rb_node, st); | |
1fa8f6d6 VG |
1406 | } |
1407 | ||
1408 | static void | |
8184f93e | 1409 | cfq_group_notify_queue_del(struct cfq_data *cfqd, struct cfq_group *cfqg) |
1fa8f6d6 VG |
1410 | { |
1411 | struct cfq_rb_root *st = &cfqd->grp_service_tree; | |
1412 | ||
1413 | BUG_ON(cfqg->nr_cfqq < 1); | |
1414 | cfqg->nr_cfqq--; | |
25bc6b07 | 1415 | |
1fa8f6d6 VG |
1416 | /* If there are other cfq queues under this group, don't delete it */ |
1417 | if (cfqg->nr_cfqq) | |
1418 | return; | |
1419 | ||
2868ef7b | 1420 | cfq_log_cfqg(cfqd, cfqg, "del_from_rr group"); |
8184f93e | 1421 | cfq_group_service_tree_del(st, cfqg); |
4d2ceea4 | 1422 | cfqg->saved_wl_slice = 0; |
155fead9 | 1423 | cfqg_stats_update_dequeue(cfqg); |
dae739eb VG |
1424 | } |
1425 | ||
167400d3 JT |
1426 | static inline unsigned int cfq_cfqq_slice_usage(struct cfq_queue *cfqq, |
1427 | unsigned int *unaccounted_time) | |
dae739eb | 1428 | { |
f75edf2d | 1429 | unsigned int slice_used; |
dae739eb VG |
1430 | |
1431 | /* | |
1432 | * Queue got expired before even a single request completed or | |
1433 | * got expired immediately after first request completion. | |
1434 | */ | |
1435 | if (!cfqq->slice_start || cfqq->slice_start == jiffies) { | |
1436 | /* | |
1437 | * Also charge the seek time incurred to the group, otherwise | |
1438 | * if there are mutiple queues in the group, each can dispatch | |
1439 | * a single request on seeky media and cause lots of seek time | |
1440 | * and group will never know it. | |
1441 | */ | |
1442 | slice_used = max_t(unsigned, (jiffies - cfqq->dispatch_start), | |
1443 | 1); | |
1444 | } else { | |
1445 | slice_used = jiffies - cfqq->slice_start; | |
167400d3 JT |
1446 | if (slice_used > cfqq->allocated_slice) { |
1447 | *unaccounted_time = slice_used - cfqq->allocated_slice; | |
f75edf2d | 1448 | slice_used = cfqq->allocated_slice; |
167400d3 JT |
1449 | } |
1450 | if (time_after(cfqq->slice_start, cfqq->dispatch_start)) | |
1451 | *unaccounted_time += cfqq->slice_start - | |
1452 | cfqq->dispatch_start; | |
dae739eb VG |
1453 | } |
1454 | ||
dae739eb VG |
1455 | return slice_used; |
1456 | } | |
1457 | ||
1458 | static void cfq_group_served(struct cfq_data *cfqd, struct cfq_group *cfqg, | |
e5ff082e | 1459 | struct cfq_queue *cfqq) |
dae739eb VG |
1460 | { |
1461 | struct cfq_rb_root *st = &cfqd->grp_service_tree; | |
167400d3 | 1462 | unsigned int used_sl, charge, unaccounted_sl = 0; |
f26bd1f0 VG |
1463 | int nr_sync = cfqg->nr_cfqq - cfqg_busy_async_queues(cfqd, cfqg) |
1464 | - cfqg->service_tree_idle.count; | |
1d3650f7 | 1465 | unsigned int vfr; |
f26bd1f0 VG |
1466 | |
1467 | BUG_ON(nr_sync < 0); | |
167400d3 | 1468 | used_sl = charge = cfq_cfqq_slice_usage(cfqq, &unaccounted_sl); |
dae739eb | 1469 | |
02b35081 VG |
1470 | if (iops_mode(cfqd)) |
1471 | charge = cfqq->slice_dispatch; | |
1472 | else if (!cfq_cfqq_sync(cfqq) && !nr_sync) | |
1473 | charge = cfqq->allocated_slice; | |
dae739eb | 1474 | |
1d3650f7 TH |
1475 | /* |
1476 | * Can't update vdisktime while on service tree and cfqg->vfraction | |
1477 | * is valid only while on it. Cache vfr, leave the service tree, | |
1478 | * update vdisktime and go back on. The re-addition to the tree | |
1479 | * will also update the weights as necessary. | |
1480 | */ | |
1481 | vfr = cfqg->vfraction; | |
8184f93e | 1482 | cfq_group_service_tree_del(st, cfqg); |
1d3650f7 | 1483 | cfqg->vdisktime += cfqg_scale_charge(charge, vfr); |
8184f93e | 1484 | cfq_group_service_tree_add(st, cfqg); |
dae739eb VG |
1485 | |
1486 | /* This group is being expired. Save the context */ | |
1487 | if (time_after(cfqd->workload_expires, jiffies)) { | |
4d2ceea4 | 1488 | cfqg->saved_wl_slice = cfqd->workload_expires |
dae739eb | 1489 | - jiffies; |
4d2ceea4 VG |
1490 | cfqg->saved_wl_type = cfqd->serving_wl_type; |
1491 | cfqg->saved_wl_class = cfqd->serving_wl_class; | |
dae739eb | 1492 | } else |
4d2ceea4 | 1493 | cfqg->saved_wl_slice = 0; |
2868ef7b VG |
1494 | |
1495 | cfq_log_cfqg(cfqd, cfqg, "served: vt=%llu min_vt=%llu", cfqg->vdisktime, | |
1496 | st->min_vdisktime); | |
fd16d263 JP |
1497 | cfq_log_cfqq(cfqq->cfqd, cfqq, |
1498 | "sl_used=%u disp=%u charge=%u iops=%u sect=%lu", | |
1499 | used_sl, cfqq->slice_dispatch, charge, | |
1500 | iops_mode(cfqd), cfqq->nr_sectors); | |
155fead9 TH |
1501 | cfqg_stats_update_timeslice_used(cfqg, used_sl, unaccounted_sl); |
1502 | cfqg_stats_set_start_empty_time(cfqg); | |
1fa8f6d6 VG |
1503 | } |
1504 | ||
f51b802c TH |
1505 | /** |
1506 | * cfq_init_cfqg_base - initialize base part of a cfq_group | |
1507 | * @cfqg: cfq_group to initialize | |
1508 | * | |
1509 | * Initialize the base part which is used whether %CONFIG_CFQ_GROUP_IOSCHED | |
1510 | * is enabled or not. | |
1511 | */ | |
1512 | static void cfq_init_cfqg_base(struct cfq_group *cfqg) | |
1513 | { | |
1514 | struct cfq_rb_root *st; | |
1515 | int i, j; | |
1516 | ||
1517 | for_each_cfqg_st(cfqg, i, j, st) | |
1518 | *st = CFQ_RB_ROOT; | |
1519 | RB_CLEAR_NODE(&cfqg->rb_node); | |
1520 | ||
1521 | cfqg->ttime.last_end_request = jiffies; | |
1522 | } | |
1523 | ||
25fb5169 | 1524 | #ifdef CONFIG_CFQ_GROUP_IOSCHED |
24bdb8ef | 1525 | static void cfqg_stats_exit(struct cfqg_stats *stats) |
90d3839b | 1526 | { |
24bdb8ef TH |
1527 | blkg_rwstat_exit(&stats->merged); |
1528 | blkg_rwstat_exit(&stats->service_time); | |
1529 | blkg_rwstat_exit(&stats->wait_time); | |
1530 | blkg_rwstat_exit(&stats->queued); | |
24bdb8ef TH |
1531 | blkg_stat_exit(&stats->time); |
1532 | #ifdef CONFIG_DEBUG_BLK_CGROUP | |
1533 | blkg_stat_exit(&stats->unaccounted_time); | |
1534 | blkg_stat_exit(&stats->avg_queue_size_sum); | |
1535 | blkg_stat_exit(&stats->avg_queue_size_samples); | |
1536 | blkg_stat_exit(&stats->dequeue); | |
1537 | blkg_stat_exit(&stats->group_wait_time); | |
1538 | blkg_stat_exit(&stats->idle_time); | |
1539 | blkg_stat_exit(&stats->empty_time); | |
1540 | #endif | |
1541 | } | |
1542 | ||
1543 | static int cfqg_stats_init(struct cfqg_stats *stats, gfp_t gfp) | |
1544 | { | |
77ea7338 | 1545 | if (blkg_rwstat_init(&stats->merged, gfp) || |
24bdb8ef TH |
1546 | blkg_rwstat_init(&stats->service_time, gfp) || |
1547 | blkg_rwstat_init(&stats->wait_time, gfp) || | |
1548 | blkg_rwstat_init(&stats->queued, gfp) || | |
24bdb8ef TH |
1549 | blkg_stat_init(&stats->time, gfp)) |
1550 | goto err; | |
90d3839b PZ |
1551 | |
1552 | #ifdef CONFIG_DEBUG_BLK_CGROUP | |
24bdb8ef TH |
1553 | if (blkg_stat_init(&stats->unaccounted_time, gfp) || |
1554 | blkg_stat_init(&stats->avg_queue_size_sum, gfp) || | |
1555 | blkg_stat_init(&stats->avg_queue_size_samples, gfp) || | |
1556 | blkg_stat_init(&stats->dequeue, gfp) || | |
1557 | blkg_stat_init(&stats->group_wait_time, gfp) || | |
1558 | blkg_stat_init(&stats->idle_time, gfp) || | |
1559 | blkg_stat_init(&stats->empty_time, gfp)) | |
1560 | goto err; | |
90d3839b | 1561 | #endif |
24bdb8ef TH |
1562 | return 0; |
1563 | err: | |
1564 | cfqg_stats_exit(stats); | |
1565 | return -ENOMEM; | |
90d3839b PZ |
1566 | } |
1567 | ||
e4a9bde9 TH |
1568 | static struct blkcg_policy_data *cfq_cpd_alloc(gfp_t gfp) |
1569 | { | |
1570 | struct cfq_group_data *cgd; | |
1571 | ||
1572 | cgd = kzalloc(sizeof(*cgd), GFP_KERNEL); | |
1573 | if (!cgd) | |
1574 | return NULL; | |
1575 | return &cgd->cpd; | |
1576 | } | |
1577 | ||
81437648 | 1578 | static void cfq_cpd_init(struct blkcg_policy_data *cpd) |
e48453c3 | 1579 | { |
81437648 | 1580 | struct cfq_group_data *cgd = cpd_to_cfqgd(cpd); |
e48453c3 | 1581 | |
81437648 | 1582 | if (cpd_to_blkcg(cpd) == &blkcg_root) { |
e48453c3 AA |
1583 | cgd->weight = 2 * CFQ_WEIGHT_DEFAULT; |
1584 | cgd->leaf_weight = 2 * CFQ_WEIGHT_DEFAULT; | |
1585 | } else { | |
1586 | cgd->weight = CFQ_WEIGHT_DEFAULT; | |
1587 | cgd->leaf_weight = CFQ_WEIGHT_DEFAULT; | |
1588 | } | |
1589 | } | |
1590 | ||
e4a9bde9 TH |
1591 | static void cfq_cpd_free(struct blkcg_policy_data *cpd) |
1592 | { | |
1593 | kfree(cpd_to_cfqgd(cpd)); | |
1594 | } | |
1595 | ||
001bea73 TH |
1596 | static struct blkg_policy_data *cfq_pd_alloc(gfp_t gfp, int node) |
1597 | { | |
b2ce2643 TH |
1598 | struct cfq_group *cfqg; |
1599 | ||
1600 | cfqg = kzalloc_node(sizeof(*cfqg), gfp, node); | |
1601 | if (!cfqg) | |
1602 | return NULL; | |
1603 | ||
1604 | cfq_init_cfqg_base(cfqg); | |
24bdb8ef TH |
1605 | if (cfqg_stats_init(&cfqg->stats, gfp)) { |
1606 | kfree(cfqg); | |
1607 | return NULL; | |
1608 | } | |
b2ce2643 TH |
1609 | |
1610 | return &cfqg->pd; | |
001bea73 TH |
1611 | } |
1612 | ||
a9520cd6 | 1613 | static void cfq_pd_init(struct blkg_policy_data *pd) |
f469a7b4 | 1614 | { |
a9520cd6 TH |
1615 | struct cfq_group *cfqg = pd_to_cfqg(pd); |
1616 | struct cfq_group_data *cgd = blkcg_to_cfqgd(pd->blkg->blkcg); | |
25fb5169 | 1617 | |
e48453c3 AA |
1618 | cfqg->weight = cgd->weight; |
1619 | cfqg->leaf_weight = cgd->leaf_weight; | |
25fb5169 VG |
1620 | } |
1621 | ||
a9520cd6 | 1622 | static void cfq_pd_offline(struct blkg_policy_data *pd) |
0b39920b | 1623 | { |
a9520cd6 | 1624 | struct cfq_group *cfqg = pd_to_cfqg(pd); |
60a83707 TH |
1625 | int i; |
1626 | ||
1627 | for (i = 0; i < IOPRIO_BE_NR; i++) { | |
1628 | if (cfqg->async_cfqq[0][i]) | |
1629 | cfq_put_queue(cfqg->async_cfqq[0][i]); | |
1630 | if (cfqg->async_cfqq[1][i]) | |
1631 | cfq_put_queue(cfqg->async_cfqq[1][i]); | |
1632 | } | |
1633 | ||
1634 | if (cfqg->async_idle_cfqq) | |
1635 | cfq_put_queue(cfqg->async_idle_cfqq); | |
1636 | ||
0b39920b TH |
1637 | /* |
1638 | * @blkg is going offline and will be ignored by | |
1639 | * blkg_[rw]stat_recursive_sum(). Transfer stats to the parent so | |
1640 | * that they don't get lost. If IOs complete after this point, the | |
1641 | * stats for them will be lost. Oh well... | |
1642 | */ | |
60a83707 | 1643 | cfqg_stats_xfer_dead(cfqg); |
0b39920b TH |
1644 | } |
1645 | ||
001bea73 TH |
1646 | static void cfq_pd_free(struct blkg_policy_data *pd) |
1647 | { | |
24bdb8ef TH |
1648 | struct cfq_group *cfqg = pd_to_cfqg(pd); |
1649 | ||
1650 | cfqg_stats_exit(&cfqg->stats); | |
1651 | return kfree(cfqg); | |
001bea73 TH |
1652 | } |
1653 | ||
a9520cd6 | 1654 | static void cfq_pd_reset_stats(struct blkg_policy_data *pd) |
689665af | 1655 | { |
a9520cd6 | 1656 | struct cfq_group *cfqg = pd_to_cfqg(pd); |
689665af TH |
1657 | |
1658 | cfqg_stats_reset(&cfqg->stats); | |
25fb5169 VG |
1659 | } |
1660 | ||
ae118896 TH |
1661 | static struct cfq_group *cfq_lookup_cfqg(struct cfq_data *cfqd, |
1662 | struct blkcg *blkcg) | |
25fb5169 | 1663 | { |
ae118896 | 1664 | struct blkcg_gq *blkg; |
f469a7b4 | 1665 | |
ae118896 TH |
1666 | blkg = blkg_lookup(blkcg, cfqd->queue); |
1667 | if (likely(blkg)) | |
1668 | return blkg_to_cfqg(blkg); | |
1669 | return NULL; | |
25fb5169 VG |
1670 | } |
1671 | ||
1672 | static void cfq_link_cfqq_cfqg(struct cfq_queue *cfqq, struct cfq_group *cfqg) | |
1673 | { | |
25fb5169 | 1674 | cfqq->cfqg = cfqg; |
b1c35769 | 1675 | /* cfqq reference on cfqg */ |
eb7d8c07 | 1676 | cfqg_get(cfqg); |
b1c35769 VG |
1677 | } |
1678 | ||
f95a04af TH |
1679 | static u64 cfqg_prfill_weight_device(struct seq_file *sf, |
1680 | struct blkg_policy_data *pd, int off) | |
60c2bc2d | 1681 | { |
f95a04af | 1682 | struct cfq_group *cfqg = pd_to_cfqg(pd); |
3381cb8d TH |
1683 | |
1684 | if (!cfqg->dev_weight) | |
60c2bc2d | 1685 | return 0; |
f95a04af | 1686 | return __blkg_prfill_u64(sf, pd, cfqg->dev_weight); |
60c2bc2d TH |
1687 | } |
1688 | ||
2da8ca82 | 1689 | static int cfqg_print_weight_device(struct seq_file *sf, void *v) |
60c2bc2d | 1690 | { |
2da8ca82 TH |
1691 | blkcg_print_blkgs(sf, css_to_blkcg(seq_css(sf)), |
1692 | cfqg_prfill_weight_device, &blkcg_policy_cfq, | |
1693 | 0, false); | |
60c2bc2d TH |
1694 | return 0; |
1695 | } | |
1696 | ||
e71357e1 TH |
1697 | static u64 cfqg_prfill_leaf_weight_device(struct seq_file *sf, |
1698 | struct blkg_policy_data *pd, int off) | |
1699 | { | |
1700 | struct cfq_group *cfqg = pd_to_cfqg(pd); | |
1701 | ||
1702 | if (!cfqg->dev_leaf_weight) | |
1703 | return 0; | |
1704 | return __blkg_prfill_u64(sf, pd, cfqg->dev_leaf_weight); | |
1705 | } | |
1706 | ||
2da8ca82 | 1707 | static int cfqg_print_leaf_weight_device(struct seq_file *sf, void *v) |
e71357e1 | 1708 | { |
2da8ca82 TH |
1709 | blkcg_print_blkgs(sf, css_to_blkcg(seq_css(sf)), |
1710 | cfqg_prfill_leaf_weight_device, &blkcg_policy_cfq, | |
1711 | 0, false); | |
e71357e1 TH |
1712 | return 0; |
1713 | } | |
1714 | ||
2da8ca82 | 1715 | static int cfq_print_weight(struct seq_file *sf, void *v) |
60c2bc2d | 1716 | { |
e48453c3 | 1717 | struct blkcg *blkcg = css_to_blkcg(seq_css(sf)); |
9470e4a6 JA |
1718 | struct cfq_group_data *cgd = blkcg_to_cfqgd(blkcg); |
1719 | unsigned int val = 0; | |
e48453c3 | 1720 | |
9470e4a6 JA |
1721 | if (cgd) |
1722 | val = cgd->weight; | |
1723 | ||
1724 | seq_printf(sf, "%u\n", val); | |
60c2bc2d TH |
1725 | return 0; |
1726 | } | |
1727 | ||
2da8ca82 | 1728 | static int cfq_print_leaf_weight(struct seq_file *sf, void *v) |
e71357e1 | 1729 | { |
e48453c3 | 1730 | struct blkcg *blkcg = css_to_blkcg(seq_css(sf)); |
9470e4a6 JA |
1731 | struct cfq_group_data *cgd = blkcg_to_cfqgd(blkcg); |
1732 | unsigned int val = 0; | |
1733 | ||
1734 | if (cgd) | |
1735 | val = cgd->leaf_weight; | |
e48453c3 | 1736 | |
9470e4a6 | 1737 | seq_printf(sf, "%u\n", val); |
e71357e1 TH |
1738 | return 0; |
1739 | } | |
1740 | ||
451af504 TH |
1741 | static ssize_t __cfqg_set_weight_device(struct kernfs_open_file *of, |
1742 | char *buf, size_t nbytes, loff_t off, | |
1743 | bool is_leaf_weight) | |
60c2bc2d | 1744 | { |
451af504 | 1745 | struct blkcg *blkcg = css_to_blkcg(of_css(of)); |
60c2bc2d | 1746 | struct blkg_conf_ctx ctx; |
3381cb8d | 1747 | struct cfq_group *cfqg; |
e48453c3 | 1748 | struct cfq_group_data *cfqgd; |
60c2bc2d TH |
1749 | int ret; |
1750 | ||
3c798398 | 1751 | ret = blkg_conf_prep(blkcg, &blkcg_policy_cfq, buf, &ctx); |
60c2bc2d TH |
1752 | if (ret) |
1753 | return ret; | |
1754 | ||
3381cb8d | 1755 | cfqg = blkg_to_cfqg(ctx.blkg); |
e48453c3 | 1756 | cfqgd = blkcg_to_cfqgd(blkcg); |
ae994ea9 | 1757 | |
20386ce0 | 1758 | ret = -ERANGE; |
a2b1693b | 1759 | if (!ctx.v || (ctx.v >= CFQ_WEIGHT_MIN && ctx.v <= CFQ_WEIGHT_MAX)) { |
e71357e1 TH |
1760 | if (!is_leaf_weight) { |
1761 | cfqg->dev_weight = ctx.v; | |
e48453c3 | 1762 | cfqg->new_weight = ctx.v ?: cfqgd->weight; |
e71357e1 TH |
1763 | } else { |
1764 | cfqg->dev_leaf_weight = ctx.v; | |
e48453c3 | 1765 | cfqg->new_leaf_weight = ctx.v ?: cfqgd->leaf_weight; |
e71357e1 | 1766 | } |
60c2bc2d TH |
1767 | ret = 0; |
1768 | } | |
1769 | ||
1770 | blkg_conf_finish(&ctx); | |
451af504 | 1771 | return ret ?: nbytes; |
60c2bc2d TH |
1772 | } |
1773 | ||
451af504 TH |
1774 | static ssize_t cfqg_set_weight_device(struct kernfs_open_file *of, |
1775 | char *buf, size_t nbytes, loff_t off) | |
e71357e1 | 1776 | { |
451af504 | 1777 | return __cfqg_set_weight_device(of, buf, nbytes, off, false); |
e71357e1 TH |
1778 | } |
1779 | ||
451af504 TH |
1780 | static ssize_t cfqg_set_leaf_weight_device(struct kernfs_open_file *of, |
1781 | char *buf, size_t nbytes, loff_t off) | |
e71357e1 | 1782 | { |
451af504 | 1783 | return __cfqg_set_weight_device(of, buf, nbytes, off, true); |
e71357e1 TH |
1784 | } |
1785 | ||
182446d0 TH |
1786 | static int __cfq_set_weight(struct cgroup_subsys_state *css, struct cftype *cft, |
1787 | u64 val, bool is_leaf_weight) | |
60c2bc2d | 1788 | { |
182446d0 | 1789 | struct blkcg *blkcg = css_to_blkcg(css); |
3c798398 | 1790 | struct blkcg_gq *blkg; |
e48453c3 | 1791 | struct cfq_group_data *cfqgd; |
ae994ea9 | 1792 | int ret = 0; |
60c2bc2d | 1793 | |
3381cb8d | 1794 | if (val < CFQ_WEIGHT_MIN || val > CFQ_WEIGHT_MAX) |
60c2bc2d TH |
1795 | return -EINVAL; |
1796 | ||
1797 | spin_lock_irq(&blkcg->lock); | |
e48453c3 | 1798 | cfqgd = blkcg_to_cfqgd(blkcg); |
ae994ea9 JA |
1799 | if (!cfqgd) { |
1800 | ret = -EINVAL; | |
1801 | goto out; | |
1802 | } | |
e71357e1 TH |
1803 | |
1804 | if (!is_leaf_weight) | |
e48453c3 | 1805 | cfqgd->weight = val; |
e71357e1 | 1806 | else |
e48453c3 | 1807 | cfqgd->leaf_weight = val; |
60c2bc2d | 1808 | |
b67bfe0d | 1809 | hlist_for_each_entry(blkg, &blkcg->blkg_list, blkcg_node) { |
3381cb8d | 1810 | struct cfq_group *cfqg = blkg_to_cfqg(blkg); |
60c2bc2d | 1811 | |
e71357e1 TH |
1812 | if (!cfqg) |
1813 | continue; | |
1814 | ||
1815 | if (!is_leaf_weight) { | |
1816 | if (!cfqg->dev_weight) | |
e48453c3 | 1817 | cfqg->new_weight = cfqgd->weight; |
e71357e1 TH |
1818 | } else { |
1819 | if (!cfqg->dev_leaf_weight) | |
e48453c3 | 1820 | cfqg->new_leaf_weight = cfqgd->leaf_weight; |
e71357e1 | 1821 | } |
60c2bc2d TH |
1822 | } |
1823 | ||
ae994ea9 | 1824 | out: |
60c2bc2d | 1825 | spin_unlock_irq(&blkcg->lock); |
ae994ea9 | 1826 | return ret; |
60c2bc2d TH |
1827 | } |
1828 | ||
182446d0 TH |
1829 | static int cfq_set_weight(struct cgroup_subsys_state *css, struct cftype *cft, |
1830 | u64 val) | |
e71357e1 | 1831 | { |
182446d0 | 1832 | return __cfq_set_weight(css, cft, val, false); |
e71357e1 TH |
1833 | } |
1834 | ||
182446d0 TH |
1835 | static int cfq_set_leaf_weight(struct cgroup_subsys_state *css, |
1836 | struct cftype *cft, u64 val) | |
e71357e1 | 1837 | { |
182446d0 | 1838 | return __cfq_set_weight(css, cft, val, true); |
e71357e1 TH |
1839 | } |
1840 | ||
2da8ca82 | 1841 | static int cfqg_print_stat(struct seq_file *sf, void *v) |
5bc4afb1 | 1842 | { |
2da8ca82 TH |
1843 | blkcg_print_blkgs(sf, css_to_blkcg(seq_css(sf)), blkg_prfill_stat, |
1844 | &blkcg_policy_cfq, seq_cft(sf)->private, false); | |
5bc4afb1 TH |
1845 | return 0; |
1846 | } | |
1847 | ||
2da8ca82 | 1848 | static int cfqg_print_rwstat(struct seq_file *sf, void *v) |
5bc4afb1 | 1849 | { |
2da8ca82 TH |
1850 | blkcg_print_blkgs(sf, css_to_blkcg(seq_css(sf)), blkg_prfill_rwstat, |
1851 | &blkcg_policy_cfq, seq_cft(sf)->private, true); | |
5bc4afb1 TH |
1852 | return 0; |
1853 | } | |
1854 | ||
43114018 TH |
1855 | static u64 cfqg_prfill_stat_recursive(struct seq_file *sf, |
1856 | struct blkg_policy_data *pd, int off) | |
1857 | { | |
f12c74ca TH |
1858 | u64 sum = blkg_stat_recursive_sum(pd_to_blkg(pd), |
1859 | &blkcg_policy_cfq, off); | |
43114018 TH |
1860 | return __blkg_prfill_u64(sf, pd, sum); |
1861 | } | |
1862 | ||
1863 | static u64 cfqg_prfill_rwstat_recursive(struct seq_file *sf, | |
1864 | struct blkg_policy_data *pd, int off) | |
1865 | { | |
f12c74ca TH |
1866 | struct blkg_rwstat sum = blkg_rwstat_recursive_sum(pd_to_blkg(pd), |
1867 | &blkcg_policy_cfq, off); | |
43114018 TH |
1868 | return __blkg_prfill_rwstat(sf, pd, &sum); |
1869 | } | |
1870 | ||
2da8ca82 | 1871 | static int cfqg_print_stat_recursive(struct seq_file *sf, void *v) |
43114018 | 1872 | { |
2da8ca82 TH |
1873 | blkcg_print_blkgs(sf, css_to_blkcg(seq_css(sf)), |
1874 | cfqg_prfill_stat_recursive, &blkcg_policy_cfq, | |
1875 | seq_cft(sf)->private, false); | |
43114018 TH |
1876 | return 0; |
1877 | } | |
1878 | ||
2da8ca82 | 1879 | static int cfqg_print_rwstat_recursive(struct seq_file *sf, void *v) |
43114018 | 1880 | { |
2da8ca82 TH |
1881 | blkcg_print_blkgs(sf, css_to_blkcg(seq_css(sf)), |
1882 | cfqg_prfill_rwstat_recursive, &blkcg_policy_cfq, | |
1883 | seq_cft(sf)->private, true); | |
43114018 TH |
1884 | return 0; |
1885 | } | |
1886 | ||
702747ca TH |
1887 | static u64 cfqg_prfill_sectors(struct seq_file *sf, struct blkg_policy_data *pd, |
1888 | int off) | |
1889 | { | |
1890 | u64 sum = blkg_rwstat_total(&pd->blkg->stat_bytes); | |
1891 | ||
1892 | return __blkg_prfill_u64(sf, pd, sum >> 9); | |
1893 | } | |
1894 | ||
1895 | static int cfqg_print_stat_sectors(struct seq_file *sf, void *v) | |
1896 | { | |
1897 | blkcg_print_blkgs(sf, css_to_blkcg(seq_css(sf)), | |
1898 | cfqg_prfill_sectors, &blkcg_policy_cfq, 0, false); | |
1899 | return 0; | |
1900 | } | |
1901 | ||
1902 | static u64 cfqg_prfill_sectors_recursive(struct seq_file *sf, | |
1903 | struct blkg_policy_data *pd, int off) | |
1904 | { | |
1905 | struct blkg_rwstat tmp = blkg_rwstat_recursive_sum(pd->blkg, NULL, | |
1906 | offsetof(struct blkcg_gq, stat_bytes)); | |
1907 | u64 sum = atomic64_read(&tmp.aux_cnt[BLKG_RWSTAT_READ]) + | |
1908 | atomic64_read(&tmp.aux_cnt[BLKG_RWSTAT_WRITE]); | |
1909 | ||
1910 | return __blkg_prfill_u64(sf, pd, sum >> 9); | |
1911 | } | |
1912 | ||
1913 | static int cfqg_print_stat_sectors_recursive(struct seq_file *sf, void *v) | |
1914 | { | |
1915 | blkcg_print_blkgs(sf, css_to_blkcg(seq_css(sf)), | |
1916 | cfqg_prfill_sectors_recursive, &blkcg_policy_cfq, 0, | |
1917 | false); | |
1918 | return 0; | |
1919 | } | |
1920 | ||
60c2bc2d | 1921 | #ifdef CONFIG_DEBUG_BLK_CGROUP |
f95a04af TH |
1922 | static u64 cfqg_prfill_avg_queue_size(struct seq_file *sf, |
1923 | struct blkg_policy_data *pd, int off) | |
60c2bc2d | 1924 | { |
f95a04af | 1925 | struct cfq_group *cfqg = pd_to_cfqg(pd); |
155fead9 | 1926 | u64 samples = blkg_stat_read(&cfqg->stats.avg_queue_size_samples); |
60c2bc2d TH |
1927 | u64 v = 0; |
1928 | ||
1929 | if (samples) { | |
155fead9 | 1930 | v = blkg_stat_read(&cfqg->stats.avg_queue_size_sum); |
f3cff25f | 1931 | v = div64_u64(v, samples); |
60c2bc2d | 1932 | } |
f95a04af | 1933 | __blkg_prfill_u64(sf, pd, v); |
60c2bc2d TH |
1934 | return 0; |
1935 | } | |
1936 | ||
1937 | /* print avg_queue_size */ | |
2da8ca82 | 1938 | static int cfqg_print_avg_queue_size(struct seq_file *sf, void *v) |
60c2bc2d | 1939 | { |
2da8ca82 TH |
1940 | blkcg_print_blkgs(sf, css_to_blkcg(seq_css(sf)), |
1941 | cfqg_prfill_avg_queue_size, &blkcg_policy_cfq, | |
1942 | 0, false); | |
60c2bc2d TH |
1943 | return 0; |
1944 | } | |
1945 | #endif /* CONFIG_DEBUG_BLK_CGROUP */ | |
1946 | ||
880f50e2 | 1947 | static struct cftype cfq_blkcg_legacy_files[] = { |
1d3650f7 | 1948 | /* on root, weight is mapped to leaf_weight */ |
60c2bc2d TH |
1949 | { |
1950 | .name = "weight_device", | |
1d3650f7 | 1951 | .flags = CFTYPE_ONLY_ON_ROOT, |
2da8ca82 | 1952 | .seq_show = cfqg_print_leaf_weight_device, |
451af504 | 1953 | .write = cfqg_set_leaf_weight_device, |
60c2bc2d TH |
1954 | }, |
1955 | { | |
1956 | .name = "weight", | |
1d3650f7 | 1957 | .flags = CFTYPE_ONLY_ON_ROOT, |
2da8ca82 | 1958 | .seq_show = cfq_print_leaf_weight, |
1d3650f7 | 1959 | .write_u64 = cfq_set_leaf_weight, |
60c2bc2d | 1960 | }, |
e71357e1 | 1961 | |
1d3650f7 | 1962 | /* no such mapping necessary for !roots */ |
60c2bc2d TH |
1963 | { |
1964 | .name = "weight_device", | |
1d3650f7 | 1965 | .flags = CFTYPE_NOT_ON_ROOT, |
2da8ca82 | 1966 | .seq_show = cfqg_print_weight_device, |
451af504 | 1967 | .write = cfqg_set_weight_device, |
60c2bc2d TH |
1968 | }, |
1969 | { | |
1970 | .name = "weight", | |
1d3650f7 | 1971 | .flags = CFTYPE_NOT_ON_ROOT, |
2da8ca82 | 1972 | .seq_show = cfq_print_weight, |
3381cb8d | 1973 | .write_u64 = cfq_set_weight, |
60c2bc2d | 1974 | }, |
e71357e1 | 1975 | |
e71357e1 TH |
1976 | { |
1977 | .name = "leaf_weight_device", | |
2da8ca82 | 1978 | .seq_show = cfqg_print_leaf_weight_device, |
451af504 | 1979 | .write = cfqg_set_leaf_weight_device, |
e71357e1 TH |
1980 | }, |
1981 | { | |
1982 | .name = "leaf_weight", | |
2da8ca82 | 1983 | .seq_show = cfq_print_leaf_weight, |
e71357e1 TH |
1984 | .write_u64 = cfq_set_leaf_weight, |
1985 | }, | |
1986 | ||
43114018 | 1987 | /* statistics, covers only the tasks in the cfqg */ |
60c2bc2d TH |
1988 | { |
1989 | .name = "time", | |
5bc4afb1 | 1990 | .private = offsetof(struct cfq_group, stats.time), |
2da8ca82 | 1991 | .seq_show = cfqg_print_stat, |
60c2bc2d TH |
1992 | }, |
1993 | { | |
1994 | .name = "sectors", | |
702747ca | 1995 | .seq_show = cfqg_print_stat_sectors, |
60c2bc2d TH |
1996 | }, |
1997 | { | |
1998 | .name = "io_service_bytes", | |
77ea7338 TH |
1999 | .private = (unsigned long)&blkcg_policy_cfq, |
2000 | .seq_show = blkg_print_stat_bytes, | |
60c2bc2d TH |
2001 | }, |
2002 | { | |
2003 | .name = "io_serviced", | |
77ea7338 TH |
2004 | .private = (unsigned long)&blkcg_policy_cfq, |
2005 | .seq_show = blkg_print_stat_ios, | |
60c2bc2d TH |
2006 | }, |
2007 | { | |
2008 | .name = "io_service_time", | |
5bc4afb1 | 2009 | .private = offsetof(struct cfq_group, stats.service_time), |
2da8ca82 | 2010 | .seq_show = cfqg_print_rwstat, |
60c2bc2d TH |
2011 | }, |
2012 | { | |
2013 | .name = "io_wait_time", | |
5bc4afb1 | 2014 | .private = offsetof(struct cfq_group, stats.wait_time), |
2da8ca82 | 2015 | .seq_show = cfqg_print_rwstat, |
60c2bc2d TH |
2016 | }, |
2017 | { | |
2018 | .name = "io_merged", | |
5bc4afb1 | 2019 | .private = offsetof(struct cfq_group, stats.merged), |
2da8ca82 | 2020 | .seq_show = cfqg_print_rwstat, |
60c2bc2d TH |
2021 | }, |
2022 | { | |
2023 | .name = "io_queued", | |
5bc4afb1 | 2024 | .private = offsetof(struct cfq_group, stats.queued), |
2da8ca82 | 2025 | .seq_show = cfqg_print_rwstat, |
60c2bc2d | 2026 | }, |
43114018 TH |
2027 | |
2028 | /* the same statictics which cover the cfqg and its descendants */ | |
2029 | { | |
2030 | .name = "time_recursive", | |
2031 | .private = offsetof(struct cfq_group, stats.time), | |
2da8ca82 | 2032 | .seq_show = cfqg_print_stat_recursive, |
43114018 TH |
2033 | }, |
2034 | { | |
2035 | .name = "sectors_recursive", | |
702747ca | 2036 | .seq_show = cfqg_print_stat_sectors_recursive, |
43114018 TH |
2037 | }, |
2038 | { | |
2039 | .name = "io_service_bytes_recursive", | |
77ea7338 TH |
2040 | .private = (unsigned long)&blkcg_policy_cfq, |
2041 | .seq_show = blkg_print_stat_bytes_recursive, | |
43114018 TH |
2042 | }, |
2043 | { | |
2044 | .name = "io_serviced_recursive", | |
77ea7338 TH |
2045 | .private = (unsigned long)&blkcg_policy_cfq, |
2046 | .seq_show = blkg_print_stat_ios_recursive, | |
43114018 TH |
2047 | }, |
2048 | { | |
2049 | .name = "io_service_time_recursive", | |
2050 | .private = offsetof(struct cfq_group, stats.service_time), | |
2da8ca82 | 2051 | .seq_show = cfqg_print_rwstat_recursive, |
43114018 TH |
2052 | }, |
2053 | { | |
2054 | .name = "io_wait_time_recursive", | |
2055 | .private = offsetof(struct cfq_group, stats.wait_time), | |
2da8ca82 | 2056 | .seq_show = cfqg_print_rwstat_recursive, |
43114018 TH |
2057 | }, |
2058 | { | |
2059 | .name = "io_merged_recursive", | |
2060 | .private = offsetof(struct cfq_group, stats.merged), | |
2da8ca82 | 2061 | .seq_show = cfqg_print_rwstat_recursive, |
43114018 TH |
2062 | }, |
2063 | { | |
2064 | .name = "io_queued_recursive", | |
2065 | .private = offsetof(struct cfq_group, stats.queued), | |
2da8ca82 | 2066 | .seq_show = cfqg_print_rwstat_recursive, |
43114018 | 2067 | }, |
60c2bc2d TH |
2068 | #ifdef CONFIG_DEBUG_BLK_CGROUP |
2069 | { | |
2070 | .name = "avg_queue_size", | |
2da8ca82 | 2071 | .seq_show = cfqg_print_avg_queue_size, |
60c2bc2d TH |
2072 | }, |
2073 | { | |
2074 | .name = "group_wait_time", | |
5bc4afb1 | 2075 | .private = offsetof(struct cfq_group, stats.group_wait_time), |
2da8ca82 | 2076 | .seq_show = cfqg_print_stat, |
60c2bc2d TH |
2077 | }, |
2078 | { | |
2079 | .name = "idle_time", | |
5bc4afb1 | 2080 | .private = offsetof(struct cfq_group, stats.idle_time), |
2da8ca82 | 2081 | .seq_show = cfqg_print_stat, |
60c2bc2d TH |
2082 | }, |
2083 | { | |
2084 | .name = "empty_time", | |
5bc4afb1 | 2085 | .private = offsetof(struct cfq_group, stats.empty_time), |
2da8ca82 | 2086 | .seq_show = cfqg_print_stat, |
60c2bc2d TH |
2087 | }, |
2088 | { | |
2089 | .name = "dequeue", | |
5bc4afb1 | 2090 | .private = offsetof(struct cfq_group, stats.dequeue), |
2da8ca82 | 2091 | .seq_show = cfqg_print_stat, |
60c2bc2d TH |
2092 | }, |
2093 | { | |
2094 | .name = "unaccounted_time", | |
5bc4afb1 | 2095 | .private = offsetof(struct cfq_group, stats.unaccounted_time), |
2da8ca82 | 2096 | .seq_show = cfqg_print_stat, |
60c2bc2d TH |
2097 | }, |
2098 | #endif /* CONFIG_DEBUG_BLK_CGROUP */ | |
2099 | { } /* terminate */ | |
2100 | }; | |
25fb5169 | 2101 | #else /* GROUP_IOSCHED */ |
ae118896 TH |
2102 | static struct cfq_group *cfq_lookup_cfqg(struct cfq_data *cfqd, |
2103 | struct blkcg *blkcg) | |
25fb5169 | 2104 | { |
f51b802c | 2105 | return cfqd->root_group; |
25fb5169 | 2106 | } |
7f1dc8a2 | 2107 | |
25fb5169 VG |
2108 | static inline void |
2109 | cfq_link_cfqq_cfqg(struct cfq_queue *cfqq, struct cfq_group *cfqg) { | |
2110 | cfqq->cfqg = cfqg; | |
2111 | } | |
2112 | ||
2113 | #endif /* GROUP_IOSCHED */ | |
2114 | ||
498d3aa2 | 2115 | /* |
c0324a02 | 2116 | * The cfqd->service_trees holds all pending cfq_queue's that have |
498d3aa2 JA |
2117 | * requests waiting to be processed. It is sorted in the order that |
2118 | * we will service the queues. | |
2119 | */ | |
a36e71f9 | 2120 | static void cfq_service_tree_add(struct cfq_data *cfqd, struct cfq_queue *cfqq, |
a6151c3a | 2121 | bool add_front) |
d9e7620e | 2122 | { |
0871714e JA |
2123 | struct rb_node **p, *parent; |
2124 | struct cfq_queue *__cfqq; | |
d9e7620e | 2125 | unsigned long rb_key; |
34b98d03 | 2126 | struct cfq_rb_root *st; |
498d3aa2 | 2127 | int left; |
dae739eb | 2128 | int new_cfqq = 1; |
ae30c286 | 2129 | |
34b98d03 | 2130 | st = st_for(cfqq->cfqg, cfqq_class(cfqq), cfqq_type(cfqq)); |
0871714e JA |
2131 | if (cfq_class_idle(cfqq)) { |
2132 | rb_key = CFQ_IDLE_DELAY; | |
34b98d03 | 2133 | parent = rb_last(&st->rb); |
0871714e JA |
2134 | if (parent && parent != &cfqq->rb_node) { |
2135 | __cfqq = rb_entry(parent, struct cfq_queue, rb_node); | |
2136 | rb_key += __cfqq->rb_key; | |
2137 | } else | |
2138 | rb_key += jiffies; | |
2139 | } else if (!add_front) { | |
b9c8946b JA |
2140 | /* |
2141 | * Get our rb key offset. Subtract any residual slice | |
2142 | * value carried from last service. A negative resid | |
2143 | * count indicates slice overrun, and this should position | |
2144 | * the next service time further away in the tree. | |
2145 | */ | |
edd75ffd | 2146 | rb_key = cfq_slice_offset(cfqd, cfqq) + jiffies; |
b9c8946b | 2147 | rb_key -= cfqq->slice_resid; |
edd75ffd | 2148 | cfqq->slice_resid = 0; |
48e025e6 CZ |
2149 | } else { |
2150 | rb_key = -HZ; | |
34b98d03 | 2151 | __cfqq = cfq_rb_first(st); |
48e025e6 CZ |
2152 | rb_key += __cfqq ? __cfqq->rb_key : jiffies; |
2153 | } | |
1da177e4 | 2154 | |
d9e7620e | 2155 | if (!RB_EMPTY_NODE(&cfqq->rb_node)) { |
dae739eb | 2156 | new_cfqq = 0; |
99f9628a | 2157 | /* |
d9e7620e | 2158 | * same position, nothing more to do |
99f9628a | 2159 | */ |
34b98d03 | 2160 | if (rb_key == cfqq->rb_key && cfqq->service_tree == st) |
d9e7620e | 2161 | return; |
1da177e4 | 2162 | |
aa6f6a3d CZ |
2163 | cfq_rb_erase(&cfqq->rb_node, cfqq->service_tree); |
2164 | cfqq->service_tree = NULL; | |
1da177e4 | 2165 | } |
d9e7620e | 2166 | |
498d3aa2 | 2167 | left = 1; |
0871714e | 2168 | parent = NULL; |
34b98d03 VG |
2169 | cfqq->service_tree = st; |
2170 | p = &st->rb.rb_node; | |
d9e7620e JA |
2171 | while (*p) { |
2172 | parent = *p; | |
2173 | __cfqq = rb_entry(parent, struct cfq_queue, rb_node); | |
2174 | ||
0c534e0a | 2175 | /* |
c0324a02 | 2176 | * sort by key, that represents service time. |
0c534e0a | 2177 | */ |
c0324a02 | 2178 | if (time_before(rb_key, __cfqq->rb_key)) |
1f23f121 | 2179 | p = &parent->rb_left; |
c0324a02 | 2180 | else { |
1f23f121 | 2181 | p = &parent->rb_right; |
cc09e299 | 2182 | left = 0; |
c0324a02 | 2183 | } |
d9e7620e JA |
2184 | } |
2185 | ||
cc09e299 | 2186 | if (left) |
34b98d03 | 2187 | st->left = &cfqq->rb_node; |
cc09e299 | 2188 | |
d9e7620e JA |
2189 | cfqq->rb_key = rb_key; |
2190 | rb_link_node(&cfqq->rb_node, parent, p); | |
34b98d03 VG |
2191 | rb_insert_color(&cfqq->rb_node, &st->rb); |
2192 | st->count++; | |
20359f27 | 2193 | if (add_front || !new_cfqq) |
dae739eb | 2194 | return; |
8184f93e | 2195 | cfq_group_notify_queue_add(cfqd, cfqq->cfqg); |
1da177e4 LT |
2196 | } |
2197 | ||
a36e71f9 | 2198 | static struct cfq_queue * |
f2d1f0ae JA |
2199 | cfq_prio_tree_lookup(struct cfq_data *cfqd, struct rb_root *root, |
2200 | sector_t sector, struct rb_node **ret_parent, | |
2201 | struct rb_node ***rb_link) | |
a36e71f9 | 2202 | { |
a36e71f9 JA |
2203 | struct rb_node **p, *parent; |
2204 | struct cfq_queue *cfqq = NULL; | |
2205 | ||
2206 | parent = NULL; | |
2207 | p = &root->rb_node; | |
2208 | while (*p) { | |
2209 | struct rb_node **n; | |
2210 | ||
2211 | parent = *p; | |
2212 | cfqq = rb_entry(parent, struct cfq_queue, p_node); | |
2213 | ||
2214 | /* | |
2215 | * Sort strictly based on sector. Smallest to the left, | |
2216 | * largest to the right. | |
2217 | */ | |
2e46e8b2 | 2218 | if (sector > blk_rq_pos(cfqq->next_rq)) |
a36e71f9 | 2219 | n = &(*p)->rb_right; |
2e46e8b2 | 2220 | else if (sector < blk_rq_pos(cfqq->next_rq)) |
a36e71f9 JA |
2221 | n = &(*p)->rb_left; |
2222 | else | |
2223 | break; | |
2224 | p = n; | |
3ac6c9f8 | 2225 | cfqq = NULL; |
a36e71f9 JA |
2226 | } |
2227 | ||
2228 | *ret_parent = parent; | |
2229 | if (rb_link) | |
2230 | *rb_link = p; | |
3ac6c9f8 | 2231 | return cfqq; |
a36e71f9 JA |
2232 | } |
2233 | ||
2234 | static void cfq_prio_tree_add(struct cfq_data *cfqd, struct cfq_queue *cfqq) | |
2235 | { | |
a36e71f9 JA |
2236 | struct rb_node **p, *parent; |
2237 | struct cfq_queue *__cfqq; | |
2238 | ||
f2d1f0ae JA |
2239 | if (cfqq->p_root) { |
2240 | rb_erase(&cfqq->p_node, cfqq->p_root); | |
2241 | cfqq->p_root = NULL; | |
2242 | } | |
a36e71f9 JA |
2243 | |
2244 | if (cfq_class_idle(cfqq)) | |
2245 | return; | |
2246 | if (!cfqq->next_rq) | |
2247 | return; | |
2248 | ||
f2d1f0ae | 2249 | cfqq->p_root = &cfqd->prio_trees[cfqq->org_ioprio]; |
2e46e8b2 TH |
2250 | __cfqq = cfq_prio_tree_lookup(cfqd, cfqq->p_root, |
2251 | blk_rq_pos(cfqq->next_rq), &parent, &p); | |
3ac6c9f8 JA |
2252 | if (!__cfqq) { |
2253 | rb_link_node(&cfqq->p_node, parent, p); | |
f2d1f0ae JA |
2254 | rb_insert_color(&cfqq->p_node, cfqq->p_root); |
2255 | } else | |
2256 | cfqq->p_root = NULL; | |
a36e71f9 JA |
2257 | } |
2258 | ||
498d3aa2 JA |
2259 | /* |
2260 | * Update cfqq's position in the service tree. | |
2261 | */ | |
edd75ffd | 2262 | static void cfq_resort_rr_list(struct cfq_data *cfqd, struct cfq_queue *cfqq) |
6d048f53 | 2263 | { |
6d048f53 JA |
2264 | /* |
2265 | * Resorting requires the cfqq to be on the RR list already. | |
2266 | */ | |
a36e71f9 | 2267 | if (cfq_cfqq_on_rr(cfqq)) { |
edd75ffd | 2268 | cfq_service_tree_add(cfqd, cfqq, 0); |
a36e71f9 JA |
2269 | cfq_prio_tree_add(cfqd, cfqq); |
2270 | } | |
6d048f53 JA |
2271 | } |
2272 | ||
1da177e4 LT |
2273 | /* |
2274 | * add to busy list of queues for service, trying to be fair in ordering | |
22e2c507 | 2275 | * the pending list according to last request service |
1da177e4 | 2276 | */ |
febffd61 | 2277 | static void cfq_add_cfqq_rr(struct cfq_data *cfqd, struct cfq_queue *cfqq) |
1da177e4 | 2278 | { |
7b679138 | 2279 | cfq_log_cfqq(cfqd, cfqq, "add_to_rr"); |
3b18152c JA |
2280 | BUG_ON(cfq_cfqq_on_rr(cfqq)); |
2281 | cfq_mark_cfqq_on_rr(cfqq); | |
1da177e4 | 2282 | cfqd->busy_queues++; |
ef8a41df SL |
2283 | if (cfq_cfqq_sync(cfqq)) |
2284 | cfqd->busy_sync_queues++; | |
1da177e4 | 2285 | |
edd75ffd | 2286 | cfq_resort_rr_list(cfqd, cfqq); |
1da177e4 LT |
2287 | } |
2288 | ||
498d3aa2 JA |
2289 | /* |
2290 | * Called when the cfqq no longer has requests pending, remove it from | |
2291 | * the service tree. | |
2292 | */ | |
febffd61 | 2293 | static void cfq_del_cfqq_rr(struct cfq_data *cfqd, struct cfq_queue *cfqq) |
1da177e4 | 2294 | { |
7b679138 | 2295 | cfq_log_cfqq(cfqd, cfqq, "del_from_rr"); |
3b18152c JA |
2296 | BUG_ON(!cfq_cfqq_on_rr(cfqq)); |
2297 | cfq_clear_cfqq_on_rr(cfqq); | |
1da177e4 | 2298 | |
aa6f6a3d CZ |
2299 | if (!RB_EMPTY_NODE(&cfqq->rb_node)) { |
2300 | cfq_rb_erase(&cfqq->rb_node, cfqq->service_tree); | |
2301 | cfqq->service_tree = NULL; | |
2302 | } | |
f2d1f0ae JA |
2303 | if (cfqq->p_root) { |
2304 | rb_erase(&cfqq->p_node, cfqq->p_root); | |
2305 | cfqq->p_root = NULL; | |
2306 | } | |
d9e7620e | 2307 | |
8184f93e | 2308 | cfq_group_notify_queue_del(cfqd, cfqq->cfqg); |
1da177e4 LT |
2309 | BUG_ON(!cfqd->busy_queues); |
2310 | cfqd->busy_queues--; | |
ef8a41df SL |
2311 | if (cfq_cfqq_sync(cfqq)) |
2312 | cfqd->busy_sync_queues--; | |
1da177e4 LT |
2313 | } |
2314 | ||
2315 | /* | |
2316 | * rb tree support functions | |
2317 | */ | |
febffd61 | 2318 | static void cfq_del_rq_rb(struct request *rq) |
1da177e4 | 2319 | { |
5e705374 | 2320 | struct cfq_queue *cfqq = RQ_CFQQ(rq); |
5e705374 | 2321 | const int sync = rq_is_sync(rq); |
1da177e4 | 2322 | |
b4878f24 JA |
2323 | BUG_ON(!cfqq->queued[sync]); |
2324 | cfqq->queued[sync]--; | |
1da177e4 | 2325 | |
5e705374 | 2326 | elv_rb_del(&cfqq->sort_list, rq); |
1da177e4 | 2327 | |
f04a6424 VG |
2328 | if (cfq_cfqq_on_rr(cfqq) && RB_EMPTY_ROOT(&cfqq->sort_list)) { |
2329 | /* | |
2330 | * Queue will be deleted from service tree when we actually | |
2331 | * expire it later. Right now just remove it from prio tree | |
2332 | * as it is empty. | |
2333 | */ | |
2334 | if (cfqq->p_root) { | |
2335 | rb_erase(&cfqq->p_node, cfqq->p_root); | |
2336 | cfqq->p_root = NULL; | |
2337 | } | |
2338 | } | |
1da177e4 LT |
2339 | } |
2340 | ||
5e705374 | 2341 | static void cfq_add_rq_rb(struct request *rq) |
1da177e4 | 2342 | { |
5e705374 | 2343 | struct cfq_queue *cfqq = RQ_CFQQ(rq); |
1da177e4 | 2344 | struct cfq_data *cfqd = cfqq->cfqd; |
796d5116 | 2345 | struct request *prev; |
1da177e4 | 2346 | |
5380a101 | 2347 | cfqq->queued[rq_is_sync(rq)]++; |
1da177e4 | 2348 | |
796d5116 | 2349 | elv_rb_add(&cfqq->sort_list, rq); |
5fccbf61 JA |
2350 | |
2351 | if (!cfq_cfqq_on_rr(cfqq)) | |
2352 | cfq_add_cfqq_rr(cfqd, cfqq); | |
5044eed4 JA |
2353 | |
2354 | /* | |
2355 | * check if this request is a better next-serve candidate | |
2356 | */ | |
a36e71f9 | 2357 | prev = cfqq->next_rq; |
cf7c25cf | 2358 | cfqq->next_rq = cfq_choose_req(cfqd, cfqq->next_rq, rq, cfqd->last_position); |
a36e71f9 JA |
2359 | |
2360 | /* | |
2361 | * adjust priority tree position, if ->next_rq changes | |
2362 | */ | |
2363 | if (prev != cfqq->next_rq) | |
2364 | cfq_prio_tree_add(cfqd, cfqq); | |
2365 | ||
5044eed4 | 2366 | BUG_ON(!cfqq->next_rq); |
1da177e4 LT |
2367 | } |
2368 | ||
febffd61 | 2369 | static void cfq_reposition_rq_rb(struct cfq_queue *cfqq, struct request *rq) |
1da177e4 | 2370 | { |
5380a101 JA |
2371 | elv_rb_del(&cfqq->sort_list, rq); |
2372 | cfqq->queued[rq_is_sync(rq)]--; | |
155fead9 | 2373 | cfqg_stats_update_io_remove(RQ_CFQG(rq), rq->cmd_flags); |
5e705374 | 2374 | cfq_add_rq_rb(rq); |
155fead9 TH |
2375 | cfqg_stats_update_io_add(RQ_CFQG(rq), cfqq->cfqd->serving_group, |
2376 | rq->cmd_flags); | |
1da177e4 LT |
2377 | } |
2378 | ||
206dc69b JA |
2379 | static struct request * |
2380 | cfq_find_rq_fmerge(struct cfq_data *cfqd, struct bio *bio) | |
1da177e4 | 2381 | { |
206dc69b | 2382 | struct task_struct *tsk = current; |
c5869807 | 2383 | struct cfq_io_cq *cic; |
206dc69b | 2384 | struct cfq_queue *cfqq; |
1da177e4 | 2385 | |
4ac845a2 | 2386 | cic = cfq_cic_lookup(cfqd, tsk->io_context); |
91fac317 VT |
2387 | if (!cic) |
2388 | return NULL; | |
2389 | ||
2390 | cfqq = cic_to_cfqq(cic, cfq_bio_sync(bio)); | |
f73a1c7d KO |
2391 | if (cfqq) |
2392 | return elv_rb_find(&cfqq->sort_list, bio_end_sector(bio)); | |
1da177e4 | 2393 | |
1da177e4 LT |
2394 | return NULL; |
2395 | } | |
2396 | ||
165125e1 | 2397 | static void cfq_activate_request(struct request_queue *q, struct request *rq) |
1da177e4 | 2398 | { |
22e2c507 | 2399 | struct cfq_data *cfqd = q->elevator->elevator_data; |
3b18152c | 2400 | |
53c583d2 | 2401 | cfqd->rq_in_driver++; |
7b679138 | 2402 | cfq_log_cfqq(cfqd, RQ_CFQQ(rq), "activate rq, drv=%d", |
53c583d2 | 2403 | cfqd->rq_in_driver); |
25776e35 | 2404 | |
5b93629b | 2405 | cfqd->last_position = blk_rq_pos(rq) + blk_rq_sectors(rq); |
1da177e4 LT |
2406 | } |
2407 | ||
165125e1 | 2408 | static void cfq_deactivate_request(struct request_queue *q, struct request *rq) |
1da177e4 | 2409 | { |
b4878f24 JA |
2410 | struct cfq_data *cfqd = q->elevator->elevator_data; |
2411 | ||
53c583d2 CZ |
2412 | WARN_ON(!cfqd->rq_in_driver); |
2413 | cfqd->rq_in_driver--; | |
7b679138 | 2414 | cfq_log_cfqq(cfqd, RQ_CFQQ(rq), "deactivate rq, drv=%d", |
53c583d2 | 2415 | cfqd->rq_in_driver); |
1da177e4 LT |
2416 | } |
2417 | ||
b4878f24 | 2418 | static void cfq_remove_request(struct request *rq) |
1da177e4 | 2419 | { |
5e705374 | 2420 | struct cfq_queue *cfqq = RQ_CFQQ(rq); |
21183b07 | 2421 | |
5e705374 JA |
2422 | if (cfqq->next_rq == rq) |
2423 | cfqq->next_rq = cfq_find_next_rq(cfqq->cfqd, cfqq, rq); | |
1da177e4 | 2424 | |
b4878f24 | 2425 | list_del_init(&rq->queuelist); |
5e705374 | 2426 | cfq_del_rq_rb(rq); |
374f84ac | 2427 | |
45333d5a | 2428 | cfqq->cfqd->rq_queued--; |
155fead9 | 2429 | cfqg_stats_update_io_remove(RQ_CFQG(rq), rq->cmd_flags); |
65299a3b CH |
2430 | if (rq->cmd_flags & REQ_PRIO) { |
2431 | WARN_ON(!cfqq->prio_pending); | |
2432 | cfqq->prio_pending--; | |
b53d1ed7 | 2433 | } |
1da177e4 LT |
2434 | } |
2435 | ||
165125e1 JA |
2436 | static int cfq_merge(struct request_queue *q, struct request **req, |
2437 | struct bio *bio) | |
1da177e4 LT |
2438 | { |
2439 | struct cfq_data *cfqd = q->elevator->elevator_data; | |
2440 | struct request *__rq; | |
1da177e4 | 2441 | |
206dc69b | 2442 | __rq = cfq_find_rq_fmerge(cfqd, bio); |
22e2c507 | 2443 | if (__rq && elv_rq_merge_ok(__rq, bio)) { |
9817064b JA |
2444 | *req = __rq; |
2445 | return ELEVATOR_FRONT_MERGE; | |
1da177e4 LT |
2446 | } |
2447 | ||
2448 | return ELEVATOR_NO_MERGE; | |
1da177e4 LT |
2449 | } |
2450 | ||
165125e1 | 2451 | static void cfq_merged_request(struct request_queue *q, struct request *req, |
21183b07 | 2452 | int type) |
1da177e4 | 2453 | { |
21183b07 | 2454 | if (type == ELEVATOR_FRONT_MERGE) { |
5e705374 | 2455 | struct cfq_queue *cfqq = RQ_CFQQ(req); |
1da177e4 | 2456 | |
5e705374 | 2457 | cfq_reposition_rq_rb(cfqq, req); |
1da177e4 | 2458 | } |
1da177e4 LT |
2459 | } |
2460 | ||
812d4026 DS |
2461 | static void cfq_bio_merged(struct request_queue *q, struct request *req, |
2462 | struct bio *bio) | |
2463 | { | |
155fead9 | 2464 | cfqg_stats_update_io_merged(RQ_CFQG(req), bio->bi_rw); |
812d4026 DS |
2465 | } |
2466 | ||
1da177e4 | 2467 | static void |
165125e1 | 2468 | cfq_merged_requests(struct request_queue *q, struct request *rq, |
1da177e4 LT |
2469 | struct request *next) |
2470 | { | |
cf7c25cf | 2471 | struct cfq_queue *cfqq = RQ_CFQQ(rq); |
4a0b75c7 SL |
2472 | struct cfq_data *cfqd = q->elevator->elevator_data; |
2473 | ||
22e2c507 JA |
2474 | /* |
2475 | * reposition in fifo if next is older than rq | |
2476 | */ | |
2477 | if (!list_empty(&rq->queuelist) && !list_empty(&next->queuelist) && | |
8b4922d3 | 2478 | time_before(next->fifo_time, rq->fifo_time) && |
3d106fba | 2479 | cfqq == RQ_CFQQ(next)) { |
22e2c507 | 2480 | list_move(&rq->queuelist, &next->queuelist); |
8b4922d3 | 2481 | rq->fifo_time = next->fifo_time; |
30996f40 | 2482 | } |
22e2c507 | 2483 | |
cf7c25cf CZ |
2484 | if (cfqq->next_rq == next) |
2485 | cfqq->next_rq = rq; | |
b4878f24 | 2486 | cfq_remove_request(next); |
155fead9 | 2487 | cfqg_stats_update_io_merged(RQ_CFQG(rq), next->cmd_flags); |
4a0b75c7 SL |
2488 | |
2489 | cfqq = RQ_CFQQ(next); | |
2490 | /* | |
2491 | * all requests of this queue are merged to other queues, delete it | |
2492 | * from the service tree. If it's the active_queue, | |
2493 | * cfq_dispatch_requests() will choose to expire it or do idle | |
2494 | */ | |
2495 | if (cfq_cfqq_on_rr(cfqq) && RB_EMPTY_ROOT(&cfqq->sort_list) && | |
2496 | cfqq != cfqd->active_queue) | |
2497 | cfq_del_cfqq_rr(cfqd, cfqq); | |
22e2c507 JA |
2498 | } |
2499 | ||
165125e1 | 2500 | static int cfq_allow_merge(struct request_queue *q, struct request *rq, |
da775265 JA |
2501 | struct bio *bio) |
2502 | { | |
2503 | struct cfq_data *cfqd = q->elevator->elevator_data; | |
c5869807 | 2504 | struct cfq_io_cq *cic; |
da775265 | 2505 | struct cfq_queue *cfqq; |
da775265 JA |
2506 | |
2507 | /* | |
ec8acb69 | 2508 | * Disallow merge of a sync bio into an async request. |
da775265 | 2509 | */ |
91fac317 | 2510 | if (cfq_bio_sync(bio) && !rq_is_sync(rq)) |
a6151c3a | 2511 | return false; |
da775265 JA |
2512 | |
2513 | /* | |
f1a4f4d3 | 2514 | * Lookup the cfqq that this bio will be queued with and allow |
07c2bd37 | 2515 | * merge only if rq is queued there. |
f1a4f4d3 | 2516 | */ |
07c2bd37 TH |
2517 | cic = cfq_cic_lookup(cfqd, current->io_context); |
2518 | if (!cic) | |
2519 | return false; | |
719d3402 | 2520 | |
91fac317 | 2521 | cfqq = cic_to_cfqq(cic, cfq_bio_sync(bio)); |
a6151c3a | 2522 | return cfqq == RQ_CFQQ(rq); |
da775265 JA |
2523 | } |
2524 | ||
812df48d DS |
2525 | static inline void cfq_del_timer(struct cfq_data *cfqd, struct cfq_queue *cfqq) |
2526 | { | |
2527 | del_timer(&cfqd->idle_slice_timer); | |
155fead9 | 2528 | cfqg_stats_update_idle_time(cfqq->cfqg); |
812df48d DS |
2529 | } |
2530 | ||
febffd61 JA |
2531 | static void __cfq_set_active_queue(struct cfq_data *cfqd, |
2532 | struct cfq_queue *cfqq) | |
22e2c507 JA |
2533 | { |
2534 | if (cfqq) { | |
3bf10fea | 2535 | cfq_log_cfqq(cfqd, cfqq, "set_active wl_class:%d wl_type:%d", |
4d2ceea4 | 2536 | cfqd->serving_wl_class, cfqd->serving_wl_type); |
155fead9 | 2537 | cfqg_stats_update_avg_queue_size(cfqq->cfqg); |
62a37f6b JT |
2538 | cfqq->slice_start = 0; |
2539 | cfqq->dispatch_start = jiffies; | |
2540 | cfqq->allocated_slice = 0; | |
2541 | cfqq->slice_end = 0; | |
2542 | cfqq->slice_dispatch = 0; | |
2543 | cfqq->nr_sectors = 0; | |
2544 | ||
2545 | cfq_clear_cfqq_wait_request(cfqq); | |
2546 | cfq_clear_cfqq_must_dispatch(cfqq); | |
2547 | cfq_clear_cfqq_must_alloc_slice(cfqq); | |
2548 | cfq_clear_cfqq_fifo_expire(cfqq); | |
2549 | cfq_mark_cfqq_slice_new(cfqq); | |
2550 | ||
2551 | cfq_del_timer(cfqd, cfqq); | |
22e2c507 JA |
2552 | } |
2553 | ||
2554 | cfqd->active_queue = cfqq; | |
2555 | } | |
2556 | ||
7b14e3b5 JA |
2557 | /* |
2558 | * current cfqq expired its slice (or was too idle), select new one | |
2559 | */ | |
2560 | static void | |
2561 | __cfq_slice_expired(struct cfq_data *cfqd, struct cfq_queue *cfqq, | |
e5ff082e | 2562 | bool timed_out) |
7b14e3b5 | 2563 | { |
7b679138 JA |
2564 | cfq_log_cfqq(cfqd, cfqq, "slice expired t=%d", timed_out); |
2565 | ||
7b14e3b5 | 2566 | if (cfq_cfqq_wait_request(cfqq)) |
812df48d | 2567 | cfq_del_timer(cfqd, cfqq); |
7b14e3b5 | 2568 | |
7b14e3b5 | 2569 | cfq_clear_cfqq_wait_request(cfqq); |
f75edf2d | 2570 | cfq_clear_cfqq_wait_busy(cfqq); |
7b14e3b5 | 2571 | |
ae54abed SL |
2572 | /* |
2573 | * If this cfqq is shared between multiple processes, check to | |
2574 | * make sure that those processes are still issuing I/Os within | |
2575 | * the mean seek distance. If not, it may be time to break the | |
2576 | * queues apart again. | |
2577 | */ | |
2578 | if (cfq_cfqq_coop(cfqq) && CFQQ_SEEKY(cfqq)) | |
2579 | cfq_mark_cfqq_split_coop(cfqq); | |
2580 | ||
7b14e3b5 | 2581 | /* |
6084cdda | 2582 | * store what was left of this slice, if the queue idled/timed out |
7b14e3b5 | 2583 | */ |
c553f8e3 SL |
2584 | if (timed_out) { |
2585 | if (cfq_cfqq_slice_new(cfqq)) | |
ba5bd520 | 2586 | cfqq->slice_resid = cfq_scaled_cfqq_slice(cfqd, cfqq); |
c553f8e3 SL |
2587 | else |
2588 | cfqq->slice_resid = cfqq->slice_end - jiffies; | |
7b679138 JA |
2589 | cfq_log_cfqq(cfqd, cfqq, "resid=%ld", cfqq->slice_resid); |
2590 | } | |
7b14e3b5 | 2591 | |
e5ff082e | 2592 | cfq_group_served(cfqd, cfqq->cfqg, cfqq); |
dae739eb | 2593 | |
f04a6424 VG |
2594 | if (cfq_cfqq_on_rr(cfqq) && RB_EMPTY_ROOT(&cfqq->sort_list)) |
2595 | cfq_del_cfqq_rr(cfqd, cfqq); | |
2596 | ||
edd75ffd | 2597 | cfq_resort_rr_list(cfqd, cfqq); |
7b14e3b5 JA |
2598 | |
2599 | if (cfqq == cfqd->active_queue) | |
2600 | cfqd->active_queue = NULL; | |
2601 | ||
2602 | if (cfqd->active_cic) { | |
11a3122f | 2603 | put_io_context(cfqd->active_cic->icq.ioc); |
7b14e3b5 JA |
2604 | cfqd->active_cic = NULL; |
2605 | } | |
7b14e3b5 JA |
2606 | } |
2607 | ||
e5ff082e | 2608 | static inline void cfq_slice_expired(struct cfq_data *cfqd, bool timed_out) |
7b14e3b5 JA |
2609 | { |
2610 | struct cfq_queue *cfqq = cfqd->active_queue; | |
2611 | ||
2612 | if (cfqq) | |
e5ff082e | 2613 | __cfq_slice_expired(cfqd, cfqq, timed_out); |
7b14e3b5 JA |
2614 | } |
2615 | ||
498d3aa2 JA |
2616 | /* |
2617 | * Get next queue for service. Unless we have a queue preemption, | |
2618 | * we'll simply select the first cfqq in the service tree. | |
2619 | */ | |
6d048f53 | 2620 | static struct cfq_queue *cfq_get_next_queue(struct cfq_data *cfqd) |
22e2c507 | 2621 | { |
34b98d03 VG |
2622 | struct cfq_rb_root *st = st_for(cfqd->serving_group, |
2623 | cfqd->serving_wl_class, cfqd->serving_wl_type); | |
d9e7620e | 2624 | |
f04a6424 VG |
2625 | if (!cfqd->rq_queued) |
2626 | return NULL; | |
2627 | ||
1fa8f6d6 | 2628 | /* There is nothing to dispatch */ |
34b98d03 | 2629 | if (!st) |
1fa8f6d6 | 2630 | return NULL; |
34b98d03 | 2631 | if (RB_EMPTY_ROOT(&st->rb)) |
c0324a02 | 2632 | return NULL; |
34b98d03 | 2633 | return cfq_rb_first(st); |
6d048f53 JA |
2634 | } |
2635 | ||
f04a6424 VG |
2636 | static struct cfq_queue *cfq_get_next_queue_forced(struct cfq_data *cfqd) |
2637 | { | |
25fb5169 | 2638 | struct cfq_group *cfqg; |
f04a6424 VG |
2639 | struct cfq_queue *cfqq; |
2640 | int i, j; | |
2641 | struct cfq_rb_root *st; | |
2642 | ||
2643 | if (!cfqd->rq_queued) | |
2644 | return NULL; | |
2645 | ||
25fb5169 VG |
2646 | cfqg = cfq_get_next_cfqg(cfqd); |
2647 | if (!cfqg) | |
2648 | return NULL; | |
2649 | ||
f04a6424 VG |
2650 | for_each_cfqg_st(cfqg, i, j, st) |
2651 | if ((cfqq = cfq_rb_first(st)) != NULL) | |
2652 | return cfqq; | |
2653 | return NULL; | |
2654 | } | |
2655 | ||
498d3aa2 JA |
2656 | /* |
2657 | * Get and set a new active queue for service. | |
2658 | */ | |
a36e71f9 JA |
2659 | static struct cfq_queue *cfq_set_active_queue(struct cfq_data *cfqd, |
2660 | struct cfq_queue *cfqq) | |
6d048f53 | 2661 | { |
e00ef799 | 2662 | if (!cfqq) |
a36e71f9 | 2663 | cfqq = cfq_get_next_queue(cfqd); |
6d048f53 | 2664 | |
22e2c507 | 2665 | __cfq_set_active_queue(cfqd, cfqq); |
3b18152c | 2666 | return cfqq; |
22e2c507 JA |
2667 | } |
2668 | ||
d9e7620e JA |
2669 | static inline sector_t cfq_dist_from_last(struct cfq_data *cfqd, |
2670 | struct request *rq) | |
2671 | { | |
83096ebf TH |
2672 | if (blk_rq_pos(rq) >= cfqd->last_position) |
2673 | return blk_rq_pos(rq) - cfqd->last_position; | |
d9e7620e | 2674 | else |
83096ebf | 2675 | return cfqd->last_position - blk_rq_pos(rq); |
d9e7620e JA |
2676 | } |
2677 | ||
b2c18e1e | 2678 | static inline int cfq_rq_close(struct cfq_data *cfqd, struct cfq_queue *cfqq, |
e9ce335d | 2679 | struct request *rq) |
6d048f53 | 2680 | { |
e9ce335d | 2681 | return cfq_dist_from_last(cfqd, rq) <= CFQQ_CLOSE_THR; |
6d048f53 JA |
2682 | } |
2683 | ||
a36e71f9 JA |
2684 | static struct cfq_queue *cfqq_close(struct cfq_data *cfqd, |
2685 | struct cfq_queue *cur_cfqq) | |
2686 | { | |
f2d1f0ae | 2687 | struct rb_root *root = &cfqd->prio_trees[cur_cfqq->org_ioprio]; |
a36e71f9 JA |
2688 | struct rb_node *parent, *node; |
2689 | struct cfq_queue *__cfqq; | |
2690 | sector_t sector = cfqd->last_position; | |
2691 | ||
2692 | if (RB_EMPTY_ROOT(root)) | |
2693 | return NULL; | |
2694 | ||
2695 | /* | |
2696 | * First, if we find a request starting at the end of the last | |
2697 | * request, choose it. | |
2698 | */ | |
f2d1f0ae | 2699 | __cfqq = cfq_prio_tree_lookup(cfqd, root, sector, &parent, NULL); |
a36e71f9 JA |
2700 | if (__cfqq) |
2701 | return __cfqq; | |
2702 | ||
2703 | /* | |
2704 | * If the exact sector wasn't found, the parent of the NULL leaf | |
2705 | * will contain the closest sector. | |
2706 | */ | |
2707 | __cfqq = rb_entry(parent, struct cfq_queue, p_node); | |
e9ce335d | 2708 | if (cfq_rq_close(cfqd, cur_cfqq, __cfqq->next_rq)) |
a36e71f9 JA |
2709 | return __cfqq; |
2710 | ||
2e46e8b2 | 2711 | if (blk_rq_pos(__cfqq->next_rq) < sector) |
a36e71f9 JA |
2712 | node = rb_next(&__cfqq->p_node); |
2713 | else | |
2714 | node = rb_prev(&__cfqq->p_node); | |
2715 | if (!node) | |
2716 | return NULL; | |
2717 | ||
2718 | __cfqq = rb_entry(node, struct cfq_queue, p_node); | |
e9ce335d | 2719 | if (cfq_rq_close(cfqd, cur_cfqq, __cfqq->next_rq)) |
a36e71f9 JA |
2720 | return __cfqq; |
2721 | ||
2722 | return NULL; | |
2723 | } | |
2724 | ||
2725 | /* | |
2726 | * cfqd - obvious | |
2727 | * cur_cfqq - passed in so that we don't decide that the current queue is | |
2728 | * closely cooperating with itself. | |
2729 | * | |
2730 | * So, basically we're assuming that that cur_cfqq has dispatched at least | |
2731 | * one request, and that cfqd->last_position reflects a position on the disk | |
2732 | * associated with the I/O issued by cur_cfqq. I'm not sure this is a valid | |
2733 | * assumption. | |
2734 | */ | |
2735 | static struct cfq_queue *cfq_close_cooperator(struct cfq_data *cfqd, | |
b3b6d040 | 2736 | struct cfq_queue *cur_cfqq) |
6d048f53 | 2737 | { |
a36e71f9 JA |
2738 | struct cfq_queue *cfqq; |
2739 | ||
39c01b21 DS |
2740 | if (cfq_class_idle(cur_cfqq)) |
2741 | return NULL; | |
e6c5bc73 JM |
2742 | if (!cfq_cfqq_sync(cur_cfqq)) |
2743 | return NULL; | |
2744 | if (CFQQ_SEEKY(cur_cfqq)) | |
2745 | return NULL; | |
2746 | ||
b9d8f4c7 GJ |
2747 | /* |
2748 | * Don't search priority tree if it's the only queue in the group. | |
2749 | */ | |
2750 | if (cur_cfqq->cfqg->nr_cfqq == 1) | |
2751 | return NULL; | |
2752 | ||
6d048f53 | 2753 | /* |
d9e7620e JA |
2754 | * We should notice if some of the queues are cooperating, eg |
2755 | * working closely on the same area of the disk. In that case, | |
2756 | * we can group them together and don't waste time idling. | |
6d048f53 | 2757 | */ |
a36e71f9 JA |
2758 | cfqq = cfqq_close(cfqd, cur_cfqq); |
2759 | if (!cfqq) | |
2760 | return NULL; | |
2761 | ||
8682e1f1 VG |
2762 | /* If new queue belongs to different cfq_group, don't choose it */ |
2763 | if (cur_cfqq->cfqg != cfqq->cfqg) | |
2764 | return NULL; | |
2765 | ||
df5fe3e8 JM |
2766 | /* |
2767 | * It only makes sense to merge sync queues. | |
2768 | */ | |
2769 | if (!cfq_cfqq_sync(cfqq)) | |
2770 | return NULL; | |
e6c5bc73 JM |
2771 | if (CFQQ_SEEKY(cfqq)) |
2772 | return NULL; | |
df5fe3e8 | 2773 | |
c0324a02 CZ |
2774 | /* |
2775 | * Do not merge queues of different priority classes | |
2776 | */ | |
2777 | if (cfq_class_rt(cfqq) != cfq_class_rt(cur_cfqq)) | |
2778 | return NULL; | |
2779 | ||
a36e71f9 | 2780 | return cfqq; |
6d048f53 JA |
2781 | } |
2782 | ||
a6d44e98 CZ |
2783 | /* |
2784 | * Determine whether we should enforce idle window for this queue. | |
2785 | */ | |
2786 | ||
2787 | static bool cfq_should_idle(struct cfq_data *cfqd, struct cfq_queue *cfqq) | |
2788 | { | |
3bf10fea | 2789 | enum wl_class_t wl_class = cfqq_class(cfqq); |
34b98d03 | 2790 | struct cfq_rb_root *st = cfqq->service_tree; |
a6d44e98 | 2791 | |
34b98d03 VG |
2792 | BUG_ON(!st); |
2793 | BUG_ON(!st->count); | |
f04a6424 | 2794 | |
b6508c16 VG |
2795 | if (!cfqd->cfq_slice_idle) |
2796 | return false; | |
2797 | ||
a6d44e98 | 2798 | /* We never do for idle class queues. */ |
3bf10fea | 2799 | if (wl_class == IDLE_WORKLOAD) |
a6d44e98 CZ |
2800 | return false; |
2801 | ||
2802 | /* We do for queues that were marked with idle window flag. */ | |
3c764b7a SL |
2803 | if (cfq_cfqq_idle_window(cfqq) && |
2804 | !(blk_queue_nonrot(cfqd->queue) && cfqd->hw_tag)) | |
a6d44e98 CZ |
2805 | return true; |
2806 | ||
2807 | /* | |
2808 | * Otherwise, we do only if they are the last ones | |
2809 | * in their service tree. | |
2810 | */ | |
34b98d03 VG |
2811 | if (st->count == 1 && cfq_cfqq_sync(cfqq) && |
2812 | !cfq_io_thinktime_big(cfqd, &st->ttime, false)) | |
c1e44756 | 2813 | return true; |
34b98d03 | 2814 | cfq_log_cfqq(cfqd, cfqq, "Not idling. st->count:%d", st->count); |
c1e44756 | 2815 | return false; |
a6d44e98 CZ |
2816 | } |
2817 | ||
6d048f53 | 2818 | static void cfq_arm_slice_timer(struct cfq_data *cfqd) |
22e2c507 | 2819 | { |
1792669c | 2820 | struct cfq_queue *cfqq = cfqd->active_queue; |
c5869807 | 2821 | struct cfq_io_cq *cic; |
80bdf0c7 | 2822 | unsigned long sl, group_idle = 0; |
7b14e3b5 | 2823 | |
a68bbddb | 2824 | /* |
f7d7b7a7 JA |
2825 | * SSD device without seek penalty, disable idling. But only do so |
2826 | * for devices that support queuing, otherwise we still have a problem | |
2827 | * with sync vs async workloads. | |
a68bbddb | 2828 | */ |
f7d7b7a7 | 2829 | if (blk_queue_nonrot(cfqd->queue) && cfqd->hw_tag) |
a68bbddb JA |
2830 | return; |
2831 | ||
dd67d051 | 2832 | WARN_ON(!RB_EMPTY_ROOT(&cfqq->sort_list)); |
6d048f53 | 2833 | WARN_ON(cfq_cfqq_slice_new(cfqq)); |
22e2c507 JA |
2834 | |
2835 | /* | |
2836 | * idle is disabled, either manually or by past process history | |
2837 | */ | |
80bdf0c7 VG |
2838 | if (!cfq_should_idle(cfqd, cfqq)) { |
2839 | /* no queue idling. Check for group idling */ | |
2840 | if (cfqd->cfq_group_idle) | |
2841 | group_idle = cfqd->cfq_group_idle; | |
2842 | else | |
2843 | return; | |
2844 | } | |
6d048f53 | 2845 | |
7b679138 | 2846 | /* |
8e550632 | 2847 | * still active requests from this queue, don't idle |
7b679138 | 2848 | */ |
8e550632 | 2849 | if (cfqq->dispatched) |
7b679138 JA |
2850 | return; |
2851 | ||
22e2c507 JA |
2852 | /* |
2853 | * task has exited, don't wait | |
2854 | */ | |
206dc69b | 2855 | cic = cfqd->active_cic; |
f6e8d01b | 2856 | if (!cic || !atomic_read(&cic->icq.ioc->active_ref)) |
6d048f53 JA |
2857 | return; |
2858 | ||
355b659c CZ |
2859 | /* |
2860 | * If our average think time is larger than the remaining time | |
2861 | * slice, then don't idle. This avoids overrunning the allotted | |
2862 | * time slice. | |
2863 | */ | |
383cd721 SL |
2864 | if (sample_valid(cic->ttime.ttime_samples) && |
2865 | (cfqq->slice_end - jiffies < cic->ttime.ttime_mean)) { | |
fd16d263 | 2866 | cfq_log_cfqq(cfqd, cfqq, "Not idling. think_time:%lu", |
383cd721 | 2867 | cic->ttime.ttime_mean); |
355b659c | 2868 | return; |
b1ffe737 | 2869 | } |
355b659c | 2870 | |
80bdf0c7 VG |
2871 | /* There are other queues in the group, don't do group idle */ |
2872 | if (group_idle && cfqq->cfqg->nr_cfqq > 1) | |
2873 | return; | |
2874 | ||
3b18152c | 2875 | cfq_mark_cfqq_wait_request(cfqq); |
22e2c507 | 2876 | |
80bdf0c7 VG |
2877 | if (group_idle) |
2878 | sl = cfqd->cfq_group_idle; | |
2879 | else | |
2880 | sl = cfqd->cfq_slice_idle; | |
206dc69b | 2881 | |
7b14e3b5 | 2882 | mod_timer(&cfqd->idle_slice_timer, jiffies + sl); |
155fead9 | 2883 | cfqg_stats_set_start_idle_time(cfqq->cfqg); |
80bdf0c7 VG |
2884 | cfq_log_cfqq(cfqd, cfqq, "arm_idle: %lu group_idle: %d", sl, |
2885 | group_idle ? 1 : 0); | |
1da177e4 LT |
2886 | } |
2887 | ||
498d3aa2 JA |
2888 | /* |
2889 | * Move request from internal lists to the request queue dispatch list. | |
2890 | */ | |
165125e1 | 2891 | static void cfq_dispatch_insert(struct request_queue *q, struct request *rq) |
1da177e4 | 2892 | { |
3ed9a296 | 2893 | struct cfq_data *cfqd = q->elevator->elevator_data; |
5e705374 | 2894 | struct cfq_queue *cfqq = RQ_CFQQ(rq); |
22e2c507 | 2895 | |
7b679138 JA |
2896 | cfq_log_cfqq(cfqd, cfqq, "dispatch_insert"); |
2897 | ||
06d21886 | 2898 | cfqq->next_rq = cfq_find_next_rq(cfqd, cfqq, rq); |
5380a101 | 2899 | cfq_remove_request(rq); |
6d048f53 | 2900 | cfqq->dispatched++; |
80bdf0c7 | 2901 | (RQ_CFQG(rq))->dispatched++; |
5380a101 | 2902 | elv_dispatch_sort(q, rq); |
3ed9a296 | 2903 | |
53c583d2 | 2904 | cfqd->rq_in_flight[cfq_cfqq_sync(cfqq)]++; |
c4e7893e | 2905 | cfqq->nr_sectors += blk_rq_sectors(rq); |
1da177e4 LT |
2906 | } |
2907 | ||
2908 | /* | |
2909 | * return expired entry, or NULL to just start from scratch in rbtree | |
2910 | */ | |
febffd61 | 2911 | static struct request *cfq_check_fifo(struct cfq_queue *cfqq) |
1da177e4 | 2912 | { |
30996f40 | 2913 | struct request *rq = NULL; |
1da177e4 | 2914 | |
3b18152c | 2915 | if (cfq_cfqq_fifo_expire(cfqq)) |
1da177e4 | 2916 | return NULL; |
cb887411 JA |
2917 | |
2918 | cfq_mark_cfqq_fifo_expire(cfqq); | |
2919 | ||
89850f7e JA |
2920 | if (list_empty(&cfqq->fifo)) |
2921 | return NULL; | |
1da177e4 | 2922 | |
89850f7e | 2923 | rq = rq_entry_fifo(cfqq->fifo.next); |
8b4922d3 | 2924 | if (time_before(jiffies, rq->fifo_time)) |
7b679138 | 2925 | rq = NULL; |
1da177e4 | 2926 | |
30996f40 | 2927 | cfq_log_cfqq(cfqq->cfqd, cfqq, "fifo=%p", rq); |
6d048f53 | 2928 | return rq; |
1da177e4 LT |
2929 | } |
2930 | ||
22e2c507 JA |
2931 | static inline int |
2932 | cfq_prio_to_maxrq(struct cfq_data *cfqd, struct cfq_queue *cfqq) | |
2933 | { | |
2934 | const int base_rq = cfqd->cfq_slice_async_rq; | |
1da177e4 | 2935 | |
22e2c507 | 2936 | WARN_ON(cfqq->ioprio >= IOPRIO_BE_NR); |
1da177e4 | 2937 | |
b9f8ce05 | 2938 | return 2 * base_rq * (IOPRIO_BE_NR - cfqq->ioprio); |
1da177e4 LT |
2939 | } |
2940 | ||
df5fe3e8 JM |
2941 | /* |
2942 | * Must be called with the queue_lock held. | |
2943 | */ | |
2944 | static int cfqq_process_refs(struct cfq_queue *cfqq) | |
2945 | { | |
2946 | int process_refs, io_refs; | |
2947 | ||
2948 | io_refs = cfqq->allocated[READ] + cfqq->allocated[WRITE]; | |
30d7b944 | 2949 | process_refs = cfqq->ref - io_refs; |
df5fe3e8 JM |
2950 | BUG_ON(process_refs < 0); |
2951 | return process_refs; | |
2952 | } | |
2953 | ||
2954 | static void cfq_setup_merge(struct cfq_queue *cfqq, struct cfq_queue *new_cfqq) | |
2955 | { | |
e6c5bc73 | 2956 | int process_refs, new_process_refs; |
df5fe3e8 JM |
2957 | struct cfq_queue *__cfqq; |
2958 | ||
c10b61f0 JM |
2959 | /* |
2960 | * If there are no process references on the new_cfqq, then it is | |
2961 | * unsafe to follow the ->new_cfqq chain as other cfqq's in the | |
2962 | * chain may have dropped their last reference (not just their | |
2963 | * last process reference). | |
2964 | */ | |
2965 | if (!cfqq_process_refs(new_cfqq)) | |
2966 | return; | |
2967 | ||
df5fe3e8 JM |
2968 | /* Avoid a circular list and skip interim queue merges */ |
2969 | while ((__cfqq = new_cfqq->new_cfqq)) { | |
2970 | if (__cfqq == cfqq) | |
2971 | return; | |
2972 | new_cfqq = __cfqq; | |
2973 | } | |
2974 | ||
2975 | process_refs = cfqq_process_refs(cfqq); | |
c10b61f0 | 2976 | new_process_refs = cfqq_process_refs(new_cfqq); |
df5fe3e8 JM |
2977 | /* |
2978 | * If the process for the cfqq has gone away, there is no | |
2979 | * sense in merging the queues. | |
2980 | */ | |
c10b61f0 | 2981 | if (process_refs == 0 || new_process_refs == 0) |
df5fe3e8 JM |
2982 | return; |
2983 | ||
e6c5bc73 JM |
2984 | /* |
2985 | * Merge in the direction of the lesser amount of work. | |
2986 | */ | |
e6c5bc73 JM |
2987 | if (new_process_refs >= process_refs) { |
2988 | cfqq->new_cfqq = new_cfqq; | |
30d7b944 | 2989 | new_cfqq->ref += process_refs; |
e6c5bc73 JM |
2990 | } else { |
2991 | new_cfqq->new_cfqq = cfqq; | |
30d7b944 | 2992 | cfqq->ref += new_process_refs; |
e6c5bc73 | 2993 | } |
df5fe3e8 JM |
2994 | } |
2995 | ||
6d816ec7 | 2996 | static enum wl_type_t cfq_choose_wl_type(struct cfq_data *cfqd, |
3bf10fea | 2997 | struct cfq_group *cfqg, enum wl_class_t wl_class) |
718eee05 CZ |
2998 | { |
2999 | struct cfq_queue *queue; | |
3000 | int i; | |
3001 | bool key_valid = false; | |
3002 | unsigned long lowest_key = 0; | |
3003 | enum wl_type_t cur_best = SYNC_NOIDLE_WORKLOAD; | |
3004 | ||
65b32a57 VG |
3005 | for (i = 0; i <= SYNC_WORKLOAD; ++i) { |
3006 | /* select the one with lowest rb_key */ | |
34b98d03 | 3007 | queue = cfq_rb_first(st_for(cfqg, wl_class, i)); |
718eee05 CZ |
3008 | if (queue && |
3009 | (!key_valid || time_before(queue->rb_key, lowest_key))) { | |
3010 | lowest_key = queue->rb_key; | |
3011 | cur_best = i; | |
3012 | key_valid = true; | |
3013 | } | |
3014 | } | |
3015 | ||
3016 | return cur_best; | |
3017 | } | |
3018 | ||
6d816ec7 VG |
3019 | static void |
3020 | choose_wl_class_and_type(struct cfq_data *cfqd, struct cfq_group *cfqg) | |
718eee05 | 3021 | { |
718eee05 CZ |
3022 | unsigned slice; |
3023 | unsigned count; | |
cdb16e8f | 3024 | struct cfq_rb_root *st; |
58ff82f3 | 3025 | unsigned group_slice; |
4d2ceea4 | 3026 | enum wl_class_t original_class = cfqd->serving_wl_class; |
1fa8f6d6 | 3027 | |
718eee05 | 3028 | /* Choose next priority. RT > BE > IDLE */ |
58ff82f3 | 3029 | if (cfq_group_busy_queues_wl(RT_WORKLOAD, cfqd, cfqg)) |
4d2ceea4 | 3030 | cfqd->serving_wl_class = RT_WORKLOAD; |
58ff82f3 | 3031 | else if (cfq_group_busy_queues_wl(BE_WORKLOAD, cfqd, cfqg)) |
4d2ceea4 | 3032 | cfqd->serving_wl_class = BE_WORKLOAD; |
718eee05 | 3033 | else { |
4d2ceea4 | 3034 | cfqd->serving_wl_class = IDLE_WORKLOAD; |
718eee05 CZ |
3035 | cfqd->workload_expires = jiffies + 1; |
3036 | return; | |
3037 | } | |
3038 | ||
4d2ceea4 | 3039 | if (original_class != cfqd->serving_wl_class) |
e4ea0c16 SL |
3040 | goto new_workload; |
3041 | ||
718eee05 CZ |
3042 | /* |
3043 | * For RT and BE, we have to choose also the type | |
3044 | * (SYNC, SYNC_NOIDLE, ASYNC), and to compute a workload | |
3045 | * expiration time | |
3046 | */ | |
34b98d03 | 3047 | st = st_for(cfqg, cfqd->serving_wl_class, cfqd->serving_wl_type); |
cdb16e8f | 3048 | count = st->count; |
718eee05 CZ |
3049 | |
3050 | /* | |
65b32a57 | 3051 | * check workload expiration, and that we still have other queues ready |
718eee05 | 3052 | */ |
65b32a57 | 3053 | if (count && !time_after(jiffies, cfqd->workload_expires)) |
718eee05 CZ |
3054 | return; |
3055 | ||
e4ea0c16 | 3056 | new_workload: |
718eee05 | 3057 | /* otherwise select new workload type */ |
6d816ec7 | 3058 | cfqd->serving_wl_type = cfq_choose_wl_type(cfqd, cfqg, |
4d2ceea4 | 3059 | cfqd->serving_wl_class); |
34b98d03 | 3060 | st = st_for(cfqg, cfqd->serving_wl_class, cfqd->serving_wl_type); |
cdb16e8f | 3061 | count = st->count; |
718eee05 CZ |
3062 | |
3063 | /* | |
3064 | * the workload slice is computed as a fraction of target latency | |
3065 | * proportional to the number of queues in that workload, over | |
3066 | * all the queues in the same priority class | |
3067 | */ | |
58ff82f3 VG |
3068 | group_slice = cfq_group_slice(cfqd, cfqg); |
3069 | ||
3070 | slice = group_slice * count / | |
4d2ceea4 VG |
3071 | max_t(unsigned, cfqg->busy_queues_avg[cfqd->serving_wl_class], |
3072 | cfq_group_busy_queues_wl(cfqd->serving_wl_class, cfqd, | |
3bf10fea | 3073 | cfqg)); |
718eee05 | 3074 | |
4d2ceea4 | 3075 | if (cfqd->serving_wl_type == ASYNC_WORKLOAD) { |
f26bd1f0 VG |
3076 | unsigned int tmp; |
3077 | ||
3078 | /* | |
3079 | * Async queues are currently system wide. Just taking | |
3080 | * proportion of queues with-in same group will lead to higher | |
3081 | * async ratio system wide as generally root group is going | |
3082 | * to have higher weight. A more accurate thing would be to | |
3083 | * calculate system wide asnc/sync ratio. | |
3084 | */ | |
5bf14c07 TM |
3085 | tmp = cfqd->cfq_target_latency * |
3086 | cfqg_busy_async_queues(cfqd, cfqg); | |
f26bd1f0 VG |
3087 | tmp = tmp/cfqd->busy_queues; |
3088 | slice = min_t(unsigned, slice, tmp); | |
3089 | ||
718eee05 CZ |
3090 | /* async workload slice is scaled down according to |
3091 | * the sync/async slice ratio. */ | |
3092 | slice = slice * cfqd->cfq_slice[0] / cfqd->cfq_slice[1]; | |
f26bd1f0 | 3093 | } else |
718eee05 CZ |
3094 | /* sync workload slice is at least 2 * cfq_slice_idle */ |
3095 | slice = max(slice, 2 * cfqd->cfq_slice_idle); | |
3096 | ||
3097 | slice = max_t(unsigned, slice, CFQ_MIN_TT); | |
b1ffe737 | 3098 | cfq_log(cfqd, "workload slice:%d", slice); |
718eee05 CZ |
3099 | cfqd->workload_expires = jiffies + slice; |
3100 | } | |
3101 | ||
1fa8f6d6 VG |
3102 | static struct cfq_group *cfq_get_next_cfqg(struct cfq_data *cfqd) |
3103 | { | |
3104 | struct cfq_rb_root *st = &cfqd->grp_service_tree; | |
25bc6b07 | 3105 | struct cfq_group *cfqg; |
1fa8f6d6 VG |
3106 | |
3107 | if (RB_EMPTY_ROOT(&st->rb)) | |
3108 | return NULL; | |
25bc6b07 | 3109 | cfqg = cfq_rb_first_group(st); |
25bc6b07 VG |
3110 | update_min_vdisktime(st); |
3111 | return cfqg; | |
1fa8f6d6 VG |
3112 | } |
3113 | ||
cdb16e8f VG |
3114 | static void cfq_choose_cfqg(struct cfq_data *cfqd) |
3115 | { | |
1fa8f6d6 VG |
3116 | struct cfq_group *cfqg = cfq_get_next_cfqg(cfqd); |
3117 | ||
3118 | cfqd->serving_group = cfqg; | |
dae739eb VG |
3119 | |
3120 | /* Restore the workload type data */ | |
4d2ceea4 VG |
3121 | if (cfqg->saved_wl_slice) { |
3122 | cfqd->workload_expires = jiffies + cfqg->saved_wl_slice; | |
3123 | cfqd->serving_wl_type = cfqg->saved_wl_type; | |
3124 | cfqd->serving_wl_class = cfqg->saved_wl_class; | |
66ae2919 GJ |
3125 | } else |
3126 | cfqd->workload_expires = jiffies - 1; | |
3127 | ||
6d816ec7 | 3128 | choose_wl_class_and_type(cfqd, cfqg); |
cdb16e8f VG |
3129 | } |
3130 | ||
22e2c507 | 3131 | /* |
498d3aa2 JA |
3132 | * Select a queue for service. If we have a current active queue, |
3133 | * check whether to continue servicing it, or retrieve and set a new one. | |
22e2c507 | 3134 | */ |
1b5ed5e1 | 3135 | static struct cfq_queue *cfq_select_queue(struct cfq_data *cfqd) |
1da177e4 | 3136 | { |
a36e71f9 | 3137 | struct cfq_queue *cfqq, *new_cfqq = NULL; |
1da177e4 | 3138 | |
22e2c507 JA |
3139 | cfqq = cfqd->active_queue; |
3140 | if (!cfqq) | |
3141 | goto new_queue; | |
1da177e4 | 3142 | |
f04a6424 VG |
3143 | if (!cfqd->rq_queued) |
3144 | return NULL; | |
c244bb50 VG |
3145 | |
3146 | /* | |
3147 | * We were waiting for group to get backlogged. Expire the queue | |
3148 | */ | |
3149 | if (cfq_cfqq_wait_busy(cfqq) && !RB_EMPTY_ROOT(&cfqq->sort_list)) | |
3150 | goto expire; | |
3151 | ||
22e2c507 | 3152 | /* |
6d048f53 | 3153 | * The active queue has run out of time, expire it and select new. |
22e2c507 | 3154 | */ |
7667aa06 VG |
3155 | if (cfq_slice_used(cfqq) && !cfq_cfqq_must_dispatch(cfqq)) { |
3156 | /* | |
3157 | * If slice had not expired at the completion of last request | |
3158 | * we might not have turned on wait_busy flag. Don't expire | |
3159 | * the queue yet. Allow the group to get backlogged. | |
3160 | * | |
3161 | * The very fact that we have used the slice, that means we | |
3162 | * have been idling all along on this queue and it should be | |
3163 | * ok to wait for this request to complete. | |
3164 | */ | |
82bbbf28 VG |
3165 | if (cfqq->cfqg->nr_cfqq == 1 && RB_EMPTY_ROOT(&cfqq->sort_list) |
3166 | && cfqq->dispatched && cfq_should_idle(cfqd, cfqq)) { | |
3167 | cfqq = NULL; | |
7667aa06 | 3168 | goto keep_queue; |
82bbbf28 | 3169 | } else |
80bdf0c7 | 3170 | goto check_group_idle; |
7667aa06 | 3171 | } |
1da177e4 | 3172 | |
22e2c507 | 3173 | /* |
6d048f53 JA |
3174 | * The active queue has requests and isn't expired, allow it to |
3175 | * dispatch. | |
22e2c507 | 3176 | */ |
dd67d051 | 3177 | if (!RB_EMPTY_ROOT(&cfqq->sort_list)) |
22e2c507 | 3178 | goto keep_queue; |
6d048f53 | 3179 | |
a36e71f9 JA |
3180 | /* |
3181 | * If another queue has a request waiting within our mean seek | |
3182 | * distance, let it run. The expire code will check for close | |
3183 | * cooperators and put the close queue at the front of the service | |
df5fe3e8 | 3184 | * tree. If possible, merge the expiring queue with the new cfqq. |
a36e71f9 | 3185 | */ |
b3b6d040 | 3186 | new_cfqq = cfq_close_cooperator(cfqd, cfqq); |
df5fe3e8 JM |
3187 | if (new_cfqq) { |
3188 | if (!cfqq->new_cfqq) | |
3189 | cfq_setup_merge(cfqq, new_cfqq); | |
a36e71f9 | 3190 | goto expire; |
df5fe3e8 | 3191 | } |
a36e71f9 | 3192 | |
6d048f53 JA |
3193 | /* |
3194 | * No requests pending. If the active queue still has requests in | |
3195 | * flight or is idling for a new request, allow either of these | |
3196 | * conditions to happen (or time out) before selecting a new queue. | |
3197 | */ | |
80bdf0c7 VG |
3198 | if (timer_pending(&cfqd->idle_slice_timer)) { |
3199 | cfqq = NULL; | |
3200 | goto keep_queue; | |
3201 | } | |
3202 | ||
8e1ac665 SL |
3203 | /* |
3204 | * This is a deep seek queue, but the device is much faster than | |
3205 | * the queue can deliver, don't idle | |
3206 | **/ | |
3207 | if (CFQQ_SEEKY(cfqq) && cfq_cfqq_idle_window(cfqq) && | |
3208 | (cfq_cfqq_slice_new(cfqq) || | |
3209 | (cfqq->slice_end - jiffies > jiffies - cfqq->slice_start))) { | |
3210 | cfq_clear_cfqq_deep(cfqq); | |
3211 | cfq_clear_cfqq_idle_window(cfqq); | |
3212 | } | |
3213 | ||
80bdf0c7 VG |
3214 | if (cfqq->dispatched && cfq_should_idle(cfqd, cfqq)) { |
3215 | cfqq = NULL; | |
3216 | goto keep_queue; | |
3217 | } | |
3218 | ||
3219 | /* | |
3220 | * If group idle is enabled and there are requests dispatched from | |
3221 | * this group, wait for requests to complete. | |
3222 | */ | |
3223 | check_group_idle: | |
7700fc4f SL |
3224 | if (cfqd->cfq_group_idle && cfqq->cfqg->nr_cfqq == 1 && |
3225 | cfqq->cfqg->dispatched && | |
3226 | !cfq_io_thinktime_big(cfqd, &cfqq->cfqg->ttime, true)) { | |
caaa5f9f JA |
3227 | cfqq = NULL; |
3228 | goto keep_queue; | |
22e2c507 JA |
3229 | } |
3230 | ||
3b18152c | 3231 | expire: |
e5ff082e | 3232 | cfq_slice_expired(cfqd, 0); |
3b18152c | 3233 | new_queue: |
718eee05 CZ |
3234 | /* |
3235 | * Current queue expired. Check if we have to switch to a new | |
3236 | * service tree | |
3237 | */ | |
3238 | if (!new_cfqq) | |
cdb16e8f | 3239 | cfq_choose_cfqg(cfqd); |
718eee05 | 3240 | |
a36e71f9 | 3241 | cfqq = cfq_set_active_queue(cfqd, new_cfqq); |
22e2c507 | 3242 | keep_queue: |
3b18152c | 3243 | return cfqq; |
22e2c507 JA |
3244 | } |
3245 | ||
febffd61 | 3246 | static int __cfq_forced_dispatch_cfqq(struct cfq_queue *cfqq) |
d9e7620e JA |
3247 | { |
3248 | int dispatched = 0; | |
3249 | ||
3250 | while (cfqq->next_rq) { | |
3251 | cfq_dispatch_insert(cfqq->cfqd->queue, cfqq->next_rq); | |
3252 | dispatched++; | |
3253 | } | |
3254 | ||
3255 | BUG_ON(!list_empty(&cfqq->fifo)); | |
f04a6424 VG |
3256 | |
3257 | /* By default cfqq is not expired if it is empty. Do it explicitly */ | |
e5ff082e | 3258 | __cfq_slice_expired(cfqq->cfqd, cfqq, 0); |
d9e7620e JA |
3259 | return dispatched; |
3260 | } | |
3261 | ||
498d3aa2 JA |
3262 | /* |
3263 | * Drain our current requests. Used for barriers and when switching | |
3264 | * io schedulers on-the-fly. | |
3265 | */ | |
d9e7620e | 3266 | static int cfq_forced_dispatch(struct cfq_data *cfqd) |
1b5ed5e1 | 3267 | { |
0871714e | 3268 | struct cfq_queue *cfqq; |
d9e7620e | 3269 | int dispatched = 0; |
cdb16e8f | 3270 | |
3440c49f | 3271 | /* Expire the timeslice of the current active queue first */ |
e5ff082e | 3272 | cfq_slice_expired(cfqd, 0); |
3440c49f DS |
3273 | while ((cfqq = cfq_get_next_queue_forced(cfqd)) != NULL) { |
3274 | __cfq_set_active_queue(cfqd, cfqq); | |
f04a6424 | 3275 | dispatched += __cfq_forced_dispatch_cfqq(cfqq); |
3440c49f | 3276 | } |
1b5ed5e1 | 3277 | |
1b5ed5e1 TH |
3278 | BUG_ON(cfqd->busy_queues); |
3279 | ||
6923715a | 3280 | cfq_log(cfqd, "forced_dispatch=%d", dispatched); |
1b5ed5e1 TH |
3281 | return dispatched; |
3282 | } | |
3283 | ||
abc3c744 SL |
3284 | static inline bool cfq_slice_used_soon(struct cfq_data *cfqd, |
3285 | struct cfq_queue *cfqq) | |
3286 | { | |
3287 | /* the queue hasn't finished any request, can't estimate */ | |
3288 | if (cfq_cfqq_slice_new(cfqq)) | |
c1e44756 | 3289 | return true; |
abc3c744 SL |
3290 | if (time_after(jiffies + cfqd->cfq_slice_idle * cfqq->dispatched, |
3291 | cfqq->slice_end)) | |
c1e44756 | 3292 | return true; |
abc3c744 | 3293 | |
c1e44756 | 3294 | return false; |
abc3c744 SL |
3295 | } |
3296 | ||
0b182d61 | 3297 | static bool cfq_may_dispatch(struct cfq_data *cfqd, struct cfq_queue *cfqq) |
2f5cb738 | 3298 | { |
2f5cb738 | 3299 | unsigned int max_dispatch; |
22e2c507 | 3300 | |
5ad531db JA |
3301 | /* |
3302 | * Drain async requests before we start sync IO | |
3303 | */ | |
53c583d2 | 3304 | if (cfq_should_idle(cfqd, cfqq) && cfqd->rq_in_flight[BLK_RW_ASYNC]) |
0b182d61 | 3305 | return false; |
5ad531db | 3306 | |
2f5cb738 JA |
3307 | /* |
3308 | * If this is an async queue and we have sync IO in flight, let it wait | |
3309 | */ | |
53c583d2 | 3310 | if (cfqd->rq_in_flight[BLK_RW_SYNC] && !cfq_cfqq_sync(cfqq)) |
0b182d61 | 3311 | return false; |
2f5cb738 | 3312 | |
abc3c744 | 3313 | max_dispatch = max_t(unsigned int, cfqd->cfq_quantum / 2, 1); |
2f5cb738 JA |
3314 | if (cfq_class_idle(cfqq)) |
3315 | max_dispatch = 1; | |
b4878f24 | 3316 | |
2f5cb738 JA |
3317 | /* |
3318 | * Does this cfqq already have too much IO in flight? | |
3319 | */ | |
3320 | if (cfqq->dispatched >= max_dispatch) { | |
ef8a41df | 3321 | bool promote_sync = false; |
2f5cb738 JA |
3322 | /* |
3323 | * idle queue must always only have a single IO in flight | |
3324 | */ | |
3ed9a296 | 3325 | if (cfq_class_idle(cfqq)) |
0b182d61 | 3326 | return false; |
3ed9a296 | 3327 | |
ef8a41df | 3328 | /* |
c4ade94f LS |
3329 | * If there is only one sync queue |
3330 | * we can ignore async queue here and give the sync | |
ef8a41df SL |
3331 | * queue no dispatch limit. The reason is a sync queue can |
3332 | * preempt async queue, limiting the sync queue doesn't make | |
3333 | * sense. This is useful for aiostress test. | |
3334 | */ | |
c4ade94f LS |
3335 | if (cfq_cfqq_sync(cfqq) && cfqd->busy_sync_queues == 1) |
3336 | promote_sync = true; | |
ef8a41df | 3337 | |
2f5cb738 JA |
3338 | /* |
3339 | * We have other queues, don't allow more IO from this one | |
3340 | */ | |
ef8a41df SL |
3341 | if (cfqd->busy_queues > 1 && cfq_slice_used_soon(cfqd, cfqq) && |
3342 | !promote_sync) | |
0b182d61 | 3343 | return false; |
9ede209e | 3344 | |
365722bb | 3345 | /* |
474b18cc | 3346 | * Sole queue user, no limit |
365722bb | 3347 | */ |
ef8a41df | 3348 | if (cfqd->busy_queues == 1 || promote_sync) |
abc3c744 SL |
3349 | max_dispatch = -1; |
3350 | else | |
3351 | /* | |
3352 | * Normally we start throttling cfqq when cfq_quantum/2 | |
3353 | * requests have been dispatched. But we can drive | |
3354 | * deeper queue depths at the beginning of slice | |
3355 | * subjected to upper limit of cfq_quantum. | |
3356 | * */ | |
3357 | max_dispatch = cfqd->cfq_quantum; | |
8e296755 JA |
3358 | } |
3359 | ||
3360 | /* | |
3361 | * Async queues must wait a bit before being allowed dispatch. | |
3362 | * We also ramp up the dispatch depth gradually for async IO, | |
3363 | * based on the last sync IO we serviced | |
3364 | */ | |
963b72fc | 3365 | if (!cfq_cfqq_sync(cfqq) && cfqd->cfq_latency) { |
573412b2 | 3366 | unsigned long last_sync = jiffies - cfqd->last_delayed_sync; |
8e296755 | 3367 | unsigned int depth; |
365722bb | 3368 | |
61f0c1dc | 3369 | depth = last_sync / cfqd->cfq_slice[1]; |
e00c54c3 JA |
3370 | if (!depth && !cfqq->dispatched) |
3371 | depth = 1; | |
8e296755 JA |
3372 | if (depth < max_dispatch) |
3373 | max_dispatch = depth; | |
2f5cb738 | 3374 | } |
3ed9a296 | 3375 | |
0b182d61 JA |
3376 | /* |
3377 | * If we're below the current max, allow a dispatch | |
3378 | */ | |
3379 | return cfqq->dispatched < max_dispatch; | |
3380 | } | |
3381 | ||
3382 | /* | |
3383 | * Dispatch a request from cfqq, moving them to the request queue | |
3384 | * dispatch list. | |
3385 | */ | |
3386 | static bool cfq_dispatch_request(struct cfq_data *cfqd, struct cfq_queue *cfqq) | |
3387 | { | |
3388 | struct request *rq; | |
3389 | ||
3390 | BUG_ON(RB_EMPTY_ROOT(&cfqq->sort_list)); | |
3391 | ||
3392 | if (!cfq_may_dispatch(cfqd, cfqq)) | |
3393 | return false; | |
3394 | ||
3395 | /* | |
3396 | * follow expired path, else get first next available | |
3397 | */ | |
3398 | rq = cfq_check_fifo(cfqq); | |
3399 | if (!rq) | |
3400 | rq = cfqq->next_rq; | |
3401 | ||
3402 | /* | |
3403 | * insert request into driver dispatch list | |
3404 | */ | |
3405 | cfq_dispatch_insert(cfqd->queue, rq); | |
3406 | ||
3407 | if (!cfqd->active_cic) { | |
c5869807 | 3408 | struct cfq_io_cq *cic = RQ_CIC(rq); |
0b182d61 | 3409 | |
c5869807 | 3410 | atomic_long_inc(&cic->icq.ioc->refcount); |
0b182d61 JA |
3411 | cfqd->active_cic = cic; |
3412 | } | |
3413 | ||
3414 | return true; | |
3415 | } | |
3416 | ||
3417 | /* | |
3418 | * Find the cfqq that we need to service and move a request from that to the | |
3419 | * dispatch list | |
3420 | */ | |
3421 | static int cfq_dispatch_requests(struct request_queue *q, int force) | |
3422 | { | |
3423 | struct cfq_data *cfqd = q->elevator->elevator_data; | |
3424 | struct cfq_queue *cfqq; | |
3425 | ||
3426 | if (!cfqd->busy_queues) | |
3427 | return 0; | |
3428 | ||
3429 | if (unlikely(force)) | |
3430 | return cfq_forced_dispatch(cfqd); | |
3431 | ||
3432 | cfqq = cfq_select_queue(cfqd); | |
3433 | if (!cfqq) | |
8e296755 JA |
3434 | return 0; |
3435 | ||
2f5cb738 | 3436 | /* |
0b182d61 | 3437 | * Dispatch a request from this cfqq, if it is allowed |
2f5cb738 | 3438 | */ |
0b182d61 JA |
3439 | if (!cfq_dispatch_request(cfqd, cfqq)) |
3440 | return 0; | |
3441 | ||
2f5cb738 | 3442 | cfqq->slice_dispatch++; |
b029195d | 3443 | cfq_clear_cfqq_must_dispatch(cfqq); |
22e2c507 | 3444 | |
2f5cb738 JA |
3445 | /* |
3446 | * expire an async queue immediately if it has used up its slice. idle | |
3447 | * queue always expire after 1 dispatch round. | |
3448 | */ | |
3449 | if (cfqd->busy_queues > 1 && ((!cfq_cfqq_sync(cfqq) && | |
3450 | cfqq->slice_dispatch >= cfq_prio_to_maxrq(cfqd, cfqq)) || | |
3451 | cfq_class_idle(cfqq))) { | |
3452 | cfqq->slice_end = jiffies + 1; | |
e5ff082e | 3453 | cfq_slice_expired(cfqd, 0); |
1da177e4 LT |
3454 | } |
3455 | ||
b217a903 | 3456 | cfq_log_cfqq(cfqd, cfqq, "dispatched a request"); |
2f5cb738 | 3457 | return 1; |
1da177e4 LT |
3458 | } |
3459 | ||
1da177e4 | 3460 | /* |
5e705374 JA |
3461 | * task holds one reference to the queue, dropped when task exits. each rq |
3462 | * in-flight on this queue also holds a reference, dropped when rq is freed. | |
1da177e4 | 3463 | * |
b1c35769 | 3464 | * Each cfq queue took a reference on the parent group. Drop it now. |
1da177e4 LT |
3465 | * queue lock must be held here. |
3466 | */ | |
3467 | static void cfq_put_queue(struct cfq_queue *cfqq) | |
3468 | { | |
22e2c507 | 3469 | struct cfq_data *cfqd = cfqq->cfqd; |
0bbfeb83 | 3470 | struct cfq_group *cfqg; |
22e2c507 | 3471 | |
30d7b944 | 3472 | BUG_ON(cfqq->ref <= 0); |
1da177e4 | 3473 | |
30d7b944 SL |
3474 | cfqq->ref--; |
3475 | if (cfqq->ref) | |
1da177e4 LT |
3476 | return; |
3477 | ||
7b679138 | 3478 | cfq_log_cfqq(cfqd, cfqq, "put_queue"); |
1da177e4 | 3479 | BUG_ON(rb_first(&cfqq->sort_list)); |
22e2c507 | 3480 | BUG_ON(cfqq->allocated[READ] + cfqq->allocated[WRITE]); |
b1c35769 | 3481 | cfqg = cfqq->cfqg; |
1da177e4 | 3482 | |
28f95cbc | 3483 | if (unlikely(cfqd->active_queue == cfqq)) { |
e5ff082e | 3484 | __cfq_slice_expired(cfqd, cfqq, 0); |
23e018a1 | 3485 | cfq_schedule_dispatch(cfqd); |
28f95cbc | 3486 | } |
22e2c507 | 3487 | |
f04a6424 | 3488 | BUG_ON(cfq_cfqq_on_rr(cfqq)); |
1da177e4 | 3489 | kmem_cache_free(cfq_pool, cfqq); |
eb7d8c07 | 3490 | cfqg_put(cfqg); |
1da177e4 LT |
3491 | } |
3492 | ||
d02a2c07 | 3493 | static void cfq_put_cooperator(struct cfq_queue *cfqq) |
1da177e4 | 3494 | { |
df5fe3e8 JM |
3495 | struct cfq_queue *__cfqq, *next; |
3496 | ||
df5fe3e8 JM |
3497 | /* |
3498 | * If this queue was scheduled to merge with another queue, be | |
3499 | * sure to drop the reference taken on that queue (and others in | |
3500 | * the merge chain). See cfq_setup_merge and cfq_merge_cfqqs. | |
3501 | */ | |
3502 | __cfqq = cfqq->new_cfqq; | |
3503 | while (__cfqq) { | |
3504 | if (__cfqq == cfqq) { | |
3505 | WARN(1, "cfqq->new_cfqq loop detected\n"); | |
3506 | break; | |
3507 | } | |
3508 | next = __cfqq->new_cfqq; | |
3509 | cfq_put_queue(__cfqq); | |
3510 | __cfqq = next; | |
3511 | } | |
d02a2c07 SL |
3512 | } |
3513 | ||
3514 | static void cfq_exit_cfqq(struct cfq_data *cfqd, struct cfq_queue *cfqq) | |
3515 | { | |
3516 | if (unlikely(cfqq == cfqd->active_queue)) { | |
3517 | __cfq_slice_expired(cfqd, cfqq, 0); | |
3518 | cfq_schedule_dispatch(cfqd); | |
3519 | } | |
3520 | ||
3521 | cfq_put_cooperator(cfqq); | |
df5fe3e8 | 3522 | |
89850f7e JA |
3523 | cfq_put_queue(cfqq); |
3524 | } | |
22e2c507 | 3525 | |
9b84cacd TH |
3526 | static void cfq_init_icq(struct io_cq *icq) |
3527 | { | |
3528 | struct cfq_io_cq *cic = icq_to_cic(icq); | |
3529 | ||
3530 | cic->ttime.last_end_request = jiffies; | |
3531 | } | |
3532 | ||
c5869807 | 3533 | static void cfq_exit_icq(struct io_cq *icq) |
89850f7e | 3534 | { |
c5869807 | 3535 | struct cfq_io_cq *cic = icq_to_cic(icq); |
283287a5 | 3536 | struct cfq_data *cfqd = cic_to_cfqd(cic); |
4faa3c81 | 3537 | |
563180a4 TH |
3538 | if (cic_to_cfqq(cic, false)) { |
3539 | cfq_exit_cfqq(cfqd, cic_to_cfqq(cic, false)); | |
3540 | cic_set_cfqq(cic, NULL, false); | |
12a05732 AV |
3541 | } |
3542 | ||
563180a4 TH |
3543 | if (cic_to_cfqq(cic, true)) { |
3544 | cfq_exit_cfqq(cfqd, cic_to_cfqq(cic, true)); | |
3545 | cic_set_cfqq(cic, NULL, true); | |
12a05732 | 3546 | } |
89850f7e JA |
3547 | } |
3548 | ||
abede6da | 3549 | static void cfq_init_prio_data(struct cfq_queue *cfqq, struct cfq_io_cq *cic) |
22e2c507 JA |
3550 | { |
3551 | struct task_struct *tsk = current; | |
3552 | int ioprio_class; | |
3553 | ||
3b18152c | 3554 | if (!cfq_cfqq_prio_changed(cfqq)) |
22e2c507 JA |
3555 | return; |
3556 | ||
598971bf | 3557 | ioprio_class = IOPRIO_PRIO_CLASS(cic->ioprio); |
22e2c507 | 3558 | switch (ioprio_class) { |
fe094d98 JA |
3559 | default: |
3560 | printk(KERN_ERR "cfq: bad prio %x\n", ioprio_class); | |
3561 | case IOPRIO_CLASS_NONE: | |
3562 | /* | |
6d63c275 | 3563 | * no prio set, inherit CPU scheduling settings |
fe094d98 JA |
3564 | */ |
3565 | cfqq->ioprio = task_nice_ioprio(tsk); | |
6d63c275 | 3566 | cfqq->ioprio_class = task_nice_ioclass(tsk); |
fe094d98 JA |
3567 | break; |
3568 | case IOPRIO_CLASS_RT: | |
598971bf | 3569 | cfqq->ioprio = IOPRIO_PRIO_DATA(cic->ioprio); |
fe094d98 JA |
3570 | cfqq->ioprio_class = IOPRIO_CLASS_RT; |
3571 | break; | |
3572 | case IOPRIO_CLASS_BE: | |
598971bf | 3573 | cfqq->ioprio = IOPRIO_PRIO_DATA(cic->ioprio); |
fe094d98 JA |
3574 | cfqq->ioprio_class = IOPRIO_CLASS_BE; |
3575 | break; | |
3576 | case IOPRIO_CLASS_IDLE: | |
3577 | cfqq->ioprio_class = IOPRIO_CLASS_IDLE; | |
3578 | cfqq->ioprio = 7; | |
3579 | cfq_clear_cfqq_idle_window(cfqq); | |
3580 | break; | |
22e2c507 JA |
3581 | } |
3582 | ||
3583 | /* | |
3584 | * keep track of original prio settings in case we have to temporarily | |
3585 | * elevate the priority of this queue | |
3586 | */ | |
3587 | cfqq->org_ioprio = cfqq->ioprio; | |
3b18152c | 3588 | cfq_clear_cfqq_prio_changed(cfqq); |
22e2c507 JA |
3589 | } |
3590 | ||
598971bf | 3591 | static void check_ioprio_changed(struct cfq_io_cq *cic, struct bio *bio) |
22e2c507 | 3592 | { |
598971bf | 3593 | int ioprio = cic->icq.ioc->ioprio; |
bca4b914 | 3594 | struct cfq_data *cfqd = cic_to_cfqd(cic); |
478a82b0 | 3595 | struct cfq_queue *cfqq; |
35e6077c | 3596 | |
598971bf TH |
3597 | /* |
3598 | * Check whether ioprio has changed. The condition may trigger | |
3599 | * spuriously on a newly created cic but there's no harm. | |
3600 | */ | |
3601 | if (unlikely(!cfqd) || likely(cic->ioprio == ioprio)) | |
caaa5f9f JA |
3602 | return; |
3603 | ||
563180a4 | 3604 | cfqq = cic_to_cfqq(cic, false); |
caaa5f9f | 3605 | if (cfqq) { |
563180a4 | 3606 | cfq_put_queue(cfqq); |
2da8de0b | 3607 | cfqq = cfq_get_queue(cfqd, BLK_RW_ASYNC, cic, bio); |
563180a4 | 3608 | cic_set_cfqq(cic, cfqq, false); |
22e2c507 | 3609 | } |
caaa5f9f | 3610 | |
563180a4 | 3611 | cfqq = cic_to_cfqq(cic, true); |
caaa5f9f JA |
3612 | if (cfqq) |
3613 | cfq_mark_cfqq_prio_changed(cfqq); | |
598971bf TH |
3614 | |
3615 | cic->ioprio = ioprio; | |
22e2c507 JA |
3616 | } |
3617 | ||
d5036d77 | 3618 | static void cfq_init_cfqq(struct cfq_data *cfqd, struct cfq_queue *cfqq, |
a6151c3a | 3619 | pid_t pid, bool is_sync) |
d5036d77 JA |
3620 | { |
3621 | RB_CLEAR_NODE(&cfqq->rb_node); | |
3622 | RB_CLEAR_NODE(&cfqq->p_node); | |
3623 | INIT_LIST_HEAD(&cfqq->fifo); | |
3624 | ||
30d7b944 | 3625 | cfqq->ref = 0; |
d5036d77 JA |
3626 | cfqq->cfqd = cfqd; |
3627 | ||
3628 | cfq_mark_cfqq_prio_changed(cfqq); | |
3629 | ||
3630 | if (is_sync) { | |
3631 | if (!cfq_class_idle(cfqq)) | |
3632 | cfq_mark_cfqq_idle_window(cfqq); | |
3633 | cfq_mark_cfqq_sync(cfqq); | |
3634 | } | |
3635 | cfqq->pid = pid; | |
3636 | } | |
3637 | ||
24610333 | 3638 | #ifdef CONFIG_CFQ_GROUP_IOSCHED |
598971bf | 3639 | static void check_blkcg_changed(struct cfq_io_cq *cic, struct bio *bio) |
24610333 | 3640 | { |
bca4b914 | 3641 | struct cfq_data *cfqd = cic_to_cfqd(cic); |
60a83707 | 3642 | struct cfq_queue *cfqq; |
f4da8072 | 3643 | uint64_t serial_nr; |
24610333 | 3644 | |
598971bf | 3645 | rcu_read_lock(); |
f4da8072 | 3646 | serial_nr = bio_blkcg(bio)->css.serial_nr; |
598971bf | 3647 | rcu_read_unlock(); |
24610333 | 3648 | |
598971bf TH |
3649 | /* |
3650 | * Check whether blkcg has changed. The condition may trigger | |
3651 | * spuriously on a newly created cic but there's no harm. | |
3652 | */ | |
f4da8072 | 3653 | if (unlikely(!cfqd) || likely(cic->blkcg_serial_nr == serial_nr)) |
598971bf | 3654 | return; |
24610333 | 3655 | |
60a83707 TH |
3656 | /* |
3657 | * Drop reference to queues. New queues will be assigned in new | |
3658 | * group upon arrival of fresh requests. | |
3659 | */ | |
3660 | cfqq = cic_to_cfqq(cic, false); | |
3661 | if (cfqq) { | |
3662 | cfq_log_cfqq(cfqd, cfqq, "changed cgroup"); | |
3663 | cic_set_cfqq(cic, NULL, false); | |
3664 | cfq_put_queue(cfqq); | |
3665 | } | |
3666 | ||
3667 | cfqq = cic_to_cfqq(cic, true); | |
3668 | if (cfqq) { | |
3669 | cfq_log_cfqq(cfqd, cfqq, "changed cgroup"); | |
3670 | cic_set_cfqq(cic, NULL, true); | |
3671 | cfq_put_queue(cfqq); | |
24610333 | 3672 | } |
598971bf | 3673 | |
f4da8072 | 3674 | cic->blkcg_serial_nr = serial_nr; |
24610333 | 3675 | } |
598971bf TH |
3676 | #else |
3677 | static inline void check_blkcg_changed(struct cfq_io_cq *cic, struct bio *bio) { } | |
24610333 VG |
3678 | #endif /* CONFIG_CFQ_GROUP_IOSCHED */ |
3679 | ||
c2dea2d1 | 3680 | static struct cfq_queue ** |
60a83707 | 3681 | cfq_async_queue_prio(struct cfq_group *cfqg, int ioprio_class, int ioprio) |
c2dea2d1 | 3682 | { |
fe094d98 | 3683 | switch (ioprio_class) { |
c2dea2d1 | 3684 | case IOPRIO_CLASS_RT: |
60a83707 | 3685 | return &cfqg->async_cfqq[0][ioprio]; |
598971bf TH |
3686 | case IOPRIO_CLASS_NONE: |
3687 | ioprio = IOPRIO_NORM; | |
3688 | /* fall through */ | |
c2dea2d1 | 3689 | case IOPRIO_CLASS_BE: |
60a83707 | 3690 | return &cfqg->async_cfqq[1][ioprio]; |
c2dea2d1 | 3691 | case IOPRIO_CLASS_IDLE: |
60a83707 | 3692 | return &cfqg->async_idle_cfqq; |
c2dea2d1 VT |
3693 | default: |
3694 | BUG(); | |
3695 | } | |
3696 | } | |
3697 | ||
15c31be4 | 3698 | static struct cfq_queue * |
abede6da | 3699 | cfq_get_queue(struct cfq_data *cfqd, bool is_sync, struct cfq_io_cq *cic, |
2da8de0b | 3700 | struct bio *bio) |
15c31be4 | 3701 | { |
c6ce1943 JM |
3702 | int ioprio_class = IOPRIO_PRIO_CLASS(cic->ioprio); |
3703 | int ioprio = IOPRIO_PRIO_DATA(cic->ioprio); | |
d4aad7ff | 3704 | struct cfq_queue **async_cfqq = NULL; |
4ebc1c61 | 3705 | struct cfq_queue *cfqq; |
322731ed TH |
3706 | struct cfq_group *cfqg; |
3707 | ||
3708 | rcu_read_lock(); | |
ae118896 | 3709 | cfqg = cfq_lookup_cfqg(cfqd, bio_blkcg(bio)); |
322731ed TH |
3710 | if (!cfqg) { |
3711 | cfqq = &cfqd->oom_cfqq; | |
3712 | goto out; | |
3713 | } | |
15c31be4 | 3714 | |
c2dea2d1 | 3715 | if (!is_sync) { |
c6ce1943 JM |
3716 | if (!ioprio_valid(cic->ioprio)) { |
3717 | struct task_struct *tsk = current; | |
3718 | ioprio = task_nice_ioprio(tsk); | |
3719 | ioprio_class = task_nice_ioclass(tsk); | |
3720 | } | |
60a83707 | 3721 | async_cfqq = cfq_async_queue_prio(cfqg, ioprio_class, ioprio); |
c2dea2d1 | 3722 | cfqq = *async_cfqq; |
4ebc1c61 TH |
3723 | if (cfqq) |
3724 | goto out; | |
c2dea2d1 VT |
3725 | } |
3726 | ||
d4aad7ff TH |
3727 | cfqq = kmem_cache_alloc_node(cfq_pool, GFP_NOWAIT | __GFP_ZERO, |
3728 | cfqd->queue->node); | |
3729 | if (!cfqq) { | |
3730 | cfqq = &cfqd->oom_cfqq; | |
3731 | goto out; | |
3732 | } | |
3733 | ||
3734 | cfq_init_cfqq(cfqd, cfqq, current->pid, is_sync); | |
3735 | cfq_init_prio_data(cfqq, cic); | |
3736 | cfq_link_cfqq_cfqg(cfqq, cfqg); | |
3737 | cfq_log_cfqq(cfqd, cfqq, "alloced"); | |
15c31be4 | 3738 | |
d4aad7ff TH |
3739 | if (async_cfqq) { |
3740 | /* a new async queue is created, pin and remember */ | |
30d7b944 | 3741 | cfqq->ref++; |
c2dea2d1 | 3742 | *async_cfqq = cfqq; |
15c31be4 | 3743 | } |
4ebc1c61 | 3744 | out: |
30d7b944 | 3745 | cfqq->ref++; |
322731ed | 3746 | rcu_read_unlock(); |
15c31be4 JA |
3747 | return cfqq; |
3748 | } | |
3749 | ||
22e2c507 | 3750 | static void |
383cd721 | 3751 | __cfq_update_io_thinktime(struct cfq_ttime *ttime, unsigned long slice_idle) |
1da177e4 | 3752 | { |
383cd721 SL |
3753 | unsigned long elapsed = jiffies - ttime->last_end_request; |
3754 | elapsed = min(elapsed, 2UL * slice_idle); | |
db3b5848 | 3755 | |
383cd721 SL |
3756 | ttime->ttime_samples = (7*ttime->ttime_samples + 256) / 8; |
3757 | ttime->ttime_total = (7*ttime->ttime_total + 256*elapsed) / 8; | |
3758 | ttime->ttime_mean = (ttime->ttime_total + 128) / ttime->ttime_samples; | |
3759 | } | |
3760 | ||
3761 | static void | |
3762 | cfq_update_io_thinktime(struct cfq_data *cfqd, struct cfq_queue *cfqq, | |
c5869807 | 3763 | struct cfq_io_cq *cic) |
383cd721 | 3764 | { |
f5f2b6ce | 3765 | if (cfq_cfqq_sync(cfqq)) { |
383cd721 | 3766 | __cfq_update_io_thinktime(&cic->ttime, cfqd->cfq_slice_idle); |
f5f2b6ce SL |
3767 | __cfq_update_io_thinktime(&cfqq->service_tree->ttime, |
3768 | cfqd->cfq_slice_idle); | |
3769 | } | |
7700fc4f SL |
3770 | #ifdef CONFIG_CFQ_GROUP_IOSCHED |
3771 | __cfq_update_io_thinktime(&cfqq->cfqg->ttime, cfqd->cfq_group_idle); | |
3772 | #endif | |
22e2c507 | 3773 | } |
1da177e4 | 3774 | |
206dc69b | 3775 | static void |
b2c18e1e | 3776 | cfq_update_io_seektime(struct cfq_data *cfqd, struct cfq_queue *cfqq, |
6d048f53 | 3777 | struct request *rq) |
206dc69b | 3778 | { |
3dde36dd | 3779 | sector_t sdist = 0; |
41647e7a | 3780 | sector_t n_sec = blk_rq_sectors(rq); |
3dde36dd CZ |
3781 | if (cfqq->last_request_pos) { |
3782 | if (cfqq->last_request_pos < blk_rq_pos(rq)) | |
3783 | sdist = blk_rq_pos(rq) - cfqq->last_request_pos; | |
3784 | else | |
3785 | sdist = cfqq->last_request_pos - blk_rq_pos(rq); | |
3786 | } | |
206dc69b | 3787 | |
3dde36dd | 3788 | cfqq->seek_history <<= 1; |
41647e7a CZ |
3789 | if (blk_queue_nonrot(cfqd->queue)) |
3790 | cfqq->seek_history |= (n_sec < CFQQ_SECT_THR_NONROT); | |
3791 | else | |
3792 | cfqq->seek_history |= (sdist > CFQQ_SEEK_THR); | |
206dc69b | 3793 | } |
1da177e4 | 3794 | |
22e2c507 JA |
3795 | /* |
3796 | * Disable idle window if the process thinks too long or seeks so much that | |
3797 | * it doesn't matter | |
3798 | */ | |
3799 | static void | |
3800 | cfq_update_idle_window(struct cfq_data *cfqd, struct cfq_queue *cfqq, | |
c5869807 | 3801 | struct cfq_io_cq *cic) |
22e2c507 | 3802 | { |
7b679138 | 3803 | int old_idle, enable_idle; |
1be92f2f | 3804 | |
0871714e JA |
3805 | /* |
3806 | * Don't idle for async or idle io prio class | |
3807 | */ | |
3808 | if (!cfq_cfqq_sync(cfqq) || cfq_class_idle(cfqq)) | |
1be92f2f JA |
3809 | return; |
3810 | ||
c265a7f4 | 3811 | enable_idle = old_idle = cfq_cfqq_idle_window(cfqq); |
1da177e4 | 3812 | |
76280aff CZ |
3813 | if (cfqq->queued[0] + cfqq->queued[1] >= 4) |
3814 | cfq_mark_cfqq_deep(cfqq); | |
3815 | ||
749ef9f8 CZ |
3816 | if (cfqq->next_rq && (cfqq->next_rq->cmd_flags & REQ_NOIDLE)) |
3817 | enable_idle = 0; | |
f6e8d01b | 3818 | else if (!atomic_read(&cic->icq.ioc->active_ref) || |
c5869807 TH |
3819 | !cfqd->cfq_slice_idle || |
3820 | (!cfq_cfqq_deep(cfqq) && CFQQ_SEEKY(cfqq))) | |
22e2c507 | 3821 | enable_idle = 0; |
383cd721 SL |
3822 | else if (sample_valid(cic->ttime.ttime_samples)) { |
3823 | if (cic->ttime.ttime_mean > cfqd->cfq_slice_idle) | |
22e2c507 JA |
3824 | enable_idle = 0; |
3825 | else | |
3826 | enable_idle = 1; | |
1da177e4 LT |
3827 | } |
3828 | ||
7b679138 JA |
3829 | if (old_idle != enable_idle) { |
3830 | cfq_log_cfqq(cfqd, cfqq, "idle=%d", enable_idle); | |
3831 | if (enable_idle) | |
3832 | cfq_mark_cfqq_idle_window(cfqq); | |
3833 | else | |
3834 | cfq_clear_cfqq_idle_window(cfqq); | |
3835 | } | |
22e2c507 | 3836 | } |
1da177e4 | 3837 | |
22e2c507 JA |
3838 | /* |
3839 | * Check if new_cfqq should preempt the currently active queue. Return 0 for | |
3840 | * no or if we aren't sure, a 1 will cause a preempt. | |
3841 | */ | |
a6151c3a | 3842 | static bool |
22e2c507 | 3843 | cfq_should_preempt(struct cfq_data *cfqd, struct cfq_queue *new_cfqq, |
5e705374 | 3844 | struct request *rq) |
22e2c507 | 3845 | { |
6d048f53 | 3846 | struct cfq_queue *cfqq; |
22e2c507 | 3847 | |
6d048f53 JA |
3848 | cfqq = cfqd->active_queue; |
3849 | if (!cfqq) | |
a6151c3a | 3850 | return false; |
22e2c507 | 3851 | |
6d048f53 | 3852 | if (cfq_class_idle(new_cfqq)) |
a6151c3a | 3853 | return false; |
22e2c507 JA |
3854 | |
3855 | if (cfq_class_idle(cfqq)) | |
a6151c3a | 3856 | return true; |
1e3335de | 3857 | |
875feb63 DS |
3858 | /* |
3859 | * Don't allow a non-RT request to preempt an ongoing RT cfqq timeslice. | |
3860 | */ | |
3861 | if (cfq_class_rt(cfqq) && !cfq_class_rt(new_cfqq)) | |
3862 | return false; | |
3863 | ||
374f84ac JA |
3864 | /* |
3865 | * if the new request is sync, but the currently running queue is | |
3866 | * not, let the sync request have priority. | |
3867 | */ | |
5e705374 | 3868 | if (rq_is_sync(rq) && !cfq_cfqq_sync(cfqq)) |
a6151c3a | 3869 | return true; |
1e3335de | 3870 | |
8682e1f1 VG |
3871 | if (new_cfqq->cfqg != cfqq->cfqg) |
3872 | return false; | |
3873 | ||
3874 | if (cfq_slice_used(cfqq)) | |
3875 | return true; | |
3876 | ||
3877 | /* Allow preemption only if we are idling on sync-noidle tree */ | |
4d2ceea4 | 3878 | if (cfqd->serving_wl_type == SYNC_NOIDLE_WORKLOAD && |
8682e1f1 VG |
3879 | cfqq_type(new_cfqq) == SYNC_NOIDLE_WORKLOAD && |
3880 | new_cfqq->service_tree->count == 2 && | |
3881 | RB_EMPTY_ROOT(&cfqq->sort_list)) | |
3882 | return true; | |
3883 | ||
b53d1ed7 JA |
3884 | /* |
3885 | * So both queues are sync. Let the new request get disk time if | |
3886 | * it's a metadata request and the current queue is doing regular IO. | |
3887 | */ | |
65299a3b | 3888 | if ((rq->cmd_flags & REQ_PRIO) && !cfqq->prio_pending) |
b53d1ed7 JA |
3889 | return true; |
3890 | ||
3a9a3f6c DS |
3891 | /* |
3892 | * Allow an RT request to pre-empt an ongoing non-RT cfqq timeslice. | |
3893 | */ | |
3894 | if (cfq_class_rt(new_cfqq) && !cfq_class_rt(cfqq)) | |
a6151c3a | 3895 | return true; |
3a9a3f6c | 3896 | |
d2d59e18 SL |
3897 | /* An idle queue should not be idle now for some reason */ |
3898 | if (RB_EMPTY_ROOT(&cfqq->sort_list) && !cfq_should_idle(cfqd, cfqq)) | |
3899 | return true; | |
3900 | ||
1e3335de | 3901 | if (!cfqd->active_cic || !cfq_cfqq_wait_request(cfqq)) |
a6151c3a | 3902 | return false; |
1e3335de JA |
3903 | |
3904 | /* | |
3905 | * if this request is as-good as one we would expect from the | |
3906 | * current cfqq, let it preempt | |
3907 | */ | |
e9ce335d | 3908 | if (cfq_rq_close(cfqd, cfqq, rq)) |
a6151c3a | 3909 | return true; |
1e3335de | 3910 | |
a6151c3a | 3911 | return false; |
22e2c507 JA |
3912 | } |
3913 | ||
3914 | /* | |
3915 | * cfqq preempts the active queue. if we allowed preempt with no slice left, | |
3916 | * let it have half of its nominal slice. | |
3917 | */ | |
3918 | static void cfq_preempt_queue(struct cfq_data *cfqd, struct cfq_queue *cfqq) | |
3919 | { | |
df0793ab SL |
3920 | enum wl_type_t old_type = cfqq_type(cfqd->active_queue); |
3921 | ||
7b679138 | 3922 | cfq_log_cfqq(cfqd, cfqq, "preempt"); |
df0793ab | 3923 | cfq_slice_expired(cfqd, 1); |
22e2c507 | 3924 | |
f8ae6e3e SL |
3925 | /* |
3926 | * workload type is changed, don't save slice, otherwise preempt | |
3927 | * doesn't happen | |
3928 | */ | |
df0793ab | 3929 | if (old_type != cfqq_type(cfqq)) |
4d2ceea4 | 3930 | cfqq->cfqg->saved_wl_slice = 0; |
f8ae6e3e | 3931 | |
bf572256 JA |
3932 | /* |
3933 | * Put the new queue at the front of the of the current list, | |
3934 | * so we know that it will be selected next. | |
3935 | */ | |
3936 | BUG_ON(!cfq_cfqq_on_rr(cfqq)); | |
edd75ffd JA |
3937 | |
3938 | cfq_service_tree_add(cfqd, cfqq, 1); | |
eda5e0c9 | 3939 | |
62a37f6b JT |
3940 | cfqq->slice_end = 0; |
3941 | cfq_mark_cfqq_slice_new(cfqq); | |
22e2c507 JA |
3942 | } |
3943 | ||
22e2c507 | 3944 | /* |
5e705374 | 3945 | * Called when a new fs request (rq) is added (to cfqq). Check if there's |
22e2c507 JA |
3946 | * something we should do about it |
3947 | */ | |
3948 | static void | |
5e705374 JA |
3949 | cfq_rq_enqueued(struct cfq_data *cfqd, struct cfq_queue *cfqq, |
3950 | struct request *rq) | |
22e2c507 | 3951 | { |
c5869807 | 3952 | struct cfq_io_cq *cic = RQ_CIC(rq); |
12e9fddd | 3953 | |
45333d5a | 3954 | cfqd->rq_queued++; |
65299a3b CH |
3955 | if (rq->cmd_flags & REQ_PRIO) |
3956 | cfqq->prio_pending++; | |
374f84ac | 3957 | |
383cd721 | 3958 | cfq_update_io_thinktime(cfqd, cfqq, cic); |
b2c18e1e | 3959 | cfq_update_io_seektime(cfqd, cfqq, rq); |
9c2c38a1 JA |
3960 | cfq_update_idle_window(cfqd, cfqq, cic); |
3961 | ||
b2c18e1e | 3962 | cfqq->last_request_pos = blk_rq_pos(rq) + blk_rq_sectors(rq); |
22e2c507 JA |
3963 | |
3964 | if (cfqq == cfqd->active_queue) { | |
3965 | /* | |
b029195d JA |
3966 | * Remember that we saw a request from this process, but |
3967 | * don't start queuing just yet. Otherwise we risk seeing lots | |
3968 | * of tiny requests, because we disrupt the normal plugging | |
d6ceb25e JA |
3969 | * and merging. If the request is already larger than a single |
3970 | * page, let it rip immediately. For that case we assume that | |
2d870722 JA |
3971 | * merging is already done. Ditto for a busy system that |
3972 | * has other work pending, don't risk delaying until the | |
3973 | * idle timer unplug to continue working. | |
22e2c507 | 3974 | */ |
d6ceb25e | 3975 | if (cfq_cfqq_wait_request(cfqq)) { |
2d870722 JA |
3976 | if (blk_rq_bytes(rq) > PAGE_CACHE_SIZE || |
3977 | cfqd->busy_queues > 1) { | |
812df48d | 3978 | cfq_del_timer(cfqd, cfqq); |
554554f6 | 3979 | cfq_clear_cfqq_wait_request(cfqq); |
24ecfbe2 | 3980 | __blk_run_queue(cfqd->queue); |
a11cdaa7 | 3981 | } else { |
155fead9 | 3982 | cfqg_stats_update_idle_time(cfqq->cfqg); |
bf791937 | 3983 | cfq_mark_cfqq_must_dispatch(cfqq); |
a11cdaa7 | 3984 | } |
d6ceb25e | 3985 | } |
5e705374 | 3986 | } else if (cfq_should_preempt(cfqd, cfqq, rq)) { |
22e2c507 JA |
3987 | /* |
3988 | * not the active queue - expire current slice if it is | |
3989 | * idle and has expired it's mean thinktime or this new queue | |
3a9a3f6c DS |
3990 | * has some old slice time left and is of higher priority or |
3991 | * this new queue is RT and the current one is BE | |
22e2c507 JA |
3992 | */ |
3993 | cfq_preempt_queue(cfqd, cfqq); | |
24ecfbe2 | 3994 | __blk_run_queue(cfqd->queue); |
22e2c507 | 3995 | } |
1da177e4 LT |
3996 | } |
3997 | ||
165125e1 | 3998 | static void cfq_insert_request(struct request_queue *q, struct request *rq) |
1da177e4 | 3999 | { |
b4878f24 | 4000 | struct cfq_data *cfqd = q->elevator->elevator_data; |
5e705374 | 4001 | struct cfq_queue *cfqq = RQ_CFQQ(rq); |
22e2c507 | 4002 | |
7b679138 | 4003 | cfq_log_cfqq(cfqd, cfqq, "insert_request"); |
abede6da | 4004 | cfq_init_prio_data(cfqq, RQ_CIC(rq)); |
1da177e4 | 4005 | |
8b4922d3 | 4006 | rq->fifo_time = jiffies + cfqd->cfq_fifo_expire[rq_is_sync(rq)]; |
22e2c507 | 4007 | list_add_tail(&rq->queuelist, &cfqq->fifo); |
aa6f6a3d | 4008 | cfq_add_rq_rb(rq); |
155fead9 TH |
4009 | cfqg_stats_update_io_add(RQ_CFQG(rq), cfqd->serving_group, |
4010 | rq->cmd_flags); | |
5e705374 | 4011 | cfq_rq_enqueued(cfqd, cfqq, rq); |
1da177e4 LT |
4012 | } |
4013 | ||
45333d5a AC |
4014 | /* |
4015 | * Update hw_tag based on peak queue depth over 50 samples under | |
4016 | * sufficient load. | |
4017 | */ | |
4018 | static void cfq_update_hw_tag(struct cfq_data *cfqd) | |
4019 | { | |
1a1238a7 SL |
4020 | struct cfq_queue *cfqq = cfqd->active_queue; |
4021 | ||
53c583d2 CZ |
4022 | if (cfqd->rq_in_driver > cfqd->hw_tag_est_depth) |
4023 | cfqd->hw_tag_est_depth = cfqd->rq_in_driver; | |
e459dd08 CZ |
4024 | |
4025 | if (cfqd->hw_tag == 1) | |
4026 | return; | |
45333d5a AC |
4027 | |
4028 | if (cfqd->rq_queued <= CFQ_HW_QUEUE_MIN && | |
53c583d2 | 4029 | cfqd->rq_in_driver <= CFQ_HW_QUEUE_MIN) |
45333d5a AC |
4030 | return; |
4031 | ||
1a1238a7 SL |
4032 | /* |
4033 | * If active queue hasn't enough requests and can idle, cfq might not | |
4034 | * dispatch sufficient requests to hardware. Don't zero hw_tag in this | |
4035 | * case | |
4036 | */ | |
4037 | if (cfqq && cfq_cfqq_idle_window(cfqq) && | |
4038 | cfqq->dispatched + cfqq->queued[0] + cfqq->queued[1] < | |
53c583d2 | 4039 | CFQ_HW_QUEUE_MIN && cfqd->rq_in_driver < CFQ_HW_QUEUE_MIN) |
1a1238a7 SL |
4040 | return; |
4041 | ||
45333d5a AC |
4042 | if (cfqd->hw_tag_samples++ < 50) |
4043 | return; | |
4044 | ||
e459dd08 | 4045 | if (cfqd->hw_tag_est_depth >= CFQ_HW_QUEUE_MIN) |
45333d5a AC |
4046 | cfqd->hw_tag = 1; |
4047 | else | |
4048 | cfqd->hw_tag = 0; | |
45333d5a AC |
4049 | } |
4050 | ||
7667aa06 VG |
4051 | static bool cfq_should_wait_busy(struct cfq_data *cfqd, struct cfq_queue *cfqq) |
4052 | { | |
c5869807 | 4053 | struct cfq_io_cq *cic = cfqd->active_cic; |
7667aa06 | 4054 | |
02a8f01b JT |
4055 | /* If the queue already has requests, don't wait */ |
4056 | if (!RB_EMPTY_ROOT(&cfqq->sort_list)) | |
4057 | return false; | |
4058 | ||
7667aa06 VG |
4059 | /* If there are other queues in the group, don't wait */ |
4060 | if (cfqq->cfqg->nr_cfqq > 1) | |
4061 | return false; | |
4062 | ||
7700fc4f SL |
4063 | /* the only queue in the group, but think time is big */ |
4064 | if (cfq_io_thinktime_big(cfqd, &cfqq->cfqg->ttime, true)) | |
4065 | return false; | |
4066 | ||
7667aa06 VG |
4067 | if (cfq_slice_used(cfqq)) |
4068 | return true; | |
4069 | ||
4070 | /* if slice left is less than think time, wait busy */ | |
383cd721 SL |
4071 | if (cic && sample_valid(cic->ttime.ttime_samples) |
4072 | && (cfqq->slice_end - jiffies < cic->ttime.ttime_mean)) | |
7667aa06 VG |
4073 | return true; |
4074 | ||
4075 | /* | |
4076 | * If think times is less than a jiffy than ttime_mean=0 and above | |
4077 | * will not be true. It might happen that slice has not expired yet | |
4078 | * but will expire soon (4-5 ns) during select_queue(). To cover the | |
4079 | * case where think time is less than a jiffy, mark the queue wait | |
4080 | * busy if only 1 jiffy is left in the slice. | |
4081 | */ | |
4082 | if (cfqq->slice_end - jiffies == 1) | |
4083 | return true; | |
4084 | ||
4085 | return false; | |
4086 | } | |
4087 | ||
165125e1 | 4088 | static void cfq_completed_request(struct request_queue *q, struct request *rq) |
1da177e4 | 4089 | { |
5e705374 | 4090 | struct cfq_queue *cfqq = RQ_CFQQ(rq); |
b4878f24 | 4091 | struct cfq_data *cfqd = cfqq->cfqd; |
5380a101 | 4092 | const int sync = rq_is_sync(rq); |
b4878f24 | 4093 | unsigned long now; |
1da177e4 | 4094 | |
b4878f24 | 4095 | now = jiffies; |
33659ebb CH |
4096 | cfq_log_cfqq(cfqd, cfqq, "complete rqnoidle %d", |
4097 | !!(rq->cmd_flags & REQ_NOIDLE)); | |
1da177e4 | 4098 | |
45333d5a AC |
4099 | cfq_update_hw_tag(cfqd); |
4100 | ||
53c583d2 | 4101 | WARN_ON(!cfqd->rq_in_driver); |
6d048f53 | 4102 | WARN_ON(!cfqq->dispatched); |
53c583d2 | 4103 | cfqd->rq_in_driver--; |
6d048f53 | 4104 | cfqq->dispatched--; |
80bdf0c7 | 4105 | (RQ_CFQG(rq))->dispatched--; |
155fead9 TH |
4106 | cfqg_stats_update_completion(cfqq->cfqg, rq_start_time_ns(rq), |
4107 | rq_io_start_time_ns(rq), rq->cmd_flags); | |
1da177e4 | 4108 | |
53c583d2 | 4109 | cfqd->rq_in_flight[cfq_cfqq_sync(cfqq)]--; |
3ed9a296 | 4110 | |
365722bb | 4111 | if (sync) { |
34b98d03 | 4112 | struct cfq_rb_root *st; |
f5f2b6ce | 4113 | |
383cd721 | 4114 | RQ_CIC(rq)->ttime.last_end_request = now; |
f5f2b6ce SL |
4115 | |
4116 | if (cfq_cfqq_on_rr(cfqq)) | |
34b98d03 | 4117 | st = cfqq->service_tree; |
f5f2b6ce | 4118 | else |
34b98d03 VG |
4119 | st = st_for(cfqq->cfqg, cfqq_class(cfqq), |
4120 | cfqq_type(cfqq)); | |
4121 | ||
4122 | st->ttime.last_end_request = now; | |
573412b2 CZ |
4123 | if (!time_after(rq->start_time + cfqd->cfq_fifo_expire[1], now)) |
4124 | cfqd->last_delayed_sync = now; | |
365722bb | 4125 | } |
caaa5f9f | 4126 | |
7700fc4f SL |
4127 | #ifdef CONFIG_CFQ_GROUP_IOSCHED |
4128 | cfqq->cfqg->ttime.last_end_request = now; | |
4129 | #endif | |
4130 | ||
caaa5f9f JA |
4131 | /* |
4132 | * If this is the active queue, check if it needs to be expired, | |
4133 | * or if we want to idle in case it has no pending requests. | |
4134 | */ | |
4135 | if (cfqd->active_queue == cfqq) { | |
a36e71f9 JA |
4136 | const bool cfqq_empty = RB_EMPTY_ROOT(&cfqq->sort_list); |
4137 | ||
44f7c160 JA |
4138 | if (cfq_cfqq_slice_new(cfqq)) { |
4139 | cfq_set_prio_slice(cfqd, cfqq); | |
4140 | cfq_clear_cfqq_slice_new(cfqq); | |
4141 | } | |
f75edf2d VG |
4142 | |
4143 | /* | |
7667aa06 VG |
4144 | * Should we wait for next request to come in before we expire |
4145 | * the queue. | |
f75edf2d | 4146 | */ |
7667aa06 | 4147 | if (cfq_should_wait_busy(cfqd, cfqq)) { |
80bdf0c7 VG |
4148 | unsigned long extend_sl = cfqd->cfq_slice_idle; |
4149 | if (!cfqd->cfq_slice_idle) | |
4150 | extend_sl = cfqd->cfq_group_idle; | |
4151 | cfqq->slice_end = jiffies + extend_sl; | |
f75edf2d | 4152 | cfq_mark_cfqq_wait_busy(cfqq); |
b1ffe737 | 4153 | cfq_log_cfqq(cfqd, cfqq, "will busy wait"); |
f75edf2d VG |
4154 | } |
4155 | ||
a36e71f9 | 4156 | /* |
8e550632 CZ |
4157 | * Idling is not enabled on: |
4158 | * - expired queues | |
4159 | * - idle-priority queues | |
4160 | * - async queues | |
4161 | * - queues with still some requests queued | |
4162 | * - when there is a close cooperator | |
a36e71f9 | 4163 | */ |
0871714e | 4164 | if (cfq_slice_used(cfqq) || cfq_class_idle(cfqq)) |
e5ff082e | 4165 | cfq_slice_expired(cfqd, 1); |
8e550632 CZ |
4166 | else if (sync && cfqq_empty && |
4167 | !cfq_close_cooperator(cfqd, cfqq)) { | |
749ef9f8 | 4168 | cfq_arm_slice_timer(cfqd); |
8e550632 | 4169 | } |
caaa5f9f | 4170 | } |
6d048f53 | 4171 | |
53c583d2 | 4172 | if (!cfqd->rq_in_driver) |
23e018a1 | 4173 | cfq_schedule_dispatch(cfqd); |
1da177e4 LT |
4174 | } |
4175 | ||
89850f7e | 4176 | static inline int __cfq_may_queue(struct cfq_queue *cfqq) |
22e2c507 | 4177 | { |
1b379d8d | 4178 | if (cfq_cfqq_wait_request(cfqq) && !cfq_cfqq_must_alloc_slice(cfqq)) { |
3b18152c | 4179 | cfq_mark_cfqq_must_alloc_slice(cfqq); |
22e2c507 | 4180 | return ELV_MQUEUE_MUST; |
3b18152c | 4181 | } |
1da177e4 | 4182 | |
22e2c507 | 4183 | return ELV_MQUEUE_MAY; |
22e2c507 JA |
4184 | } |
4185 | ||
165125e1 | 4186 | static int cfq_may_queue(struct request_queue *q, int rw) |
22e2c507 JA |
4187 | { |
4188 | struct cfq_data *cfqd = q->elevator->elevator_data; | |
4189 | struct task_struct *tsk = current; | |
c5869807 | 4190 | struct cfq_io_cq *cic; |
22e2c507 JA |
4191 | struct cfq_queue *cfqq; |
4192 | ||
4193 | /* | |
4194 | * don't force setup of a queue from here, as a call to may_queue | |
4195 | * does not necessarily imply that a request actually will be queued. | |
4196 | * so just lookup a possibly existing queue, or return 'may queue' | |
4197 | * if that fails | |
4198 | */ | |
4ac845a2 | 4199 | cic = cfq_cic_lookup(cfqd, tsk->io_context); |
91fac317 VT |
4200 | if (!cic) |
4201 | return ELV_MQUEUE_MAY; | |
4202 | ||
b0b78f81 | 4203 | cfqq = cic_to_cfqq(cic, rw_is_sync(rw)); |
22e2c507 | 4204 | if (cfqq) { |
abede6da | 4205 | cfq_init_prio_data(cfqq, cic); |
22e2c507 | 4206 | |
89850f7e | 4207 | return __cfq_may_queue(cfqq); |
22e2c507 JA |
4208 | } |
4209 | ||
4210 | return ELV_MQUEUE_MAY; | |
1da177e4 LT |
4211 | } |
4212 | ||
1da177e4 LT |
4213 | /* |
4214 | * queue lock held here | |
4215 | */ | |
bb37b94c | 4216 | static void cfq_put_request(struct request *rq) |
1da177e4 | 4217 | { |
5e705374 | 4218 | struct cfq_queue *cfqq = RQ_CFQQ(rq); |
1da177e4 | 4219 | |
5e705374 | 4220 | if (cfqq) { |
22e2c507 | 4221 | const int rw = rq_data_dir(rq); |
1da177e4 | 4222 | |
22e2c507 JA |
4223 | BUG_ON(!cfqq->allocated[rw]); |
4224 | cfqq->allocated[rw]--; | |
1da177e4 | 4225 | |
7f1dc8a2 | 4226 | /* Put down rq reference on cfqg */ |
eb7d8c07 | 4227 | cfqg_put(RQ_CFQG(rq)); |
a612fddf TH |
4228 | rq->elv.priv[0] = NULL; |
4229 | rq->elv.priv[1] = NULL; | |
7f1dc8a2 | 4230 | |
1da177e4 LT |
4231 | cfq_put_queue(cfqq); |
4232 | } | |
4233 | } | |
4234 | ||
df5fe3e8 | 4235 | static struct cfq_queue * |
c5869807 | 4236 | cfq_merge_cfqqs(struct cfq_data *cfqd, struct cfq_io_cq *cic, |
df5fe3e8 JM |
4237 | struct cfq_queue *cfqq) |
4238 | { | |
4239 | cfq_log_cfqq(cfqd, cfqq, "merging with queue %p", cfqq->new_cfqq); | |
4240 | cic_set_cfqq(cic, cfqq->new_cfqq, 1); | |
b3b6d040 | 4241 | cfq_mark_cfqq_coop(cfqq->new_cfqq); |
df5fe3e8 JM |
4242 | cfq_put_queue(cfqq); |
4243 | return cic_to_cfqq(cic, 1); | |
4244 | } | |
4245 | ||
e6c5bc73 JM |
4246 | /* |
4247 | * Returns NULL if a new cfqq should be allocated, or the old cfqq if this | |
4248 | * was the last process referring to said cfqq. | |
4249 | */ | |
4250 | static struct cfq_queue * | |
c5869807 | 4251 | split_cfqq(struct cfq_io_cq *cic, struct cfq_queue *cfqq) |
e6c5bc73 JM |
4252 | { |
4253 | if (cfqq_process_refs(cfqq) == 1) { | |
e6c5bc73 JM |
4254 | cfqq->pid = current->pid; |
4255 | cfq_clear_cfqq_coop(cfqq); | |
ae54abed | 4256 | cfq_clear_cfqq_split_coop(cfqq); |
e6c5bc73 JM |
4257 | return cfqq; |
4258 | } | |
4259 | ||
4260 | cic_set_cfqq(cic, NULL, 1); | |
d02a2c07 SL |
4261 | |
4262 | cfq_put_cooperator(cfqq); | |
4263 | ||
e6c5bc73 JM |
4264 | cfq_put_queue(cfqq); |
4265 | return NULL; | |
4266 | } | |
1da177e4 | 4267 | /* |
22e2c507 | 4268 | * Allocate cfq data structures associated with this request. |
1da177e4 | 4269 | */ |
22e2c507 | 4270 | static int |
852c788f TH |
4271 | cfq_set_request(struct request_queue *q, struct request *rq, struct bio *bio, |
4272 | gfp_t gfp_mask) | |
1da177e4 LT |
4273 | { |
4274 | struct cfq_data *cfqd = q->elevator->elevator_data; | |
f1f8cc94 | 4275 | struct cfq_io_cq *cic = icq_to_cic(rq->elv.icq); |
1da177e4 | 4276 | const int rw = rq_data_dir(rq); |
a6151c3a | 4277 | const bool is_sync = rq_is_sync(rq); |
22e2c507 | 4278 | struct cfq_queue *cfqq; |
1da177e4 | 4279 | |
216284c3 | 4280 | spin_lock_irq(q->queue_lock); |
f1f8cc94 | 4281 | |
598971bf TH |
4282 | check_ioprio_changed(cic, bio); |
4283 | check_blkcg_changed(cic, bio); | |
e6c5bc73 | 4284 | new_queue: |
91fac317 | 4285 | cfqq = cic_to_cfqq(cic, is_sync); |
32f2e807 | 4286 | if (!cfqq || cfqq == &cfqd->oom_cfqq) { |
bce6133b TH |
4287 | if (cfqq) |
4288 | cfq_put_queue(cfqq); | |
2da8de0b | 4289 | cfqq = cfq_get_queue(cfqd, is_sync, cic, bio); |
91fac317 | 4290 | cic_set_cfqq(cic, cfqq, is_sync); |
df5fe3e8 | 4291 | } else { |
e6c5bc73 JM |
4292 | /* |
4293 | * If the queue was seeky for too long, break it apart. | |
4294 | */ | |
ae54abed | 4295 | if (cfq_cfqq_coop(cfqq) && cfq_cfqq_split_coop(cfqq)) { |
e6c5bc73 JM |
4296 | cfq_log_cfqq(cfqd, cfqq, "breaking apart cfqq"); |
4297 | cfqq = split_cfqq(cic, cfqq); | |
4298 | if (!cfqq) | |
4299 | goto new_queue; | |
4300 | } | |
4301 | ||
df5fe3e8 JM |
4302 | /* |
4303 | * Check to see if this queue is scheduled to merge with | |
4304 | * another, closely cooperating queue. The merging of | |
4305 | * queues happens here as it must be done in process context. | |
4306 | * The reference on new_cfqq was taken in merge_cfqqs. | |
4307 | */ | |
4308 | if (cfqq->new_cfqq) | |
4309 | cfqq = cfq_merge_cfqqs(cfqd, cic, cfqq); | |
91fac317 | 4310 | } |
1da177e4 LT |
4311 | |
4312 | cfqq->allocated[rw]++; | |
1da177e4 | 4313 | |
6fae9c25 | 4314 | cfqq->ref++; |
eb7d8c07 | 4315 | cfqg_get(cfqq->cfqg); |
a612fddf | 4316 | rq->elv.priv[0] = cfqq; |
1adaf3dd | 4317 | rq->elv.priv[1] = cfqq->cfqg; |
216284c3 | 4318 | spin_unlock_irq(q->queue_lock); |
5e705374 | 4319 | return 0; |
1da177e4 LT |
4320 | } |
4321 | ||
65f27f38 | 4322 | static void cfq_kick_queue(struct work_struct *work) |
22e2c507 | 4323 | { |
65f27f38 | 4324 | struct cfq_data *cfqd = |
23e018a1 | 4325 | container_of(work, struct cfq_data, unplug_work); |
165125e1 | 4326 | struct request_queue *q = cfqd->queue; |
22e2c507 | 4327 | |
40bb54d1 | 4328 | spin_lock_irq(q->queue_lock); |
24ecfbe2 | 4329 | __blk_run_queue(cfqd->queue); |
40bb54d1 | 4330 | spin_unlock_irq(q->queue_lock); |
22e2c507 JA |
4331 | } |
4332 | ||
4333 | /* | |
4334 | * Timer running if the active_queue is currently idling inside its time slice | |
4335 | */ | |
4336 | static void cfq_idle_slice_timer(unsigned long data) | |
4337 | { | |
4338 | struct cfq_data *cfqd = (struct cfq_data *) data; | |
4339 | struct cfq_queue *cfqq; | |
4340 | unsigned long flags; | |
3c6bd2f8 | 4341 | int timed_out = 1; |
22e2c507 | 4342 | |
7b679138 JA |
4343 | cfq_log(cfqd, "idle timer fired"); |
4344 | ||
22e2c507 JA |
4345 | spin_lock_irqsave(cfqd->queue->queue_lock, flags); |
4346 | ||
fe094d98 JA |
4347 | cfqq = cfqd->active_queue; |
4348 | if (cfqq) { | |
3c6bd2f8 JA |
4349 | timed_out = 0; |
4350 | ||
b029195d JA |
4351 | /* |
4352 | * We saw a request before the queue expired, let it through | |
4353 | */ | |
4354 | if (cfq_cfqq_must_dispatch(cfqq)) | |
4355 | goto out_kick; | |
4356 | ||
22e2c507 JA |
4357 | /* |
4358 | * expired | |
4359 | */ | |
44f7c160 | 4360 | if (cfq_slice_used(cfqq)) |
22e2c507 JA |
4361 | goto expire; |
4362 | ||
4363 | /* | |
4364 | * only expire and reinvoke request handler, if there are | |
4365 | * other queues with pending requests | |
4366 | */ | |
caaa5f9f | 4367 | if (!cfqd->busy_queues) |
22e2c507 | 4368 | goto out_cont; |
22e2c507 JA |
4369 | |
4370 | /* | |
4371 | * not expired and it has a request pending, let it dispatch | |
4372 | */ | |
75e50984 | 4373 | if (!RB_EMPTY_ROOT(&cfqq->sort_list)) |
22e2c507 | 4374 | goto out_kick; |
76280aff CZ |
4375 | |
4376 | /* | |
4377 | * Queue depth flag is reset only when the idle didn't succeed | |
4378 | */ | |
4379 | cfq_clear_cfqq_deep(cfqq); | |
22e2c507 JA |
4380 | } |
4381 | expire: | |
e5ff082e | 4382 | cfq_slice_expired(cfqd, timed_out); |
22e2c507 | 4383 | out_kick: |
23e018a1 | 4384 | cfq_schedule_dispatch(cfqd); |
22e2c507 JA |
4385 | out_cont: |
4386 | spin_unlock_irqrestore(cfqd->queue->queue_lock, flags); | |
4387 | } | |
4388 | ||
3b18152c JA |
4389 | static void cfq_shutdown_timer_wq(struct cfq_data *cfqd) |
4390 | { | |
4391 | del_timer_sync(&cfqd->idle_slice_timer); | |
23e018a1 | 4392 | cancel_work_sync(&cfqd->unplug_work); |
3b18152c | 4393 | } |
22e2c507 | 4394 | |
b374d18a | 4395 | static void cfq_exit_queue(struct elevator_queue *e) |
1da177e4 | 4396 | { |
22e2c507 | 4397 | struct cfq_data *cfqd = e->elevator_data; |
165125e1 | 4398 | struct request_queue *q = cfqd->queue; |
22e2c507 | 4399 | |
3b18152c | 4400 | cfq_shutdown_timer_wq(cfqd); |
e2d74ac0 | 4401 | |
d9ff4187 | 4402 | spin_lock_irq(q->queue_lock); |
e2d74ac0 | 4403 | |
d9ff4187 | 4404 | if (cfqd->active_queue) |
e5ff082e | 4405 | __cfq_slice_expired(cfqd, cfqd->active_queue, 0); |
e2d74ac0 | 4406 | |
03aa264a TH |
4407 | spin_unlock_irq(q->queue_lock); |
4408 | ||
a90d742e AV |
4409 | cfq_shutdown_timer_wq(cfqd); |
4410 | ||
ffea73fc TH |
4411 | #ifdef CONFIG_CFQ_GROUP_IOSCHED |
4412 | blkcg_deactivate_policy(q, &blkcg_policy_cfq); | |
4413 | #else | |
f51b802c | 4414 | kfree(cfqd->root_group); |
2abae55f | 4415 | #endif |
56edf7d7 | 4416 | kfree(cfqd); |
1da177e4 LT |
4417 | } |
4418 | ||
d50235b7 | 4419 | static int cfq_init_queue(struct request_queue *q, struct elevator_type *e) |
1da177e4 LT |
4420 | { |
4421 | struct cfq_data *cfqd; | |
3c798398 | 4422 | struct blkcg_gq *blkg __maybe_unused; |
a2b1693b | 4423 | int i, ret; |
d50235b7 JM |
4424 | struct elevator_queue *eq; |
4425 | ||
4426 | eq = elevator_alloc(q, e); | |
4427 | if (!eq) | |
4428 | return -ENOMEM; | |
1da177e4 | 4429 | |
c1b511eb | 4430 | cfqd = kzalloc_node(sizeof(*cfqd), GFP_KERNEL, q->node); |
d50235b7 JM |
4431 | if (!cfqd) { |
4432 | kobject_put(&eq->kobj); | |
b2fab5ac | 4433 | return -ENOMEM; |
d50235b7 JM |
4434 | } |
4435 | eq->elevator_data = cfqd; | |
80b15c73 | 4436 | |
f51b802c | 4437 | cfqd->queue = q; |
d50235b7 JM |
4438 | spin_lock_irq(q->queue_lock); |
4439 | q->elevator = eq; | |
4440 | spin_unlock_irq(q->queue_lock); | |
f51b802c | 4441 | |
1fa8f6d6 VG |
4442 | /* Init root service tree */ |
4443 | cfqd->grp_service_tree = CFQ_RB_ROOT; | |
4444 | ||
f51b802c | 4445 | /* Init root group and prefer root group over other groups by default */ |
25fb5169 | 4446 | #ifdef CONFIG_CFQ_GROUP_IOSCHED |
3c798398 | 4447 | ret = blkcg_activate_policy(q, &blkcg_policy_cfq); |
a2b1693b TH |
4448 | if (ret) |
4449 | goto out_free; | |
f51b802c | 4450 | |
a2b1693b | 4451 | cfqd->root_group = blkg_to_cfqg(q->root_blkg); |
f51b802c | 4452 | #else |
a2b1693b | 4453 | ret = -ENOMEM; |
f51b802c TH |
4454 | cfqd->root_group = kzalloc_node(sizeof(*cfqd->root_group), |
4455 | GFP_KERNEL, cfqd->queue->node); | |
a2b1693b TH |
4456 | if (!cfqd->root_group) |
4457 | goto out_free; | |
5624a4e4 | 4458 | |
a2b1693b TH |
4459 | cfq_init_cfqg_base(cfqd->root_group); |
4460 | #endif | |
3381cb8d | 4461 | cfqd->root_group->weight = 2 * CFQ_WEIGHT_DEFAULT; |
e71357e1 | 4462 | cfqd->root_group->leaf_weight = 2 * CFQ_WEIGHT_DEFAULT; |
5624a4e4 | 4463 | |
26a2ac00 JA |
4464 | /* |
4465 | * Not strictly needed (since RB_ROOT just clears the node and we | |
4466 | * zeroed cfqd on alloc), but better be safe in case someone decides | |
4467 | * to add magic to the rb code | |
4468 | */ | |
4469 | for (i = 0; i < CFQ_PRIO_LISTS; i++) | |
4470 | cfqd->prio_trees[i] = RB_ROOT; | |
4471 | ||
6118b70b | 4472 | /* |
d4aad7ff | 4473 | * Our fallback cfqq if cfq_get_queue() runs into OOM issues. |
6118b70b | 4474 | * Grab a permanent reference to it, so that the normal code flow |
f51b802c TH |
4475 | * will not attempt to free it. oom_cfqq is linked to root_group |
4476 | * but shouldn't hold a reference as it'll never be unlinked. Lose | |
4477 | * the reference from linking right away. | |
6118b70b JA |
4478 | */ |
4479 | cfq_init_cfqq(cfqd, &cfqd->oom_cfqq, 1, 0); | |
30d7b944 | 4480 | cfqd->oom_cfqq.ref++; |
1adaf3dd TH |
4481 | |
4482 | spin_lock_irq(q->queue_lock); | |
f51b802c | 4483 | cfq_link_cfqq_cfqg(&cfqd->oom_cfqq, cfqd->root_group); |
eb7d8c07 | 4484 | cfqg_put(cfqd->root_group); |
1adaf3dd | 4485 | spin_unlock_irq(q->queue_lock); |
1da177e4 | 4486 | |
22e2c507 JA |
4487 | init_timer(&cfqd->idle_slice_timer); |
4488 | cfqd->idle_slice_timer.function = cfq_idle_slice_timer; | |
4489 | cfqd->idle_slice_timer.data = (unsigned long) cfqd; | |
4490 | ||
23e018a1 | 4491 | INIT_WORK(&cfqd->unplug_work, cfq_kick_queue); |
22e2c507 | 4492 | |
1da177e4 | 4493 | cfqd->cfq_quantum = cfq_quantum; |
22e2c507 JA |
4494 | cfqd->cfq_fifo_expire[0] = cfq_fifo_expire[0]; |
4495 | cfqd->cfq_fifo_expire[1] = cfq_fifo_expire[1]; | |
1da177e4 LT |
4496 | cfqd->cfq_back_max = cfq_back_max; |
4497 | cfqd->cfq_back_penalty = cfq_back_penalty; | |
22e2c507 JA |
4498 | cfqd->cfq_slice[0] = cfq_slice_async; |
4499 | cfqd->cfq_slice[1] = cfq_slice_sync; | |
5bf14c07 | 4500 | cfqd->cfq_target_latency = cfq_target_latency; |
22e2c507 | 4501 | cfqd->cfq_slice_async_rq = cfq_slice_async_rq; |
0bb97947 | 4502 | cfqd->cfq_slice_idle = cfq_slice_idle; |
80bdf0c7 | 4503 | cfqd->cfq_group_idle = cfq_group_idle; |
963b72fc | 4504 | cfqd->cfq_latency = 1; |
e459dd08 | 4505 | cfqd->hw_tag = -1; |
edc71131 CZ |
4506 | /* |
4507 | * we optimistically start assuming sync ops weren't delayed in last | |
4508 | * second, in order to have larger depth for async operations. | |
4509 | */ | |
573412b2 | 4510 | cfqd->last_delayed_sync = jiffies - HZ; |
b2fab5ac | 4511 | return 0; |
a2b1693b TH |
4512 | |
4513 | out_free: | |
4514 | kfree(cfqd); | |
d50235b7 | 4515 | kobject_put(&eq->kobj); |
a2b1693b | 4516 | return ret; |
1da177e4 LT |
4517 | } |
4518 | ||
0bb97947 JA |
4519 | static void cfq_registered_queue(struct request_queue *q) |
4520 | { | |
4521 | struct elevator_queue *e = q->elevator; | |
4522 | struct cfq_data *cfqd = e->elevator_data; | |
4523 | ||
4524 | /* | |
4525 | * Default to IOPS mode with no idling for SSDs | |
4526 | */ | |
4527 | if (blk_queue_nonrot(q)) | |
4528 | cfqd->cfq_slice_idle = 0; | |
4529 | } | |
4530 | ||
1da177e4 LT |
4531 | /* |
4532 | * sysfs parts below --> | |
4533 | */ | |
1da177e4 LT |
4534 | static ssize_t |
4535 | cfq_var_show(unsigned int var, char *page) | |
4536 | { | |
176167ad | 4537 | return sprintf(page, "%u\n", var); |
1da177e4 LT |
4538 | } |
4539 | ||
4540 | static ssize_t | |
4541 | cfq_var_store(unsigned int *var, const char *page, size_t count) | |
4542 | { | |
4543 | char *p = (char *) page; | |
4544 | ||
4545 | *var = simple_strtoul(p, &p, 10); | |
4546 | return count; | |
4547 | } | |
4548 | ||
1da177e4 | 4549 | #define SHOW_FUNCTION(__FUNC, __VAR, __CONV) \ |
b374d18a | 4550 | static ssize_t __FUNC(struct elevator_queue *e, char *page) \ |
1da177e4 | 4551 | { \ |
3d1ab40f | 4552 | struct cfq_data *cfqd = e->elevator_data; \ |
1da177e4 LT |
4553 | unsigned int __data = __VAR; \ |
4554 | if (__CONV) \ | |
4555 | __data = jiffies_to_msecs(__data); \ | |
4556 | return cfq_var_show(__data, (page)); \ | |
4557 | } | |
4558 | SHOW_FUNCTION(cfq_quantum_show, cfqd->cfq_quantum, 0); | |
22e2c507 JA |
4559 | SHOW_FUNCTION(cfq_fifo_expire_sync_show, cfqd->cfq_fifo_expire[1], 1); |
4560 | SHOW_FUNCTION(cfq_fifo_expire_async_show, cfqd->cfq_fifo_expire[0], 1); | |
e572ec7e AV |
4561 | SHOW_FUNCTION(cfq_back_seek_max_show, cfqd->cfq_back_max, 0); |
4562 | SHOW_FUNCTION(cfq_back_seek_penalty_show, cfqd->cfq_back_penalty, 0); | |
22e2c507 | 4563 | SHOW_FUNCTION(cfq_slice_idle_show, cfqd->cfq_slice_idle, 1); |
80bdf0c7 | 4564 | SHOW_FUNCTION(cfq_group_idle_show, cfqd->cfq_group_idle, 1); |
22e2c507 JA |
4565 | SHOW_FUNCTION(cfq_slice_sync_show, cfqd->cfq_slice[1], 1); |
4566 | SHOW_FUNCTION(cfq_slice_async_show, cfqd->cfq_slice[0], 1); | |
4567 | SHOW_FUNCTION(cfq_slice_async_rq_show, cfqd->cfq_slice_async_rq, 0); | |
963b72fc | 4568 | SHOW_FUNCTION(cfq_low_latency_show, cfqd->cfq_latency, 0); |
5bf14c07 | 4569 | SHOW_FUNCTION(cfq_target_latency_show, cfqd->cfq_target_latency, 1); |
1da177e4 LT |
4570 | #undef SHOW_FUNCTION |
4571 | ||
4572 | #define STORE_FUNCTION(__FUNC, __PTR, MIN, MAX, __CONV) \ | |
b374d18a | 4573 | static ssize_t __FUNC(struct elevator_queue *e, const char *page, size_t count) \ |
1da177e4 | 4574 | { \ |
3d1ab40f | 4575 | struct cfq_data *cfqd = e->elevator_data; \ |
1da177e4 LT |
4576 | unsigned int __data; \ |
4577 | int ret = cfq_var_store(&__data, (page), count); \ | |
4578 | if (__data < (MIN)) \ | |
4579 | __data = (MIN); \ | |
4580 | else if (__data > (MAX)) \ | |
4581 | __data = (MAX); \ | |
4582 | if (__CONV) \ | |
4583 | *(__PTR) = msecs_to_jiffies(__data); \ | |
4584 | else \ | |
4585 | *(__PTR) = __data; \ | |
4586 | return ret; \ | |
4587 | } | |
4588 | STORE_FUNCTION(cfq_quantum_store, &cfqd->cfq_quantum, 1, UINT_MAX, 0); | |
fe094d98 JA |
4589 | STORE_FUNCTION(cfq_fifo_expire_sync_store, &cfqd->cfq_fifo_expire[1], 1, |
4590 | UINT_MAX, 1); | |
4591 | STORE_FUNCTION(cfq_fifo_expire_async_store, &cfqd->cfq_fifo_expire[0], 1, | |
4592 | UINT_MAX, 1); | |
e572ec7e | 4593 | STORE_FUNCTION(cfq_back_seek_max_store, &cfqd->cfq_back_max, 0, UINT_MAX, 0); |
fe094d98 JA |
4594 | STORE_FUNCTION(cfq_back_seek_penalty_store, &cfqd->cfq_back_penalty, 1, |
4595 | UINT_MAX, 0); | |
22e2c507 | 4596 | STORE_FUNCTION(cfq_slice_idle_store, &cfqd->cfq_slice_idle, 0, UINT_MAX, 1); |
80bdf0c7 | 4597 | STORE_FUNCTION(cfq_group_idle_store, &cfqd->cfq_group_idle, 0, UINT_MAX, 1); |
22e2c507 JA |
4598 | STORE_FUNCTION(cfq_slice_sync_store, &cfqd->cfq_slice[1], 1, UINT_MAX, 1); |
4599 | STORE_FUNCTION(cfq_slice_async_store, &cfqd->cfq_slice[0], 1, UINT_MAX, 1); | |
fe094d98 JA |
4600 | STORE_FUNCTION(cfq_slice_async_rq_store, &cfqd->cfq_slice_async_rq, 1, |
4601 | UINT_MAX, 0); | |
963b72fc | 4602 | STORE_FUNCTION(cfq_low_latency_store, &cfqd->cfq_latency, 0, 1, 0); |
5bf14c07 | 4603 | STORE_FUNCTION(cfq_target_latency_store, &cfqd->cfq_target_latency, 1, UINT_MAX, 1); |
1da177e4 LT |
4604 | #undef STORE_FUNCTION |
4605 | ||
e572ec7e AV |
4606 | #define CFQ_ATTR(name) \ |
4607 | __ATTR(name, S_IRUGO|S_IWUSR, cfq_##name##_show, cfq_##name##_store) | |
4608 | ||
4609 | static struct elv_fs_entry cfq_attrs[] = { | |
4610 | CFQ_ATTR(quantum), | |
e572ec7e AV |
4611 | CFQ_ATTR(fifo_expire_sync), |
4612 | CFQ_ATTR(fifo_expire_async), | |
4613 | CFQ_ATTR(back_seek_max), | |
4614 | CFQ_ATTR(back_seek_penalty), | |
4615 | CFQ_ATTR(slice_sync), | |
4616 | CFQ_ATTR(slice_async), | |
4617 | CFQ_ATTR(slice_async_rq), | |
4618 | CFQ_ATTR(slice_idle), | |
80bdf0c7 | 4619 | CFQ_ATTR(group_idle), |
963b72fc | 4620 | CFQ_ATTR(low_latency), |
5bf14c07 | 4621 | CFQ_ATTR(target_latency), |
e572ec7e | 4622 | __ATTR_NULL |
1da177e4 LT |
4623 | }; |
4624 | ||
1da177e4 LT |
4625 | static struct elevator_type iosched_cfq = { |
4626 | .ops = { | |
4627 | .elevator_merge_fn = cfq_merge, | |
4628 | .elevator_merged_fn = cfq_merged_request, | |
4629 | .elevator_merge_req_fn = cfq_merged_requests, | |
da775265 | 4630 | .elevator_allow_merge_fn = cfq_allow_merge, |
812d4026 | 4631 | .elevator_bio_merged_fn = cfq_bio_merged, |
b4878f24 | 4632 | .elevator_dispatch_fn = cfq_dispatch_requests, |
1da177e4 | 4633 | .elevator_add_req_fn = cfq_insert_request, |
b4878f24 | 4634 | .elevator_activate_req_fn = cfq_activate_request, |
1da177e4 | 4635 | .elevator_deactivate_req_fn = cfq_deactivate_request, |
1da177e4 | 4636 | .elevator_completed_req_fn = cfq_completed_request, |
21183b07 JA |
4637 | .elevator_former_req_fn = elv_rb_former_request, |
4638 | .elevator_latter_req_fn = elv_rb_latter_request, | |
9b84cacd | 4639 | .elevator_init_icq_fn = cfq_init_icq, |
7e5a8794 | 4640 | .elevator_exit_icq_fn = cfq_exit_icq, |
1da177e4 LT |
4641 | .elevator_set_req_fn = cfq_set_request, |
4642 | .elevator_put_req_fn = cfq_put_request, | |
4643 | .elevator_may_queue_fn = cfq_may_queue, | |
4644 | .elevator_init_fn = cfq_init_queue, | |
4645 | .elevator_exit_fn = cfq_exit_queue, | |
0bb97947 | 4646 | .elevator_registered_fn = cfq_registered_queue, |
1da177e4 | 4647 | }, |
3d3c2379 TH |
4648 | .icq_size = sizeof(struct cfq_io_cq), |
4649 | .icq_align = __alignof__(struct cfq_io_cq), | |
3d1ab40f | 4650 | .elevator_attrs = cfq_attrs, |
3d3c2379 | 4651 | .elevator_name = "cfq", |
1da177e4 LT |
4652 | .elevator_owner = THIS_MODULE, |
4653 | }; | |
4654 | ||
3e252066 | 4655 | #ifdef CONFIG_CFQ_GROUP_IOSCHED |
3c798398 | 4656 | static struct blkcg_policy blkcg_policy_cfq = { |
880f50e2 | 4657 | .legacy_cftypes = cfq_blkcg_legacy_files, |
f9fcc2d3 | 4658 | |
e4a9bde9 | 4659 | .cpd_alloc_fn = cfq_cpd_alloc, |
e48453c3 | 4660 | .cpd_init_fn = cfq_cpd_init, |
e4a9bde9 TH |
4661 | .cpd_free_fn = cfq_cpd_free, |
4662 | ||
001bea73 | 4663 | .pd_alloc_fn = cfq_pd_alloc, |
f9fcc2d3 | 4664 | .pd_init_fn = cfq_pd_init, |
0b39920b | 4665 | .pd_offline_fn = cfq_pd_offline, |
001bea73 | 4666 | .pd_free_fn = cfq_pd_free, |
f9fcc2d3 | 4667 | .pd_reset_stats_fn = cfq_pd_reset_stats, |
3e252066 | 4668 | }; |
3e252066 VG |
4669 | #endif |
4670 | ||
1da177e4 LT |
4671 | static int __init cfq_init(void) |
4672 | { | |
3d3c2379 TH |
4673 | int ret; |
4674 | ||
22e2c507 JA |
4675 | /* |
4676 | * could be 0 on HZ < 1000 setups | |
4677 | */ | |
4678 | if (!cfq_slice_async) | |
4679 | cfq_slice_async = 1; | |
4680 | if (!cfq_slice_idle) | |
4681 | cfq_slice_idle = 1; | |
4682 | ||
80bdf0c7 VG |
4683 | #ifdef CONFIG_CFQ_GROUP_IOSCHED |
4684 | if (!cfq_group_idle) | |
4685 | cfq_group_idle = 1; | |
8bd435b3 | 4686 | |
3c798398 | 4687 | ret = blkcg_policy_register(&blkcg_policy_cfq); |
8bd435b3 TH |
4688 | if (ret) |
4689 | return ret; | |
ffea73fc TH |
4690 | #else |
4691 | cfq_group_idle = 0; | |
4692 | #endif | |
8bd435b3 | 4693 | |
fd794956 | 4694 | ret = -ENOMEM; |
3d3c2379 TH |
4695 | cfq_pool = KMEM_CACHE(cfq_queue, 0); |
4696 | if (!cfq_pool) | |
8bd435b3 | 4697 | goto err_pol_unreg; |
1da177e4 | 4698 | |
3d3c2379 | 4699 | ret = elv_register(&iosched_cfq); |
8bd435b3 TH |
4700 | if (ret) |
4701 | goto err_free_pool; | |
3d3c2379 | 4702 | |
2fdd82bd | 4703 | return 0; |
8bd435b3 TH |
4704 | |
4705 | err_free_pool: | |
4706 | kmem_cache_destroy(cfq_pool); | |
4707 | err_pol_unreg: | |
ffea73fc | 4708 | #ifdef CONFIG_CFQ_GROUP_IOSCHED |
3c798398 | 4709 | blkcg_policy_unregister(&blkcg_policy_cfq); |
ffea73fc | 4710 | #endif |
8bd435b3 | 4711 | return ret; |
1da177e4 LT |
4712 | } |
4713 | ||
4714 | static void __exit cfq_exit(void) | |
4715 | { | |
ffea73fc | 4716 | #ifdef CONFIG_CFQ_GROUP_IOSCHED |
3c798398 | 4717 | blkcg_policy_unregister(&blkcg_policy_cfq); |
ffea73fc | 4718 | #endif |
1da177e4 | 4719 | elv_unregister(&iosched_cfq); |
3d3c2379 | 4720 | kmem_cache_destroy(cfq_pool); |
1da177e4 LT |
4721 | } |
4722 | ||
4723 | module_init(cfq_init); | |
4724 | module_exit(cfq_exit); | |
4725 | ||
4726 | MODULE_AUTHOR("Jens Axboe"); | |
4727 | MODULE_LICENSE("GPL"); | |
4728 | MODULE_DESCRIPTION("Completely Fair Queueing IO scheduler"); |