]>
Commit | Line | Data |
---|---|---|
61989a80 NG |
1 | /* |
2 | * zsmalloc memory allocator | |
3 | * | |
4 | * Copyright (C) 2011 Nitin Gupta | |
31fc00bb | 5 | * Copyright (C) 2012, 2013 Minchan Kim |
61989a80 NG |
6 | * |
7 | * This code is released using a dual license strategy: BSD/GPL | |
8 | * You can choose the license that better fits your requirements. | |
9 | * | |
10 | * Released under the terms of 3-clause BSD License | |
11 | * Released under the terms of GNU General Public License Version 2.0 | |
12 | */ | |
13 | ||
2db51dae | 14 | /* |
2db51dae NG |
15 | * Following is how we use various fields and flags of underlying |
16 | * struct page(s) to form a zspage. | |
17 | * | |
18 | * Usage of struct page fields: | |
3783689a | 19 | * page->private: points to zspage |
48b4800a MK |
20 | * page->freelist(index): links together all component pages of a zspage |
21 | * For the huge page, this is always 0, so we use this field | |
22 | * to store handle. | |
fd854463 | 23 | * page->units: first object offset in a subpage of zspage |
2db51dae NG |
24 | * |
25 | * Usage of struct page flags: | |
26 | * PG_private: identifies the first component page | |
399d8eeb | 27 | * PG_owner_priv_1: identifies the huge component page |
2db51dae NG |
28 | * |
29 | */ | |
30 | ||
4abaac9b DS |
31 | #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt |
32 | ||
61989a80 NG |
33 | #include <linux/module.h> |
34 | #include <linux/kernel.h> | |
312fcae2 | 35 | #include <linux/sched.h> |
50d34394 | 36 | #include <linux/magic.h> |
61989a80 NG |
37 | #include <linux/bitops.h> |
38 | #include <linux/errno.h> | |
39 | #include <linux/highmem.h> | |
61989a80 NG |
40 | #include <linux/string.h> |
41 | #include <linux/slab.h> | |
ca5999fd | 42 | #include <linux/pgtable.h> |
65fddcfc | 43 | #include <asm/tlbflush.h> |
61989a80 NG |
44 | #include <linux/cpumask.h> |
45 | #include <linux/cpu.h> | |
0cbb613f | 46 | #include <linux/vmalloc.h> |
759b26b2 | 47 | #include <linux/preempt.h> |
0959c63f | 48 | #include <linux/spinlock.h> |
93144ca3 | 49 | #include <linux/shrinker.h> |
0959c63f | 50 | #include <linux/types.h> |
0f050d99 | 51 | #include <linux/debugfs.h> |
bcf1647d | 52 | #include <linux/zsmalloc.h> |
c795779d | 53 | #include <linux/zpool.h> |
48b4800a | 54 | #include <linux/mount.h> |
8e9231f8 | 55 | #include <linux/pseudo_fs.h> |
dd4123f3 | 56 | #include <linux/migrate.h> |
701d6785 | 57 | #include <linux/wait.h> |
48b4800a | 58 | #include <linux/pagemap.h> |
cdc346b3 | 59 | #include <linux/fs.h> |
48b4800a MK |
60 | |
61 | #define ZSPAGE_MAGIC 0x58 | |
0959c63f SJ |
62 | |
63 | /* | |
64 | * This must be power of 2 and greater than of equal to sizeof(link_free). | |
65 | * These two conditions ensure that any 'struct link_free' itself doesn't | |
66 | * span more than 1 page which avoids complex case of mapping 2 pages simply | |
67 | * to restore link_free pointer values. | |
68 | */ | |
69 | #define ZS_ALIGN 8 | |
70 | ||
71 | /* | |
72 | * A single 'zspage' is composed of up to 2^N discontiguous 0-order (single) | |
73 | * pages. ZS_MAX_ZSPAGE_ORDER defines upper limit on N. | |
74 | */ | |
75 | #define ZS_MAX_ZSPAGE_ORDER 2 | |
76 | #define ZS_MAX_PAGES_PER_ZSPAGE (_AC(1, UL) << ZS_MAX_ZSPAGE_ORDER) | |
77 | ||
2e40e163 MK |
78 | #define ZS_HANDLE_SIZE (sizeof(unsigned long)) |
79 | ||
0959c63f SJ |
80 | /* |
81 | * Object location (<PFN>, <obj_idx>) is encoded as | |
b956b5ac | 82 | * a single (unsigned long) handle value. |
0959c63f | 83 | * |
bfd093f5 | 84 | * Note that object index <obj_idx> starts from 0. |
0959c63f SJ |
85 | * |
86 | * This is made more complicated by various memory models and PAE. | |
87 | */ | |
88 | ||
02390b87 KS |
89 | #ifndef MAX_POSSIBLE_PHYSMEM_BITS |
90 | #ifdef MAX_PHYSMEM_BITS | |
91 | #define MAX_POSSIBLE_PHYSMEM_BITS MAX_PHYSMEM_BITS | |
92 | #else | |
0959c63f SJ |
93 | /* |
94 | * If this definition of MAX_PHYSMEM_BITS is used, OBJ_INDEX_BITS will just | |
95 | * be PAGE_SHIFT | |
96 | */ | |
02390b87 | 97 | #define MAX_POSSIBLE_PHYSMEM_BITS BITS_PER_LONG |
0959c63f SJ |
98 | #endif |
99 | #endif | |
02390b87 KS |
100 | |
101 | #define _PFN_BITS (MAX_POSSIBLE_PHYSMEM_BITS - PAGE_SHIFT) | |
312fcae2 MK |
102 | |
103 | /* | |
104 | * Memory for allocating for handle keeps object position by | |
105 | * encoding <page, obj_idx> and the encoded value has a room | |
106 | * in least bit(ie, look at obj_to_location). | |
107 | * We use the bit to synchronize between object access by | |
108 | * user and migration. | |
109 | */ | |
110 | #define HANDLE_PIN_BIT 0 | |
111 | ||
112 | /* | |
113 | * Head in allocated object should have OBJ_ALLOCATED_TAG | |
114 | * to identify the object was allocated or not. | |
115 | * It's okay to add the status bit in the least bit because | |
116 | * header keeps handle which is 4byte-aligned address so we | |
117 | * have room for two bit at least. | |
118 | */ | |
119 | #define OBJ_ALLOCATED_TAG 1 | |
120 | #define OBJ_TAG_BITS 1 | |
121 | #define OBJ_INDEX_BITS (BITS_PER_LONG - _PFN_BITS - OBJ_TAG_BITS) | |
0959c63f SJ |
122 | #define OBJ_INDEX_MASK ((_AC(1, UL) << OBJ_INDEX_BITS) - 1) |
123 | ||
cf8e0fed JM |
124 | #define FULLNESS_BITS 2 |
125 | #define CLASS_BITS 8 | |
126 | #define ISOLATED_BITS 3 | |
127 | #define MAGIC_VAL_BITS 8 | |
128 | ||
0959c63f SJ |
129 | #define MAX(a, b) ((a) >= (b) ? (a) : (b)) |
130 | /* ZS_MIN_ALLOC_SIZE must be multiple of ZS_ALIGN */ | |
131 | #define ZS_MIN_ALLOC_SIZE \ | |
132 | MAX(32, (ZS_MAX_PAGES_PER_ZSPAGE << PAGE_SHIFT >> OBJ_INDEX_BITS)) | |
2e40e163 | 133 | /* each chunk includes extra space to keep handle */ |
7b60a685 | 134 | #define ZS_MAX_ALLOC_SIZE PAGE_SIZE |
0959c63f SJ |
135 | |
136 | /* | |
7eb52512 | 137 | * On systems with 4K page size, this gives 255 size classes! There is a |
0959c63f SJ |
138 | * trader-off here: |
139 | * - Large number of size classes is potentially wasteful as free page are | |
140 | * spread across these classes | |
141 | * - Small number of size classes causes large internal fragmentation | |
142 | * - Probably its better to use specific size classes (empirically | |
143 | * determined). NOTE: all those class sizes must be set as multiple of | |
144 | * ZS_ALIGN to make sure link_free itself never has to span 2 pages. | |
145 | * | |
146 | * ZS_MIN_ALLOC_SIZE and ZS_SIZE_CLASS_DELTA must be multiple of ZS_ALIGN | |
147 | * (reason above) | |
148 | */ | |
3783689a | 149 | #define ZS_SIZE_CLASS_DELTA (PAGE_SIZE >> CLASS_BITS) |
cf8e0fed JM |
150 | #define ZS_SIZE_CLASSES (DIV_ROUND_UP(ZS_MAX_ALLOC_SIZE - ZS_MIN_ALLOC_SIZE, \ |
151 | ZS_SIZE_CLASS_DELTA) + 1) | |
0959c63f | 152 | |
0959c63f | 153 | enum fullness_group { |
0959c63f | 154 | ZS_EMPTY, |
48b4800a MK |
155 | ZS_ALMOST_EMPTY, |
156 | ZS_ALMOST_FULL, | |
157 | ZS_FULL, | |
158 | NR_ZS_FULLNESS, | |
0959c63f SJ |
159 | }; |
160 | ||
0f050d99 | 161 | enum zs_stat_type { |
48b4800a MK |
162 | CLASS_EMPTY, |
163 | CLASS_ALMOST_EMPTY, | |
164 | CLASS_ALMOST_FULL, | |
165 | CLASS_FULL, | |
0f050d99 GM |
166 | OBJ_ALLOCATED, |
167 | OBJ_USED, | |
48b4800a | 168 | NR_ZS_STAT_TYPE, |
0f050d99 GM |
169 | }; |
170 | ||
0f050d99 GM |
171 | struct zs_size_stat { |
172 | unsigned long objs[NR_ZS_STAT_TYPE]; | |
173 | }; | |
174 | ||
57244594 SS |
175 | #ifdef CONFIG_ZSMALLOC_STAT |
176 | static struct dentry *zs_stat_root; | |
0f050d99 GM |
177 | #endif |
178 | ||
48b4800a MK |
179 | #ifdef CONFIG_COMPACTION |
180 | static struct vfsmount *zsmalloc_mnt; | |
181 | #endif | |
182 | ||
0959c63f SJ |
183 | /* |
184 | * We assign a page to ZS_ALMOST_EMPTY fullness group when: | |
185 | * n <= N / f, where | |
186 | * n = number of allocated objects | |
187 | * N = total number of objects zspage can store | |
6dd9737e | 188 | * f = fullness_threshold_frac |
0959c63f SJ |
189 | * |
190 | * Similarly, we assign zspage to: | |
191 | * ZS_ALMOST_FULL when n > N / f | |
192 | * ZS_EMPTY when n == 0 | |
193 | * ZS_FULL when n == N | |
194 | * | |
195 | * (see: fix_fullness_group()) | |
196 | */ | |
197 | static const int fullness_threshold_frac = 4; | |
010b495e | 198 | static size_t huge_class_size; |
0959c63f SJ |
199 | |
200 | struct size_class { | |
57244594 | 201 | spinlock_t lock; |
48b4800a | 202 | struct list_head fullness_list[NR_ZS_FULLNESS]; |
0959c63f SJ |
203 | /* |
204 | * Size of objects stored in this class. Must be multiple | |
205 | * of ZS_ALIGN. | |
206 | */ | |
207 | int size; | |
1fc6e27d | 208 | int objs_per_zspage; |
7dfa4612 WY |
209 | /* Number of PAGE_SIZE sized pages to combine to form a 'zspage' */ |
210 | int pages_per_zspage; | |
48b4800a MK |
211 | |
212 | unsigned int index; | |
213 | struct zs_size_stat stats; | |
0959c63f SJ |
214 | }; |
215 | ||
48b4800a MK |
216 | /* huge object: pages_per_zspage == 1 && maxobj_per_zspage == 1 */ |
217 | static void SetPageHugeObject(struct page *page) | |
218 | { | |
219 | SetPageOwnerPriv1(page); | |
220 | } | |
221 | ||
222 | static void ClearPageHugeObject(struct page *page) | |
223 | { | |
224 | ClearPageOwnerPriv1(page); | |
225 | } | |
226 | ||
227 | static int PageHugeObject(struct page *page) | |
228 | { | |
229 | return PageOwnerPriv1(page); | |
230 | } | |
231 | ||
0959c63f SJ |
232 | /* |
233 | * Placed within free objects to form a singly linked list. | |
3783689a | 234 | * For every zspage, zspage->freeobj gives head of this list. |
0959c63f SJ |
235 | * |
236 | * This must be power of 2 and less than or equal to ZS_ALIGN | |
237 | */ | |
238 | struct link_free { | |
2e40e163 MK |
239 | union { |
240 | /* | |
bfd093f5 | 241 | * Free object index; |
2e40e163 MK |
242 | * It's valid for non-allocated object |
243 | */ | |
bfd093f5 | 244 | unsigned long next; |
2e40e163 MK |
245 | /* |
246 | * Handle of allocated object. | |
247 | */ | |
248 | unsigned long handle; | |
249 | }; | |
0959c63f SJ |
250 | }; |
251 | ||
252 | struct zs_pool { | |
6f3526d6 | 253 | const char *name; |
0f050d99 | 254 | |
cf8e0fed | 255 | struct size_class *size_class[ZS_SIZE_CLASSES]; |
2e40e163 | 256 | struct kmem_cache *handle_cachep; |
3783689a | 257 | struct kmem_cache *zspage_cachep; |
0959c63f | 258 | |
13de8933 | 259 | atomic_long_t pages_allocated; |
0f050d99 | 260 | |
7d3f3938 | 261 | struct zs_pool_stats stats; |
ab9d306d SS |
262 | |
263 | /* Compact classes */ | |
264 | struct shrinker shrinker; | |
93144ca3 | 265 | |
0f050d99 GM |
266 | #ifdef CONFIG_ZSMALLOC_STAT |
267 | struct dentry *stat_dentry; | |
268 | #endif | |
48b4800a MK |
269 | #ifdef CONFIG_COMPACTION |
270 | struct inode *inode; | |
271 | struct work_struct free_work; | |
701d6785 HB |
272 | /* A wait queue for when migration races with async_free_zspage() */ |
273 | struct wait_queue_head migration_wait; | |
274 | atomic_long_t isolated_pages; | |
275 | bool destroying; | |
48b4800a | 276 | #endif |
0959c63f | 277 | }; |
61989a80 | 278 | |
3783689a MK |
279 | struct zspage { |
280 | struct { | |
281 | unsigned int fullness:FULLNESS_BITS; | |
85d492f2 | 282 | unsigned int class:CLASS_BITS + 1; |
48b4800a MK |
283 | unsigned int isolated:ISOLATED_BITS; |
284 | unsigned int magic:MAGIC_VAL_BITS; | |
3783689a MK |
285 | }; |
286 | unsigned int inuse; | |
bfd093f5 | 287 | unsigned int freeobj; |
3783689a MK |
288 | struct page *first_page; |
289 | struct list_head list; /* fullness list */ | |
48b4800a MK |
290 | #ifdef CONFIG_COMPACTION |
291 | rwlock_t lock; | |
292 | #endif | |
3783689a | 293 | }; |
61989a80 | 294 | |
f553646a | 295 | struct mapping_area { |
f553646a | 296 | char *vm_buf; /* copy buffer for objects that span pages */ |
f553646a SJ |
297 | char *vm_addr; /* address of kmap_atomic()'ed pages */ |
298 | enum zs_mapmode vm_mm; /* mapping mode */ | |
299 | }; | |
300 | ||
48b4800a MK |
301 | #ifdef CONFIG_COMPACTION |
302 | static int zs_register_migration(struct zs_pool *pool); | |
303 | static void zs_unregister_migration(struct zs_pool *pool); | |
304 | static void migrate_lock_init(struct zspage *zspage); | |
305 | static void migrate_read_lock(struct zspage *zspage); | |
306 | static void migrate_read_unlock(struct zspage *zspage); | |
307 | static void kick_deferred_free(struct zs_pool *pool); | |
308 | static void init_deferred_free(struct zs_pool *pool); | |
309 | static void SetZsPageMovable(struct zs_pool *pool, struct zspage *zspage); | |
310 | #else | |
311 | static int zsmalloc_mount(void) { return 0; } | |
312 | static void zsmalloc_unmount(void) {} | |
313 | static int zs_register_migration(struct zs_pool *pool) { return 0; } | |
314 | static void zs_unregister_migration(struct zs_pool *pool) {} | |
315 | static void migrate_lock_init(struct zspage *zspage) {} | |
316 | static void migrate_read_lock(struct zspage *zspage) {} | |
317 | static void migrate_read_unlock(struct zspage *zspage) {} | |
318 | static void kick_deferred_free(struct zs_pool *pool) {} | |
319 | static void init_deferred_free(struct zs_pool *pool) {} | |
320 | static void SetZsPageMovable(struct zs_pool *pool, struct zspage *zspage) {} | |
321 | #endif | |
322 | ||
3783689a | 323 | static int create_cache(struct zs_pool *pool) |
2e40e163 MK |
324 | { |
325 | pool->handle_cachep = kmem_cache_create("zs_handle", ZS_HANDLE_SIZE, | |
326 | 0, 0, NULL); | |
3783689a MK |
327 | if (!pool->handle_cachep) |
328 | return 1; | |
329 | ||
330 | pool->zspage_cachep = kmem_cache_create("zspage", sizeof(struct zspage), | |
331 | 0, 0, NULL); | |
332 | if (!pool->zspage_cachep) { | |
333 | kmem_cache_destroy(pool->handle_cachep); | |
334 | pool->handle_cachep = NULL; | |
335 | return 1; | |
336 | } | |
337 | ||
338 | return 0; | |
2e40e163 MK |
339 | } |
340 | ||
3783689a | 341 | static void destroy_cache(struct zs_pool *pool) |
2e40e163 | 342 | { |
cd10add0 | 343 | kmem_cache_destroy(pool->handle_cachep); |
3783689a | 344 | kmem_cache_destroy(pool->zspage_cachep); |
2e40e163 MK |
345 | } |
346 | ||
3783689a | 347 | static unsigned long cache_alloc_handle(struct zs_pool *pool, gfp_t gfp) |
2e40e163 MK |
348 | { |
349 | return (unsigned long)kmem_cache_alloc(pool->handle_cachep, | |
48b4800a | 350 | gfp & ~(__GFP_HIGHMEM|__GFP_MOVABLE)); |
2e40e163 MK |
351 | } |
352 | ||
3783689a | 353 | static void cache_free_handle(struct zs_pool *pool, unsigned long handle) |
2e40e163 MK |
354 | { |
355 | kmem_cache_free(pool->handle_cachep, (void *)handle); | |
356 | } | |
357 | ||
3783689a MK |
358 | static struct zspage *cache_alloc_zspage(struct zs_pool *pool, gfp_t flags) |
359 | { | |
48b4800a MK |
360 | return kmem_cache_alloc(pool->zspage_cachep, |
361 | flags & ~(__GFP_HIGHMEM|__GFP_MOVABLE)); | |
399d8eeb | 362 | } |
3783689a MK |
363 | |
364 | static void cache_free_zspage(struct zs_pool *pool, struct zspage *zspage) | |
365 | { | |
366 | kmem_cache_free(pool->zspage_cachep, zspage); | |
367 | } | |
368 | ||
2e40e163 MK |
369 | static void record_obj(unsigned long handle, unsigned long obj) |
370 | { | |
c102f07c JL |
371 | /* |
372 | * lsb of @obj represents handle lock while other bits | |
373 | * represent object value the handle is pointing so | |
374 | * updating shouldn't do store tearing. | |
375 | */ | |
376 | WRITE_ONCE(*(unsigned long *)handle, obj); | |
2e40e163 MK |
377 | } |
378 | ||
c795779d DS |
379 | /* zpool driver */ |
380 | ||
381 | #ifdef CONFIG_ZPOOL | |
382 | ||
6f3526d6 | 383 | static void *zs_zpool_create(const char *name, gfp_t gfp, |
78672779 | 384 | const struct zpool_ops *zpool_ops, |
479305fd | 385 | struct zpool *zpool) |
c795779d | 386 | { |
d0d8da2d SS |
387 | /* |
388 | * Ignore global gfp flags: zs_malloc() may be invoked from | |
389 | * different contexts and its caller must provide a valid | |
390 | * gfp mask. | |
391 | */ | |
392 | return zs_create_pool(name); | |
c795779d DS |
393 | } |
394 | ||
395 | static void zs_zpool_destroy(void *pool) | |
396 | { | |
397 | zs_destroy_pool(pool); | |
398 | } | |
399 | ||
400 | static int zs_zpool_malloc(void *pool, size_t size, gfp_t gfp, | |
401 | unsigned long *handle) | |
402 | { | |
d0d8da2d | 403 | *handle = zs_malloc(pool, size, gfp); |
c795779d DS |
404 | return *handle ? 0 : -1; |
405 | } | |
406 | static void zs_zpool_free(void *pool, unsigned long handle) | |
407 | { | |
408 | zs_free(pool, handle); | |
409 | } | |
410 | ||
c795779d DS |
411 | static void *zs_zpool_map(void *pool, unsigned long handle, |
412 | enum zpool_mapmode mm) | |
413 | { | |
414 | enum zs_mapmode zs_mm; | |
415 | ||
416 | switch (mm) { | |
417 | case ZPOOL_MM_RO: | |
418 | zs_mm = ZS_MM_RO; | |
419 | break; | |
420 | case ZPOOL_MM_WO: | |
421 | zs_mm = ZS_MM_WO; | |
422 | break; | |
e4a9bc58 | 423 | case ZPOOL_MM_RW: |
c795779d DS |
424 | default: |
425 | zs_mm = ZS_MM_RW; | |
426 | break; | |
427 | } | |
428 | ||
429 | return zs_map_object(pool, handle, zs_mm); | |
430 | } | |
431 | static void zs_zpool_unmap(void *pool, unsigned long handle) | |
432 | { | |
433 | zs_unmap_object(pool, handle); | |
434 | } | |
435 | ||
436 | static u64 zs_zpool_total_size(void *pool) | |
437 | { | |
722cdc17 | 438 | return zs_get_total_pages(pool) << PAGE_SHIFT; |
c795779d DS |
439 | } |
440 | ||
441 | static struct zpool_driver zs_zpool_driver = { | |
c165f25d HZ |
442 | .type = "zsmalloc", |
443 | .owner = THIS_MODULE, | |
444 | .create = zs_zpool_create, | |
445 | .destroy = zs_zpool_destroy, | |
446 | .malloc_support_movable = true, | |
447 | .malloc = zs_zpool_malloc, | |
448 | .free = zs_zpool_free, | |
449 | .map = zs_zpool_map, | |
450 | .unmap = zs_zpool_unmap, | |
451 | .total_size = zs_zpool_total_size, | |
c795779d DS |
452 | }; |
453 | ||
137f8cff | 454 | MODULE_ALIAS("zpool-zsmalloc"); |
c795779d DS |
455 | #endif /* CONFIG_ZPOOL */ |
456 | ||
61989a80 NG |
457 | /* per-cpu VM mapping areas for zspage accesses that cross page boundaries */ |
458 | static DEFINE_PER_CPU(struct mapping_area, zs_map_area); | |
459 | ||
48b4800a MK |
460 | static bool is_zspage_isolated(struct zspage *zspage) |
461 | { | |
462 | return zspage->isolated; | |
463 | } | |
464 | ||
3457f414 | 465 | static __maybe_unused int is_first_page(struct page *page) |
61989a80 | 466 | { |
a27545bf | 467 | return PagePrivate(page); |
61989a80 NG |
468 | } |
469 | ||
48b4800a | 470 | /* Protected by class->lock */ |
3783689a | 471 | static inline int get_zspage_inuse(struct zspage *zspage) |
4f42047b | 472 | { |
3783689a | 473 | return zspage->inuse; |
4f42047b MK |
474 | } |
475 | ||
4f42047b | 476 | |
3783689a | 477 | static inline void mod_zspage_inuse(struct zspage *zspage, int val) |
4f42047b | 478 | { |
3783689a | 479 | zspage->inuse += val; |
4f42047b MK |
480 | } |
481 | ||
48b4800a | 482 | static inline struct page *get_first_page(struct zspage *zspage) |
4f42047b | 483 | { |
48b4800a | 484 | struct page *first_page = zspage->first_page; |
3783689a | 485 | |
48b4800a MK |
486 | VM_BUG_ON_PAGE(!is_first_page(first_page), first_page); |
487 | return first_page; | |
4f42047b MK |
488 | } |
489 | ||
48b4800a | 490 | static inline int get_first_obj_offset(struct page *page) |
4f42047b | 491 | { |
48b4800a MK |
492 | return page->units; |
493 | } | |
3783689a | 494 | |
48b4800a MK |
495 | static inline void set_first_obj_offset(struct page *page, int offset) |
496 | { | |
497 | page->units = offset; | |
4f42047b MK |
498 | } |
499 | ||
bfd093f5 | 500 | static inline unsigned int get_freeobj(struct zspage *zspage) |
4f42047b | 501 | { |
bfd093f5 | 502 | return zspage->freeobj; |
4f42047b MK |
503 | } |
504 | ||
bfd093f5 | 505 | static inline void set_freeobj(struct zspage *zspage, unsigned int obj) |
4f42047b | 506 | { |
bfd093f5 | 507 | zspage->freeobj = obj; |
4f42047b MK |
508 | } |
509 | ||
3783689a | 510 | static void get_zspage_mapping(struct zspage *zspage, |
a4209467 | 511 | unsigned int *class_idx, |
61989a80 NG |
512 | enum fullness_group *fullness) |
513 | { | |
48b4800a MK |
514 | BUG_ON(zspage->magic != ZSPAGE_MAGIC); |
515 | ||
3783689a MK |
516 | *fullness = zspage->fullness; |
517 | *class_idx = zspage->class; | |
61989a80 NG |
518 | } |
519 | ||
3783689a | 520 | static void set_zspage_mapping(struct zspage *zspage, |
a4209467 | 521 | unsigned int class_idx, |
61989a80 NG |
522 | enum fullness_group fullness) |
523 | { | |
3783689a MK |
524 | zspage->class = class_idx; |
525 | zspage->fullness = fullness; | |
61989a80 NG |
526 | } |
527 | ||
c3e3e88a NC |
528 | /* |
529 | * zsmalloc divides the pool into various size classes where each | |
530 | * class maintains a list of zspages where each zspage is divided | |
531 | * into equal sized chunks. Each allocation falls into one of these | |
532 | * classes depending on its size. This function returns index of the | |
533 | * size class which has chunk size big enough to hold the give size. | |
534 | */ | |
61989a80 NG |
535 | static int get_size_class_index(int size) |
536 | { | |
537 | int idx = 0; | |
538 | ||
539 | if (likely(size > ZS_MIN_ALLOC_SIZE)) | |
540 | idx = DIV_ROUND_UP(size - ZS_MIN_ALLOC_SIZE, | |
541 | ZS_SIZE_CLASS_DELTA); | |
542 | ||
cf8e0fed | 543 | return min_t(int, ZS_SIZE_CLASSES - 1, idx); |
61989a80 NG |
544 | } |
545 | ||
3eb95fea | 546 | /* type can be of enum type zs_stat_type or fullness_group */ |
248ca1b0 | 547 | static inline void zs_stat_inc(struct size_class *class, |
3eb95fea | 548 | int type, unsigned long cnt) |
248ca1b0 | 549 | { |
48b4800a | 550 | class->stats.objs[type] += cnt; |
248ca1b0 MK |
551 | } |
552 | ||
3eb95fea | 553 | /* type can be of enum type zs_stat_type or fullness_group */ |
248ca1b0 | 554 | static inline void zs_stat_dec(struct size_class *class, |
3eb95fea | 555 | int type, unsigned long cnt) |
248ca1b0 | 556 | { |
48b4800a | 557 | class->stats.objs[type] -= cnt; |
248ca1b0 MK |
558 | } |
559 | ||
3eb95fea | 560 | /* type can be of enum type zs_stat_type or fullness_group */ |
248ca1b0 | 561 | static inline unsigned long zs_stat_get(struct size_class *class, |
3eb95fea | 562 | int type) |
248ca1b0 | 563 | { |
48b4800a | 564 | return class->stats.objs[type]; |
248ca1b0 MK |
565 | } |
566 | ||
57244594 SS |
567 | #ifdef CONFIG_ZSMALLOC_STAT |
568 | ||
4abaac9b | 569 | static void __init zs_stat_init(void) |
248ca1b0 | 570 | { |
4abaac9b DS |
571 | if (!debugfs_initialized()) { |
572 | pr_warn("debugfs not available, stat dir not created\n"); | |
573 | return; | |
574 | } | |
248ca1b0 MK |
575 | |
576 | zs_stat_root = debugfs_create_dir("zsmalloc", NULL); | |
248ca1b0 MK |
577 | } |
578 | ||
579 | static void __exit zs_stat_exit(void) | |
580 | { | |
581 | debugfs_remove_recursive(zs_stat_root); | |
582 | } | |
583 | ||
1120ed54 SS |
584 | static unsigned long zs_can_compact(struct size_class *class); |
585 | ||
248ca1b0 MK |
586 | static int zs_stats_size_show(struct seq_file *s, void *v) |
587 | { | |
588 | int i; | |
589 | struct zs_pool *pool = s->private; | |
590 | struct size_class *class; | |
591 | int objs_per_zspage; | |
592 | unsigned long class_almost_full, class_almost_empty; | |
1120ed54 | 593 | unsigned long obj_allocated, obj_used, pages_used, freeable; |
248ca1b0 MK |
594 | unsigned long total_class_almost_full = 0, total_class_almost_empty = 0; |
595 | unsigned long total_objs = 0, total_used_objs = 0, total_pages = 0; | |
1120ed54 | 596 | unsigned long total_freeable = 0; |
248ca1b0 | 597 | |
1120ed54 | 598 | seq_printf(s, " %5s %5s %11s %12s %13s %10s %10s %16s %8s\n", |
248ca1b0 MK |
599 | "class", "size", "almost_full", "almost_empty", |
600 | "obj_allocated", "obj_used", "pages_used", | |
1120ed54 | 601 | "pages_per_zspage", "freeable"); |
248ca1b0 | 602 | |
cf8e0fed | 603 | for (i = 0; i < ZS_SIZE_CLASSES; i++) { |
248ca1b0 MK |
604 | class = pool->size_class[i]; |
605 | ||
606 | if (class->index != i) | |
607 | continue; | |
608 | ||
609 | spin_lock(&class->lock); | |
610 | class_almost_full = zs_stat_get(class, CLASS_ALMOST_FULL); | |
611 | class_almost_empty = zs_stat_get(class, CLASS_ALMOST_EMPTY); | |
612 | obj_allocated = zs_stat_get(class, OBJ_ALLOCATED); | |
613 | obj_used = zs_stat_get(class, OBJ_USED); | |
1120ed54 | 614 | freeable = zs_can_compact(class); |
248ca1b0 MK |
615 | spin_unlock(&class->lock); |
616 | ||
b4fd07a0 | 617 | objs_per_zspage = class->objs_per_zspage; |
248ca1b0 MK |
618 | pages_used = obj_allocated / objs_per_zspage * |
619 | class->pages_per_zspage; | |
620 | ||
1120ed54 SS |
621 | seq_printf(s, " %5u %5u %11lu %12lu %13lu" |
622 | " %10lu %10lu %16d %8lu\n", | |
248ca1b0 MK |
623 | i, class->size, class_almost_full, class_almost_empty, |
624 | obj_allocated, obj_used, pages_used, | |
1120ed54 | 625 | class->pages_per_zspage, freeable); |
248ca1b0 MK |
626 | |
627 | total_class_almost_full += class_almost_full; | |
628 | total_class_almost_empty += class_almost_empty; | |
629 | total_objs += obj_allocated; | |
630 | total_used_objs += obj_used; | |
631 | total_pages += pages_used; | |
1120ed54 | 632 | total_freeable += freeable; |
248ca1b0 MK |
633 | } |
634 | ||
635 | seq_puts(s, "\n"); | |
1120ed54 | 636 | seq_printf(s, " %5s %5s %11lu %12lu %13lu %10lu %10lu %16s %8lu\n", |
248ca1b0 MK |
637 | "Total", "", total_class_almost_full, |
638 | total_class_almost_empty, total_objs, | |
1120ed54 | 639 | total_used_objs, total_pages, "", total_freeable); |
248ca1b0 MK |
640 | |
641 | return 0; | |
642 | } | |
5ad35093 | 643 | DEFINE_SHOW_ATTRIBUTE(zs_stats_size); |
248ca1b0 | 644 | |
d34f6157 | 645 | static void zs_pool_stat_create(struct zs_pool *pool, const char *name) |
248ca1b0 | 646 | { |
4abaac9b DS |
647 | if (!zs_stat_root) { |
648 | pr_warn("no root stat dir, not creating <%s> stat dir\n", name); | |
d34f6157 | 649 | return; |
4abaac9b | 650 | } |
248ca1b0 | 651 | |
4268509a GKH |
652 | pool->stat_dentry = debugfs_create_dir(name, zs_stat_root); |
653 | ||
654 | debugfs_create_file("classes", S_IFREG | 0444, pool->stat_dentry, pool, | |
655 | &zs_stats_size_fops); | |
248ca1b0 MK |
656 | } |
657 | ||
658 | static void zs_pool_stat_destroy(struct zs_pool *pool) | |
659 | { | |
660 | debugfs_remove_recursive(pool->stat_dentry); | |
661 | } | |
662 | ||
663 | #else /* CONFIG_ZSMALLOC_STAT */ | |
4abaac9b | 664 | static void __init zs_stat_init(void) |
248ca1b0 | 665 | { |
248ca1b0 MK |
666 | } |
667 | ||
668 | static void __exit zs_stat_exit(void) | |
669 | { | |
670 | } | |
671 | ||
d34f6157 | 672 | static inline void zs_pool_stat_create(struct zs_pool *pool, const char *name) |
248ca1b0 | 673 | { |
248ca1b0 MK |
674 | } |
675 | ||
676 | static inline void zs_pool_stat_destroy(struct zs_pool *pool) | |
677 | { | |
678 | } | |
248ca1b0 MK |
679 | #endif |
680 | ||
48b4800a | 681 | |
c3e3e88a NC |
682 | /* |
683 | * For each size class, zspages are divided into different groups | |
684 | * depending on how "full" they are. This was done so that we could | |
685 | * easily find empty or nearly empty zspages when we try to shrink | |
686 | * the pool (not yet implemented). This function returns fullness | |
687 | * status of the given page. | |
688 | */ | |
1fc6e27d | 689 | static enum fullness_group get_fullness_group(struct size_class *class, |
3783689a | 690 | struct zspage *zspage) |
61989a80 | 691 | { |
1fc6e27d | 692 | int inuse, objs_per_zspage; |
61989a80 | 693 | enum fullness_group fg; |
830e4bc5 | 694 | |
3783689a | 695 | inuse = get_zspage_inuse(zspage); |
1fc6e27d | 696 | objs_per_zspage = class->objs_per_zspage; |
61989a80 NG |
697 | |
698 | if (inuse == 0) | |
699 | fg = ZS_EMPTY; | |
1fc6e27d | 700 | else if (inuse == objs_per_zspage) |
61989a80 | 701 | fg = ZS_FULL; |
1fc6e27d | 702 | else if (inuse <= 3 * objs_per_zspage / fullness_threshold_frac) |
61989a80 NG |
703 | fg = ZS_ALMOST_EMPTY; |
704 | else | |
705 | fg = ZS_ALMOST_FULL; | |
706 | ||
707 | return fg; | |
708 | } | |
709 | ||
c3e3e88a NC |
710 | /* |
711 | * Each size class maintains various freelists and zspages are assigned | |
712 | * to one of these freelists based on the number of live objects they | |
713 | * have. This functions inserts the given zspage into the freelist | |
714 | * identified by <class, fullness_group>. | |
715 | */ | |
251cbb95 | 716 | static void insert_zspage(struct size_class *class, |
3783689a MK |
717 | struct zspage *zspage, |
718 | enum fullness_group fullness) | |
61989a80 | 719 | { |
3783689a | 720 | struct zspage *head; |
61989a80 | 721 | |
48b4800a | 722 | zs_stat_inc(class, fullness, 1); |
3783689a MK |
723 | head = list_first_entry_or_null(&class->fullness_list[fullness], |
724 | struct zspage, list); | |
58f17117 | 725 | /* |
3783689a MK |
726 | * We want to see more ZS_FULL pages and less almost empty/full. |
727 | * Put pages with higher ->inuse first. | |
58f17117 | 728 | */ |
3783689a MK |
729 | if (head) { |
730 | if (get_zspage_inuse(zspage) < get_zspage_inuse(head)) { | |
731 | list_add(&zspage->list, &head->list); | |
732 | return; | |
733 | } | |
734 | } | |
735 | list_add(&zspage->list, &class->fullness_list[fullness]); | |
61989a80 NG |
736 | } |
737 | ||
c3e3e88a NC |
738 | /* |
739 | * This function removes the given zspage from the freelist identified | |
740 | * by <class, fullness_group>. | |
741 | */ | |
251cbb95 | 742 | static void remove_zspage(struct size_class *class, |
3783689a MK |
743 | struct zspage *zspage, |
744 | enum fullness_group fullness) | |
61989a80 | 745 | { |
3783689a | 746 | VM_BUG_ON(list_empty(&class->fullness_list[fullness])); |
48b4800a | 747 | VM_BUG_ON(is_zspage_isolated(zspage)); |
61989a80 | 748 | |
3783689a | 749 | list_del_init(&zspage->list); |
48b4800a | 750 | zs_stat_dec(class, fullness, 1); |
61989a80 NG |
751 | } |
752 | ||
c3e3e88a NC |
753 | /* |
754 | * Each size class maintains zspages in different fullness groups depending | |
755 | * on the number of live objects they contain. When allocating or freeing | |
756 | * objects, the fullness status of the page can change, say, from ALMOST_FULL | |
757 | * to ALMOST_EMPTY when freeing an object. This function checks if such | |
758 | * a status change has occurred for the given page and accordingly moves the | |
759 | * page from the freelist of the old fullness group to that of the new | |
760 | * fullness group. | |
761 | */ | |
c7806261 | 762 | static enum fullness_group fix_fullness_group(struct size_class *class, |
3783689a | 763 | struct zspage *zspage) |
61989a80 NG |
764 | { |
765 | int class_idx; | |
61989a80 NG |
766 | enum fullness_group currfg, newfg; |
767 | ||
3783689a MK |
768 | get_zspage_mapping(zspage, &class_idx, &currfg); |
769 | newfg = get_fullness_group(class, zspage); | |
61989a80 NG |
770 | if (newfg == currfg) |
771 | goto out; | |
772 | ||
48b4800a MK |
773 | if (!is_zspage_isolated(zspage)) { |
774 | remove_zspage(class, zspage, currfg); | |
775 | insert_zspage(class, zspage, newfg); | |
776 | } | |
777 | ||
3783689a | 778 | set_zspage_mapping(zspage, class_idx, newfg); |
61989a80 NG |
779 | |
780 | out: | |
781 | return newfg; | |
782 | } | |
783 | ||
784 | /* | |
785 | * We have to decide on how many pages to link together | |
786 | * to form a zspage for each size class. This is important | |
787 | * to reduce wastage due to unusable space left at end of | |
788 | * each zspage which is given as: | |
888fa374 YX |
789 | * wastage = Zp % class_size |
790 | * usage = Zp - wastage | |
61989a80 NG |
791 | * where Zp = zspage size = k * PAGE_SIZE where k = 1, 2, ... |
792 | * | |
793 | * For example, for size class of 3/8 * PAGE_SIZE, we should | |
794 | * link together 3 PAGE_SIZE sized pages to form a zspage | |
795 | * since then we can perfectly fit in 8 such objects. | |
796 | */ | |
2e3b6154 | 797 | static int get_pages_per_zspage(int class_size) |
61989a80 NG |
798 | { |
799 | int i, max_usedpc = 0; | |
800 | /* zspage order which gives maximum used size per KB */ | |
801 | int max_usedpc_order = 1; | |
802 | ||
84d4faab | 803 | for (i = 1; i <= ZS_MAX_PAGES_PER_ZSPAGE; i++) { |
61989a80 NG |
804 | int zspage_size; |
805 | int waste, usedpc; | |
806 | ||
807 | zspage_size = i * PAGE_SIZE; | |
808 | waste = zspage_size % class_size; | |
809 | usedpc = (zspage_size - waste) * 100 / zspage_size; | |
810 | ||
811 | if (usedpc > max_usedpc) { | |
812 | max_usedpc = usedpc; | |
813 | max_usedpc_order = i; | |
814 | } | |
815 | } | |
816 | ||
817 | return max_usedpc_order; | |
818 | } | |
819 | ||
3783689a | 820 | static struct zspage *get_zspage(struct page *page) |
61989a80 | 821 | { |
48b4800a MK |
822 | struct zspage *zspage = (struct zspage *)page->private; |
823 | ||
824 | BUG_ON(zspage->magic != ZSPAGE_MAGIC); | |
825 | return zspage; | |
61989a80 NG |
826 | } |
827 | ||
828 | static struct page *get_next_page(struct page *page) | |
829 | { | |
48b4800a MK |
830 | if (unlikely(PageHugeObject(page))) |
831 | return NULL; | |
832 | ||
833 | return page->freelist; | |
61989a80 NG |
834 | } |
835 | ||
bfd093f5 MK |
836 | /** |
837 | * obj_to_location - get (<page>, <obj_idx>) from encoded object value | |
e8b098fc | 838 | * @obj: the encoded object value |
bfd093f5 MK |
839 | * @page: page object resides in zspage |
840 | * @obj_idx: object index | |
67296874 | 841 | */ |
bfd093f5 MK |
842 | static void obj_to_location(unsigned long obj, struct page **page, |
843 | unsigned int *obj_idx) | |
61989a80 | 844 | { |
bfd093f5 MK |
845 | obj >>= OBJ_TAG_BITS; |
846 | *page = pfn_to_page(obj >> OBJ_INDEX_BITS); | |
847 | *obj_idx = (obj & OBJ_INDEX_MASK); | |
848 | } | |
61989a80 | 849 | |
bfd093f5 MK |
850 | /** |
851 | * location_to_obj - get obj value encoded from (<page>, <obj_idx>) | |
852 | * @page: page object resides in zspage | |
853 | * @obj_idx: object index | |
854 | */ | |
855 | static unsigned long location_to_obj(struct page *page, unsigned int obj_idx) | |
856 | { | |
857 | unsigned long obj; | |
61989a80 | 858 | |
312fcae2 | 859 | obj = page_to_pfn(page) << OBJ_INDEX_BITS; |
bfd093f5 | 860 | obj |= obj_idx & OBJ_INDEX_MASK; |
312fcae2 | 861 | obj <<= OBJ_TAG_BITS; |
61989a80 | 862 | |
bfd093f5 | 863 | return obj; |
61989a80 NG |
864 | } |
865 | ||
2e40e163 MK |
866 | static unsigned long handle_to_obj(unsigned long handle) |
867 | { | |
868 | return *(unsigned long *)handle; | |
869 | } | |
870 | ||
48b4800a | 871 | static unsigned long obj_to_head(struct page *page, void *obj) |
312fcae2 | 872 | { |
48b4800a | 873 | if (unlikely(PageHugeObject(page))) { |
830e4bc5 | 874 | VM_BUG_ON_PAGE(!is_first_page(page), page); |
3783689a | 875 | return page->index; |
7b60a685 MK |
876 | } else |
877 | return *(unsigned long *)obj; | |
312fcae2 MK |
878 | } |
879 | ||
48b4800a MK |
880 | static inline int testpin_tag(unsigned long handle) |
881 | { | |
882 | return bit_spin_is_locked(HANDLE_PIN_BIT, (unsigned long *)handle); | |
883 | } | |
884 | ||
312fcae2 MK |
885 | static inline int trypin_tag(unsigned long handle) |
886 | { | |
1b8320b6 | 887 | return bit_spin_trylock(HANDLE_PIN_BIT, (unsigned long *)handle); |
312fcae2 MK |
888 | } |
889 | ||
70c7ec95 | 890 | static void pin_tag(unsigned long handle) __acquires(bitlock) |
312fcae2 | 891 | { |
1b8320b6 | 892 | bit_spin_lock(HANDLE_PIN_BIT, (unsigned long *)handle); |
312fcae2 MK |
893 | } |
894 | ||
bc22b18b | 895 | static void unpin_tag(unsigned long handle) __releases(bitlock) |
312fcae2 | 896 | { |
1b8320b6 | 897 | bit_spin_unlock(HANDLE_PIN_BIT, (unsigned long *)handle); |
312fcae2 MK |
898 | } |
899 | ||
f4477e90 NG |
900 | static void reset_page(struct page *page) |
901 | { | |
48b4800a | 902 | __ClearPageMovable(page); |
18fd06bf | 903 | ClearPagePrivate(page); |
f4477e90 | 904 | set_page_private(page, 0); |
48b4800a MK |
905 | page_mapcount_reset(page); |
906 | ClearPageHugeObject(page); | |
907 | page->freelist = NULL; | |
908 | } | |
909 | ||
4d0a5402 | 910 | static int trylock_zspage(struct zspage *zspage) |
48b4800a MK |
911 | { |
912 | struct page *cursor, *fail; | |
913 | ||
914 | for (cursor = get_first_page(zspage); cursor != NULL; cursor = | |
915 | get_next_page(cursor)) { | |
916 | if (!trylock_page(cursor)) { | |
917 | fail = cursor; | |
918 | goto unlock; | |
919 | } | |
920 | } | |
921 | ||
922 | return 1; | |
923 | unlock: | |
924 | for (cursor = get_first_page(zspage); cursor != fail; cursor = | |
925 | get_next_page(cursor)) | |
926 | unlock_page(cursor); | |
927 | ||
928 | return 0; | |
f4477e90 NG |
929 | } |
930 | ||
48b4800a MK |
931 | static void __free_zspage(struct zs_pool *pool, struct size_class *class, |
932 | struct zspage *zspage) | |
61989a80 | 933 | { |
3783689a | 934 | struct page *page, *next; |
48b4800a MK |
935 | enum fullness_group fg; |
936 | unsigned int class_idx; | |
937 | ||
938 | get_zspage_mapping(zspage, &class_idx, &fg); | |
939 | ||
940 | assert_spin_locked(&class->lock); | |
61989a80 | 941 | |
3783689a | 942 | VM_BUG_ON(get_zspage_inuse(zspage)); |
48b4800a | 943 | VM_BUG_ON(fg != ZS_EMPTY); |
61989a80 | 944 | |
48b4800a | 945 | next = page = get_first_page(zspage); |
3783689a | 946 | do { |
48b4800a MK |
947 | VM_BUG_ON_PAGE(!PageLocked(page), page); |
948 | next = get_next_page(page); | |
3783689a | 949 | reset_page(page); |
48b4800a | 950 | unlock_page(page); |
91537fee | 951 | dec_zone_page_state(page, NR_ZSPAGES); |
3783689a MK |
952 | put_page(page); |
953 | page = next; | |
954 | } while (page != NULL); | |
61989a80 | 955 | |
3783689a | 956 | cache_free_zspage(pool, zspage); |
48b4800a | 957 | |
b4fd07a0 | 958 | zs_stat_dec(class, OBJ_ALLOCATED, class->objs_per_zspage); |
48b4800a MK |
959 | atomic_long_sub(class->pages_per_zspage, |
960 | &pool->pages_allocated); | |
961 | } | |
962 | ||
963 | static void free_zspage(struct zs_pool *pool, struct size_class *class, | |
964 | struct zspage *zspage) | |
965 | { | |
966 | VM_BUG_ON(get_zspage_inuse(zspage)); | |
967 | VM_BUG_ON(list_empty(&zspage->list)); | |
968 | ||
969 | if (!trylock_zspage(zspage)) { | |
970 | kick_deferred_free(pool); | |
971 | return; | |
972 | } | |
973 | ||
974 | remove_zspage(class, zspage, ZS_EMPTY); | |
975 | __free_zspage(pool, class, zspage); | |
61989a80 NG |
976 | } |
977 | ||
978 | /* Initialize a newly allocated zspage */ | |
3783689a | 979 | static void init_zspage(struct size_class *class, struct zspage *zspage) |
61989a80 | 980 | { |
bfd093f5 | 981 | unsigned int freeobj = 1; |
61989a80 | 982 | unsigned long off = 0; |
48b4800a | 983 | struct page *page = get_first_page(zspage); |
830e4bc5 | 984 | |
61989a80 NG |
985 | while (page) { |
986 | struct page *next_page; | |
987 | struct link_free *link; | |
af4ee5e9 | 988 | void *vaddr; |
61989a80 | 989 | |
3783689a | 990 | set_first_obj_offset(page, off); |
61989a80 | 991 | |
af4ee5e9 MK |
992 | vaddr = kmap_atomic(page); |
993 | link = (struct link_free *)vaddr + off / sizeof(*link); | |
5538c562 DS |
994 | |
995 | while ((off += class->size) < PAGE_SIZE) { | |
3b1d9ca6 | 996 | link->next = freeobj++ << OBJ_TAG_BITS; |
5538c562 | 997 | link += class->size / sizeof(*link); |
61989a80 NG |
998 | } |
999 | ||
1000 | /* | |
1001 | * We now come to the last (full or partial) object on this | |
1002 | * page, which must point to the first object on the next | |
1003 | * page (if present) | |
1004 | */ | |
1005 | next_page = get_next_page(page); | |
bfd093f5 | 1006 | if (next_page) { |
3b1d9ca6 | 1007 | link->next = freeobj++ << OBJ_TAG_BITS; |
bfd093f5 MK |
1008 | } else { |
1009 | /* | |
3b1d9ca6 | 1010 | * Reset OBJ_TAG_BITS bit to last link to tell |
bfd093f5 MK |
1011 | * whether it's allocated object or not. |
1012 | */ | |
01a6ad9a | 1013 | link->next = -1UL << OBJ_TAG_BITS; |
bfd093f5 | 1014 | } |
af4ee5e9 | 1015 | kunmap_atomic(vaddr); |
61989a80 | 1016 | page = next_page; |
5538c562 | 1017 | off %= PAGE_SIZE; |
61989a80 | 1018 | } |
bdb0af7c | 1019 | |
bfd093f5 | 1020 | set_freeobj(zspage, 0); |
61989a80 NG |
1021 | } |
1022 | ||
48b4800a MK |
1023 | static void create_page_chain(struct size_class *class, struct zspage *zspage, |
1024 | struct page *pages[]) | |
61989a80 | 1025 | { |
bdb0af7c MK |
1026 | int i; |
1027 | struct page *page; | |
1028 | struct page *prev_page = NULL; | |
48b4800a | 1029 | int nr_pages = class->pages_per_zspage; |
61989a80 NG |
1030 | |
1031 | /* | |
1032 | * Allocate individual pages and link them together as: | |
48b4800a | 1033 | * 1. all pages are linked together using page->freelist |
3783689a | 1034 | * 2. each sub-page point to zspage using page->private |
61989a80 | 1035 | * |
3783689a | 1036 | * we set PG_private to identify the first page (i.e. no other sub-page |
22c5cef1 | 1037 | * has this flag set). |
61989a80 | 1038 | */ |
bdb0af7c MK |
1039 | for (i = 0; i < nr_pages; i++) { |
1040 | page = pages[i]; | |
3783689a | 1041 | set_page_private(page, (unsigned long)zspage); |
48b4800a | 1042 | page->freelist = NULL; |
bdb0af7c | 1043 | if (i == 0) { |
3783689a | 1044 | zspage->first_page = page; |
a27545bf | 1045 | SetPagePrivate(page); |
48b4800a MK |
1046 | if (unlikely(class->objs_per_zspage == 1 && |
1047 | class->pages_per_zspage == 1)) | |
1048 | SetPageHugeObject(page); | |
3783689a | 1049 | } else { |
48b4800a | 1050 | prev_page->freelist = page; |
61989a80 | 1051 | } |
61989a80 NG |
1052 | prev_page = page; |
1053 | } | |
bdb0af7c | 1054 | } |
61989a80 | 1055 | |
bdb0af7c MK |
1056 | /* |
1057 | * Allocate a zspage for the given size class | |
1058 | */ | |
3783689a MK |
1059 | static struct zspage *alloc_zspage(struct zs_pool *pool, |
1060 | struct size_class *class, | |
1061 | gfp_t gfp) | |
bdb0af7c MK |
1062 | { |
1063 | int i; | |
bdb0af7c | 1064 | struct page *pages[ZS_MAX_PAGES_PER_ZSPAGE]; |
3783689a MK |
1065 | struct zspage *zspage = cache_alloc_zspage(pool, gfp); |
1066 | ||
1067 | if (!zspage) | |
1068 | return NULL; | |
1069 | ||
1070 | memset(zspage, 0, sizeof(struct zspage)); | |
48b4800a MK |
1071 | zspage->magic = ZSPAGE_MAGIC; |
1072 | migrate_lock_init(zspage); | |
61989a80 | 1073 | |
bdb0af7c MK |
1074 | for (i = 0; i < class->pages_per_zspage; i++) { |
1075 | struct page *page; | |
61989a80 | 1076 | |
3783689a | 1077 | page = alloc_page(gfp); |
bdb0af7c | 1078 | if (!page) { |
91537fee MK |
1079 | while (--i >= 0) { |
1080 | dec_zone_page_state(pages[i], NR_ZSPAGES); | |
bdb0af7c | 1081 | __free_page(pages[i]); |
91537fee | 1082 | } |
3783689a | 1083 | cache_free_zspage(pool, zspage); |
bdb0af7c MK |
1084 | return NULL; |
1085 | } | |
91537fee MK |
1086 | |
1087 | inc_zone_page_state(page, NR_ZSPAGES); | |
bdb0af7c | 1088 | pages[i] = page; |
61989a80 NG |
1089 | } |
1090 | ||
48b4800a | 1091 | create_page_chain(class, zspage, pages); |
3783689a | 1092 | init_zspage(class, zspage); |
bdb0af7c | 1093 | |
3783689a | 1094 | return zspage; |
61989a80 NG |
1095 | } |
1096 | ||
3783689a | 1097 | static struct zspage *find_get_zspage(struct size_class *class) |
61989a80 NG |
1098 | { |
1099 | int i; | |
3783689a | 1100 | struct zspage *zspage; |
61989a80 | 1101 | |
48b4800a | 1102 | for (i = ZS_ALMOST_FULL; i >= ZS_EMPTY; i--) { |
3783689a MK |
1103 | zspage = list_first_entry_or_null(&class->fullness_list[i], |
1104 | struct zspage, list); | |
1105 | if (zspage) | |
61989a80 NG |
1106 | break; |
1107 | } | |
1108 | ||
3783689a | 1109 | return zspage; |
61989a80 NG |
1110 | } |
1111 | ||
f553646a SJ |
1112 | static inline int __zs_cpu_up(struct mapping_area *area) |
1113 | { | |
1114 | /* | |
1115 | * Make sure we don't leak memory if a cpu UP notification | |
1116 | * and zs_init() race and both call zs_cpu_up() on the same cpu | |
1117 | */ | |
1118 | if (area->vm_buf) | |
1119 | return 0; | |
40f9fb8c | 1120 | area->vm_buf = kmalloc(ZS_MAX_ALLOC_SIZE, GFP_KERNEL); |
f553646a SJ |
1121 | if (!area->vm_buf) |
1122 | return -ENOMEM; | |
1123 | return 0; | |
1124 | } | |
1125 | ||
1126 | static inline void __zs_cpu_down(struct mapping_area *area) | |
1127 | { | |
40f9fb8c | 1128 | kfree(area->vm_buf); |
f553646a SJ |
1129 | area->vm_buf = NULL; |
1130 | } | |
1131 | ||
1132 | static void *__zs_map_object(struct mapping_area *area, | |
1133 | struct page *pages[2], int off, int size) | |
5f601902 | 1134 | { |
5f601902 SJ |
1135 | int sizes[2]; |
1136 | void *addr; | |
f553646a | 1137 | char *buf = area->vm_buf; |
5f601902 | 1138 | |
f553646a SJ |
1139 | /* disable page faults to match kmap_atomic() return conditions */ |
1140 | pagefault_disable(); | |
1141 | ||
1142 | /* no read fastpath */ | |
1143 | if (area->vm_mm == ZS_MM_WO) | |
1144 | goto out; | |
5f601902 SJ |
1145 | |
1146 | sizes[0] = PAGE_SIZE - off; | |
1147 | sizes[1] = size - sizes[0]; | |
1148 | ||
5f601902 SJ |
1149 | /* copy object to per-cpu buffer */ |
1150 | addr = kmap_atomic(pages[0]); | |
1151 | memcpy(buf, addr + off, sizes[0]); | |
1152 | kunmap_atomic(addr); | |
1153 | addr = kmap_atomic(pages[1]); | |
1154 | memcpy(buf + sizes[0], addr, sizes[1]); | |
1155 | kunmap_atomic(addr); | |
f553646a SJ |
1156 | out: |
1157 | return area->vm_buf; | |
5f601902 SJ |
1158 | } |
1159 | ||
f553646a SJ |
1160 | static void __zs_unmap_object(struct mapping_area *area, |
1161 | struct page *pages[2], int off, int size) | |
5f601902 | 1162 | { |
5f601902 SJ |
1163 | int sizes[2]; |
1164 | void *addr; | |
2e40e163 | 1165 | char *buf; |
5f601902 | 1166 | |
f553646a SJ |
1167 | /* no write fastpath */ |
1168 | if (area->vm_mm == ZS_MM_RO) | |
1169 | goto out; | |
5f601902 | 1170 | |
7b60a685 | 1171 | buf = area->vm_buf; |
a82cbf07 YX |
1172 | buf = buf + ZS_HANDLE_SIZE; |
1173 | size -= ZS_HANDLE_SIZE; | |
1174 | off += ZS_HANDLE_SIZE; | |
2e40e163 | 1175 | |
5f601902 SJ |
1176 | sizes[0] = PAGE_SIZE - off; |
1177 | sizes[1] = size - sizes[0]; | |
1178 | ||
1179 | /* copy per-cpu buffer to object */ | |
1180 | addr = kmap_atomic(pages[0]); | |
1181 | memcpy(addr + off, buf, sizes[0]); | |
1182 | kunmap_atomic(addr); | |
1183 | addr = kmap_atomic(pages[1]); | |
1184 | memcpy(addr, buf + sizes[0], sizes[1]); | |
1185 | kunmap_atomic(addr); | |
f553646a SJ |
1186 | |
1187 | out: | |
1188 | /* enable page faults to match kunmap_atomic() return conditions */ | |
1189 | pagefault_enable(); | |
5f601902 | 1190 | } |
61989a80 | 1191 | |
215c89d0 | 1192 | static int zs_cpu_prepare(unsigned int cpu) |
61989a80 | 1193 | { |
61989a80 NG |
1194 | struct mapping_area *area; |
1195 | ||
215c89d0 SAS |
1196 | area = &per_cpu(zs_map_area, cpu); |
1197 | return __zs_cpu_up(area); | |
61989a80 NG |
1198 | } |
1199 | ||
215c89d0 | 1200 | static int zs_cpu_dead(unsigned int cpu) |
61989a80 | 1201 | { |
215c89d0 | 1202 | struct mapping_area *area; |
40f9fb8c | 1203 | |
215c89d0 SAS |
1204 | area = &per_cpu(zs_map_area, cpu); |
1205 | __zs_cpu_down(area); | |
1206 | return 0; | |
b1b00a5b SS |
1207 | } |
1208 | ||
64d90465 GM |
1209 | static bool can_merge(struct size_class *prev, int pages_per_zspage, |
1210 | int objs_per_zspage) | |
9eec4cd5 | 1211 | { |
64d90465 GM |
1212 | if (prev->pages_per_zspage == pages_per_zspage && |
1213 | prev->objs_per_zspage == objs_per_zspage) | |
1214 | return true; | |
9eec4cd5 | 1215 | |
64d90465 | 1216 | return false; |
9eec4cd5 JK |
1217 | } |
1218 | ||
3783689a | 1219 | static bool zspage_full(struct size_class *class, struct zspage *zspage) |
312fcae2 | 1220 | { |
3783689a | 1221 | return get_zspage_inuse(zspage) == class->objs_per_zspage; |
312fcae2 MK |
1222 | } |
1223 | ||
66cdef66 GM |
1224 | unsigned long zs_get_total_pages(struct zs_pool *pool) |
1225 | { | |
1226 | return atomic_long_read(&pool->pages_allocated); | |
1227 | } | |
1228 | EXPORT_SYMBOL_GPL(zs_get_total_pages); | |
1229 | ||
4bbc0bc0 | 1230 | /** |
66cdef66 GM |
1231 | * zs_map_object - get address of allocated object from handle. |
1232 | * @pool: pool from which the object was allocated | |
1233 | * @handle: handle returned from zs_malloc | |
e8b098fc | 1234 | * @mm: maping mode to use |
4bbc0bc0 | 1235 | * |
66cdef66 GM |
1236 | * Before using an object allocated from zs_malloc, it must be mapped using |
1237 | * this function. When done with the object, it must be unmapped using | |
1238 | * zs_unmap_object. | |
4bbc0bc0 | 1239 | * |
66cdef66 GM |
1240 | * Only one object can be mapped per cpu at a time. There is no protection |
1241 | * against nested mappings. | |
1242 | * | |
1243 | * This function returns with preemption and page faults disabled. | |
4bbc0bc0 | 1244 | */ |
66cdef66 GM |
1245 | void *zs_map_object(struct zs_pool *pool, unsigned long handle, |
1246 | enum zs_mapmode mm) | |
61989a80 | 1247 | { |
3783689a | 1248 | struct zspage *zspage; |
66cdef66 | 1249 | struct page *page; |
bfd093f5 MK |
1250 | unsigned long obj, off; |
1251 | unsigned int obj_idx; | |
61989a80 | 1252 | |
66cdef66 GM |
1253 | unsigned int class_idx; |
1254 | enum fullness_group fg; | |
1255 | struct size_class *class; | |
1256 | struct mapping_area *area; | |
1257 | struct page *pages[2]; | |
2e40e163 | 1258 | void *ret; |
61989a80 | 1259 | |
9eec4cd5 | 1260 | /* |
66cdef66 GM |
1261 | * Because we use per-cpu mapping areas shared among the |
1262 | * pools/users, we can't allow mapping in interrupt context | |
1263 | * because it can corrupt another users mappings. | |
9eec4cd5 | 1264 | */ |
1aedcafb | 1265 | BUG_ON(in_interrupt()); |
61989a80 | 1266 | |
312fcae2 MK |
1267 | /* From now on, migration cannot move the object */ |
1268 | pin_tag(handle); | |
1269 | ||
2e40e163 MK |
1270 | obj = handle_to_obj(handle); |
1271 | obj_to_location(obj, &page, &obj_idx); | |
3783689a | 1272 | zspage = get_zspage(page); |
48b4800a MK |
1273 | |
1274 | /* migration cannot move any subpage in this zspage */ | |
1275 | migrate_read_lock(zspage); | |
1276 | ||
3783689a | 1277 | get_zspage_mapping(zspage, &class_idx, &fg); |
66cdef66 | 1278 | class = pool->size_class[class_idx]; |
bfd093f5 | 1279 | off = (class->size * obj_idx) & ~PAGE_MASK; |
df8b5bb9 | 1280 | |
66cdef66 GM |
1281 | area = &get_cpu_var(zs_map_area); |
1282 | area->vm_mm = mm; | |
1283 | if (off + class->size <= PAGE_SIZE) { | |
1284 | /* this object is contained entirely within a page */ | |
1285 | area->vm_addr = kmap_atomic(page); | |
2e40e163 MK |
1286 | ret = area->vm_addr + off; |
1287 | goto out; | |
61989a80 NG |
1288 | } |
1289 | ||
66cdef66 GM |
1290 | /* this object spans two pages */ |
1291 | pages[0] = page; | |
1292 | pages[1] = get_next_page(page); | |
1293 | BUG_ON(!pages[1]); | |
9eec4cd5 | 1294 | |
2e40e163 MK |
1295 | ret = __zs_map_object(area, pages, off, class->size); |
1296 | out: | |
48b4800a | 1297 | if (likely(!PageHugeObject(page))) |
7b60a685 MK |
1298 | ret += ZS_HANDLE_SIZE; |
1299 | ||
1300 | return ret; | |
61989a80 | 1301 | } |
66cdef66 | 1302 | EXPORT_SYMBOL_GPL(zs_map_object); |
61989a80 | 1303 | |
66cdef66 | 1304 | void zs_unmap_object(struct zs_pool *pool, unsigned long handle) |
61989a80 | 1305 | { |
3783689a | 1306 | struct zspage *zspage; |
66cdef66 | 1307 | struct page *page; |
bfd093f5 MK |
1308 | unsigned long obj, off; |
1309 | unsigned int obj_idx; | |
61989a80 | 1310 | |
66cdef66 GM |
1311 | unsigned int class_idx; |
1312 | enum fullness_group fg; | |
1313 | struct size_class *class; | |
1314 | struct mapping_area *area; | |
9eec4cd5 | 1315 | |
2e40e163 MK |
1316 | obj = handle_to_obj(handle); |
1317 | obj_to_location(obj, &page, &obj_idx); | |
3783689a MK |
1318 | zspage = get_zspage(page); |
1319 | get_zspage_mapping(zspage, &class_idx, &fg); | |
66cdef66 | 1320 | class = pool->size_class[class_idx]; |
bfd093f5 | 1321 | off = (class->size * obj_idx) & ~PAGE_MASK; |
61989a80 | 1322 | |
66cdef66 GM |
1323 | area = this_cpu_ptr(&zs_map_area); |
1324 | if (off + class->size <= PAGE_SIZE) | |
1325 | kunmap_atomic(area->vm_addr); | |
1326 | else { | |
1327 | struct page *pages[2]; | |
40f9fb8c | 1328 | |
66cdef66 GM |
1329 | pages[0] = page; |
1330 | pages[1] = get_next_page(page); | |
1331 | BUG_ON(!pages[1]); | |
1332 | ||
1333 | __zs_unmap_object(area, pages, off, class->size); | |
1334 | } | |
1335 | put_cpu_var(zs_map_area); | |
48b4800a MK |
1336 | |
1337 | migrate_read_unlock(zspage); | |
312fcae2 | 1338 | unpin_tag(handle); |
61989a80 | 1339 | } |
66cdef66 | 1340 | EXPORT_SYMBOL_GPL(zs_unmap_object); |
61989a80 | 1341 | |
010b495e SS |
1342 | /** |
1343 | * zs_huge_class_size() - Returns the size (in bytes) of the first huge | |
1344 | * zsmalloc &size_class. | |
1345 | * @pool: zsmalloc pool to use | |
1346 | * | |
1347 | * The function returns the size of the first huge class - any object of equal | |
1348 | * or bigger size will be stored in zspage consisting of a single physical | |
1349 | * page. | |
1350 | * | |
1351 | * Context: Any context. | |
1352 | * | |
1353 | * Return: the size (in bytes) of the first huge zsmalloc &size_class. | |
1354 | */ | |
1355 | size_t zs_huge_class_size(struct zs_pool *pool) | |
1356 | { | |
1357 | return huge_class_size; | |
1358 | } | |
1359 | EXPORT_SYMBOL_GPL(zs_huge_class_size); | |
1360 | ||
251cbb95 | 1361 | static unsigned long obj_malloc(struct size_class *class, |
3783689a | 1362 | struct zspage *zspage, unsigned long handle) |
c7806261 | 1363 | { |
bfd093f5 | 1364 | int i, nr_page, offset; |
c7806261 MK |
1365 | unsigned long obj; |
1366 | struct link_free *link; | |
1367 | ||
1368 | struct page *m_page; | |
bfd093f5 | 1369 | unsigned long m_offset; |
c7806261 MK |
1370 | void *vaddr; |
1371 | ||
312fcae2 | 1372 | handle |= OBJ_ALLOCATED_TAG; |
3783689a | 1373 | obj = get_freeobj(zspage); |
bfd093f5 MK |
1374 | |
1375 | offset = obj * class->size; | |
1376 | nr_page = offset >> PAGE_SHIFT; | |
1377 | m_offset = offset & ~PAGE_MASK; | |
1378 | m_page = get_first_page(zspage); | |
1379 | ||
1380 | for (i = 0; i < nr_page; i++) | |
1381 | m_page = get_next_page(m_page); | |
c7806261 MK |
1382 | |
1383 | vaddr = kmap_atomic(m_page); | |
1384 | link = (struct link_free *)vaddr + m_offset / sizeof(*link); | |
3b1d9ca6 | 1385 | set_freeobj(zspage, link->next >> OBJ_TAG_BITS); |
48b4800a | 1386 | if (likely(!PageHugeObject(m_page))) |
7b60a685 MK |
1387 | /* record handle in the header of allocated chunk */ |
1388 | link->handle = handle; | |
1389 | else | |
3783689a MK |
1390 | /* record handle to page->index */ |
1391 | zspage->first_page->index = handle; | |
1392 | ||
c7806261 | 1393 | kunmap_atomic(vaddr); |
3783689a | 1394 | mod_zspage_inuse(zspage, 1); |
c7806261 MK |
1395 | zs_stat_inc(class, OBJ_USED, 1); |
1396 | ||
bfd093f5 MK |
1397 | obj = location_to_obj(m_page, obj); |
1398 | ||
c7806261 MK |
1399 | return obj; |
1400 | } | |
1401 | ||
1402 | ||
61989a80 NG |
1403 | /** |
1404 | * zs_malloc - Allocate block of given size from pool. | |
1405 | * @pool: pool to allocate from | |
1406 | * @size: size of block to allocate | |
fd854463 | 1407 | * @gfp: gfp flags when allocating object |
61989a80 | 1408 | * |
00a61d86 | 1409 | * On success, handle to the allocated object is returned, |
c2344348 | 1410 | * otherwise 0. |
61989a80 NG |
1411 | * Allocation requests with size > ZS_MAX_ALLOC_SIZE will fail. |
1412 | */ | |
d0d8da2d | 1413 | unsigned long zs_malloc(struct zs_pool *pool, size_t size, gfp_t gfp) |
61989a80 | 1414 | { |
2e40e163 | 1415 | unsigned long handle, obj; |
61989a80 | 1416 | struct size_class *class; |
48b4800a | 1417 | enum fullness_group newfg; |
3783689a | 1418 | struct zspage *zspage; |
61989a80 | 1419 | |
7b60a685 | 1420 | if (unlikely(!size || size > ZS_MAX_ALLOC_SIZE)) |
2e40e163 MK |
1421 | return 0; |
1422 | ||
3783689a | 1423 | handle = cache_alloc_handle(pool, gfp); |
2e40e163 | 1424 | if (!handle) |
c2344348 | 1425 | return 0; |
61989a80 | 1426 | |
2e40e163 MK |
1427 | /* extra space in chunk to keep the handle */ |
1428 | size += ZS_HANDLE_SIZE; | |
9eec4cd5 | 1429 | class = pool->size_class[get_size_class_index(size)]; |
61989a80 NG |
1430 | |
1431 | spin_lock(&class->lock); | |
3783689a | 1432 | zspage = find_get_zspage(class); |
48b4800a MK |
1433 | if (likely(zspage)) { |
1434 | obj = obj_malloc(class, zspage, handle); | |
1435 | /* Now move the zspage to another fullness group, if required */ | |
1436 | fix_fullness_group(class, zspage); | |
1437 | record_obj(handle, obj); | |
61989a80 | 1438 | spin_unlock(&class->lock); |
61989a80 | 1439 | |
48b4800a MK |
1440 | return handle; |
1441 | } | |
0f050d99 | 1442 | |
48b4800a MK |
1443 | spin_unlock(&class->lock); |
1444 | ||
1445 | zspage = alloc_zspage(pool, class, gfp); | |
1446 | if (!zspage) { | |
1447 | cache_free_handle(pool, handle); | |
1448 | return 0; | |
61989a80 NG |
1449 | } |
1450 | ||
48b4800a | 1451 | spin_lock(&class->lock); |
3783689a | 1452 | obj = obj_malloc(class, zspage, handle); |
48b4800a MK |
1453 | newfg = get_fullness_group(class, zspage); |
1454 | insert_zspage(class, zspage, newfg); | |
1455 | set_zspage_mapping(zspage, class->index, newfg); | |
2e40e163 | 1456 | record_obj(handle, obj); |
48b4800a MK |
1457 | atomic_long_add(class->pages_per_zspage, |
1458 | &pool->pages_allocated); | |
b4fd07a0 | 1459 | zs_stat_inc(class, OBJ_ALLOCATED, class->objs_per_zspage); |
48b4800a MK |
1460 | |
1461 | /* We completely set up zspage so mark them as movable */ | |
1462 | SetZsPageMovable(pool, zspage); | |
61989a80 NG |
1463 | spin_unlock(&class->lock); |
1464 | ||
2e40e163 | 1465 | return handle; |
61989a80 NG |
1466 | } |
1467 | EXPORT_SYMBOL_GPL(zs_malloc); | |
1468 | ||
1ee47165 | 1469 | static void obj_free(struct size_class *class, unsigned long obj) |
61989a80 NG |
1470 | { |
1471 | struct link_free *link; | |
3783689a MK |
1472 | struct zspage *zspage; |
1473 | struct page *f_page; | |
bfd093f5 MK |
1474 | unsigned long f_offset; |
1475 | unsigned int f_objidx; | |
af4ee5e9 | 1476 | void *vaddr; |
61989a80 | 1477 | |
312fcae2 | 1478 | obj &= ~OBJ_ALLOCATED_TAG; |
2e40e163 | 1479 | obj_to_location(obj, &f_page, &f_objidx); |
bfd093f5 | 1480 | f_offset = (class->size * f_objidx) & ~PAGE_MASK; |
3783689a | 1481 | zspage = get_zspage(f_page); |
61989a80 | 1482 | |
c7806261 | 1483 | vaddr = kmap_atomic(f_page); |
61989a80 NG |
1484 | |
1485 | /* Insert this object in containing zspage's freelist */ | |
af4ee5e9 | 1486 | link = (struct link_free *)(vaddr + f_offset); |
3b1d9ca6 | 1487 | link->next = get_freeobj(zspage) << OBJ_TAG_BITS; |
af4ee5e9 | 1488 | kunmap_atomic(vaddr); |
bfd093f5 | 1489 | set_freeobj(zspage, f_objidx); |
3783689a | 1490 | mod_zspage_inuse(zspage, -1); |
0f050d99 | 1491 | zs_stat_dec(class, OBJ_USED, 1); |
c7806261 MK |
1492 | } |
1493 | ||
1494 | void zs_free(struct zs_pool *pool, unsigned long handle) | |
1495 | { | |
3783689a MK |
1496 | struct zspage *zspage; |
1497 | struct page *f_page; | |
bfd093f5 MK |
1498 | unsigned long obj; |
1499 | unsigned int f_objidx; | |
c7806261 MK |
1500 | int class_idx; |
1501 | struct size_class *class; | |
1502 | enum fullness_group fullness; | |
48b4800a | 1503 | bool isolated; |
c7806261 MK |
1504 | |
1505 | if (unlikely(!handle)) | |
1506 | return; | |
1507 | ||
312fcae2 | 1508 | pin_tag(handle); |
c7806261 | 1509 | obj = handle_to_obj(handle); |
c7806261 | 1510 | obj_to_location(obj, &f_page, &f_objidx); |
3783689a | 1511 | zspage = get_zspage(f_page); |
c7806261 | 1512 | |
48b4800a MK |
1513 | migrate_read_lock(zspage); |
1514 | ||
3783689a | 1515 | get_zspage_mapping(zspage, &class_idx, &fullness); |
c7806261 MK |
1516 | class = pool->size_class[class_idx]; |
1517 | ||
1518 | spin_lock(&class->lock); | |
1ee47165 | 1519 | obj_free(class, obj); |
3783689a | 1520 | fullness = fix_fullness_group(class, zspage); |
48b4800a MK |
1521 | if (fullness != ZS_EMPTY) { |
1522 | migrate_read_unlock(zspage); | |
1523 | goto out; | |
312fcae2 | 1524 | } |
48b4800a MK |
1525 | |
1526 | isolated = is_zspage_isolated(zspage); | |
1527 | migrate_read_unlock(zspage); | |
1528 | /* If zspage is isolated, zs_page_putback will free the zspage */ | |
1529 | if (likely(!isolated)) | |
1530 | free_zspage(pool, class, zspage); | |
1531 | out: | |
1532 | ||
61989a80 | 1533 | spin_unlock(&class->lock); |
312fcae2 | 1534 | unpin_tag(handle); |
3783689a | 1535 | cache_free_handle(pool, handle); |
312fcae2 MK |
1536 | } |
1537 | EXPORT_SYMBOL_GPL(zs_free); | |
1538 | ||
251cbb95 MK |
1539 | static void zs_object_copy(struct size_class *class, unsigned long dst, |
1540 | unsigned long src) | |
312fcae2 MK |
1541 | { |
1542 | struct page *s_page, *d_page; | |
bfd093f5 | 1543 | unsigned int s_objidx, d_objidx; |
312fcae2 MK |
1544 | unsigned long s_off, d_off; |
1545 | void *s_addr, *d_addr; | |
1546 | int s_size, d_size, size; | |
1547 | int written = 0; | |
1548 | ||
1549 | s_size = d_size = class->size; | |
1550 | ||
1551 | obj_to_location(src, &s_page, &s_objidx); | |
1552 | obj_to_location(dst, &d_page, &d_objidx); | |
1553 | ||
bfd093f5 MK |
1554 | s_off = (class->size * s_objidx) & ~PAGE_MASK; |
1555 | d_off = (class->size * d_objidx) & ~PAGE_MASK; | |
312fcae2 MK |
1556 | |
1557 | if (s_off + class->size > PAGE_SIZE) | |
1558 | s_size = PAGE_SIZE - s_off; | |
1559 | ||
1560 | if (d_off + class->size > PAGE_SIZE) | |
1561 | d_size = PAGE_SIZE - d_off; | |
1562 | ||
1563 | s_addr = kmap_atomic(s_page); | |
1564 | d_addr = kmap_atomic(d_page); | |
1565 | ||
1566 | while (1) { | |
1567 | size = min(s_size, d_size); | |
1568 | memcpy(d_addr + d_off, s_addr + s_off, size); | |
1569 | written += size; | |
1570 | ||
1571 | if (written == class->size) | |
1572 | break; | |
1573 | ||
495819ea SS |
1574 | s_off += size; |
1575 | s_size -= size; | |
1576 | d_off += size; | |
1577 | d_size -= size; | |
1578 | ||
1579 | if (s_off >= PAGE_SIZE) { | |
312fcae2 MK |
1580 | kunmap_atomic(d_addr); |
1581 | kunmap_atomic(s_addr); | |
1582 | s_page = get_next_page(s_page); | |
312fcae2 MK |
1583 | s_addr = kmap_atomic(s_page); |
1584 | d_addr = kmap_atomic(d_page); | |
1585 | s_size = class->size - written; | |
1586 | s_off = 0; | |
312fcae2 MK |
1587 | } |
1588 | ||
495819ea | 1589 | if (d_off >= PAGE_SIZE) { |
312fcae2 MK |
1590 | kunmap_atomic(d_addr); |
1591 | d_page = get_next_page(d_page); | |
312fcae2 MK |
1592 | d_addr = kmap_atomic(d_page); |
1593 | d_size = class->size - written; | |
1594 | d_off = 0; | |
312fcae2 MK |
1595 | } |
1596 | } | |
1597 | ||
1598 | kunmap_atomic(d_addr); | |
1599 | kunmap_atomic(s_addr); | |
1600 | } | |
1601 | ||
1602 | /* | |
1603 | * Find alloced object in zspage from index object and | |
1604 | * return handle. | |
1605 | */ | |
251cbb95 | 1606 | static unsigned long find_alloced_obj(struct size_class *class, |
cf675acb | 1607 | struct page *page, int *obj_idx) |
312fcae2 MK |
1608 | { |
1609 | unsigned long head; | |
1610 | int offset = 0; | |
cf675acb | 1611 | int index = *obj_idx; |
312fcae2 MK |
1612 | unsigned long handle = 0; |
1613 | void *addr = kmap_atomic(page); | |
1614 | ||
3783689a | 1615 | offset = get_first_obj_offset(page); |
312fcae2 MK |
1616 | offset += class->size * index; |
1617 | ||
1618 | while (offset < PAGE_SIZE) { | |
48b4800a | 1619 | head = obj_to_head(page, addr + offset); |
312fcae2 MK |
1620 | if (head & OBJ_ALLOCATED_TAG) { |
1621 | handle = head & ~OBJ_ALLOCATED_TAG; | |
1622 | if (trypin_tag(handle)) | |
1623 | break; | |
1624 | handle = 0; | |
1625 | } | |
1626 | ||
1627 | offset += class->size; | |
1628 | index++; | |
1629 | } | |
1630 | ||
1631 | kunmap_atomic(addr); | |
cf675acb GM |
1632 | |
1633 | *obj_idx = index; | |
1634 | ||
312fcae2 MK |
1635 | return handle; |
1636 | } | |
1637 | ||
1638 | struct zs_compact_control { | |
3783689a | 1639 | /* Source spage for migration which could be a subpage of zspage */ |
312fcae2 MK |
1640 | struct page *s_page; |
1641 | /* Destination page for migration which should be a first page | |
1642 | * of zspage. */ | |
1643 | struct page *d_page; | |
1644 | /* Starting object index within @s_page which used for live object | |
1645 | * in the subpage. */ | |
41b88e14 | 1646 | int obj_idx; |
312fcae2 MK |
1647 | }; |
1648 | ||
1649 | static int migrate_zspage(struct zs_pool *pool, struct size_class *class, | |
1650 | struct zs_compact_control *cc) | |
1651 | { | |
1652 | unsigned long used_obj, free_obj; | |
1653 | unsigned long handle; | |
1654 | struct page *s_page = cc->s_page; | |
1655 | struct page *d_page = cc->d_page; | |
41b88e14 | 1656 | int obj_idx = cc->obj_idx; |
312fcae2 MK |
1657 | int ret = 0; |
1658 | ||
1659 | while (1) { | |
cf675acb | 1660 | handle = find_alloced_obj(class, s_page, &obj_idx); |
312fcae2 MK |
1661 | if (!handle) { |
1662 | s_page = get_next_page(s_page); | |
1663 | if (!s_page) | |
1664 | break; | |
41b88e14 | 1665 | obj_idx = 0; |
312fcae2 MK |
1666 | continue; |
1667 | } | |
1668 | ||
1669 | /* Stop if there is no more space */ | |
3783689a | 1670 | if (zspage_full(class, get_zspage(d_page))) { |
312fcae2 MK |
1671 | unpin_tag(handle); |
1672 | ret = -ENOMEM; | |
1673 | break; | |
1674 | } | |
1675 | ||
1676 | used_obj = handle_to_obj(handle); | |
3783689a | 1677 | free_obj = obj_malloc(class, get_zspage(d_page), handle); |
251cbb95 | 1678 | zs_object_copy(class, free_obj, used_obj); |
41b88e14 | 1679 | obj_idx++; |
c102f07c JL |
1680 | /* |
1681 | * record_obj updates handle's value to free_obj and it will | |
1682 | * invalidate lock bit(ie, HANDLE_PIN_BIT) of handle, which | |
1683 | * breaks synchronization using pin_tag(e,g, zs_free) so | |
1684 | * let's keep the lock bit. | |
1685 | */ | |
1686 | free_obj |= BIT(HANDLE_PIN_BIT); | |
312fcae2 MK |
1687 | record_obj(handle, free_obj); |
1688 | unpin_tag(handle); | |
1ee47165 | 1689 | obj_free(class, used_obj); |
312fcae2 MK |
1690 | } |
1691 | ||
1692 | /* Remember last position in this iteration */ | |
1693 | cc->s_page = s_page; | |
41b88e14 | 1694 | cc->obj_idx = obj_idx; |
312fcae2 MK |
1695 | |
1696 | return ret; | |
1697 | } | |
1698 | ||
3783689a | 1699 | static struct zspage *isolate_zspage(struct size_class *class, bool source) |
312fcae2 MK |
1700 | { |
1701 | int i; | |
3783689a MK |
1702 | struct zspage *zspage; |
1703 | enum fullness_group fg[2] = {ZS_ALMOST_EMPTY, ZS_ALMOST_FULL}; | |
312fcae2 | 1704 | |
3783689a MK |
1705 | if (!source) { |
1706 | fg[0] = ZS_ALMOST_FULL; | |
1707 | fg[1] = ZS_ALMOST_EMPTY; | |
1708 | } | |
1709 | ||
1710 | for (i = 0; i < 2; i++) { | |
1711 | zspage = list_first_entry_or_null(&class->fullness_list[fg[i]], | |
1712 | struct zspage, list); | |
1713 | if (zspage) { | |
48b4800a | 1714 | VM_BUG_ON(is_zspage_isolated(zspage)); |
3783689a MK |
1715 | remove_zspage(class, zspage, fg[i]); |
1716 | return zspage; | |
312fcae2 MK |
1717 | } |
1718 | } | |
1719 | ||
3783689a | 1720 | return zspage; |
312fcae2 MK |
1721 | } |
1722 | ||
860c707d | 1723 | /* |
3783689a | 1724 | * putback_zspage - add @zspage into right class's fullness list |
860c707d | 1725 | * @class: destination class |
3783689a | 1726 | * @zspage: target page |
860c707d | 1727 | * |
3783689a | 1728 | * Return @zspage's fullness_group |
860c707d | 1729 | */ |
4aa409ca | 1730 | static enum fullness_group putback_zspage(struct size_class *class, |
3783689a | 1731 | struct zspage *zspage) |
312fcae2 | 1732 | { |
312fcae2 MK |
1733 | enum fullness_group fullness; |
1734 | ||
48b4800a MK |
1735 | VM_BUG_ON(is_zspage_isolated(zspage)); |
1736 | ||
3783689a MK |
1737 | fullness = get_fullness_group(class, zspage); |
1738 | insert_zspage(class, zspage, fullness); | |
1739 | set_zspage_mapping(zspage, class->index, fullness); | |
839373e6 | 1740 | |
860c707d | 1741 | return fullness; |
61989a80 | 1742 | } |
312fcae2 | 1743 | |
48b4800a | 1744 | #ifdef CONFIG_COMPACTION |
4d0a5402 CIK |
1745 | /* |
1746 | * To prevent zspage destroy during migration, zspage freeing should | |
1747 | * hold locks of all pages in the zspage. | |
1748 | */ | |
1749 | static void lock_zspage(struct zspage *zspage) | |
1750 | { | |
1751 | struct page *page = get_first_page(zspage); | |
1752 | ||
1753 | do { | |
1754 | lock_page(page); | |
1755 | } while ((page = get_next_page(page)) != NULL); | |
1756 | } | |
1757 | ||
8e9231f8 | 1758 | static int zs_init_fs_context(struct fs_context *fc) |
48b4800a | 1759 | { |
8e9231f8 | 1760 | return init_pseudo(fc, ZSMALLOC_MAGIC) ? 0 : -ENOMEM; |
48b4800a MK |
1761 | } |
1762 | ||
1763 | static struct file_system_type zsmalloc_fs = { | |
1764 | .name = "zsmalloc", | |
8e9231f8 | 1765 | .init_fs_context = zs_init_fs_context, |
48b4800a MK |
1766 | .kill_sb = kill_anon_super, |
1767 | }; | |
1768 | ||
1769 | static int zsmalloc_mount(void) | |
1770 | { | |
1771 | int ret = 0; | |
1772 | ||
1773 | zsmalloc_mnt = kern_mount(&zsmalloc_fs); | |
1774 | if (IS_ERR(zsmalloc_mnt)) | |
1775 | ret = PTR_ERR(zsmalloc_mnt); | |
1776 | ||
1777 | return ret; | |
1778 | } | |
1779 | ||
1780 | static void zsmalloc_unmount(void) | |
1781 | { | |
1782 | kern_unmount(zsmalloc_mnt); | |
1783 | } | |
1784 | ||
1785 | static void migrate_lock_init(struct zspage *zspage) | |
1786 | { | |
1787 | rwlock_init(&zspage->lock); | |
1788 | } | |
1789 | ||
cfc451cf | 1790 | static void migrate_read_lock(struct zspage *zspage) __acquires(&zspage->lock) |
48b4800a MK |
1791 | { |
1792 | read_lock(&zspage->lock); | |
1793 | } | |
1794 | ||
8a374ccc | 1795 | static void migrate_read_unlock(struct zspage *zspage) __releases(&zspage->lock) |
48b4800a MK |
1796 | { |
1797 | read_unlock(&zspage->lock); | |
1798 | } | |
1799 | ||
1800 | static void migrate_write_lock(struct zspage *zspage) | |
1801 | { | |
1802 | write_lock(&zspage->lock); | |
1803 | } | |
1804 | ||
1805 | static void migrate_write_unlock(struct zspage *zspage) | |
1806 | { | |
1807 | write_unlock(&zspage->lock); | |
1808 | } | |
1809 | ||
1810 | /* Number of isolated subpage for *page migration* in this zspage */ | |
1811 | static void inc_zspage_isolation(struct zspage *zspage) | |
1812 | { | |
1813 | zspage->isolated++; | |
1814 | } | |
1815 | ||
1816 | static void dec_zspage_isolation(struct zspage *zspage) | |
1817 | { | |
1818 | zspage->isolated--; | |
1819 | } | |
1820 | ||
1a87aa03 HB |
1821 | static void putback_zspage_deferred(struct zs_pool *pool, |
1822 | struct size_class *class, | |
1823 | struct zspage *zspage) | |
1824 | { | |
1825 | enum fullness_group fg; | |
1826 | ||
1827 | fg = putback_zspage(class, zspage); | |
1828 | if (fg == ZS_EMPTY) | |
1829 | schedule_work(&pool->free_work); | |
1830 | ||
1831 | } | |
1832 | ||
701d6785 HB |
1833 | static inline void zs_pool_dec_isolated(struct zs_pool *pool) |
1834 | { | |
1835 | VM_BUG_ON(atomic_long_read(&pool->isolated_pages) <= 0); | |
1836 | atomic_long_dec(&pool->isolated_pages); | |
1837 | /* | |
1838 | * There's no possibility of racing, since wait_for_isolated_drain() | |
1839 | * checks the isolated count under &class->lock after enqueuing | |
1840 | * on migration_wait. | |
1841 | */ | |
1842 | if (atomic_long_read(&pool->isolated_pages) == 0 && pool->destroying) | |
1843 | wake_up_all(&pool->migration_wait); | |
1844 | } | |
1845 | ||
48b4800a MK |
1846 | static void replace_sub_page(struct size_class *class, struct zspage *zspage, |
1847 | struct page *newpage, struct page *oldpage) | |
1848 | { | |
1849 | struct page *page; | |
1850 | struct page *pages[ZS_MAX_PAGES_PER_ZSPAGE] = {NULL, }; | |
1851 | int idx = 0; | |
1852 | ||
1853 | page = get_first_page(zspage); | |
1854 | do { | |
1855 | if (page == oldpage) | |
1856 | pages[idx] = newpage; | |
1857 | else | |
1858 | pages[idx] = page; | |
1859 | idx++; | |
1860 | } while ((page = get_next_page(page)) != NULL); | |
1861 | ||
1862 | create_page_chain(class, zspage, pages); | |
1863 | set_first_obj_offset(newpage, get_first_obj_offset(oldpage)); | |
1864 | if (unlikely(PageHugeObject(oldpage))) | |
1865 | newpage->index = oldpage->index; | |
1866 | __SetPageMovable(newpage, page_mapping(oldpage)); | |
1867 | } | |
1868 | ||
4d0a5402 | 1869 | static bool zs_page_isolate(struct page *page, isolate_mode_t mode) |
48b4800a MK |
1870 | { |
1871 | struct zs_pool *pool; | |
1872 | struct size_class *class; | |
1873 | int class_idx; | |
1874 | enum fullness_group fullness; | |
1875 | struct zspage *zspage; | |
1876 | struct address_space *mapping; | |
1877 | ||
1878 | /* | |
1879 | * Page is locked so zspage couldn't be destroyed. For detail, look at | |
1880 | * lock_zspage in free_zspage. | |
1881 | */ | |
1882 | VM_BUG_ON_PAGE(!PageMovable(page), page); | |
1883 | VM_BUG_ON_PAGE(PageIsolated(page), page); | |
1884 | ||
1885 | zspage = get_zspage(page); | |
1886 | ||
1887 | /* | |
1888 | * Without class lock, fullness could be stale while class_idx is okay | |
1889 | * because class_idx is constant unless page is freed so we should get | |
1890 | * fullness again under class lock. | |
1891 | */ | |
1892 | get_zspage_mapping(zspage, &class_idx, &fullness); | |
1893 | mapping = page_mapping(page); | |
1894 | pool = mapping->private_data; | |
1895 | class = pool->size_class[class_idx]; | |
1896 | ||
1897 | spin_lock(&class->lock); | |
1898 | if (get_zspage_inuse(zspage) == 0) { | |
1899 | spin_unlock(&class->lock); | |
1900 | return false; | |
1901 | } | |
1902 | ||
1903 | /* zspage is isolated for object migration */ | |
1904 | if (list_empty(&zspage->list) && !is_zspage_isolated(zspage)) { | |
1905 | spin_unlock(&class->lock); | |
1906 | return false; | |
1907 | } | |
1908 | ||
1909 | /* | |
1910 | * If this is first time isolation for the zspage, isolate zspage from | |
1911 | * size_class to prevent further object allocation from the zspage. | |
1912 | */ | |
1913 | if (!list_empty(&zspage->list) && !is_zspage_isolated(zspage)) { | |
1914 | get_zspage_mapping(zspage, &class_idx, &fullness); | |
701d6785 | 1915 | atomic_long_inc(&pool->isolated_pages); |
48b4800a MK |
1916 | remove_zspage(class, zspage, fullness); |
1917 | } | |
1918 | ||
1919 | inc_zspage_isolation(zspage); | |
1920 | spin_unlock(&class->lock); | |
1921 | ||
1922 | return true; | |
1923 | } | |
1924 | ||
4d0a5402 | 1925 | static int zs_page_migrate(struct address_space *mapping, struct page *newpage, |
48b4800a MK |
1926 | struct page *page, enum migrate_mode mode) |
1927 | { | |
1928 | struct zs_pool *pool; | |
1929 | struct size_class *class; | |
1930 | int class_idx; | |
1931 | enum fullness_group fullness; | |
1932 | struct zspage *zspage; | |
1933 | struct page *dummy; | |
1934 | void *s_addr, *d_addr, *addr; | |
1935 | int offset, pos; | |
1936 | unsigned long handle, head; | |
1937 | unsigned long old_obj, new_obj; | |
1938 | unsigned int obj_idx; | |
1939 | int ret = -EAGAIN; | |
1940 | ||
2916ecc0 JG |
1941 | /* |
1942 | * We cannot support the _NO_COPY case here, because copy needs to | |
1943 | * happen under the zs lock, which does not work with | |
1944 | * MIGRATE_SYNC_NO_COPY workflow. | |
1945 | */ | |
1946 | if (mode == MIGRATE_SYNC_NO_COPY) | |
1947 | return -EINVAL; | |
1948 | ||
48b4800a MK |
1949 | VM_BUG_ON_PAGE(!PageMovable(page), page); |
1950 | VM_BUG_ON_PAGE(!PageIsolated(page), page); | |
1951 | ||
1952 | zspage = get_zspage(page); | |
1953 | ||
1954 | /* Concurrent compactor cannot migrate any subpage in zspage */ | |
1955 | migrate_write_lock(zspage); | |
1956 | get_zspage_mapping(zspage, &class_idx, &fullness); | |
1957 | pool = mapping->private_data; | |
1958 | class = pool->size_class[class_idx]; | |
1959 | offset = get_first_obj_offset(page); | |
1960 | ||
1961 | spin_lock(&class->lock); | |
1962 | if (!get_zspage_inuse(zspage)) { | |
77ff4657 HZ |
1963 | /* |
1964 | * Set "offset" to end of the page so that every loops | |
1965 | * skips unnecessary object scanning. | |
1966 | */ | |
1967 | offset = PAGE_SIZE; | |
48b4800a MK |
1968 | } |
1969 | ||
1970 | pos = offset; | |
1971 | s_addr = kmap_atomic(page); | |
1972 | while (pos < PAGE_SIZE) { | |
1973 | head = obj_to_head(page, s_addr + pos); | |
1974 | if (head & OBJ_ALLOCATED_TAG) { | |
1975 | handle = head & ~OBJ_ALLOCATED_TAG; | |
1976 | if (!trypin_tag(handle)) | |
1977 | goto unpin_objects; | |
1978 | } | |
1979 | pos += class->size; | |
1980 | } | |
1981 | ||
1982 | /* | |
1983 | * Here, any user cannot access all objects in the zspage so let's move. | |
1984 | */ | |
1985 | d_addr = kmap_atomic(newpage); | |
1986 | memcpy(d_addr, s_addr, PAGE_SIZE); | |
1987 | kunmap_atomic(d_addr); | |
1988 | ||
1989 | for (addr = s_addr + offset; addr < s_addr + pos; | |
1990 | addr += class->size) { | |
1991 | head = obj_to_head(page, addr); | |
1992 | if (head & OBJ_ALLOCATED_TAG) { | |
1993 | handle = head & ~OBJ_ALLOCATED_TAG; | |
1994 | if (!testpin_tag(handle)) | |
1995 | BUG(); | |
1996 | ||
1997 | old_obj = handle_to_obj(handle); | |
1998 | obj_to_location(old_obj, &dummy, &obj_idx); | |
1999 | new_obj = (unsigned long)location_to_obj(newpage, | |
2000 | obj_idx); | |
2001 | new_obj |= BIT(HANDLE_PIN_BIT); | |
2002 | record_obj(handle, new_obj); | |
2003 | } | |
2004 | } | |
2005 | ||
2006 | replace_sub_page(class, zspage, newpage, page); | |
2007 | get_page(newpage); | |
2008 | ||
2009 | dec_zspage_isolation(zspage); | |
2010 | ||
2011 | /* | |
2012 | * Page migration is done so let's putback isolated zspage to | |
2013 | * the list if @page is final isolated subpage in the zspage. | |
2014 | */ | |
701d6785 HB |
2015 | if (!is_zspage_isolated(zspage)) { |
2016 | /* | |
2017 | * We cannot race with zs_destroy_pool() here because we wait | |
2018 | * for isolation to hit zero before we start destroying. | |
2019 | * Also, we ensure that everyone can see pool->destroying before | |
2020 | * we start waiting. | |
2021 | */ | |
1a87aa03 | 2022 | putback_zspage_deferred(pool, class, zspage); |
701d6785 HB |
2023 | zs_pool_dec_isolated(pool); |
2024 | } | |
48b4800a | 2025 | |
ac8f05da CM |
2026 | if (page_zone(newpage) != page_zone(page)) { |
2027 | dec_zone_page_state(page, NR_ZSPAGES); | |
2028 | inc_zone_page_state(newpage, NR_ZSPAGES); | |
2029 | } | |
2030 | ||
48b4800a MK |
2031 | reset_page(page); |
2032 | put_page(page); | |
2033 | page = newpage; | |
2034 | ||
dd4123f3 | 2035 | ret = MIGRATEPAGE_SUCCESS; |
48b4800a MK |
2036 | unpin_objects: |
2037 | for (addr = s_addr + offset; addr < s_addr + pos; | |
2038 | addr += class->size) { | |
2039 | head = obj_to_head(page, addr); | |
2040 | if (head & OBJ_ALLOCATED_TAG) { | |
2041 | handle = head & ~OBJ_ALLOCATED_TAG; | |
2042 | if (!testpin_tag(handle)) | |
2043 | BUG(); | |
2044 | unpin_tag(handle); | |
2045 | } | |
2046 | } | |
2047 | kunmap_atomic(s_addr); | |
48b4800a MK |
2048 | spin_unlock(&class->lock); |
2049 | migrate_write_unlock(zspage); | |
2050 | ||
2051 | return ret; | |
2052 | } | |
2053 | ||
4d0a5402 | 2054 | static void zs_page_putback(struct page *page) |
48b4800a MK |
2055 | { |
2056 | struct zs_pool *pool; | |
2057 | struct size_class *class; | |
2058 | int class_idx; | |
2059 | enum fullness_group fg; | |
2060 | struct address_space *mapping; | |
2061 | struct zspage *zspage; | |
2062 | ||
2063 | VM_BUG_ON_PAGE(!PageMovable(page), page); | |
2064 | VM_BUG_ON_PAGE(!PageIsolated(page), page); | |
2065 | ||
2066 | zspage = get_zspage(page); | |
2067 | get_zspage_mapping(zspage, &class_idx, &fg); | |
2068 | mapping = page_mapping(page); | |
2069 | pool = mapping->private_data; | |
2070 | class = pool->size_class[class_idx]; | |
2071 | ||
2072 | spin_lock(&class->lock); | |
2073 | dec_zspage_isolation(zspage); | |
2074 | if (!is_zspage_isolated(zspage)) { | |
48b4800a MK |
2075 | /* |
2076 | * Due to page_lock, we cannot free zspage immediately | |
2077 | * so let's defer. | |
2078 | */ | |
1a87aa03 | 2079 | putback_zspage_deferred(pool, class, zspage); |
701d6785 | 2080 | zs_pool_dec_isolated(pool); |
48b4800a MK |
2081 | } |
2082 | spin_unlock(&class->lock); | |
2083 | } | |
2084 | ||
4d0a5402 | 2085 | static const struct address_space_operations zsmalloc_aops = { |
48b4800a MK |
2086 | .isolate_page = zs_page_isolate, |
2087 | .migratepage = zs_page_migrate, | |
2088 | .putback_page = zs_page_putback, | |
2089 | }; | |
2090 | ||
2091 | static int zs_register_migration(struct zs_pool *pool) | |
2092 | { | |
2093 | pool->inode = alloc_anon_inode(zsmalloc_mnt->mnt_sb); | |
2094 | if (IS_ERR(pool->inode)) { | |
2095 | pool->inode = NULL; | |
2096 | return 1; | |
2097 | } | |
2098 | ||
2099 | pool->inode->i_mapping->private_data = pool; | |
2100 | pool->inode->i_mapping->a_ops = &zsmalloc_aops; | |
2101 | return 0; | |
2102 | } | |
2103 | ||
701d6785 HB |
2104 | static bool pool_isolated_are_drained(struct zs_pool *pool) |
2105 | { | |
2106 | return atomic_long_read(&pool->isolated_pages) == 0; | |
2107 | } | |
2108 | ||
2109 | /* Function for resolving migration */ | |
2110 | static void wait_for_isolated_drain(struct zs_pool *pool) | |
2111 | { | |
2112 | ||
2113 | /* | |
2114 | * We're in the process of destroying the pool, so there are no | |
2115 | * active allocations. zs_page_isolate() fails for completely free | |
2116 | * zspages, so we need only wait for the zs_pool's isolated | |
2117 | * count to hit zero. | |
2118 | */ | |
2119 | wait_event(pool->migration_wait, | |
2120 | pool_isolated_are_drained(pool)); | |
2121 | } | |
2122 | ||
48b4800a MK |
2123 | static void zs_unregister_migration(struct zs_pool *pool) |
2124 | { | |
701d6785 HB |
2125 | pool->destroying = true; |
2126 | /* | |
2127 | * We need a memory barrier here to ensure global visibility of | |
2128 | * pool->destroying. Thus pool->isolated pages will either be 0 in which | |
2129 | * case we don't care, or it will be > 0 and pool->destroying will | |
2130 | * ensure that we wake up once isolation hits 0. | |
2131 | */ | |
2132 | smp_mb(); | |
2133 | wait_for_isolated_drain(pool); /* This can block */ | |
48b4800a | 2134 | flush_work(&pool->free_work); |
c3491eca | 2135 | iput(pool->inode); |
48b4800a MK |
2136 | } |
2137 | ||
2138 | /* | |
2139 | * Caller should hold page_lock of all pages in the zspage | |
2140 | * In here, we cannot use zspage meta data. | |
2141 | */ | |
2142 | static void async_free_zspage(struct work_struct *work) | |
2143 | { | |
2144 | int i; | |
2145 | struct size_class *class; | |
2146 | unsigned int class_idx; | |
2147 | enum fullness_group fullness; | |
2148 | struct zspage *zspage, *tmp; | |
2149 | LIST_HEAD(free_pages); | |
2150 | struct zs_pool *pool = container_of(work, struct zs_pool, | |
2151 | free_work); | |
2152 | ||
cf8e0fed | 2153 | for (i = 0; i < ZS_SIZE_CLASSES; i++) { |
48b4800a MK |
2154 | class = pool->size_class[i]; |
2155 | if (class->index != i) | |
2156 | continue; | |
2157 | ||
2158 | spin_lock(&class->lock); | |
2159 | list_splice_init(&class->fullness_list[ZS_EMPTY], &free_pages); | |
2160 | spin_unlock(&class->lock); | |
2161 | } | |
2162 | ||
2163 | ||
2164 | list_for_each_entry_safe(zspage, tmp, &free_pages, list) { | |
2165 | list_del(&zspage->list); | |
2166 | lock_zspage(zspage); | |
2167 | ||
2168 | get_zspage_mapping(zspage, &class_idx, &fullness); | |
2169 | VM_BUG_ON(fullness != ZS_EMPTY); | |
2170 | class = pool->size_class[class_idx]; | |
2171 | spin_lock(&class->lock); | |
2172 | __free_zspage(pool, pool->size_class[class_idx], zspage); | |
2173 | spin_unlock(&class->lock); | |
2174 | } | |
2175 | }; | |
2176 | ||
2177 | static void kick_deferred_free(struct zs_pool *pool) | |
2178 | { | |
2179 | schedule_work(&pool->free_work); | |
2180 | } | |
2181 | ||
2182 | static void init_deferred_free(struct zs_pool *pool) | |
2183 | { | |
2184 | INIT_WORK(&pool->free_work, async_free_zspage); | |
2185 | } | |
2186 | ||
2187 | static void SetZsPageMovable(struct zs_pool *pool, struct zspage *zspage) | |
2188 | { | |
2189 | struct page *page = get_first_page(zspage); | |
2190 | ||
2191 | do { | |
2192 | WARN_ON(!trylock_page(page)); | |
2193 | __SetPageMovable(page, pool->inode->i_mapping); | |
2194 | unlock_page(page); | |
2195 | } while ((page = get_next_page(page)) != NULL); | |
2196 | } | |
2197 | #endif | |
2198 | ||
04f05909 SS |
2199 | /* |
2200 | * | |
2201 | * Based on the number of unused allocated objects calculate | |
2202 | * and return the number of pages that we can free. | |
04f05909 SS |
2203 | */ |
2204 | static unsigned long zs_can_compact(struct size_class *class) | |
2205 | { | |
2206 | unsigned long obj_wasted; | |
44f43e99 SS |
2207 | unsigned long obj_allocated = zs_stat_get(class, OBJ_ALLOCATED); |
2208 | unsigned long obj_used = zs_stat_get(class, OBJ_USED); | |
04f05909 | 2209 | |
44f43e99 SS |
2210 | if (obj_allocated <= obj_used) |
2211 | return 0; | |
04f05909 | 2212 | |
44f43e99 | 2213 | obj_wasted = obj_allocated - obj_used; |
b4fd07a0 | 2214 | obj_wasted /= class->objs_per_zspage; |
04f05909 | 2215 | |
6cbf16b3 | 2216 | return obj_wasted * class->pages_per_zspage; |
04f05909 SS |
2217 | } |
2218 | ||
7d3f3938 | 2219 | static void __zs_compact(struct zs_pool *pool, struct size_class *class) |
312fcae2 | 2220 | { |
312fcae2 | 2221 | struct zs_compact_control cc; |
3783689a MK |
2222 | struct zspage *src_zspage; |
2223 | struct zspage *dst_zspage = NULL; | |
312fcae2 | 2224 | |
312fcae2 | 2225 | spin_lock(&class->lock); |
3783689a | 2226 | while ((src_zspage = isolate_zspage(class, true))) { |
312fcae2 | 2227 | |
04f05909 SS |
2228 | if (!zs_can_compact(class)) |
2229 | break; | |
2230 | ||
41b88e14 | 2231 | cc.obj_idx = 0; |
48b4800a | 2232 | cc.s_page = get_first_page(src_zspage); |
312fcae2 | 2233 | |
3783689a | 2234 | while ((dst_zspage = isolate_zspage(class, false))) { |
48b4800a | 2235 | cc.d_page = get_first_page(dst_zspage); |
312fcae2 | 2236 | /* |
0dc63d48 SS |
2237 | * If there is no more space in dst_page, resched |
2238 | * and see if anyone had allocated another zspage. | |
312fcae2 MK |
2239 | */ |
2240 | if (!migrate_zspage(pool, class, &cc)) | |
2241 | break; | |
2242 | ||
4aa409ca | 2243 | putback_zspage(class, dst_zspage); |
312fcae2 MK |
2244 | } |
2245 | ||
2246 | /* Stop if we couldn't find slot */ | |
3783689a | 2247 | if (dst_zspage == NULL) |
312fcae2 MK |
2248 | break; |
2249 | ||
4aa409ca MK |
2250 | putback_zspage(class, dst_zspage); |
2251 | if (putback_zspage(class, src_zspage) == ZS_EMPTY) { | |
48b4800a | 2252 | free_zspage(pool, class, src_zspage); |
6cbf16b3 | 2253 | pool->stats.pages_compacted += class->pages_per_zspage; |
4aa409ca | 2254 | } |
312fcae2 | 2255 | spin_unlock(&class->lock); |
312fcae2 MK |
2256 | cond_resched(); |
2257 | spin_lock(&class->lock); | |
2258 | } | |
2259 | ||
3783689a | 2260 | if (src_zspage) |
4aa409ca | 2261 | putback_zspage(class, src_zspage); |
312fcae2 | 2262 | |
7d3f3938 | 2263 | spin_unlock(&class->lock); |
312fcae2 MK |
2264 | } |
2265 | ||
2266 | unsigned long zs_compact(struct zs_pool *pool) | |
2267 | { | |
2268 | int i; | |
312fcae2 MK |
2269 | struct size_class *class; |
2270 | ||
cf8e0fed | 2271 | for (i = ZS_SIZE_CLASSES - 1; i >= 0; i--) { |
312fcae2 MK |
2272 | class = pool->size_class[i]; |
2273 | if (!class) | |
2274 | continue; | |
2275 | if (class->index != i) | |
2276 | continue; | |
7d3f3938 | 2277 | __zs_compact(pool, class); |
312fcae2 MK |
2278 | } |
2279 | ||
860c707d | 2280 | return pool->stats.pages_compacted; |
312fcae2 MK |
2281 | } |
2282 | EXPORT_SYMBOL_GPL(zs_compact); | |
61989a80 | 2283 | |
7d3f3938 SS |
2284 | void zs_pool_stats(struct zs_pool *pool, struct zs_pool_stats *stats) |
2285 | { | |
2286 | memcpy(stats, &pool->stats, sizeof(struct zs_pool_stats)); | |
2287 | } | |
2288 | EXPORT_SYMBOL_GPL(zs_pool_stats); | |
2289 | ||
ab9d306d SS |
2290 | static unsigned long zs_shrinker_scan(struct shrinker *shrinker, |
2291 | struct shrink_control *sc) | |
2292 | { | |
2293 | unsigned long pages_freed; | |
2294 | struct zs_pool *pool = container_of(shrinker, struct zs_pool, | |
2295 | shrinker); | |
2296 | ||
2297 | pages_freed = pool->stats.pages_compacted; | |
2298 | /* | |
2299 | * Compact classes and calculate compaction delta. | |
2300 | * Can run concurrently with a manually triggered | |
2301 | * (by user) compaction. | |
2302 | */ | |
2303 | pages_freed = zs_compact(pool) - pages_freed; | |
2304 | ||
2305 | return pages_freed ? pages_freed : SHRINK_STOP; | |
2306 | } | |
2307 | ||
2308 | static unsigned long zs_shrinker_count(struct shrinker *shrinker, | |
2309 | struct shrink_control *sc) | |
2310 | { | |
2311 | int i; | |
2312 | struct size_class *class; | |
2313 | unsigned long pages_to_free = 0; | |
2314 | struct zs_pool *pool = container_of(shrinker, struct zs_pool, | |
2315 | shrinker); | |
2316 | ||
cf8e0fed | 2317 | for (i = ZS_SIZE_CLASSES - 1; i >= 0; i--) { |
ab9d306d SS |
2318 | class = pool->size_class[i]; |
2319 | if (!class) | |
2320 | continue; | |
2321 | if (class->index != i) | |
2322 | continue; | |
2323 | ||
ab9d306d | 2324 | pages_to_free += zs_can_compact(class); |
ab9d306d SS |
2325 | } |
2326 | ||
2327 | return pages_to_free; | |
2328 | } | |
2329 | ||
2330 | static void zs_unregister_shrinker(struct zs_pool *pool) | |
2331 | { | |
93144ca3 | 2332 | unregister_shrinker(&pool->shrinker); |
ab9d306d SS |
2333 | } |
2334 | ||
2335 | static int zs_register_shrinker(struct zs_pool *pool) | |
2336 | { | |
2337 | pool->shrinker.scan_objects = zs_shrinker_scan; | |
2338 | pool->shrinker.count_objects = zs_shrinker_count; | |
2339 | pool->shrinker.batch = 0; | |
2340 | pool->shrinker.seeks = DEFAULT_SEEKS; | |
2341 | ||
2342 | return register_shrinker(&pool->shrinker); | |
2343 | } | |
2344 | ||
00a61d86 | 2345 | /** |
66cdef66 | 2346 | * zs_create_pool - Creates an allocation pool to work from. |
fd854463 | 2347 | * @name: pool name to be created |
166cfda7 | 2348 | * |
66cdef66 GM |
2349 | * This function must be called before anything when using |
2350 | * the zsmalloc allocator. | |
166cfda7 | 2351 | * |
66cdef66 GM |
2352 | * On success, a pointer to the newly created pool is returned, |
2353 | * otherwise NULL. | |
396b7fd6 | 2354 | */ |
d0d8da2d | 2355 | struct zs_pool *zs_create_pool(const char *name) |
61989a80 | 2356 | { |
66cdef66 GM |
2357 | int i; |
2358 | struct zs_pool *pool; | |
2359 | struct size_class *prev_class = NULL; | |
61989a80 | 2360 | |
66cdef66 GM |
2361 | pool = kzalloc(sizeof(*pool), GFP_KERNEL); |
2362 | if (!pool) | |
2363 | return NULL; | |
61989a80 | 2364 | |
48b4800a | 2365 | init_deferred_free(pool); |
61989a80 | 2366 | |
2e40e163 MK |
2367 | pool->name = kstrdup(name, GFP_KERNEL); |
2368 | if (!pool->name) | |
2369 | goto err; | |
2370 | ||
441e254c | 2371 | #ifdef CONFIG_COMPACTION |
701d6785 | 2372 | init_waitqueue_head(&pool->migration_wait); |
441e254c | 2373 | #endif |
701d6785 | 2374 | |
3783689a | 2375 | if (create_cache(pool)) |
2e40e163 MK |
2376 | goto err; |
2377 | ||
c60369f0 | 2378 | /* |
399d8eeb | 2379 | * Iterate reversely, because, size of size_class that we want to use |
66cdef66 | 2380 | * for merging should be larger or equal to current size. |
c60369f0 | 2381 | */ |
cf8e0fed | 2382 | for (i = ZS_SIZE_CLASSES - 1; i >= 0; i--) { |
66cdef66 GM |
2383 | int size; |
2384 | int pages_per_zspage; | |
64d90465 | 2385 | int objs_per_zspage; |
66cdef66 | 2386 | struct size_class *class; |
3783689a | 2387 | int fullness = 0; |
c60369f0 | 2388 | |
66cdef66 GM |
2389 | size = ZS_MIN_ALLOC_SIZE + i * ZS_SIZE_CLASS_DELTA; |
2390 | if (size > ZS_MAX_ALLOC_SIZE) | |
2391 | size = ZS_MAX_ALLOC_SIZE; | |
2392 | pages_per_zspage = get_pages_per_zspage(size); | |
64d90465 | 2393 | objs_per_zspage = pages_per_zspage * PAGE_SIZE / size; |
61989a80 | 2394 | |
010b495e SS |
2395 | /* |
2396 | * We iterate from biggest down to smallest classes, | |
2397 | * so huge_class_size holds the size of the first huge | |
2398 | * class. Any object bigger than or equal to that will | |
2399 | * endup in the huge class. | |
2400 | */ | |
2401 | if (pages_per_zspage != 1 && objs_per_zspage != 1 && | |
2402 | !huge_class_size) { | |
2403 | huge_class_size = size; | |
2404 | /* | |
2405 | * The object uses ZS_HANDLE_SIZE bytes to store the | |
2406 | * handle. We need to subtract it, because zs_malloc() | |
2407 | * unconditionally adds handle size before it performs | |
2408 | * size class search - so object may be smaller than | |
2409 | * huge class size, yet it still can end up in the huge | |
2410 | * class because it grows by ZS_HANDLE_SIZE extra bytes | |
2411 | * right before class lookup. | |
2412 | */ | |
2413 | huge_class_size -= (ZS_HANDLE_SIZE - 1); | |
2414 | } | |
2415 | ||
66cdef66 GM |
2416 | /* |
2417 | * size_class is used for normal zsmalloc operation such | |
2418 | * as alloc/free for that size. Although it is natural that we | |
2419 | * have one size_class for each size, there is a chance that we | |
2420 | * can get more memory utilization if we use one size_class for | |
2421 | * many different sizes whose size_class have same | |
2422 | * characteristics. So, we makes size_class point to | |
2423 | * previous size_class if possible. | |
2424 | */ | |
2425 | if (prev_class) { | |
64d90465 | 2426 | if (can_merge(prev_class, pages_per_zspage, objs_per_zspage)) { |
66cdef66 GM |
2427 | pool->size_class[i] = prev_class; |
2428 | continue; | |
2429 | } | |
2430 | } | |
2431 | ||
2432 | class = kzalloc(sizeof(struct size_class), GFP_KERNEL); | |
2433 | if (!class) | |
2434 | goto err; | |
2435 | ||
2436 | class->size = size; | |
2437 | class->index = i; | |
2438 | class->pages_per_zspage = pages_per_zspage; | |
64d90465 | 2439 | class->objs_per_zspage = objs_per_zspage; |
66cdef66 GM |
2440 | spin_lock_init(&class->lock); |
2441 | pool->size_class[i] = class; | |
48b4800a MK |
2442 | for (fullness = ZS_EMPTY; fullness < NR_ZS_FULLNESS; |
2443 | fullness++) | |
3783689a | 2444 | INIT_LIST_HEAD(&class->fullness_list[fullness]); |
66cdef66 GM |
2445 | |
2446 | prev_class = class; | |
61989a80 NG |
2447 | } |
2448 | ||
d34f6157 DS |
2449 | /* debug only, don't abort if it fails */ |
2450 | zs_pool_stat_create(pool, name); | |
0f050d99 | 2451 | |
48b4800a MK |
2452 | if (zs_register_migration(pool)) |
2453 | goto err; | |
2454 | ||
ab9d306d | 2455 | /* |
93144ca3 AK |
2456 | * Not critical since shrinker is only used to trigger internal |
2457 | * defragmentation of the pool which is pretty optional thing. If | |
2458 | * registration fails we still can use the pool normally and user can | |
2459 | * trigger compaction manually. Thus, ignore return code. | |
ab9d306d | 2460 | */ |
93144ca3 AK |
2461 | zs_register_shrinker(pool); |
2462 | ||
66cdef66 GM |
2463 | return pool; |
2464 | ||
2465 | err: | |
2466 | zs_destroy_pool(pool); | |
2467 | return NULL; | |
61989a80 | 2468 | } |
66cdef66 | 2469 | EXPORT_SYMBOL_GPL(zs_create_pool); |
61989a80 | 2470 | |
66cdef66 | 2471 | void zs_destroy_pool(struct zs_pool *pool) |
61989a80 | 2472 | { |
66cdef66 | 2473 | int i; |
61989a80 | 2474 | |
ab9d306d | 2475 | zs_unregister_shrinker(pool); |
48b4800a | 2476 | zs_unregister_migration(pool); |
0f050d99 GM |
2477 | zs_pool_stat_destroy(pool); |
2478 | ||
cf8e0fed | 2479 | for (i = 0; i < ZS_SIZE_CLASSES; i++) { |
66cdef66 GM |
2480 | int fg; |
2481 | struct size_class *class = pool->size_class[i]; | |
61989a80 | 2482 | |
66cdef66 GM |
2483 | if (!class) |
2484 | continue; | |
61989a80 | 2485 | |
66cdef66 GM |
2486 | if (class->index != i) |
2487 | continue; | |
61989a80 | 2488 | |
48b4800a | 2489 | for (fg = ZS_EMPTY; fg < NR_ZS_FULLNESS; fg++) { |
3783689a | 2490 | if (!list_empty(&class->fullness_list[fg])) { |
66cdef66 GM |
2491 | pr_info("Freeing non-empty class with size %db, fullness group %d\n", |
2492 | class->size, fg); | |
2493 | } | |
2494 | } | |
2495 | kfree(class); | |
2496 | } | |
f553646a | 2497 | |
3783689a | 2498 | destroy_cache(pool); |
0f050d99 | 2499 | kfree(pool->name); |
66cdef66 GM |
2500 | kfree(pool); |
2501 | } | |
2502 | EXPORT_SYMBOL_GPL(zs_destroy_pool); | |
b7418510 | 2503 | |
66cdef66 GM |
2504 | static int __init zs_init(void) |
2505 | { | |
48b4800a MK |
2506 | int ret; |
2507 | ||
2508 | ret = zsmalloc_mount(); | |
2509 | if (ret) | |
2510 | goto out; | |
2511 | ||
215c89d0 SAS |
2512 | ret = cpuhp_setup_state(CPUHP_MM_ZS_PREPARE, "mm/zsmalloc:prepare", |
2513 | zs_cpu_prepare, zs_cpu_dead); | |
0f050d99 | 2514 | if (ret) |
215c89d0 | 2515 | goto hp_setup_fail; |
66cdef66 | 2516 | |
66cdef66 GM |
2517 | #ifdef CONFIG_ZPOOL |
2518 | zpool_register_driver(&zs_zpool_driver); | |
2519 | #endif | |
0f050d99 | 2520 | |
4abaac9b DS |
2521 | zs_stat_init(); |
2522 | ||
66cdef66 | 2523 | return 0; |
0f050d99 | 2524 | |
215c89d0 | 2525 | hp_setup_fail: |
48b4800a MK |
2526 | zsmalloc_unmount(); |
2527 | out: | |
0f050d99 | 2528 | return ret; |
61989a80 | 2529 | } |
61989a80 | 2530 | |
66cdef66 | 2531 | static void __exit zs_exit(void) |
61989a80 | 2532 | { |
66cdef66 GM |
2533 | #ifdef CONFIG_ZPOOL |
2534 | zpool_unregister_driver(&zs_zpool_driver); | |
2535 | #endif | |
48b4800a | 2536 | zsmalloc_unmount(); |
215c89d0 | 2537 | cpuhp_remove_state(CPUHP_MM_ZS_PREPARE); |
0f050d99 GM |
2538 | |
2539 | zs_stat_exit(); | |
61989a80 | 2540 | } |
069f101f BH |
2541 | |
2542 | module_init(zs_init); | |
2543 | module_exit(zs_exit); | |
2544 | ||
2545 | MODULE_LICENSE("Dual BSD/GPL"); | |
2546 | MODULE_AUTHOR("Nitin Gupta <ngupta@vflare.org>"); |