Commit | Line | Data |
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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 | |
27 | * PG_private2: identifies the last component page | |
48b4800a | 28 | * PG_owner_priv_1: indentifies the huge component page |
2db51dae NG |
29 | * |
30 | */ | |
31 | ||
4abaac9b DS |
32 | #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt |
33 | ||
61989a80 NG |
34 | #include <linux/module.h> |
35 | #include <linux/kernel.h> | |
312fcae2 | 36 | #include <linux/sched.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> | |
42 | #include <asm/tlbflush.h> | |
43 | #include <asm/pgtable.h> | |
44 | #include <linux/cpumask.h> | |
45 | #include <linux/cpu.h> | |
0cbb613f | 46 | #include <linux/vmalloc.h> |
759b26b2 | 47 | #include <linux/preempt.h> |
0959c63f SJ |
48 | #include <linux/spinlock.h> |
49 | #include <linux/types.h> | |
0f050d99 | 50 | #include <linux/debugfs.h> |
bcf1647d | 51 | #include <linux/zsmalloc.h> |
c795779d | 52 | #include <linux/zpool.h> |
48b4800a | 53 | #include <linux/mount.h> |
dd4123f3 | 54 | #include <linux/migrate.h> |
48b4800a MK |
55 | #include <linux/pagemap.h> |
56 | ||
57 | #define ZSPAGE_MAGIC 0x58 | |
0959c63f SJ |
58 | |
59 | /* | |
60 | * This must be power of 2 and greater than of equal to sizeof(link_free). | |
61 | * These two conditions ensure that any 'struct link_free' itself doesn't | |
62 | * span more than 1 page which avoids complex case of mapping 2 pages simply | |
63 | * to restore link_free pointer values. | |
64 | */ | |
65 | #define ZS_ALIGN 8 | |
66 | ||
67 | /* | |
68 | * A single 'zspage' is composed of up to 2^N discontiguous 0-order (single) | |
69 | * pages. ZS_MAX_ZSPAGE_ORDER defines upper limit on N. | |
70 | */ | |
71 | #define ZS_MAX_ZSPAGE_ORDER 2 | |
72 | #define ZS_MAX_PAGES_PER_ZSPAGE (_AC(1, UL) << ZS_MAX_ZSPAGE_ORDER) | |
73 | ||
2e40e163 MK |
74 | #define ZS_HANDLE_SIZE (sizeof(unsigned long)) |
75 | ||
0959c63f SJ |
76 | /* |
77 | * Object location (<PFN>, <obj_idx>) is encoded as | |
c3e3e88a | 78 | * as single (unsigned long) handle value. |
0959c63f | 79 | * |
bfd093f5 | 80 | * Note that object index <obj_idx> starts from 0. |
0959c63f SJ |
81 | * |
82 | * This is made more complicated by various memory models and PAE. | |
83 | */ | |
84 | ||
85 | #ifndef MAX_PHYSMEM_BITS | |
86 | #ifdef CONFIG_HIGHMEM64G | |
87 | #define MAX_PHYSMEM_BITS 36 | |
88 | #else /* !CONFIG_HIGHMEM64G */ | |
89 | /* | |
90 | * If this definition of MAX_PHYSMEM_BITS is used, OBJ_INDEX_BITS will just | |
91 | * be PAGE_SHIFT | |
92 | */ | |
93 | #define MAX_PHYSMEM_BITS BITS_PER_LONG | |
94 | #endif | |
95 | #endif | |
96 | #define _PFN_BITS (MAX_PHYSMEM_BITS - PAGE_SHIFT) | |
312fcae2 MK |
97 | |
98 | /* | |
99 | * Memory for allocating for handle keeps object position by | |
100 | * encoding <page, obj_idx> and the encoded value has a room | |
101 | * in least bit(ie, look at obj_to_location). | |
102 | * We use the bit to synchronize between object access by | |
103 | * user and migration. | |
104 | */ | |
105 | #define HANDLE_PIN_BIT 0 | |
106 | ||
107 | /* | |
108 | * Head in allocated object should have OBJ_ALLOCATED_TAG | |
109 | * to identify the object was allocated or not. | |
110 | * It's okay to add the status bit in the least bit because | |
111 | * header keeps handle which is 4byte-aligned address so we | |
112 | * have room for two bit at least. | |
113 | */ | |
114 | #define OBJ_ALLOCATED_TAG 1 | |
115 | #define OBJ_TAG_BITS 1 | |
116 | #define OBJ_INDEX_BITS (BITS_PER_LONG - _PFN_BITS - OBJ_TAG_BITS) | |
0959c63f SJ |
117 | #define OBJ_INDEX_MASK ((_AC(1, UL) << OBJ_INDEX_BITS) - 1) |
118 | ||
119 | #define MAX(a, b) ((a) >= (b) ? (a) : (b)) | |
120 | /* ZS_MIN_ALLOC_SIZE must be multiple of ZS_ALIGN */ | |
121 | #define ZS_MIN_ALLOC_SIZE \ | |
122 | MAX(32, (ZS_MAX_PAGES_PER_ZSPAGE << PAGE_SHIFT >> OBJ_INDEX_BITS)) | |
2e40e163 | 123 | /* each chunk includes extra space to keep handle */ |
7b60a685 | 124 | #define ZS_MAX_ALLOC_SIZE PAGE_SIZE |
0959c63f SJ |
125 | |
126 | /* | |
7eb52512 | 127 | * On systems with 4K page size, this gives 255 size classes! There is a |
0959c63f SJ |
128 | * trader-off here: |
129 | * - Large number of size classes is potentially wasteful as free page are | |
130 | * spread across these classes | |
131 | * - Small number of size classes causes large internal fragmentation | |
132 | * - Probably its better to use specific size classes (empirically | |
133 | * determined). NOTE: all those class sizes must be set as multiple of | |
134 | * ZS_ALIGN to make sure link_free itself never has to span 2 pages. | |
135 | * | |
136 | * ZS_MIN_ALLOC_SIZE and ZS_SIZE_CLASS_DELTA must be multiple of ZS_ALIGN | |
137 | * (reason above) | |
138 | */ | |
3783689a | 139 | #define ZS_SIZE_CLASS_DELTA (PAGE_SIZE >> CLASS_BITS) |
0959c63f | 140 | |
0959c63f | 141 | enum fullness_group { |
0959c63f | 142 | ZS_EMPTY, |
48b4800a MK |
143 | ZS_ALMOST_EMPTY, |
144 | ZS_ALMOST_FULL, | |
145 | ZS_FULL, | |
146 | NR_ZS_FULLNESS, | |
0959c63f SJ |
147 | }; |
148 | ||
0f050d99 | 149 | enum zs_stat_type { |
48b4800a MK |
150 | CLASS_EMPTY, |
151 | CLASS_ALMOST_EMPTY, | |
152 | CLASS_ALMOST_FULL, | |
153 | CLASS_FULL, | |
0f050d99 GM |
154 | OBJ_ALLOCATED, |
155 | OBJ_USED, | |
48b4800a | 156 | NR_ZS_STAT_TYPE, |
0f050d99 GM |
157 | }; |
158 | ||
0f050d99 GM |
159 | struct zs_size_stat { |
160 | unsigned long objs[NR_ZS_STAT_TYPE]; | |
161 | }; | |
162 | ||
57244594 SS |
163 | #ifdef CONFIG_ZSMALLOC_STAT |
164 | static struct dentry *zs_stat_root; | |
0f050d99 GM |
165 | #endif |
166 | ||
48b4800a MK |
167 | #ifdef CONFIG_COMPACTION |
168 | static struct vfsmount *zsmalloc_mnt; | |
169 | #endif | |
170 | ||
40f9fb8c MG |
171 | /* |
172 | * number of size_classes | |
173 | */ | |
174 | static int zs_size_classes; | |
175 | ||
0959c63f SJ |
176 | /* |
177 | * We assign a page to ZS_ALMOST_EMPTY fullness group when: | |
178 | * n <= N / f, where | |
179 | * n = number of allocated objects | |
180 | * N = total number of objects zspage can store | |
6dd9737e | 181 | * f = fullness_threshold_frac |
0959c63f SJ |
182 | * |
183 | * Similarly, we assign zspage to: | |
184 | * ZS_ALMOST_FULL when n > N / f | |
185 | * ZS_EMPTY when n == 0 | |
186 | * ZS_FULL when n == N | |
187 | * | |
188 | * (see: fix_fullness_group()) | |
189 | */ | |
190 | static const int fullness_threshold_frac = 4; | |
191 | ||
192 | struct size_class { | |
57244594 | 193 | spinlock_t lock; |
48b4800a | 194 | struct list_head fullness_list[NR_ZS_FULLNESS]; |
0959c63f SJ |
195 | /* |
196 | * Size of objects stored in this class. Must be multiple | |
197 | * of ZS_ALIGN. | |
198 | */ | |
199 | int size; | |
1fc6e27d | 200 | int objs_per_zspage; |
7dfa4612 WY |
201 | /* Number of PAGE_SIZE sized pages to combine to form a 'zspage' */ |
202 | int pages_per_zspage; | |
48b4800a MK |
203 | |
204 | unsigned int index; | |
205 | struct zs_size_stat stats; | |
0959c63f SJ |
206 | }; |
207 | ||
48b4800a MK |
208 | /* huge object: pages_per_zspage == 1 && maxobj_per_zspage == 1 */ |
209 | static void SetPageHugeObject(struct page *page) | |
210 | { | |
211 | SetPageOwnerPriv1(page); | |
212 | } | |
213 | ||
214 | static void ClearPageHugeObject(struct page *page) | |
215 | { | |
216 | ClearPageOwnerPriv1(page); | |
217 | } | |
218 | ||
219 | static int PageHugeObject(struct page *page) | |
220 | { | |
221 | return PageOwnerPriv1(page); | |
222 | } | |
223 | ||
0959c63f SJ |
224 | /* |
225 | * Placed within free objects to form a singly linked list. | |
3783689a | 226 | * For every zspage, zspage->freeobj gives head of this list. |
0959c63f SJ |
227 | * |
228 | * This must be power of 2 and less than or equal to ZS_ALIGN | |
229 | */ | |
230 | struct link_free { | |
2e40e163 MK |
231 | union { |
232 | /* | |
bfd093f5 | 233 | * Free object index; |
2e40e163 MK |
234 | * It's valid for non-allocated object |
235 | */ | |
bfd093f5 | 236 | unsigned long next; |
2e40e163 MK |
237 | /* |
238 | * Handle of allocated object. | |
239 | */ | |
240 | unsigned long handle; | |
241 | }; | |
0959c63f SJ |
242 | }; |
243 | ||
244 | struct zs_pool { | |
6f3526d6 | 245 | const char *name; |
0f050d99 | 246 | |
40f9fb8c | 247 | struct size_class **size_class; |
2e40e163 | 248 | struct kmem_cache *handle_cachep; |
3783689a | 249 | struct kmem_cache *zspage_cachep; |
0959c63f | 250 | |
13de8933 | 251 | atomic_long_t pages_allocated; |
0f050d99 | 252 | |
7d3f3938 | 253 | struct zs_pool_stats stats; |
ab9d306d SS |
254 | |
255 | /* Compact classes */ | |
256 | struct shrinker shrinker; | |
257 | /* | |
258 | * To signify that register_shrinker() was successful | |
259 | * and unregister_shrinker() will not Oops. | |
260 | */ | |
261 | bool shrinker_enabled; | |
0f050d99 GM |
262 | #ifdef CONFIG_ZSMALLOC_STAT |
263 | struct dentry *stat_dentry; | |
264 | #endif | |
48b4800a MK |
265 | #ifdef CONFIG_COMPACTION |
266 | struct inode *inode; | |
267 | struct work_struct free_work; | |
268 | #endif | |
0959c63f | 269 | }; |
61989a80 NG |
270 | |
271 | /* | |
272 | * A zspage's class index and fullness group | |
273 | * are encoded in its (first)page->mapping | |
274 | */ | |
3783689a MK |
275 | #define FULLNESS_BITS 2 |
276 | #define CLASS_BITS 8 | |
48b4800a MK |
277 | #define ISOLATED_BITS 3 |
278 | #define MAGIC_VAL_BITS 8 | |
4f42047b | 279 | |
3783689a MK |
280 | struct zspage { |
281 | struct { | |
282 | unsigned int fullness:FULLNESS_BITS; | |
283 | unsigned int class:CLASS_BITS; | |
48b4800a MK |
284 | unsigned int isolated:ISOLATED_BITS; |
285 | unsigned int magic:MAGIC_VAL_BITS; | |
3783689a MK |
286 | }; |
287 | unsigned int inuse; | |
bfd093f5 | 288 | unsigned int freeobj; |
3783689a MK |
289 | struct page *first_page; |
290 | struct list_head list; /* fullness list */ | |
48b4800a MK |
291 | #ifdef CONFIG_COMPACTION |
292 | rwlock_t lock; | |
293 | #endif | |
3783689a | 294 | }; |
61989a80 | 295 | |
f553646a | 296 | struct mapping_area { |
1b945aee | 297 | #ifdef CONFIG_PGTABLE_MAPPING |
f553646a SJ |
298 | struct vm_struct *vm; /* vm area for mapping object that span pages */ |
299 | #else | |
300 | char *vm_buf; /* copy buffer for objects that span pages */ | |
301 | #endif | |
302 | char *vm_addr; /* address of kmap_atomic()'ed pages */ | |
303 | enum zs_mapmode vm_mm; /* mapping mode */ | |
304 | }; | |
305 | ||
48b4800a MK |
306 | #ifdef CONFIG_COMPACTION |
307 | static int zs_register_migration(struct zs_pool *pool); | |
308 | static void zs_unregister_migration(struct zs_pool *pool); | |
309 | static void migrate_lock_init(struct zspage *zspage); | |
310 | static void migrate_read_lock(struct zspage *zspage); | |
311 | static void migrate_read_unlock(struct zspage *zspage); | |
312 | static void kick_deferred_free(struct zs_pool *pool); | |
313 | static void init_deferred_free(struct zs_pool *pool); | |
314 | static void SetZsPageMovable(struct zs_pool *pool, struct zspage *zspage); | |
315 | #else | |
316 | static int zsmalloc_mount(void) { return 0; } | |
317 | static void zsmalloc_unmount(void) {} | |
318 | static int zs_register_migration(struct zs_pool *pool) { return 0; } | |
319 | static void zs_unregister_migration(struct zs_pool *pool) {} | |
320 | static void migrate_lock_init(struct zspage *zspage) {} | |
321 | static void migrate_read_lock(struct zspage *zspage) {} | |
322 | static void migrate_read_unlock(struct zspage *zspage) {} | |
323 | static void kick_deferred_free(struct zs_pool *pool) {} | |
324 | static void init_deferred_free(struct zs_pool *pool) {} | |
325 | static void SetZsPageMovable(struct zs_pool *pool, struct zspage *zspage) {} | |
326 | #endif | |
327 | ||
3783689a | 328 | static int create_cache(struct zs_pool *pool) |
2e40e163 MK |
329 | { |
330 | pool->handle_cachep = kmem_cache_create("zs_handle", ZS_HANDLE_SIZE, | |
331 | 0, 0, NULL); | |
3783689a MK |
332 | if (!pool->handle_cachep) |
333 | return 1; | |
334 | ||
335 | pool->zspage_cachep = kmem_cache_create("zspage", sizeof(struct zspage), | |
336 | 0, 0, NULL); | |
337 | if (!pool->zspage_cachep) { | |
338 | kmem_cache_destroy(pool->handle_cachep); | |
339 | pool->handle_cachep = NULL; | |
340 | return 1; | |
341 | } | |
342 | ||
343 | return 0; | |
2e40e163 MK |
344 | } |
345 | ||
3783689a | 346 | static void destroy_cache(struct zs_pool *pool) |
2e40e163 | 347 | { |
cd10add0 | 348 | kmem_cache_destroy(pool->handle_cachep); |
3783689a | 349 | kmem_cache_destroy(pool->zspage_cachep); |
2e40e163 MK |
350 | } |
351 | ||
3783689a | 352 | static unsigned long cache_alloc_handle(struct zs_pool *pool, gfp_t gfp) |
2e40e163 MK |
353 | { |
354 | return (unsigned long)kmem_cache_alloc(pool->handle_cachep, | |
48b4800a | 355 | gfp & ~(__GFP_HIGHMEM|__GFP_MOVABLE)); |
2e40e163 MK |
356 | } |
357 | ||
3783689a | 358 | static void cache_free_handle(struct zs_pool *pool, unsigned long handle) |
2e40e163 MK |
359 | { |
360 | kmem_cache_free(pool->handle_cachep, (void *)handle); | |
361 | } | |
362 | ||
3783689a MK |
363 | static struct zspage *cache_alloc_zspage(struct zs_pool *pool, gfp_t flags) |
364 | { | |
48b4800a MK |
365 | return kmem_cache_alloc(pool->zspage_cachep, |
366 | flags & ~(__GFP_HIGHMEM|__GFP_MOVABLE)); | |
3783689a MK |
367 | }; |
368 | ||
369 | static void cache_free_zspage(struct zs_pool *pool, struct zspage *zspage) | |
370 | { | |
371 | kmem_cache_free(pool->zspage_cachep, zspage); | |
372 | } | |
373 | ||
2e40e163 MK |
374 | static void record_obj(unsigned long handle, unsigned long obj) |
375 | { | |
c102f07c JL |
376 | /* |
377 | * lsb of @obj represents handle lock while other bits | |
378 | * represent object value the handle is pointing so | |
379 | * updating shouldn't do store tearing. | |
380 | */ | |
381 | WRITE_ONCE(*(unsigned long *)handle, obj); | |
2e40e163 MK |
382 | } |
383 | ||
c795779d DS |
384 | /* zpool driver */ |
385 | ||
386 | #ifdef CONFIG_ZPOOL | |
387 | ||
6f3526d6 | 388 | static void *zs_zpool_create(const char *name, gfp_t gfp, |
78672779 | 389 | const struct zpool_ops *zpool_ops, |
479305fd | 390 | struct zpool *zpool) |
c795779d | 391 | { |
d0d8da2d SS |
392 | /* |
393 | * Ignore global gfp flags: zs_malloc() may be invoked from | |
394 | * different contexts and its caller must provide a valid | |
395 | * gfp mask. | |
396 | */ | |
397 | return zs_create_pool(name); | |
c795779d DS |
398 | } |
399 | ||
400 | static void zs_zpool_destroy(void *pool) | |
401 | { | |
402 | zs_destroy_pool(pool); | |
403 | } | |
404 | ||
405 | static int zs_zpool_malloc(void *pool, size_t size, gfp_t gfp, | |
406 | unsigned long *handle) | |
407 | { | |
d0d8da2d | 408 | *handle = zs_malloc(pool, size, gfp); |
c795779d DS |
409 | return *handle ? 0 : -1; |
410 | } | |
411 | static void zs_zpool_free(void *pool, unsigned long handle) | |
412 | { | |
413 | zs_free(pool, handle); | |
414 | } | |
415 | ||
416 | static int zs_zpool_shrink(void *pool, unsigned int pages, | |
417 | unsigned int *reclaimed) | |
418 | { | |
419 | return -EINVAL; | |
420 | } | |
421 | ||
422 | static void *zs_zpool_map(void *pool, unsigned long handle, | |
423 | enum zpool_mapmode mm) | |
424 | { | |
425 | enum zs_mapmode zs_mm; | |
426 | ||
427 | switch (mm) { | |
428 | case ZPOOL_MM_RO: | |
429 | zs_mm = ZS_MM_RO; | |
430 | break; | |
431 | case ZPOOL_MM_WO: | |
432 | zs_mm = ZS_MM_WO; | |
433 | break; | |
434 | case ZPOOL_MM_RW: /* fallthru */ | |
435 | default: | |
436 | zs_mm = ZS_MM_RW; | |
437 | break; | |
438 | } | |
439 | ||
440 | return zs_map_object(pool, handle, zs_mm); | |
441 | } | |
442 | static void zs_zpool_unmap(void *pool, unsigned long handle) | |
443 | { | |
444 | zs_unmap_object(pool, handle); | |
445 | } | |
446 | ||
447 | static u64 zs_zpool_total_size(void *pool) | |
448 | { | |
722cdc17 | 449 | return zs_get_total_pages(pool) << PAGE_SHIFT; |
c795779d DS |
450 | } |
451 | ||
452 | static struct zpool_driver zs_zpool_driver = { | |
453 | .type = "zsmalloc", | |
454 | .owner = THIS_MODULE, | |
455 | .create = zs_zpool_create, | |
456 | .destroy = zs_zpool_destroy, | |
457 | .malloc = zs_zpool_malloc, | |
458 | .free = zs_zpool_free, | |
459 | .shrink = zs_zpool_shrink, | |
460 | .map = zs_zpool_map, | |
461 | .unmap = zs_zpool_unmap, | |
462 | .total_size = zs_zpool_total_size, | |
463 | }; | |
464 | ||
137f8cff | 465 | MODULE_ALIAS("zpool-zsmalloc"); |
c795779d DS |
466 | #endif /* CONFIG_ZPOOL */ |
467 | ||
61989a80 NG |
468 | /* per-cpu VM mapping areas for zspage accesses that cross page boundaries */ |
469 | static DEFINE_PER_CPU(struct mapping_area, zs_map_area); | |
470 | ||
48b4800a MK |
471 | static bool is_zspage_isolated(struct zspage *zspage) |
472 | { | |
473 | return zspage->isolated; | |
474 | } | |
475 | ||
61989a80 NG |
476 | static int is_first_page(struct page *page) |
477 | { | |
a27545bf | 478 | return PagePrivate(page); |
61989a80 NG |
479 | } |
480 | ||
48b4800a | 481 | /* Protected by class->lock */ |
3783689a | 482 | static inline int get_zspage_inuse(struct zspage *zspage) |
4f42047b | 483 | { |
3783689a | 484 | return zspage->inuse; |
4f42047b MK |
485 | } |
486 | ||
3783689a | 487 | static inline void set_zspage_inuse(struct zspage *zspage, int val) |
4f42047b | 488 | { |
3783689a | 489 | zspage->inuse = val; |
4f42047b MK |
490 | } |
491 | ||
3783689a | 492 | static inline void mod_zspage_inuse(struct zspage *zspage, int val) |
4f42047b | 493 | { |
3783689a | 494 | zspage->inuse += val; |
4f42047b MK |
495 | } |
496 | ||
48b4800a | 497 | static inline struct page *get_first_page(struct zspage *zspage) |
4f42047b | 498 | { |
48b4800a | 499 | struct page *first_page = zspage->first_page; |
3783689a | 500 | |
48b4800a MK |
501 | VM_BUG_ON_PAGE(!is_first_page(first_page), first_page); |
502 | return first_page; | |
4f42047b MK |
503 | } |
504 | ||
48b4800a | 505 | static inline int get_first_obj_offset(struct page *page) |
4f42047b | 506 | { |
48b4800a MK |
507 | return page->units; |
508 | } | |
3783689a | 509 | |
48b4800a MK |
510 | static inline void set_first_obj_offset(struct page *page, int offset) |
511 | { | |
512 | page->units = offset; | |
4f42047b MK |
513 | } |
514 | ||
bfd093f5 | 515 | static inline unsigned int get_freeobj(struct zspage *zspage) |
4f42047b | 516 | { |
bfd093f5 | 517 | return zspage->freeobj; |
4f42047b MK |
518 | } |
519 | ||
bfd093f5 | 520 | static inline void set_freeobj(struct zspage *zspage, unsigned int obj) |
4f42047b | 521 | { |
bfd093f5 | 522 | zspage->freeobj = obj; |
4f42047b MK |
523 | } |
524 | ||
3783689a | 525 | static void get_zspage_mapping(struct zspage *zspage, |
a4209467 | 526 | unsigned int *class_idx, |
61989a80 NG |
527 | enum fullness_group *fullness) |
528 | { | |
48b4800a MK |
529 | BUG_ON(zspage->magic != ZSPAGE_MAGIC); |
530 | ||
3783689a MK |
531 | *fullness = zspage->fullness; |
532 | *class_idx = zspage->class; | |
61989a80 NG |
533 | } |
534 | ||
3783689a | 535 | static void set_zspage_mapping(struct zspage *zspage, |
a4209467 | 536 | unsigned int class_idx, |
61989a80 NG |
537 | enum fullness_group fullness) |
538 | { | |
3783689a MK |
539 | zspage->class = class_idx; |
540 | zspage->fullness = fullness; | |
61989a80 NG |
541 | } |
542 | ||
c3e3e88a NC |
543 | /* |
544 | * zsmalloc divides the pool into various size classes where each | |
545 | * class maintains a list of zspages where each zspage is divided | |
546 | * into equal sized chunks. Each allocation falls into one of these | |
547 | * classes depending on its size. This function returns index of the | |
548 | * size class which has chunk size big enough to hold the give size. | |
549 | */ | |
61989a80 NG |
550 | static int get_size_class_index(int size) |
551 | { | |
552 | int idx = 0; | |
553 | ||
554 | if (likely(size > ZS_MIN_ALLOC_SIZE)) | |
555 | idx = DIV_ROUND_UP(size - ZS_MIN_ALLOC_SIZE, | |
556 | ZS_SIZE_CLASS_DELTA); | |
557 | ||
7b60a685 | 558 | return min(zs_size_classes - 1, idx); |
61989a80 NG |
559 | } |
560 | ||
248ca1b0 MK |
561 | static inline void zs_stat_inc(struct size_class *class, |
562 | enum zs_stat_type type, unsigned long cnt) | |
563 | { | |
48b4800a | 564 | class->stats.objs[type] += cnt; |
248ca1b0 MK |
565 | } |
566 | ||
567 | static inline void zs_stat_dec(struct size_class *class, | |
568 | enum zs_stat_type type, unsigned long cnt) | |
569 | { | |
48b4800a | 570 | class->stats.objs[type] -= cnt; |
248ca1b0 MK |
571 | } |
572 | ||
573 | static inline unsigned long zs_stat_get(struct size_class *class, | |
574 | enum zs_stat_type type) | |
575 | { | |
48b4800a | 576 | return class->stats.objs[type]; |
248ca1b0 MK |
577 | } |
578 | ||
57244594 SS |
579 | #ifdef CONFIG_ZSMALLOC_STAT |
580 | ||
4abaac9b | 581 | static void __init zs_stat_init(void) |
248ca1b0 | 582 | { |
4abaac9b DS |
583 | if (!debugfs_initialized()) { |
584 | pr_warn("debugfs not available, stat dir not created\n"); | |
585 | return; | |
586 | } | |
248ca1b0 MK |
587 | |
588 | zs_stat_root = debugfs_create_dir("zsmalloc", NULL); | |
589 | if (!zs_stat_root) | |
4abaac9b | 590 | pr_warn("debugfs 'zsmalloc' stat dir creation failed\n"); |
248ca1b0 MK |
591 | } |
592 | ||
593 | static void __exit zs_stat_exit(void) | |
594 | { | |
595 | debugfs_remove_recursive(zs_stat_root); | |
596 | } | |
597 | ||
1120ed54 SS |
598 | static unsigned long zs_can_compact(struct size_class *class); |
599 | ||
248ca1b0 MK |
600 | static int zs_stats_size_show(struct seq_file *s, void *v) |
601 | { | |
602 | int i; | |
603 | struct zs_pool *pool = s->private; | |
604 | struct size_class *class; | |
605 | int objs_per_zspage; | |
606 | unsigned long class_almost_full, class_almost_empty; | |
1120ed54 | 607 | unsigned long obj_allocated, obj_used, pages_used, freeable; |
248ca1b0 MK |
608 | unsigned long total_class_almost_full = 0, total_class_almost_empty = 0; |
609 | unsigned long total_objs = 0, total_used_objs = 0, total_pages = 0; | |
1120ed54 | 610 | unsigned long total_freeable = 0; |
248ca1b0 | 611 | |
1120ed54 | 612 | seq_printf(s, " %5s %5s %11s %12s %13s %10s %10s %16s %8s\n", |
248ca1b0 MK |
613 | "class", "size", "almost_full", "almost_empty", |
614 | "obj_allocated", "obj_used", "pages_used", | |
1120ed54 | 615 | "pages_per_zspage", "freeable"); |
248ca1b0 MK |
616 | |
617 | for (i = 0; i < zs_size_classes; i++) { | |
618 | class = pool->size_class[i]; | |
619 | ||
620 | if (class->index != i) | |
621 | continue; | |
622 | ||
623 | spin_lock(&class->lock); | |
624 | class_almost_full = zs_stat_get(class, CLASS_ALMOST_FULL); | |
625 | class_almost_empty = zs_stat_get(class, CLASS_ALMOST_EMPTY); | |
626 | obj_allocated = zs_stat_get(class, OBJ_ALLOCATED); | |
627 | obj_used = zs_stat_get(class, OBJ_USED); | |
1120ed54 | 628 | freeable = zs_can_compact(class); |
248ca1b0 MK |
629 | spin_unlock(&class->lock); |
630 | ||
b4fd07a0 | 631 | objs_per_zspage = class->objs_per_zspage; |
248ca1b0 MK |
632 | pages_used = obj_allocated / objs_per_zspage * |
633 | class->pages_per_zspage; | |
634 | ||
1120ed54 SS |
635 | seq_printf(s, " %5u %5u %11lu %12lu %13lu" |
636 | " %10lu %10lu %16d %8lu\n", | |
248ca1b0 MK |
637 | i, class->size, class_almost_full, class_almost_empty, |
638 | obj_allocated, obj_used, pages_used, | |
1120ed54 | 639 | class->pages_per_zspage, freeable); |
248ca1b0 MK |
640 | |
641 | total_class_almost_full += class_almost_full; | |
642 | total_class_almost_empty += class_almost_empty; | |
643 | total_objs += obj_allocated; | |
644 | total_used_objs += obj_used; | |
645 | total_pages += pages_used; | |
1120ed54 | 646 | total_freeable += freeable; |
248ca1b0 MK |
647 | } |
648 | ||
649 | seq_puts(s, "\n"); | |
1120ed54 | 650 | seq_printf(s, " %5s %5s %11lu %12lu %13lu %10lu %10lu %16s %8lu\n", |
248ca1b0 MK |
651 | "Total", "", total_class_almost_full, |
652 | total_class_almost_empty, total_objs, | |
1120ed54 | 653 | total_used_objs, total_pages, "", total_freeable); |
248ca1b0 MK |
654 | |
655 | return 0; | |
656 | } | |
657 | ||
658 | static int zs_stats_size_open(struct inode *inode, struct file *file) | |
659 | { | |
660 | return single_open(file, zs_stats_size_show, inode->i_private); | |
661 | } | |
662 | ||
663 | static const struct file_operations zs_stat_size_ops = { | |
664 | .open = zs_stats_size_open, | |
665 | .read = seq_read, | |
666 | .llseek = seq_lseek, | |
667 | .release = single_release, | |
668 | }; | |
669 | ||
d34f6157 | 670 | static void zs_pool_stat_create(struct zs_pool *pool, const char *name) |
248ca1b0 MK |
671 | { |
672 | struct dentry *entry; | |
673 | ||
4abaac9b DS |
674 | if (!zs_stat_root) { |
675 | pr_warn("no root stat dir, not creating <%s> stat dir\n", name); | |
d34f6157 | 676 | return; |
4abaac9b | 677 | } |
248ca1b0 MK |
678 | |
679 | entry = debugfs_create_dir(name, zs_stat_root); | |
680 | if (!entry) { | |
681 | pr_warn("debugfs dir <%s> creation failed\n", name); | |
d34f6157 | 682 | return; |
248ca1b0 MK |
683 | } |
684 | pool->stat_dentry = entry; | |
685 | ||
686 | entry = debugfs_create_file("classes", S_IFREG | S_IRUGO, | |
687 | pool->stat_dentry, pool, &zs_stat_size_ops); | |
688 | if (!entry) { | |
689 | pr_warn("%s: debugfs file entry <%s> creation failed\n", | |
690 | name, "classes"); | |
4abaac9b DS |
691 | debugfs_remove_recursive(pool->stat_dentry); |
692 | pool->stat_dentry = NULL; | |
248ca1b0 | 693 | } |
248ca1b0 MK |
694 | } |
695 | ||
696 | static void zs_pool_stat_destroy(struct zs_pool *pool) | |
697 | { | |
698 | debugfs_remove_recursive(pool->stat_dentry); | |
699 | } | |
700 | ||
701 | #else /* CONFIG_ZSMALLOC_STAT */ | |
4abaac9b | 702 | static void __init zs_stat_init(void) |
248ca1b0 | 703 | { |
248ca1b0 MK |
704 | } |
705 | ||
706 | static void __exit zs_stat_exit(void) | |
707 | { | |
708 | } | |
709 | ||
d34f6157 | 710 | static inline void zs_pool_stat_create(struct zs_pool *pool, const char *name) |
248ca1b0 | 711 | { |
248ca1b0 MK |
712 | } |
713 | ||
714 | static inline void zs_pool_stat_destroy(struct zs_pool *pool) | |
715 | { | |
716 | } | |
248ca1b0 MK |
717 | #endif |
718 | ||
48b4800a | 719 | |
c3e3e88a NC |
720 | /* |
721 | * For each size class, zspages are divided into different groups | |
722 | * depending on how "full" they are. This was done so that we could | |
723 | * easily find empty or nearly empty zspages when we try to shrink | |
724 | * the pool (not yet implemented). This function returns fullness | |
725 | * status of the given page. | |
726 | */ | |
1fc6e27d | 727 | static enum fullness_group get_fullness_group(struct size_class *class, |
3783689a | 728 | struct zspage *zspage) |
61989a80 | 729 | { |
1fc6e27d | 730 | int inuse, objs_per_zspage; |
61989a80 | 731 | enum fullness_group fg; |
830e4bc5 | 732 | |
3783689a | 733 | inuse = get_zspage_inuse(zspage); |
1fc6e27d | 734 | objs_per_zspage = class->objs_per_zspage; |
61989a80 NG |
735 | |
736 | if (inuse == 0) | |
737 | fg = ZS_EMPTY; | |
1fc6e27d | 738 | else if (inuse == objs_per_zspage) |
61989a80 | 739 | fg = ZS_FULL; |
1fc6e27d | 740 | else if (inuse <= 3 * objs_per_zspage / fullness_threshold_frac) |
61989a80 NG |
741 | fg = ZS_ALMOST_EMPTY; |
742 | else | |
743 | fg = ZS_ALMOST_FULL; | |
744 | ||
745 | return fg; | |
746 | } | |
747 | ||
c3e3e88a NC |
748 | /* |
749 | * Each size class maintains various freelists and zspages are assigned | |
750 | * to one of these freelists based on the number of live objects they | |
751 | * have. This functions inserts the given zspage into the freelist | |
752 | * identified by <class, fullness_group>. | |
753 | */ | |
251cbb95 | 754 | static void insert_zspage(struct size_class *class, |
3783689a MK |
755 | struct zspage *zspage, |
756 | enum fullness_group fullness) | |
61989a80 | 757 | { |
3783689a | 758 | struct zspage *head; |
61989a80 | 759 | |
48b4800a | 760 | zs_stat_inc(class, fullness, 1); |
3783689a MK |
761 | head = list_first_entry_or_null(&class->fullness_list[fullness], |
762 | struct zspage, list); | |
58f17117 | 763 | /* |
3783689a MK |
764 | * We want to see more ZS_FULL pages and less almost empty/full. |
765 | * Put pages with higher ->inuse first. | |
58f17117 | 766 | */ |
3783689a MK |
767 | if (head) { |
768 | if (get_zspage_inuse(zspage) < get_zspage_inuse(head)) { | |
769 | list_add(&zspage->list, &head->list); | |
770 | return; | |
771 | } | |
772 | } | |
773 | list_add(&zspage->list, &class->fullness_list[fullness]); | |
61989a80 NG |
774 | } |
775 | ||
c3e3e88a NC |
776 | /* |
777 | * This function removes the given zspage from the freelist identified | |
778 | * by <class, fullness_group>. | |
779 | */ | |
251cbb95 | 780 | static void remove_zspage(struct size_class *class, |
3783689a MK |
781 | struct zspage *zspage, |
782 | enum fullness_group fullness) | |
61989a80 | 783 | { |
3783689a | 784 | VM_BUG_ON(list_empty(&class->fullness_list[fullness])); |
48b4800a | 785 | VM_BUG_ON(is_zspage_isolated(zspage)); |
61989a80 | 786 | |
3783689a | 787 | list_del_init(&zspage->list); |
48b4800a | 788 | zs_stat_dec(class, fullness, 1); |
61989a80 NG |
789 | } |
790 | ||
c3e3e88a NC |
791 | /* |
792 | * Each size class maintains zspages in different fullness groups depending | |
793 | * on the number of live objects they contain. When allocating or freeing | |
794 | * objects, the fullness status of the page can change, say, from ALMOST_FULL | |
795 | * to ALMOST_EMPTY when freeing an object. This function checks if such | |
796 | * a status change has occurred for the given page and accordingly moves the | |
797 | * page from the freelist of the old fullness group to that of the new | |
798 | * fullness group. | |
799 | */ | |
c7806261 | 800 | static enum fullness_group fix_fullness_group(struct size_class *class, |
3783689a | 801 | struct zspage *zspage) |
61989a80 NG |
802 | { |
803 | int class_idx; | |
61989a80 NG |
804 | enum fullness_group currfg, newfg; |
805 | ||
3783689a MK |
806 | get_zspage_mapping(zspage, &class_idx, &currfg); |
807 | newfg = get_fullness_group(class, zspage); | |
61989a80 NG |
808 | if (newfg == currfg) |
809 | goto out; | |
810 | ||
48b4800a MK |
811 | if (!is_zspage_isolated(zspage)) { |
812 | remove_zspage(class, zspage, currfg); | |
813 | insert_zspage(class, zspage, newfg); | |
814 | } | |
815 | ||
3783689a | 816 | set_zspage_mapping(zspage, class_idx, newfg); |
61989a80 NG |
817 | |
818 | out: | |
819 | return newfg; | |
820 | } | |
821 | ||
822 | /* | |
823 | * We have to decide on how many pages to link together | |
824 | * to form a zspage for each size class. This is important | |
825 | * to reduce wastage due to unusable space left at end of | |
826 | * each zspage which is given as: | |
888fa374 YX |
827 | * wastage = Zp % class_size |
828 | * usage = Zp - wastage | |
61989a80 NG |
829 | * where Zp = zspage size = k * PAGE_SIZE where k = 1, 2, ... |
830 | * | |
831 | * For example, for size class of 3/8 * PAGE_SIZE, we should | |
832 | * link together 3 PAGE_SIZE sized pages to form a zspage | |
833 | * since then we can perfectly fit in 8 such objects. | |
834 | */ | |
2e3b6154 | 835 | static int get_pages_per_zspage(int class_size) |
61989a80 NG |
836 | { |
837 | int i, max_usedpc = 0; | |
838 | /* zspage order which gives maximum used size per KB */ | |
839 | int max_usedpc_order = 1; | |
840 | ||
84d4faab | 841 | for (i = 1; i <= ZS_MAX_PAGES_PER_ZSPAGE; i++) { |
61989a80 NG |
842 | int zspage_size; |
843 | int waste, usedpc; | |
844 | ||
845 | zspage_size = i * PAGE_SIZE; | |
846 | waste = zspage_size % class_size; | |
847 | usedpc = (zspage_size - waste) * 100 / zspage_size; | |
848 | ||
849 | if (usedpc > max_usedpc) { | |
850 | max_usedpc = usedpc; | |
851 | max_usedpc_order = i; | |
852 | } | |
853 | } | |
854 | ||
855 | return max_usedpc_order; | |
856 | } | |
857 | ||
3783689a | 858 | static struct zspage *get_zspage(struct page *page) |
61989a80 | 859 | { |
48b4800a MK |
860 | struct zspage *zspage = (struct zspage *)page->private; |
861 | ||
862 | BUG_ON(zspage->magic != ZSPAGE_MAGIC); | |
863 | return zspage; | |
61989a80 NG |
864 | } |
865 | ||
866 | static struct page *get_next_page(struct page *page) | |
867 | { | |
48b4800a MK |
868 | if (unlikely(PageHugeObject(page))) |
869 | return NULL; | |
870 | ||
871 | return page->freelist; | |
61989a80 NG |
872 | } |
873 | ||
bfd093f5 MK |
874 | /** |
875 | * obj_to_location - get (<page>, <obj_idx>) from encoded object value | |
876 | * @page: page object resides in zspage | |
877 | * @obj_idx: object index | |
67296874 | 878 | */ |
bfd093f5 MK |
879 | static void obj_to_location(unsigned long obj, struct page **page, |
880 | unsigned int *obj_idx) | |
61989a80 | 881 | { |
bfd093f5 MK |
882 | obj >>= OBJ_TAG_BITS; |
883 | *page = pfn_to_page(obj >> OBJ_INDEX_BITS); | |
884 | *obj_idx = (obj & OBJ_INDEX_MASK); | |
885 | } | |
61989a80 | 886 | |
bfd093f5 MK |
887 | /** |
888 | * location_to_obj - get obj value encoded from (<page>, <obj_idx>) | |
889 | * @page: page object resides in zspage | |
890 | * @obj_idx: object index | |
891 | */ | |
892 | static unsigned long location_to_obj(struct page *page, unsigned int obj_idx) | |
893 | { | |
894 | unsigned long obj; | |
61989a80 | 895 | |
312fcae2 | 896 | obj = page_to_pfn(page) << OBJ_INDEX_BITS; |
bfd093f5 | 897 | obj |= obj_idx & OBJ_INDEX_MASK; |
312fcae2 | 898 | obj <<= OBJ_TAG_BITS; |
61989a80 | 899 | |
bfd093f5 | 900 | return obj; |
61989a80 NG |
901 | } |
902 | ||
2e40e163 MK |
903 | static unsigned long handle_to_obj(unsigned long handle) |
904 | { | |
905 | return *(unsigned long *)handle; | |
906 | } | |
907 | ||
48b4800a | 908 | static unsigned long obj_to_head(struct page *page, void *obj) |
312fcae2 | 909 | { |
48b4800a | 910 | if (unlikely(PageHugeObject(page))) { |
830e4bc5 | 911 | VM_BUG_ON_PAGE(!is_first_page(page), page); |
3783689a | 912 | return page->index; |
7b60a685 MK |
913 | } else |
914 | return *(unsigned long *)obj; | |
312fcae2 MK |
915 | } |
916 | ||
48b4800a MK |
917 | static inline int testpin_tag(unsigned long handle) |
918 | { | |
919 | return bit_spin_is_locked(HANDLE_PIN_BIT, (unsigned long *)handle); | |
920 | } | |
921 | ||
312fcae2 MK |
922 | static inline int trypin_tag(unsigned long handle) |
923 | { | |
1b8320b6 | 924 | return bit_spin_trylock(HANDLE_PIN_BIT, (unsigned long *)handle); |
312fcae2 MK |
925 | } |
926 | ||
927 | static void pin_tag(unsigned long handle) | |
928 | { | |
1b8320b6 | 929 | bit_spin_lock(HANDLE_PIN_BIT, (unsigned long *)handle); |
312fcae2 MK |
930 | } |
931 | ||
932 | static void unpin_tag(unsigned long handle) | |
933 | { | |
1b8320b6 | 934 | bit_spin_unlock(HANDLE_PIN_BIT, (unsigned long *)handle); |
312fcae2 MK |
935 | } |
936 | ||
f4477e90 NG |
937 | static void reset_page(struct page *page) |
938 | { | |
48b4800a | 939 | __ClearPageMovable(page); |
18fd06bf GM |
940 | ClearPagePrivate(page); |
941 | ClearPagePrivate2(page); | |
f4477e90 | 942 | set_page_private(page, 0); |
48b4800a MK |
943 | page_mapcount_reset(page); |
944 | ClearPageHugeObject(page); | |
945 | page->freelist = NULL; | |
946 | } | |
947 | ||
948 | /* | |
949 | * To prevent zspage destroy during migration, zspage freeing should | |
950 | * hold locks of all pages in the zspage. | |
951 | */ | |
952 | void lock_zspage(struct zspage *zspage) | |
953 | { | |
954 | struct page *page = get_first_page(zspage); | |
955 | ||
956 | do { | |
957 | lock_page(page); | |
958 | } while ((page = get_next_page(page)) != NULL); | |
959 | } | |
960 | ||
961 | int trylock_zspage(struct zspage *zspage) | |
962 | { | |
963 | struct page *cursor, *fail; | |
964 | ||
965 | for (cursor = get_first_page(zspage); cursor != NULL; cursor = | |
966 | get_next_page(cursor)) { | |
967 | if (!trylock_page(cursor)) { | |
968 | fail = cursor; | |
969 | goto unlock; | |
970 | } | |
971 | } | |
972 | ||
973 | return 1; | |
974 | unlock: | |
975 | for (cursor = get_first_page(zspage); cursor != fail; cursor = | |
976 | get_next_page(cursor)) | |
977 | unlock_page(cursor); | |
978 | ||
979 | return 0; | |
f4477e90 NG |
980 | } |
981 | ||
48b4800a MK |
982 | static void __free_zspage(struct zs_pool *pool, struct size_class *class, |
983 | struct zspage *zspage) | |
61989a80 | 984 | { |
3783689a | 985 | struct page *page, *next; |
48b4800a MK |
986 | enum fullness_group fg; |
987 | unsigned int class_idx; | |
988 | ||
989 | get_zspage_mapping(zspage, &class_idx, &fg); | |
990 | ||
991 | assert_spin_locked(&class->lock); | |
61989a80 | 992 | |
3783689a | 993 | VM_BUG_ON(get_zspage_inuse(zspage)); |
48b4800a | 994 | VM_BUG_ON(fg != ZS_EMPTY); |
61989a80 | 995 | |
48b4800a | 996 | next = page = get_first_page(zspage); |
3783689a | 997 | do { |
48b4800a MK |
998 | VM_BUG_ON_PAGE(!PageLocked(page), page); |
999 | next = get_next_page(page); | |
3783689a | 1000 | reset_page(page); |
48b4800a | 1001 | unlock_page(page); |
91537fee | 1002 | dec_zone_page_state(page, NR_ZSPAGES); |
3783689a MK |
1003 | put_page(page); |
1004 | page = next; | |
1005 | } while (page != NULL); | |
61989a80 | 1006 | |
3783689a | 1007 | cache_free_zspage(pool, zspage); |
48b4800a | 1008 | |
b4fd07a0 | 1009 | zs_stat_dec(class, OBJ_ALLOCATED, class->objs_per_zspage); |
48b4800a MK |
1010 | atomic_long_sub(class->pages_per_zspage, |
1011 | &pool->pages_allocated); | |
1012 | } | |
1013 | ||
1014 | static void free_zspage(struct zs_pool *pool, struct size_class *class, | |
1015 | struct zspage *zspage) | |
1016 | { | |
1017 | VM_BUG_ON(get_zspage_inuse(zspage)); | |
1018 | VM_BUG_ON(list_empty(&zspage->list)); | |
1019 | ||
1020 | if (!trylock_zspage(zspage)) { | |
1021 | kick_deferred_free(pool); | |
1022 | return; | |
1023 | } | |
1024 | ||
1025 | remove_zspage(class, zspage, ZS_EMPTY); | |
1026 | __free_zspage(pool, class, zspage); | |
61989a80 NG |
1027 | } |
1028 | ||
1029 | /* Initialize a newly allocated zspage */ | |
3783689a | 1030 | static void init_zspage(struct size_class *class, struct zspage *zspage) |
61989a80 | 1031 | { |
bfd093f5 | 1032 | unsigned int freeobj = 1; |
61989a80 | 1033 | unsigned long off = 0; |
48b4800a | 1034 | struct page *page = get_first_page(zspage); |
830e4bc5 | 1035 | |
61989a80 NG |
1036 | while (page) { |
1037 | struct page *next_page; | |
1038 | struct link_free *link; | |
af4ee5e9 | 1039 | void *vaddr; |
61989a80 | 1040 | |
3783689a | 1041 | set_first_obj_offset(page, off); |
61989a80 | 1042 | |
af4ee5e9 MK |
1043 | vaddr = kmap_atomic(page); |
1044 | link = (struct link_free *)vaddr + off / sizeof(*link); | |
5538c562 DS |
1045 | |
1046 | while ((off += class->size) < PAGE_SIZE) { | |
3b1d9ca6 | 1047 | link->next = freeobj++ << OBJ_TAG_BITS; |
5538c562 | 1048 | link += class->size / sizeof(*link); |
61989a80 NG |
1049 | } |
1050 | ||
1051 | /* | |
1052 | * We now come to the last (full or partial) object on this | |
1053 | * page, which must point to the first object on the next | |
1054 | * page (if present) | |
1055 | */ | |
1056 | next_page = get_next_page(page); | |
bfd093f5 | 1057 | if (next_page) { |
3b1d9ca6 | 1058 | link->next = freeobj++ << OBJ_TAG_BITS; |
bfd093f5 MK |
1059 | } else { |
1060 | /* | |
3b1d9ca6 | 1061 | * Reset OBJ_TAG_BITS bit to last link to tell |
bfd093f5 MK |
1062 | * whether it's allocated object or not. |
1063 | */ | |
3b1d9ca6 | 1064 | link->next = -1 << OBJ_TAG_BITS; |
bfd093f5 | 1065 | } |
af4ee5e9 | 1066 | kunmap_atomic(vaddr); |
61989a80 | 1067 | page = next_page; |
5538c562 | 1068 | off %= PAGE_SIZE; |
61989a80 | 1069 | } |
bdb0af7c | 1070 | |
bfd093f5 | 1071 | set_freeobj(zspage, 0); |
61989a80 NG |
1072 | } |
1073 | ||
48b4800a MK |
1074 | static void create_page_chain(struct size_class *class, struct zspage *zspage, |
1075 | struct page *pages[]) | |
61989a80 | 1076 | { |
bdb0af7c MK |
1077 | int i; |
1078 | struct page *page; | |
1079 | struct page *prev_page = NULL; | |
48b4800a | 1080 | int nr_pages = class->pages_per_zspage; |
61989a80 NG |
1081 | |
1082 | /* | |
1083 | * Allocate individual pages and link them together as: | |
48b4800a | 1084 | * 1. all pages are linked together using page->freelist |
3783689a | 1085 | * 2. each sub-page point to zspage using page->private |
61989a80 | 1086 | * |
3783689a MK |
1087 | * we set PG_private to identify the first page (i.e. no other sub-page |
1088 | * has this flag set) and PG_private_2 to identify the last page. | |
61989a80 | 1089 | */ |
bdb0af7c MK |
1090 | for (i = 0; i < nr_pages; i++) { |
1091 | page = pages[i]; | |
3783689a | 1092 | set_page_private(page, (unsigned long)zspage); |
48b4800a | 1093 | page->freelist = NULL; |
bdb0af7c | 1094 | if (i == 0) { |
3783689a | 1095 | zspage->first_page = page; |
a27545bf | 1096 | SetPagePrivate(page); |
48b4800a MK |
1097 | if (unlikely(class->objs_per_zspage == 1 && |
1098 | class->pages_per_zspage == 1)) | |
1099 | SetPageHugeObject(page); | |
3783689a | 1100 | } else { |
48b4800a | 1101 | prev_page->freelist = page; |
61989a80 | 1102 | } |
48b4800a | 1103 | if (i == nr_pages - 1) |
a27545bf | 1104 | SetPagePrivate2(page); |
61989a80 NG |
1105 | prev_page = page; |
1106 | } | |
bdb0af7c | 1107 | } |
61989a80 | 1108 | |
bdb0af7c MK |
1109 | /* |
1110 | * Allocate a zspage for the given size class | |
1111 | */ | |
3783689a MK |
1112 | static struct zspage *alloc_zspage(struct zs_pool *pool, |
1113 | struct size_class *class, | |
1114 | gfp_t gfp) | |
bdb0af7c MK |
1115 | { |
1116 | int i; | |
bdb0af7c | 1117 | struct page *pages[ZS_MAX_PAGES_PER_ZSPAGE]; |
3783689a MK |
1118 | struct zspage *zspage = cache_alloc_zspage(pool, gfp); |
1119 | ||
1120 | if (!zspage) | |
1121 | return NULL; | |
1122 | ||
1123 | memset(zspage, 0, sizeof(struct zspage)); | |
48b4800a MK |
1124 | zspage->magic = ZSPAGE_MAGIC; |
1125 | migrate_lock_init(zspage); | |
61989a80 | 1126 | |
bdb0af7c MK |
1127 | for (i = 0; i < class->pages_per_zspage; i++) { |
1128 | struct page *page; | |
61989a80 | 1129 | |
3783689a | 1130 | page = alloc_page(gfp); |
bdb0af7c | 1131 | if (!page) { |
91537fee MK |
1132 | while (--i >= 0) { |
1133 | dec_zone_page_state(pages[i], NR_ZSPAGES); | |
bdb0af7c | 1134 | __free_page(pages[i]); |
91537fee | 1135 | } |
3783689a | 1136 | cache_free_zspage(pool, zspage); |
bdb0af7c MK |
1137 | return NULL; |
1138 | } | |
91537fee MK |
1139 | |
1140 | inc_zone_page_state(page, NR_ZSPAGES); | |
bdb0af7c | 1141 | pages[i] = page; |
61989a80 NG |
1142 | } |
1143 | ||
48b4800a | 1144 | create_page_chain(class, zspage, pages); |
3783689a | 1145 | init_zspage(class, zspage); |
bdb0af7c | 1146 | |
3783689a | 1147 | return zspage; |
61989a80 NG |
1148 | } |
1149 | ||
3783689a | 1150 | static struct zspage *find_get_zspage(struct size_class *class) |
61989a80 NG |
1151 | { |
1152 | int i; | |
3783689a | 1153 | struct zspage *zspage; |
61989a80 | 1154 | |
48b4800a | 1155 | for (i = ZS_ALMOST_FULL; i >= ZS_EMPTY; i--) { |
3783689a MK |
1156 | zspage = list_first_entry_or_null(&class->fullness_list[i], |
1157 | struct zspage, list); | |
1158 | if (zspage) | |
61989a80 NG |
1159 | break; |
1160 | } | |
1161 | ||
3783689a | 1162 | return zspage; |
61989a80 NG |
1163 | } |
1164 | ||
1b945aee | 1165 | #ifdef CONFIG_PGTABLE_MAPPING |
f553646a SJ |
1166 | static inline int __zs_cpu_up(struct mapping_area *area) |
1167 | { | |
1168 | /* | |
1169 | * Make sure we don't leak memory if a cpu UP notification | |
1170 | * and zs_init() race and both call zs_cpu_up() on the same cpu | |
1171 | */ | |
1172 | if (area->vm) | |
1173 | return 0; | |
1174 | area->vm = alloc_vm_area(PAGE_SIZE * 2, NULL); | |
1175 | if (!area->vm) | |
1176 | return -ENOMEM; | |
1177 | return 0; | |
1178 | } | |
1179 | ||
1180 | static inline void __zs_cpu_down(struct mapping_area *area) | |
1181 | { | |
1182 | if (area->vm) | |
1183 | free_vm_area(area->vm); | |
1184 | area->vm = NULL; | |
1185 | } | |
1186 | ||
1187 | static inline void *__zs_map_object(struct mapping_area *area, | |
1188 | struct page *pages[2], int off, int size) | |
1189 | { | |
f6f8ed47 | 1190 | BUG_ON(map_vm_area(area->vm, PAGE_KERNEL, pages)); |
f553646a SJ |
1191 | area->vm_addr = area->vm->addr; |
1192 | return area->vm_addr + off; | |
1193 | } | |
1194 | ||
1195 | static inline void __zs_unmap_object(struct mapping_area *area, | |
1196 | struct page *pages[2], int off, int size) | |
1197 | { | |
1198 | unsigned long addr = (unsigned long)area->vm_addr; | |
f553646a | 1199 | |
d95abbbb | 1200 | unmap_kernel_range(addr, PAGE_SIZE * 2); |
f553646a SJ |
1201 | } |
1202 | ||
1b945aee | 1203 | #else /* CONFIG_PGTABLE_MAPPING */ |
f553646a SJ |
1204 | |
1205 | static inline int __zs_cpu_up(struct mapping_area *area) | |
1206 | { | |
1207 | /* | |
1208 | * Make sure we don't leak memory if a cpu UP notification | |
1209 | * and zs_init() race and both call zs_cpu_up() on the same cpu | |
1210 | */ | |
1211 | if (area->vm_buf) | |
1212 | return 0; | |
40f9fb8c | 1213 | area->vm_buf = kmalloc(ZS_MAX_ALLOC_SIZE, GFP_KERNEL); |
f553646a SJ |
1214 | if (!area->vm_buf) |
1215 | return -ENOMEM; | |
1216 | return 0; | |
1217 | } | |
1218 | ||
1219 | static inline void __zs_cpu_down(struct mapping_area *area) | |
1220 | { | |
40f9fb8c | 1221 | kfree(area->vm_buf); |
f553646a SJ |
1222 | area->vm_buf = NULL; |
1223 | } | |
1224 | ||
1225 | static void *__zs_map_object(struct mapping_area *area, | |
1226 | struct page *pages[2], int off, int size) | |
5f601902 | 1227 | { |
5f601902 SJ |
1228 | int sizes[2]; |
1229 | void *addr; | |
f553646a | 1230 | char *buf = area->vm_buf; |
5f601902 | 1231 | |
f553646a SJ |
1232 | /* disable page faults to match kmap_atomic() return conditions */ |
1233 | pagefault_disable(); | |
1234 | ||
1235 | /* no read fastpath */ | |
1236 | if (area->vm_mm == ZS_MM_WO) | |
1237 | goto out; | |
5f601902 SJ |
1238 | |
1239 | sizes[0] = PAGE_SIZE - off; | |
1240 | sizes[1] = size - sizes[0]; | |
1241 | ||
5f601902 SJ |
1242 | /* copy object to per-cpu buffer */ |
1243 | addr = kmap_atomic(pages[0]); | |
1244 | memcpy(buf, addr + off, sizes[0]); | |
1245 | kunmap_atomic(addr); | |
1246 | addr = kmap_atomic(pages[1]); | |
1247 | memcpy(buf + sizes[0], addr, sizes[1]); | |
1248 | kunmap_atomic(addr); | |
f553646a SJ |
1249 | out: |
1250 | return area->vm_buf; | |
5f601902 SJ |
1251 | } |
1252 | ||
f553646a SJ |
1253 | static void __zs_unmap_object(struct mapping_area *area, |
1254 | struct page *pages[2], int off, int size) | |
5f601902 | 1255 | { |
5f601902 SJ |
1256 | int sizes[2]; |
1257 | void *addr; | |
2e40e163 | 1258 | char *buf; |
5f601902 | 1259 | |
f553646a SJ |
1260 | /* no write fastpath */ |
1261 | if (area->vm_mm == ZS_MM_RO) | |
1262 | goto out; | |
5f601902 | 1263 | |
7b60a685 | 1264 | buf = area->vm_buf; |
a82cbf07 YX |
1265 | buf = buf + ZS_HANDLE_SIZE; |
1266 | size -= ZS_HANDLE_SIZE; | |
1267 | off += ZS_HANDLE_SIZE; | |
2e40e163 | 1268 | |
5f601902 SJ |
1269 | sizes[0] = PAGE_SIZE - off; |
1270 | sizes[1] = size - sizes[0]; | |
1271 | ||
1272 | /* copy per-cpu buffer to object */ | |
1273 | addr = kmap_atomic(pages[0]); | |
1274 | memcpy(addr + off, buf, sizes[0]); | |
1275 | kunmap_atomic(addr); | |
1276 | addr = kmap_atomic(pages[1]); | |
1277 | memcpy(addr, buf + sizes[0], sizes[1]); | |
1278 | kunmap_atomic(addr); | |
f553646a SJ |
1279 | |
1280 | out: | |
1281 | /* enable page faults to match kunmap_atomic() return conditions */ | |
1282 | pagefault_enable(); | |
5f601902 | 1283 | } |
61989a80 | 1284 | |
1b945aee | 1285 | #endif /* CONFIG_PGTABLE_MAPPING */ |
f553646a | 1286 | |
61989a80 NG |
1287 | static int zs_cpu_notifier(struct notifier_block *nb, unsigned long action, |
1288 | void *pcpu) | |
1289 | { | |
f553646a | 1290 | int ret, cpu = (long)pcpu; |
61989a80 NG |
1291 | struct mapping_area *area; |
1292 | ||
1293 | switch (action) { | |
1294 | case CPU_UP_PREPARE: | |
1295 | area = &per_cpu(zs_map_area, cpu); | |
f553646a SJ |
1296 | ret = __zs_cpu_up(area); |
1297 | if (ret) | |
1298 | return notifier_from_errno(ret); | |
61989a80 NG |
1299 | break; |
1300 | case CPU_DEAD: | |
1301 | case CPU_UP_CANCELED: | |
1302 | area = &per_cpu(zs_map_area, cpu); | |
f553646a | 1303 | __zs_cpu_down(area); |
61989a80 NG |
1304 | break; |
1305 | } | |
1306 | ||
1307 | return NOTIFY_OK; | |
1308 | } | |
1309 | ||
1310 | static struct notifier_block zs_cpu_nb = { | |
1311 | .notifier_call = zs_cpu_notifier | |
1312 | }; | |
1313 | ||
b1b00a5b | 1314 | static int zs_register_cpu_notifier(void) |
61989a80 | 1315 | { |
b1b00a5b | 1316 | int cpu, uninitialized_var(ret); |
61989a80 | 1317 | |
f0e71fcd SB |
1318 | cpu_notifier_register_begin(); |
1319 | ||
1320 | __register_cpu_notifier(&zs_cpu_nb); | |
61989a80 NG |
1321 | for_each_online_cpu(cpu) { |
1322 | ret = zs_cpu_notifier(NULL, CPU_UP_PREPARE, (void *)(long)cpu); | |
b1b00a5b SS |
1323 | if (notifier_to_errno(ret)) |
1324 | break; | |
61989a80 | 1325 | } |
f0e71fcd SB |
1326 | |
1327 | cpu_notifier_register_done(); | |
b1b00a5b SS |
1328 | return notifier_to_errno(ret); |
1329 | } | |
f0e71fcd | 1330 | |
66cdef66 | 1331 | static void zs_unregister_cpu_notifier(void) |
40f9fb8c | 1332 | { |
66cdef66 | 1333 | int cpu; |
40f9fb8c | 1334 | |
66cdef66 | 1335 | cpu_notifier_register_begin(); |
40f9fb8c | 1336 | |
66cdef66 GM |
1337 | for_each_online_cpu(cpu) |
1338 | zs_cpu_notifier(NULL, CPU_DEAD, (void *)(long)cpu); | |
1339 | __unregister_cpu_notifier(&zs_cpu_nb); | |
40f9fb8c | 1340 | |
66cdef66 | 1341 | cpu_notifier_register_done(); |
b1b00a5b SS |
1342 | } |
1343 | ||
35b3445e | 1344 | static void __init init_zs_size_classes(void) |
b1b00a5b | 1345 | { |
66cdef66 | 1346 | int nr; |
c795779d | 1347 | |
66cdef66 GM |
1348 | nr = (ZS_MAX_ALLOC_SIZE - ZS_MIN_ALLOC_SIZE) / ZS_SIZE_CLASS_DELTA + 1; |
1349 | if ((ZS_MAX_ALLOC_SIZE - ZS_MIN_ALLOC_SIZE) % ZS_SIZE_CLASS_DELTA) | |
1350 | nr += 1; | |
40f9fb8c | 1351 | |
66cdef66 | 1352 | zs_size_classes = nr; |
61989a80 NG |
1353 | } |
1354 | ||
64d90465 GM |
1355 | static bool can_merge(struct size_class *prev, int pages_per_zspage, |
1356 | int objs_per_zspage) | |
9eec4cd5 | 1357 | { |
64d90465 GM |
1358 | if (prev->pages_per_zspage == pages_per_zspage && |
1359 | prev->objs_per_zspage == objs_per_zspage) | |
1360 | return true; | |
9eec4cd5 | 1361 | |
64d90465 | 1362 | return false; |
9eec4cd5 JK |
1363 | } |
1364 | ||
3783689a | 1365 | static bool zspage_full(struct size_class *class, struct zspage *zspage) |
312fcae2 | 1366 | { |
3783689a | 1367 | return get_zspage_inuse(zspage) == class->objs_per_zspage; |
312fcae2 MK |
1368 | } |
1369 | ||
66cdef66 GM |
1370 | unsigned long zs_get_total_pages(struct zs_pool *pool) |
1371 | { | |
1372 | return atomic_long_read(&pool->pages_allocated); | |
1373 | } | |
1374 | EXPORT_SYMBOL_GPL(zs_get_total_pages); | |
1375 | ||
4bbc0bc0 | 1376 | /** |
66cdef66 GM |
1377 | * zs_map_object - get address of allocated object from handle. |
1378 | * @pool: pool from which the object was allocated | |
1379 | * @handle: handle returned from zs_malloc | |
4bbc0bc0 | 1380 | * |
66cdef66 GM |
1381 | * Before using an object allocated from zs_malloc, it must be mapped using |
1382 | * this function. When done with the object, it must be unmapped using | |
1383 | * zs_unmap_object. | |
4bbc0bc0 | 1384 | * |
66cdef66 GM |
1385 | * Only one object can be mapped per cpu at a time. There is no protection |
1386 | * against nested mappings. | |
1387 | * | |
1388 | * This function returns with preemption and page faults disabled. | |
4bbc0bc0 | 1389 | */ |
66cdef66 GM |
1390 | void *zs_map_object(struct zs_pool *pool, unsigned long handle, |
1391 | enum zs_mapmode mm) | |
61989a80 | 1392 | { |
3783689a | 1393 | struct zspage *zspage; |
66cdef66 | 1394 | struct page *page; |
bfd093f5 MK |
1395 | unsigned long obj, off; |
1396 | unsigned int obj_idx; | |
61989a80 | 1397 | |
66cdef66 GM |
1398 | unsigned int class_idx; |
1399 | enum fullness_group fg; | |
1400 | struct size_class *class; | |
1401 | struct mapping_area *area; | |
1402 | struct page *pages[2]; | |
2e40e163 | 1403 | void *ret; |
61989a80 | 1404 | |
9eec4cd5 | 1405 | /* |
66cdef66 GM |
1406 | * Because we use per-cpu mapping areas shared among the |
1407 | * pools/users, we can't allow mapping in interrupt context | |
1408 | * because it can corrupt another users mappings. | |
9eec4cd5 | 1409 | */ |
830e4bc5 | 1410 | WARN_ON_ONCE(in_interrupt()); |
61989a80 | 1411 | |
312fcae2 MK |
1412 | /* From now on, migration cannot move the object */ |
1413 | pin_tag(handle); | |
1414 | ||
2e40e163 MK |
1415 | obj = handle_to_obj(handle); |
1416 | obj_to_location(obj, &page, &obj_idx); | |
3783689a | 1417 | zspage = get_zspage(page); |
48b4800a MK |
1418 | |
1419 | /* migration cannot move any subpage in this zspage */ | |
1420 | migrate_read_lock(zspage); | |
1421 | ||
3783689a | 1422 | get_zspage_mapping(zspage, &class_idx, &fg); |
66cdef66 | 1423 | class = pool->size_class[class_idx]; |
bfd093f5 | 1424 | off = (class->size * obj_idx) & ~PAGE_MASK; |
df8b5bb9 | 1425 | |
66cdef66 GM |
1426 | area = &get_cpu_var(zs_map_area); |
1427 | area->vm_mm = mm; | |
1428 | if (off + class->size <= PAGE_SIZE) { | |
1429 | /* this object is contained entirely within a page */ | |
1430 | area->vm_addr = kmap_atomic(page); | |
2e40e163 MK |
1431 | ret = area->vm_addr + off; |
1432 | goto out; | |
61989a80 NG |
1433 | } |
1434 | ||
66cdef66 GM |
1435 | /* this object spans two pages */ |
1436 | pages[0] = page; | |
1437 | pages[1] = get_next_page(page); | |
1438 | BUG_ON(!pages[1]); | |
9eec4cd5 | 1439 | |
2e40e163 MK |
1440 | ret = __zs_map_object(area, pages, off, class->size); |
1441 | out: | |
48b4800a | 1442 | if (likely(!PageHugeObject(page))) |
7b60a685 MK |
1443 | ret += ZS_HANDLE_SIZE; |
1444 | ||
1445 | return ret; | |
61989a80 | 1446 | } |
66cdef66 | 1447 | EXPORT_SYMBOL_GPL(zs_map_object); |
61989a80 | 1448 | |
66cdef66 | 1449 | void zs_unmap_object(struct zs_pool *pool, unsigned long handle) |
61989a80 | 1450 | { |
3783689a | 1451 | struct zspage *zspage; |
66cdef66 | 1452 | struct page *page; |
bfd093f5 MK |
1453 | unsigned long obj, off; |
1454 | unsigned int obj_idx; | |
61989a80 | 1455 | |
66cdef66 GM |
1456 | unsigned int class_idx; |
1457 | enum fullness_group fg; | |
1458 | struct size_class *class; | |
1459 | struct mapping_area *area; | |
9eec4cd5 | 1460 | |
2e40e163 MK |
1461 | obj = handle_to_obj(handle); |
1462 | obj_to_location(obj, &page, &obj_idx); | |
3783689a MK |
1463 | zspage = get_zspage(page); |
1464 | get_zspage_mapping(zspage, &class_idx, &fg); | |
66cdef66 | 1465 | class = pool->size_class[class_idx]; |
bfd093f5 | 1466 | off = (class->size * obj_idx) & ~PAGE_MASK; |
61989a80 | 1467 | |
66cdef66 GM |
1468 | area = this_cpu_ptr(&zs_map_area); |
1469 | if (off + class->size <= PAGE_SIZE) | |
1470 | kunmap_atomic(area->vm_addr); | |
1471 | else { | |
1472 | struct page *pages[2]; | |
40f9fb8c | 1473 | |
66cdef66 GM |
1474 | pages[0] = page; |
1475 | pages[1] = get_next_page(page); | |
1476 | BUG_ON(!pages[1]); | |
1477 | ||
1478 | __zs_unmap_object(area, pages, off, class->size); | |
1479 | } | |
1480 | put_cpu_var(zs_map_area); | |
48b4800a MK |
1481 | |
1482 | migrate_read_unlock(zspage); | |
312fcae2 | 1483 | unpin_tag(handle); |
61989a80 | 1484 | } |
66cdef66 | 1485 | EXPORT_SYMBOL_GPL(zs_unmap_object); |
61989a80 | 1486 | |
251cbb95 | 1487 | static unsigned long obj_malloc(struct size_class *class, |
3783689a | 1488 | struct zspage *zspage, unsigned long handle) |
c7806261 | 1489 | { |
bfd093f5 | 1490 | int i, nr_page, offset; |
c7806261 MK |
1491 | unsigned long obj; |
1492 | struct link_free *link; | |
1493 | ||
1494 | struct page *m_page; | |
bfd093f5 | 1495 | unsigned long m_offset; |
c7806261 MK |
1496 | void *vaddr; |
1497 | ||
312fcae2 | 1498 | handle |= OBJ_ALLOCATED_TAG; |
3783689a | 1499 | obj = get_freeobj(zspage); |
bfd093f5 MK |
1500 | |
1501 | offset = obj * class->size; | |
1502 | nr_page = offset >> PAGE_SHIFT; | |
1503 | m_offset = offset & ~PAGE_MASK; | |
1504 | m_page = get_first_page(zspage); | |
1505 | ||
1506 | for (i = 0; i < nr_page; i++) | |
1507 | m_page = get_next_page(m_page); | |
c7806261 MK |
1508 | |
1509 | vaddr = kmap_atomic(m_page); | |
1510 | link = (struct link_free *)vaddr + m_offset / sizeof(*link); | |
3b1d9ca6 | 1511 | set_freeobj(zspage, link->next >> OBJ_TAG_BITS); |
48b4800a | 1512 | if (likely(!PageHugeObject(m_page))) |
7b60a685 MK |
1513 | /* record handle in the header of allocated chunk */ |
1514 | link->handle = handle; | |
1515 | else | |
3783689a MK |
1516 | /* record handle to page->index */ |
1517 | zspage->first_page->index = handle; | |
1518 | ||
c7806261 | 1519 | kunmap_atomic(vaddr); |
3783689a | 1520 | mod_zspage_inuse(zspage, 1); |
c7806261 MK |
1521 | zs_stat_inc(class, OBJ_USED, 1); |
1522 | ||
bfd093f5 MK |
1523 | obj = location_to_obj(m_page, obj); |
1524 | ||
c7806261 MK |
1525 | return obj; |
1526 | } | |
1527 | ||
1528 | ||
61989a80 NG |
1529 | /** |
1530 | * zs_malloc - Allocate block of given size from pool. | |
1531 | * @pool: pool to allocate from | |
1532 | * @size: size of block to allocate | |
fd854463 | 1533 | * @gfp: gfp flags when allocating object |
61989a80 | 1534 | * |
00a61d86 | 1535 | * On success, handle to the allocated object is returned, |
c2344348 | 1536 | * otherwise 0. |
61989a80 NG |
1537 | * Allocation requests with size > ZS_MAX_ALLOC_SIZE will fail. |
1538 | */ | |
d0d8da2d | 1539 | unsigned long zs_malloc(struct zs_pool *pool, size_t size, gfp_t gfp) |
61989a80 | 1540 | { |
2e40e163 | 1541 | unsigned long handle, obj; |
61989a80 | 1542 | struct size_class *class; |
48b4800a | 1543 | enum fullness_group newfg; |
3783689a | 1544 | struct zspage *zspage; |
61989a80 | 1545 | |
7b60a685 | 1546 | if (unlikely(!size || size > ZS_MAX_ALLOC_SIZE)) |
2e40e163 MK |
1547 | return 0; |
1548 | ||
3783689a | 1549 | handle = cache_alloc_handle(pool, gfp); |
2e40e163 | 1550 | if (!handle) |
c2344348 | 1551 | return 0; |
61989a80 | 1552 | |
2e40e163 MK |
1553 | /* extra space in chunk to keep the handle */ |
1554 | size += ZS_HANDLE_SIZE; | |
9eec4cd5 | 1555 | class = pool->size_class[get_size_class_index(size)]; |
61989a80 NG |
1556 | |
1557 | spin_lock(&class->lock); | |
3783689a | 1558 | zspage = find_get_zspage(class); |
48b4800a MK |
1559 | if (likely(zspage)) { |
1560 | obj = obj_malloc(class, zspage, handle); | |
1561 | /* Now move the zspage to another fullness group, if required */ | |
1562 | fix_fullness_group(class, zspage); | |
1563 | record_obj(handle, obj); | |
61989a80 | 1564 | spin_unlock(&class->lock); |
61989a80 | 1565 | |
48b4800a MK |
1566 | return handle; |
1567 | } | |
0f050d99 | 1568 | |
48b4800a MK |
1569 | spin_unlock(&class->lock); |
1570 | ||
1571 | zspage = alloc_zspage(pool, class, gfp); | |
1572 | if (!zspage) { | |
1573 | cache_free_handle(pool, handle); | |
1574 | return 0; | |
61989a80 NG |
1575 | } |
1576 | ||
48b4800a | 1577 | spin_lock(&class->lock); |
3783689a | 1578 | obj = obj_malloc(class, zspage, handle); |
48b4800a MK |
1579 | newfg = get_fullness_group(class, zspage); |
1580 | insert_zspage(class, zspage, newfg); | |
1581 | set_zspage_mapping(zspage, class->index, newfg); | |
2e40e163 | 1582 | record_obj(handle, obj); |
48b4800a MK |
1583 | atomic_long_add(class->pages_per_zspage, |
1584 | &pool->pages_allocated); | |
b4fd07a0 | 1585 | zs_stat_inc(class, OBJ_ALLOCATED, class->objs_per_zspage); |
48b4800a MK |
1586 | |
1587 | /* We completely set up zspage so mark them as movable */ | |
1588 | SetZsPageMovable(pool, zspage); | |
61989a80 NG |
1589 | spin_unlock(&class->lock); |
1590 | ||
2e40e163 | 1591 | return handle; |
61989a80 NG |
1592 | } |
1593 | EXPORT_SYMBOL_GPL(zs_malloc); | |
1594 | ||
1ee47165 | 1595 | static void obj_free(struct size_class *class, unsigned long obj) |
61989a80 NG |
1596 | { |
1597 | struct link_free *link; | |
3783689a MK |
1598 | struct zspage *zspage; |
1599 | struct page *f_page; | |
bfd093f5 MK |
1600 | unsigned long f_offset; |
1601 | unsigned int f_objidx; | |
af4ee5e9 | 1602 | void *vaddr; |
61989a80 | 1603 | |
312fcae2 | 1604 | obj &= ~OBJ_ALLOCATED_TAG; |
2e40e163 | 1605 | obj_to_location(obj, &f_page, &f_objidx); |
bfd093f5 | 1606 | f_offset = (class->size * f_objidx) & ~PAGE_MASK; |
3783689a | 1607 | zspage = get_zspage(f_page); |
61989a80 | 1608 | |
c7806261 | 1609 | vaddr = kmap_atomic(f_page); |
61989a80 NG |
1610 | |
1611 | /* Insert this object in containing zspage's freelist */ | |
af4ee5e9 | 1612 | link = (struct link_free *)(vaddr + f_offset); |
3b1d9ca6 | 1613 | link->next = get_freeobj(zspage) << OBJ_TAG_BITS; |
af4ee5e9 | 1614 | kunmap_atomic(vaddr); |
bfd093f5 | 1615 | set_freeobj(zspage, f_objidx); |
3783689a | 1616 | mod_zspage_inuse(zspage, -1); |
0f050d99 | 1617 | zs_stat_dec(class, OBJ_USED, 1); |
c7806261 MK |
1618 | } |
1619 | ||
1620 | void zs_free(struct zs_pool *pool, unsigned long handle) | |
1621 | { | |
3783689a MK |
1622 | struct zspage *zspage; |
1623 | struct page *f_page; | |
bfd093f5 MK |
1624 | unsigned long obj; |
1625 | unsigned int f_objidx; | |
c7806261 MK |
1626 | int class_idx; |
1627 | struct size_class *class; | |
1628 | enum fullness_group fullness; | |
48b4800a | 1629 | bool isolated; |
c7806261 MK |
1630 | |
1631 | if (unlikely(!handle)) | |
1632 | return; | |
1633 | ||
312fcae2 | 1634 | pin_tag(handle); |
c7806261 | 1635 | obj = handle_to_obj(handle); |
c7806261 | 1636 | obj_to_location(obj, &f_page, &f_objidx); |
3783689a | 1637 | zspage = get_zspage(f_page); |
c7806261 | 1638 | |
48b4800a MK |
1639 | migrate_read_lock(zspage); |
1640 | ||
3783689a | 1641 | get_zspage_mapping(zspage, &class_idx, &fullness); |
c7806261 MK |
1642 | class = pool->size_class[class_idx]; |
1643 | ||
1644 | spin_lock(&class->lock); | |
1ee47165 | 1645 | obj_free(class, obj); |
3783689a | 1646 | fullness = fix_fullness_group(class, zspage); |
48b4800a MK |
1647 | if (fullness != ZS_EMPTY) { |
1648 | migrate_read_unlock(zspage); | |
1649 | goto out; | |
312fcae2 | 1650 | } |
48b4800a MK |
1651 | |
1652 | isolated = is_zspage_isolated(zspage); | |
1653 | migrate_read_unlock(zspage); | |
1654 | /* If zspage is isolated, zs_page_putback will free the zspage */ | |
1655 | if (likely(!isolated)) | |
1656 | free_zspage(pool, class, zspage); | |
1657 | out: | |
1658 | ||
61989a80 | 1659 | spin_unlock(&class->lock); |
312fcae2 | 1660 | unpin_tag(handle); |
3783689a | 1661 | cache_free_handle(pool, handle); |
312fcae2 MK |
1662 | } |
1663 | EXPORT_SYMBOL_GPL(zs_free); | |
1664 | ||
251cbb95 MK |
1665 | static void zs_object_copy(struct size_class *class, unsigned long dst, |
1666 | unsigned long src) | |
312fcae2 MK |
1667 | { |
1668 | struct page *s_page, *d_page; | |
bfd093f5 | 1669 | unsigned int s_objidx, d_objidx; |
312fcae2 MK |
1670 | unsigned long s_off, d_off; |
1671 | void *s_addr, *d_addr; | |
1672 | int s_size, d_size, size; | |
1673 | int written = 0; | |
1674 | ||
1675 | s_size = d_size = class->size; | |
1676 | ||
1677 | obj_to_location(src, &s_page, &s_objidx); | |
1678 | obj_to_location(dst, &d_page, &d_objidx); | |
1679 | ||
bfd093f5 MK |
1680 | s_off = (class->size * s_objidx) & ~PAGE_MASK; |
1681 | d_off = (class->size * d_objidx) & ~PAGE_MASK; | |
312fcae2 MK |
1682 | |
1683 | if (s_off + class->size > PAGE_SIZE) | |
1684 | s_size = PAGE_SIZE - s_off; | |
1685 | ||
1686 | if (d_off + class->size > PAGE_SIZE) | |
1687 | d_size = PAGE_SIZE - d_off; | |
1688 | ||
1689 | s_addr = kmap_atomic(s_page); | |
1690 | d_addr = kmap_atomic(d_page); | |
1691 | ||
1692 | while (1) { | |
1693 | size = min(s_size, d_size); | |
1694 | memcpy(d_addr + d_off, s_addr + s_off, size); | |
1695 | written += size; | |
1696 | ||
1697 | if (written == class->size) | |
1698 | break; | |
1699 | ||
495819ea SS |
1700 | s_off += size; |
1701 | s_size -= size; | |
1702 | d_off += size; | |
1703 | d_size -= size; | |
1704 | ||
1705 | if (s_off >= PAGE_SIZE) { | |
312fcae2 MK |
1706 | kunmap_atomic(d_addr); |
1707 | kunmap_atomic(s_addr); | |
1708 | s_page = get_next_page(s_page); | |
312fcae2 MK |
1709 | s_addr = kmap_atomic(s_page); |
1710 | d_addr = kmap_atomic(d_page); | |
1711 | s_size = class->size - written; | |
1712 | s_off = 0; | |
312fcae2 MK |
1713 | } |
1714 | ||
495819ea | 1715 | if (d_off >= PAGE_SIZE) { |
312fcae2 MK |
1716 | kunmap_atomic(d_addr); |
1717 | d_page = get_next_page(d_page); | |
312fcae2 MK |
1718 | d_addr = kmap_atomic(d_page); |
1719 | d_size = class->size - written; | |
1720 | d_off = 0; | |
312fcae2 MK |
1721 | } |
1722 | } | |
1723 | ||
1724 | kunmap_atomic(d_addr); | |
1725 | kunmap_atomic(s_addr); | |
1726 | } | |
1727 | ||
1728 | /* | |
1729 | * Find alloced object in zspage from index object and | |
1730 | * return handle. | |
1731 | */ | |
251cbb95 | 1732 | static unsigned long find_alloced_obj(struct size_class *class, |
cf675acb | 1733 | struct page *page, int *obj_idx) |
312fcae2 MK |
1734 | { |
1735 | unsigned long head; | |
1736 | int offset = 0; | |
cf675acb | 1737 | int index = *obj_idx; |
312fcae2 MK |
1738 | unsigned long handle = 0; |
1739 | void *addr = kmap_atomic(page); | |
1740 | ||
3783689a | 1741 | offset = get_first_obj_offset(page); |
312fcae2 MK |
1742 | offset += class->size * index; |
1743 | ||
1744 | while (offset < PAGE_SIZE) { | |
48b4800a | 1745 | head = obj_to_head(page, addr + offset); |
312fcae2 MK |
1746 | if (head & OBJ_ALLOCATED_TAG) { |
1747 | handle = head & ~OBJ_ALLOCATED_TAG; | |
1748 | if (trypin_tag(handle)) | |
1749 | break; | |
1750 | handle = 0; | |
1751 | } | |
1752 | ||
1753 | offset += class->size; | |
1754 | index++; | |
1755 | } | |
1756 | ||
1757 | kunmap_atomic(addr); | |
cf675acb GM |
1758 | |
1759 | *obj_idx = index; | |
1760 | ||
312fcae2 MK |
1761 | return handle; |
1762 | } | |
1763 | ||
1764 | struct zs_compact_control { | |
3783689a | 1765 | /* Source spage for migration which could be a subpage of zspage */ |
312fcae2 MK |
1766 | struct page *s_page; |
1767 | /* Destination page for migration which should be a first page | |
1768 | * of zspage. */ | |
1769 | struct page *d_page; | |
1770 | /* Starting object index within @s_page which used for live object | |
1771 | * in the subpage. */ | |
41b88e14 | 1772 | int obj_idx; |
312fcae2 MK |
1773 | }; |
1774 | ||
1775 | static int migrate_zspage(struct zs_pool *pool, struct size_class *class, | |
1776 | struct zs_compact_control *cc) | |
1777 | { | |
1778 | unsigned long used_obj, free_obj; | |
1779 | unsigned long handle; | |
1780 | struct page *s_page = cc->s_page; | |
1781 | struct page *d_page = cc->d_page; | |
41b88e14 | 1782 | int obj_idx = cc->obj_idx; |
312fcae2 MK |
1783 | int ret = 0; |
1784 | ||
1785 | while (1) { | |
cf675acb | 1786 | handle = find_alloced_obj(class, s_page, &obj_idx); |
312fcae2 MK |
1787 | if (!handle) { |
1788 | s_page = get_next_page(s_page); | |
1789 | if (!s_page) | |
1790 | break; | |
41b88e14 | 1791 | obj_idx = 0; |
312fcae2 MK |
1792 | continue; |
1793 | } | |
1794 | ||
1795 | /* Stop if there is no more space */ | |
3783689a | 1796 | if (zspage_full(class, get_zspage(d_page))) { |
312fcae2 MK |
1797 | unpin_tag(handle); |
1798 | ret = -ENOMEM; | |
1799 | break; | |
1800 | } | |
1801 | ||
1802 | used_obj = handle_to_obj(handle); | |
3783689a | 1803 | free_obj = obj_malloc(class, get_zspage(d_page), handle); |
251cbb95 | 1804 | zs_object_copy(class, free_obj, used_obj); |
41b88e14 | 1805 | obj_idx++; |
c102f07c JL |
1806 | /* |
1807 | * record_obj updates handle's value to free_obj and it will | |
1808 | * invalidate lock bit(ie, HANDLE_PIN_BIT) of handle, which | |
1809 | * breaks synchronization using pin_tag(e,g, zs_free) so | |
1810 | * let's keep the lock bit. | |
1811 | */ | |
1812 | free_obj |= BIT(HANDLE_PIN_BIT); | |
312fcae2 MK |
1813 | record_obj(handle, free_obj); |
1814 | unpin_tag(handle); | |
1ee47165 | 1815 | obj_free(class, used_obj); |
312fcae2 MK |
1816 | } |
1817 | ||
1818 | /* Remember last position in this iteration */ | |
1819 | cc->s_page = s_page; | |
41b88e14 | 1820 | cc->obj_idx = obj_idx; |
312fcae2 MK |
1821 | |
1822 | return ret; | |
1823 | } | |
1824 | ||
3783689a | 1825 | static struct zspage *isolate_zspage(struct size_class *class, bool source) |
312fcae2 MK |
1826 | { |
1827 | int i; | |
3783689a MK |
1828 | struct zspage *zspage; |
1829 | enum fullness_group fg[2] = {ZS_ALMOST_EMPTY, ZS_ALMOST_FULL}; | |
312fcae2 | 1830 | |
3783689a MK |
1831 | if (!source) { |
1832 | fg[0] = ZS_ALMOST_FULL; | |
1833 | fg[1] = ZS_ALMOST_EMPTY; | |
1834 | } | |
1835 | ||
1836 | for (i = 0; i < 2; i++) { | |
1837 | zspage = list_first_entry_or_null(&class->fullness_list[fg[i]], | |
1838 | struct zspage, list); | |
1839 | if (zspage) { | |
48b4800a | 1840 | VM_BUG_ON(is_zspage_isolated(zspage)); |
3783689a MK |
1841 | remove_zspage(class, zspage, fg[i]); |
1842 | return zspage; | |
312fcae2 MK |
1843 | } |
1844 | } | |
1845 | ||
3783689a | 1846 | return zspage; |
312fcae2 MK |
1847 | } |
1848 | ||
860c707d | 1849 | /* |
3783689a | 1850 | * putback_zspage - add @zspage into right class's fullness list |
860c707d | 1851 | * @class: destination class |
3783689a | 1852 | * @zspage: target page |
860c707d | 1853 | * |
3783689a | 1854 | * Return @zspage's fullness_group |
860c707d | 1855 | */ |
4aa409ca | 1856 | static enum fullness_group putback_zspage(struct size_class *class, |
3783689a | 1857 | struct zspage *zspage) |
312fcae2 | 1858 | { |
312fcae2 MK |
1859 | enum fullness_group fullness; |
1860 | ||
48b4800a MK |
1861 | VM_BUG_ON(is_zspage_isolated(zspage)); |
1862 | ||
3783689a MK |
1863 | fullness = get_fullness_group(class, zspage); |
1864 | insert_zspage(class, zspage, fullness); | |
1865 | set_zspage_mapping(zspage, class->index, fullness); | |
839373e6 | 1866 | |
860c707d | 1867 | return fullness; |
61989a80 | 1868 | } |
312fcae2 | 1869 | |
48b4800a MK |
1870 | #ifdef CONFIG_COMPACTION |
1871 | static struct dentry *zs_mount(struct file_system_type *fs_type, | |
1872 | int flags, const char *dev_name, void *data) | |
1873 | { | |
1874 | static const struct dentry_operations ops = { | |
1875 | .d_dname = simple_dname, | |
1876 | }; | |
1877 | ||
1878 | return mount_pseudo(fs_type, "zsmalloc:", NULL, &ops, ZSMALLOC_MAGIC); | |
1879 | } | |
1880 | ||
1881 | static struct file_system_type zsmalloc_fs = { | |
1882 | .name = "zsmalloc", | |
1883 | .mount = zs_mount, | |
1884 | .kill_sb = kill_anon_super, | |
1885 | }; | |
1886 | ||
1887 | static int zsmalloc_mount(void) | |
1888 | { | |
1889 | int ret = 0; | |
1890 | ||
1891 | zsmalloc_mnt = kern_mount(&zsmalloc_fs); | |
1892 | if (IS_ERR(zsmalloc_mnt)) | |
1893 | ret = PTR_ERR(zsmalloc_mnt); | |
1894 | ||
1895 | return ret; | |
1896 | } | |
1897 | ||
1898 | static void zsmalloc_unmount(void) | |
1899 | { | |
1900 | kern_unmount(zsmalloc_mnt); | |
1901 | } | |
1902 | ||
1903 | static void migrate_lock_init(struct zspage *zspage) | |
1904 | { | |
1905 | rwlock_init(&zspage->lock); | |
1906 | } | |
1907 | ||
1908 | static void migrate_read_lock(struct zspage *zspage) | |
1909 | { | |
1910 | read_lock(&zspage->lock); | |
1911 | } | |
1912 | ||
1913 | static void migrate_read_unlock(struct zspage *zspage) | |
1914 | { | |
1915 | read_unlock(&zspage->lock); | |
1916 | } | |
1917 | ||
1918 | static void migrate_write_lock(struct zspage *zspage) | |
1919 | { | |
1920 | write_lock(&zspage->lock); | |
1921 | } | |
1922 | ||
1923 | static void migrate_write_unlock(struct zspage *zspage) | |
1924 | { | |
1925 | write_unlock(&zspage->lock); | |
1926 | } | |
1927 | ||
1928 | /* Number of isolated subpage for *page migration* in this zspage */ | |
1929 | static void inc_zspage_isolation(struct zspage *zspage) | |
1930 | { | |
1931 | zspage->isolated++; | |
1932 | } | |
1933 | ||
1934 | static void dec_zspage_isolation(struct zspage *zspage) | |
1935 | { | |
1936 | zspage->isolated--; | |
1937 | } | |
1938 | ||
1939 | static void replace_sub_page(struct size_class *class, struct zspage *zspage, | |
1940 | struct page *newpage, struct page *oldpage) | |
1941 | { | |
1942 | struct page *page; | |
1943 | struct page *pages[ZS_MAX_PAGES_PER_ZSPAGE] = {NULL, }; | |
1944 | int idx = 0; | |
1945 | ||
1946 | page = get_first_page(zspage); | |
1947 | do { | |
1948 | if (page == oldpage) | |
1949 | pages[idx] = newpage; | |
1950 | else | |
1951 | pages[idx] = page; | |
1952 | idx++; | |
1953 | } while ((page = get_next_page(page)) != NULL); | |
1954 | ||
1955 | create_page_chain(class, zspage, pages); | |
1956 | set_first_obj_offset(newpage, get_first_obj_offset(oldpage)); | |
1957 | if (unlikely(PageHugeObject(oldpage))) | |
1958 | newpage->index = oldpage->index; | |
1959 | __SetPageMovable(newpage, page_mapping(oldpage)); | |
1960 | } | |
1961 | ||
1962 | bool zs_page_isolate(struct page *page, isolate_mode_t mode) | |
1963 | { | |
1964 | struct zs_pool *pool; | |
1965 | struct size_class *class; | |
1966 | int class_idx; | |
1967 | enum fullness_group fullness; | |
1968 | struct zspage *zspage; | |
1969 | struct address_space *mapping; | |
1970 | ||
1971 | /* | |
1972 | * Page is locked so zspage couldn't be destroyed. For detail, look at | |
1973 | * lock_zspage in free_zspage. | |
1974 | */ | |
1975 | VM_BUG_ON_PAGE(!PageMovable(page), page); | |
1976 | VM_BUG_ON_PAGE(PageIsolated(page), page); | |
1977 | ||
1978 | zspage = get_zspage(page); | |
1979 | ||
1980 | /* | |
1981 | * Without class lock, fullness could be stale while class_idx is okay | |
1982 | * because class_idx is constant unless page is freed so we should get | |
1983 | * fullness again under class lock. | |
1984 | */ | |
1985 | get_zspage_mapping(zspage, &class_idx, &fullness); | |
1986 | mapping = page_mapping(page); | |
1987 | pool = mapping->private_data; | |
1988 | class = pool->size_class[class_idx]; | |
1989 | ||
1990 | spin_lock(&class->lock); | |
1991 | if (get_zspage_inuse(zspage) == 0) { | |
1992 | spin_unlock(&class->lock); | |
1993 | return false; | |
1994 | } | |
1995 | ||
1996 | /* zspage is isolated for object migration */ | |
1997 | if (list_empty(&zspage->list) && !is_zspage_isolated(zspage)) { | |
1998 | spin_unlock(&class->lock); | |
1999 | return false; | |
2000 | } | |
2001 | ||
2002 | /* | |
2003 | * If this is first time isolation for the zspage, isolate zspage from | |
2004 | * size_class to prevent further object allocation from the zspage. | |
2005 | */ | |
2006 | if (!list_empty(&zspage->list) && !is_zspage_isolated(zspage)) { | |
2007 | get_zspage_mapping(zspage, &class_idx, &fullness); | |
2008 | remove_zspage(class, zspage, fullness); | |
2009 | } | |
2010 | ||
2011 | inc_zspage_isolation(zspage); | |
2012 | spin_unlock(&class->lock); | |
2013 | ||
2014 | return true; | |
2015 | } | |
2016 | ||
2017 | int zs_page_migrate(struct address_space *mapping, struct page *newpage, | |
2018 | struct page *page, enum migrate_mode mode) | |
2019 | { | |
2020 | struct zs_pool *pool; | |
2021 | struct size_class *class; | |
2022 | int class_idx; | |
2023 | enum fullness_group fullness; | |
2024 | struct zspage *zspage; | |
2025 | struct page *dummy; | |
2026 | void *s_addr, *d_addr, *addr; | |
2027 | int offset, pos; | |
2028 | unsigned long handle, head; | |
2029 | unsigned long old_obj, new_obj; | |
2030 | unsigned int obj_idx; | |
2031 | int ret = -EAGAIN; | |
2032 | ||
2033 | VM_BUG_ON_PAGE(!PageMovable(page), page); | |
2034 | VM_BUG_ON_PAGE(!PageIsolated(page), page); | |
2035 | ||
2036 | zspage = get_zspage(page); | |
2037 | ||
2038 | /* Concurrent compactor cannot migrate any subpage in zspage */ | |
2039 | migrate_write_lock(zspage); | |
2040 | get_zspage_mapping(zspage, &class_idx, &fullness); | |
2041 | pool = mapping->private_data; | |
2042 | class = pool->size_class[class_idx]; | |
2043 | offset = get_first_obj_offset(page); | |
2044 | ||
2045 | spin_lock(&class->lock); | |
2046 | if (!get_zspage_inuse(zspage)) { | |
2047 | ret = -EBUSY; | |
2048 | goto unlock_class; | |
2049 | } | |
2050 | ||
2051 | pos = offset; | |
2052 | s_addr = kmap_atomic(page); | |
2053 | while (pos < PAGE_SIZE) { | |
2054 | head = obj_to_head(page, s_addr + pos); | |
2055 | if (head & OBJ_ALLOCATED_TAG) { | |
2056 | handle = head & ~OBJ_ALLOCATED_TAG; | |
2057 | if (!trypin_tag(handle)) | |
2058 | goto unpin_objects; | |
2059 | } | |
2060 | pos += class->size; | |
2061 | } | |
2062 | ||
2063 | /* | |
2064 | * Here, any user cannot access all objects in the zspage so let's move. | |
2065 | */ | |
2066 | d_addr = kmap_atomic(newpage); | |
2067 | memcpy(d_addr, s_addr, PAGE_SIZE); | |
2068 | kunmap_atomic(d_addr); | |
2069 | ||
2070 | for (addr = s_addr + offset; addr < s_addr + pos; | |
2071 | addr += class->size) { | |
2072 | head = obj_to_head(page, addr); | |
2073 | if (head & OBJ_ALLOCATED_TAG) { | |
2074 | handle = head & ~OBJ_ALLOCATED_TAG; | |
2075 | if (!testpin_tag(handle)) | |
2076 | BUG(); | |
2077 | ||
2078 | old_obj = handle_to_obj(handle); | |
2079 | obj_to_location(old_obj, &dummy, &obj_idx); | |
2080 | new_obj = (unsigned long)location_to_obj(newpage, | |
2081 | obj_idx); | |
2082 | new_obj |= BIT(HANDLE_PIN_BIT); | |
2083 | record_obj(handle, new_obj); | |
2084 | } | |
2085 | } | |
2086 | ||
2087 | replace_sub_page(class, zspage, newpage, page); | |
2088 | get_page(newpage); | |
2089 | ||
2090 | dec_zspage_isolation(zspage); | |
2091 | ||
2092 | /* | |
2093 | * Page migration is done so let's putback isolated zspage to | |
2094 | * the list if @page is final isolated subpage in the zspage. | |
2095 | */ | |
2096 | if (!is_zspage_isolated(zspage)) | |
2097 | putback_zspage(class, zspage); | |
2098 | ||
2099 | reset_page(page); | |
2100 | put_page(page); | |
2101 | page = newpage; | |
2102 | ||
dd4123f3 | 2103 | ret = MIGRATEPAGE_SUCCESS; |
48b4800a MK |
2104 | unpin_objects: |
2105 | for (addr = s_addr + offset; addr < s_addr + pos; | |
2106 | addr += class->size) { | |
2107 | head = obj_to_head(page, addr); | |
2108 | if (head & OBJ_ALLOCATED_TAG) { | |
2109 | handle = head & ~OBJ_ALLOCATED_TAG; | |
2110 | if (!testpin_tag(handle)) | |
2111 | BUG(); | |
2112 | unpin_tag(handle); | |
2113 | } | |
2114 | } | |
2115 | kunmap_atomic(s_addr); | |
2116 | unlock_class: | |
2117 | spin_unlock(&class->lock); | |
2118 | migrate_write_unlock(zspage); | |
2119 | ||
2120 | return ret; | |
2121 | } | |
2122 | ||
2123 | void zs_page_putback(struct page *page) | |
2124 | { | |
2125 | struct zs_pool *pool; | |
2126 | struct size_class *class; | |
2127 | int class_idx; | |
2128 | enum fullness_group fg; | |
2129 | struct address_space *mapping; | |
2130 | struct zspage *zspage; | |
2131 | ||
2132 | VM_BUG_ON_PAGE(!PageMovable(page), page); | |
2133 | VM_BUG_ON_PAGE(!PageIsolated(page), page); | |
2134 | ||
2135 | zspage = get_zspage(page); | |
2136 | get_zspage_mapping(zspage, &class_idx, &fg); | |
2137 | mapping = page_mapping(page); | |
2138 | pool = mapping->private_data; | |
2139 | class = pool->size_class[class_idx]; | |
2140 | ||
2141 | spin_lock(&class->lock); | |
2142 | dec_zspage_isolation(zspage); | |
2143 | if (!is_zspage_isolated(zspage)) { | |
2144 | fg = putback_zspage(class, zspage); | |
2145 | /* | |
2146 | * Due to page_lock, we cannot free zspage immediately | |
2147 | * so let's defer. | |
2148 | */ | |
2149 | if (fg == ZS_EMPTY) | |
2150 | schedule_work(&pool->free_work); | |
2151 | } | |
2152 | spin_unlock(&class->lock); | |
2153 | } | |
2154 | ||
2155 | const struct address_space_operations zsmalloc_aops = { | |
2156 | .isolate_page = zs_page_isolate, | |
2157 | .migratepage = zs_page_migrate, | |
2158 | .putback_page = zs_page_putback, | |
2159 | }; | |
2160 | ||
2161 | static int zs_register_migration(struct zs_pool *pool) | |
2162 | { | |
2163 | pool->inode = alloc_anon_inode(zsmalloc_mnt->mnt_sb); | |
2164 | if (IS_ERR(pool->inode)) { | |
2165 | pool->inode = NULL; | |
2166 | return 1; | |
2167 | } | |
2168 | ||
2169 | pool->inode->i_mapping->private_data = pool; | |
2170 | pool->inode->i_mapping->a_ops = &zsmalloc_aops; | |
2171 | return 0; | |
2172 | } | |
2173 | ||
2174 | static void zs_unregister_migration(struct zs_pool *pool) | |
2175 | { | |
2176 | flush_work(&pool->free_work); | |
c3491eca | 2177 | iput(pool->inode); |
48b4800a MK |
2178 | } |
2179 | ||
2180 | /* | |
2181 | * Caller should hold page_lock of all pages in the zspage | |
2182 | * In here, we cannot use zspage meta data. | |
2183 | */ | |
2184 | static void async_free_zspage(struct work_struct *work) | |
2185 | { | |
2186 | int i; | |
2187 | struct size_class *class; | |
2188 | unsigned int class_idx; | |
2189 | enum fullness_group fullness; | |
2190 | struct zspage *zspage, *tmp; | |
2191 | LIST_HEAD(free_pages); | |
2192 | struct zs_pool *pool = container_of(work, struct zs_pool, | |
2193 | free_work); | |
2194 | ||
2195 | for (i = 0; i < zs_size_classes; i++) { | |
2196 | class = pool->size_class[i]; | |
2197 | if (class->index != i) | |
2198 | continue; | |
2199 | ||
2200 | spin_lock(&class->lock); | |
2201 | list_splice_init(&class->fullness_list[ZS_EMPTY], &free_pages); | |
2202 | spin_unlock(&class->lock); | |
2203 | } | |
2204 | ||
2205 | ||
2206 | list_for_each_entry_safe(zspage, tmp, &free_pages, list) { | |
2207 | list_del(&zspage->list); | |
2208 | lock_zspage(zspage); | |
2209 | ||
2210 | get_zspage_mapping(zspage, &class_idx, &fullness); | |
2211 | VM_BUG_ON(fullness != ZS_EMPTY); | |
2212 | class = pool->size_class[class_idx]; | |
2213 | spin_lock(&class->lock); | |
2214 | __free_zspage(pool, pool->size_class[class_idx], zspage); | |
2215 | spin_unlock(&class->lock); | |
2216 | } | |
2217 | }; | |
2218 | ||
2219 | static void kick_deferred_free(struct zs_pool *pool) | |
2220 | { | |
2221 | schedule_work(&pool->free_work); | |
2222 | } | |
2223 | ||
2224 | static void init_deferred_free(struct zs_pool *pool) | |
2225 | { | |
2226 | INIT_WORK(&pool->free_work, async_free_zspage); | |
2227 | } | |
2228 | ||
2229 | static void SetZsPageMovable(struct zs_pool *pool, struct zspage *zspage) | |
2230 | { | |
2231 | struct page *page = get_first_page(zspage); | |
2232 | ||
2233 | do { | |
2234 | WARN_ON(!trylock_page(page)); | |
2235 | __SetPageMovable(page, pool->inode->i_mapping); | |
2236 | unlock_page(page); | |
2237 | } while ((page = get_next_page(page)) != NULL); | |
2238 | } | |
2239 | #endif | |
2240 | ||
04f05909 SS |
2241 | /* |
2242 | * | |
2243 | * Based on the number of unused allocated objects calculate | |
2244 | * and return the number of pages that we can free. | |
04f05909 SS |
2245 | */ |
2246 | static unsigned long zs_can_compact(struct size_class *class) | |
2247 | { | |
2248 | unsigned long obj_wasted; | |
44f43e99 SS |
2249 | unsigned long obj_allocated = zs_stat_get(class, OBJ_ALLOCATED); |
2250 | unsigned long obj_used = zs_stat_get(class, OBJ_USED); | |
04f05909 | 2251 | |
44f43e99 SS |
2252 | if (obj_allocated <= obj_used) |
2253 | return 0; | |
04f05909 | 2254 | |
44f43e99 | 2255 | obj_wasted = obj_allocated - obj_used; |
b4fd07a0 | 2256 | obj_wasted /= class->objs_per_zspage; |
04f05909 | 2257 | |
6cbf16b3 | 2258 | return obj_wasted * class->pages_per_zspage; |
04f05909 SS |
2259 | } |
2260 | ||
7d3f3938 | 2261 | static void __zs_compact(struct zs_pool *pool, struct size_class *class) |
312fcae2 | 2262 | { |
312fcae2 | 2263 | struct zs_compact_control cc; |
3783689a MK |
2264 | struct zspage *src_zspage; |
2265 | struct zspage *dst_zspage = NULL; | |
312fcae2 | 2266 | |
312fcae2 | 2267 | spin_lock(&class->lock); |
3783689a | 2268 | while ((src_zspage = isolate_zspage(class, true))) { |
312fcae2 | 2269 | |
04f05909 SS |
2270 | if (!zs_can_compact(class)) |
2271 | break; | |
2272 | ||
41b88e14 | 2273 | cc.obj_idx = 0; |
48b4800a | 2274 | cc.s_page = get_first_page(src_zspage); |
312fcae2 | 2275 | |
3783689a | 2276 | while ((dst_zspage = isolate_zspage(class, false))) { |
48b4800a | 2277 | cc.d_page = get_first_page(dst_zspage); |
312fcae2 | 2278 | /* |
0dc63d48 SS |
2279 | * If there is no more space in dst_page, resched |
2280 | * and see if anyone had allocated another zspage. | |
312fcae2 MK |
2281 | */ |
2282 | if (!migrate_zspage(pool, class, &cc)) | |
2283 | break; | |
2284 | ||
4aa409ca | 2285 | putback_zspage(class, dst_zspage); |
312fcae2 MK |
2286 | } |
2287 | ||
2288 | /* Stop if we couldn't find slot */ | |
3783689a | 2289 | if (dst_zspage == NULL) |
312fcae2 MK |
2290 | break; |
2291 | ||
4aa409ca MK |
2292 | putback_zspage(class, dst_zspage); |
2293 | if (putback_zspage(class, src_zspage) == ZS_EMPTY) { | |
48b4800a | 2294 | free_zspage(pool, class, src_zspage); |
6cbf16b3 | 2295 | pool->stats.pages_compacted += class->pages_per_zspage; |
4aa409ca | 2296 | } |
312fcae2 | 2297 | spin_unlock(&class->lock); |
312fcae2 MK |
2298 | cond_resched(); |
2299 | spin_lock(&class->lock); | |
2300 | } | |
2301 | ||
3783689a | 2302 | if (src_zspage) |
4aa409ca | 2303 | putback_zspage(class, src_zspage); |
312fcae2 | 2304 | |
7d3f3938 | 2305 | spin_unlock(&class->lock); |
312fcae2 MK |
2306 | } |
2307 | ||
2308 | unsigned long zs_compact(struct zs_pool *pool) | |
2309 | { | |
2310 | int i; | |
312fcae2 MK |
2311 | struct size_class *class; |
2312 | ||
2313 | for (i = zs_size_classes - 1; i >= 0; i--) { | |
2314 | class = pool->size_class[i]; | |
2315 | if (!class) | |
2316 | continue; | |
2317 | if (class->index != i) | |
2318 | continue; | |
7d3f3938 | 2319 | __zs_compact(pool, class); |
312fcae2 MK |
2320 | } |
2321 | ||
860c707d | 2322 | return pool->stats.pages_compacted; |
312fcae2 MK |
2323 | } |
2324 | EXPORT_SYMBOL_GPL(zs_compact); | |
61989a80 | 2325 | |
7d3f3938 SS |
2326 | void zs_pool_stats(struct zs_pool *pool, struct zs_pool_stats *stats) |
2327 | { | |
2328 | memcpy(stats, &pool->stats, sizeof(struct zs_pool_stats)); | |
2329 | } | |
2330 | EXPORT_SYMBOL_GPL(zs_pool_stats); | |
2331 | ||
ab9d306d SS |
2332 | static unsigned long zs_shrinker_scan(struct shrinker *shrinker, |
2333 | struct shrink_control *sc) | |
2334 | { | |
2335 | unsigned long pages_freed; | |
2336 | struct zs_pool *pool = container_of(shrinker, struct zs_pool, | |
2337 | shrinker); | |
2338 | ||
2339 | pages_freed = pool->stats.pages_compacted; | |
2340 | /* | |
2341 | * Compact classes and calculate compaction delta. | |
2342 | * Can run concurrently with a manually triggered | |
2343 | * (by user) compaction. | |
2344 | */ | |
2345 | pages_freed = zs_compact(pool) - pages_freed; | |
2346 | ||
2347 | return pages_freed ? pages_freed : SHRINK_STOP; | |
2348 | } | |
2349 | ||
2350 | static unsigned long zs_shrinker_count(struct shrinker *shrinker, | |
2351 | struct shrink_control *sc) | |
2352 | { | |
2353 | int i; | |
2354 | struct size_class *class; | |
2355 | unsigned long pages_to_free = 0; | |
2356 | struct zs_pool *pool = container_of(shrinker, struct zs_pool, | |
2357 | shrinker); | |
2358 | ||
ab9d306d SS |
2359 | for (i = zs_size_classes - 1; i >= 0; i--) { |
2360 | class = pool->size_class[i]; | |
2361 | if (!class) | |
2362 | continue; | |
2363 | if (class->index != i) | |
2364 | continue; | |
2365 | ||
ab9d306d | 2366 | pages_to_free += zs_can_compact(class); |
ab9d306d SS |
2367 | } |
2368 | ||
2369 | return pages_to_free; | |
2370 | } | |
2371 | ||
2372 | static void zs_unregister_shrinker(struct zs_pool *pool) | |
2373 | { | |
2374 | if (pool->shrinker_enabled) { | |
2375 | unregister_shrinker(&pool->shrinker); | |
2376 | pool->shrinker_enabled = false; | |
2377 | } | |
2378 | } | |
2379 | ||
2380 | static int zs_register_shrinker(struct zs_pool *pool) | |
2381 | { | |
2382 | pool->shrinker.scan_objects = zs_shrinker_scan; | |
2383 | pool->shrinker.count_objects = zs_shrinker_count; | |
2384 | pool->shrinker.batch = 0; | |
2385 | pool->shrinker.seeks = DEFAULT_SEEKS; | |
2386 | ||
2387 | return register_shrinker(&pool->shrinker); | |
2388 | } | |
2389 | ||
00a61d86 | 2390 | /** |
66cdef66 | 2391 | * zs_create_pool - Creates an allocation pool to work from. |
fd854463 | 2392 | * @name: pool name to be created |
166cfda7 | 2393 | * |
66cdef66 GM |
2394 | * This function must be called before anything when using |
2395 | * the zsmalloc allocator. | |
166cfda7 | 2396 | * |
66cdef66 GM |
2397 | * On success, a pointer to the newly created pool is returned, |
2398 | * otherwise NULL. | |
396b7fd6 | 2399 | */ |
d0d8da2d | 2400 | struct zs_pool *zs_create_pool(const char *name) |
61989a80 | 2401 | { |
66cdef66 GM |
2402 | int i; |
2403 | struct zs_pool *pool; | |
2404 | struct size_class *prev_class = NULL; | |
61989a80 | 2405 | |
66cdef66 GM |
2406 | pool = kzalloc(sizeof(*pool), GFP_KERNEL); |
2407 | if (!pool) | |
2408 | return NULL; | |
61989a80 | 2409 | |
48b4800a | 2410 | init_deferred_free(pool); |
66cdef66 GM |
2411 | pool->size_class = kcalloc(zs_size_classes, sizeof(struct size_class *), |
2412 | GFP_KERNEL); | |
2413 | if (!pool->size_class) { | |
2414 | kfree(pool); | |
2415 | return NULL; | |
2416 | } | |
61989a80 | 2417 | |
2e40e163 MK |
2418 | pool->name = kstrdup(name, GFP_KERNEL); |
2419 | if (!pool->name) | |
2420 | goto err; | |
2421 | ||
3783689a | 2422 | if (create_cache(pool)) |
2e40e163 MK |
2423 | goto err; |
2424 | ||
c60369f0 | 2425 | /* |
66cdef66 GM |
2426 | * Iterate reversly, because, size of size_class that we want to use |
2427 | * for merging should be larger or equal to current size. | |
c60369f0 | 2428 | */ |
66cdef66 GM |
2429 | for (i = zs_size_classes - 1; i >= 0; i--) { |
2430 | int size; | |
2431 | int pages_per_zspage; | |
64d90465 | 2432 | int objs_per_zspage; |
66cdef66 | 2433 | struct size_class *class; |
3783689a | 2434 | int fullness = 0; |
c60369f0 | 2435 | |
66cdef66 GM |
2436 | size = ZS_MIN_ALLOC_SIZE + i * ZS_SIZE_CLASS_DELTA; |
2437 | if (size > ZS_MAX_ALLOC_SIZE) | |
2438 | size = ZS_MAX_ALLOC_SIZE; | |
2439 | pages_per_zspage = get_pages_per_zspage(size); | |
64d90465 | 2440 | objs_per_zspage = pages_per_zspage * PAGE_SIZE / size; |
61989a80 | 2441 | |
66cdef66 GM |
2442 | /* |
2443 | * size_class is used for normal zsmalloc operation such | |
2444 | * as alloc/free for that size. Although it is natural that we | |
2445 | * have one size_class for each size, there is a chance that we | |
2446 | * can get more memory utilization if we use one size_class for | |
2447 | * many different sizes whose size_class have same | |
2448 | * characteristics. So, we makes size_class point to | |
2449 | * previous size_class if possible. | |
2450 | */ | |
2451 | if (prev_class) { | |
64d90465 | 2452 | if (can_merge(prev_class, pages_per_zspage, objs_per_zspage)) { |
66cdef66 GM |
2453 | pool->size_class[i] = prev_class; |
2454 | continue; | |
2455 | } | |
2456 | } | |
2457 | ||
2458 | class = kzalloc(sizeof(struct size_class), GFP_KERNEL); | |
2459 | if (!class) | |
2460 | goto err; | |
2461 | ||
2462 | class->size = size; | |
2463 | class->index = i; | |
2464 | class->pages_per_zspage = pages_per_zspage; | |
64d90465 | 2465 | class->objs_per_zspage = objs_per_zspage; |
66cdef66 GM |
2466 | spin_lock_init(&class->lock); |
2467 | pool->size_class[i] = class; | |
48b4800a MK |
2468 | for (fullness = ZS_EMPTY; fullness < NR_ZS_FULLNESS; |
2469 | fullness++) | |
3783689a | 2470 | INIT_LIST_HEAD(&class->fullness_list[fullness]); |
66cdef66 GM |
2471 | |
2472 | prev_class = class; | |
61989a80 NG |
2473 | } |
2474 | ||
d34f6157 DS |
2475 | /* debug only, don't abort if it fails */ |
2476 | zs_pool_stat_create(pool, name); | |
0f050d99 | 2477 | |
48b4800a MK |
2478 | if (zs_register_migration(pool)) |
2479 | goto err; | |
2480 | ||
ab9d306d SS |
2481 | /* |
2482 | * Not critical, we still can use the pool | |
2483 | * and user can trigger compaction manually. | |
2484 | */ | |
2485 | if (zs_register_shrinker(pool) == 0) | |
2486 | pool->shrinker_enabled = true; | |
66cdef66 GM |
2487 | return pool; |
2488 | ||
2489 | err: | |
2490 | zs_destroy_pool(pool); | |
2491 | return NULL; | |
61989a80 | 2492 | } |
66cdef66 | 2493 | EXPORT_SYMBOL_GPL(zs_create_pool); |
61989a80 | 2494 | |
66cdef66 | 2495 | void zs_destroy_pool(struct zs_pool *pool) |
61989a80 | 2496 | { |
66cdef66 | 2497 | int i; |
61989a80 | 2498 | |
ab9d306d | 2499 | zs_unregister_shrinker(pool); |
48b4800a | 2500 | zs_unregister_migration(pool); |
0f050d99 GM |
2501 | zs_pool_stat_destroy(pool); |
2502 | ||
66cdef66 GM |
2503 | for (i = 0; i < zs_size_classes; i++) { |
2504 | int fg; | |
2505 | struct size_class *class = pool->size_class[i]; | |
61989a80 | 2506 | |
66cdef66 GM |
2507 | if (!class) |
2508 | continue; | |
61989a80 | 2509 | |
66cdef66 GM |
2510 | if (class->index != i) |
2511 | continue; | |
61989a80 | 2512 | |
48b4800a | 2513 | for (fg = ZS_EMPTY; fg < NR_ZS_FULLNESS; fg++) { |
3783689a | 2514 | if (!list_empty(&class->fullness_list[fg])) { |
66cdef66 GM |
2515 | pr_info("Freeing non-empty class with size %db, fullness group %d\n", |
2516 | class->size, fg); | |
2517 | } | |
2518 | } | |
2519 | kfree(class); | |
2520 | } | |
f553646a | 2521 | |
3783689a | 2522 | destroy_cache(pool); |
66cdef66 | 2523 | kfree(pool->size_class); |
0f050d99 | 2524 | kfree(pool->name); |
66cdef66 GM |
2525 | kfree(pool); |
2526 | } | |
2527 | EXPORT_SYMBOL_GPL(zs_destroy_pool); | |
b7418510 | 2528 | |
66cdef66 GM |
2529 | static int __init zs_init(void) |
2530 | { | |
48b4800a MK |
2531 | int ret; |
2532 | ||
2533 | ret = zsmalloc_mount(); | |
2534 | if (ret) | |
2535 | goto out; | |
2536 | ||
2537 | ret = zs_register_cpu_notifier(); | |
66cdef66 | 2538 | |
0f050d99 GM |
2539 | if (ret) |
2540 | goto notifier_fail; | |
66cdef66 GM |
2541 | |
2542 | init_zs_size_classes(); | |
2543 | ||
2544 | #ifdef CONFIG_ZPOOL | |
2545 | zpool_register_driver(&zs_zpool_driver); | |
2546 | #endif | |
0f050d99 | 2547 | |
4abaac9b DS |
2548 | zs_stat_init(); |
2549 | ||
66cdef66 | 2550 | return 0; |
0f050d99 | 2551 | |
0f050d99 GM |
2552 | notifier_fail: |
2553 | zs_unregister_cpu_notifier(); | |
48b4800a MK |
2554 | zsmalloc_unmount(); |
2555 | out: | |
0f050d99 | 2556 | return ret; |
61989a80 | 2557 | } |
61989a80 | 2558 | |
66cdef66 | 2559 | static void __exit zs_exit(void) |
61989a80 | 2560 | { |
66cdef66 GM |
2561 | #ifdef CONFIG_ZPOOL |
2562 | zpool_unregister_driver(&zs_zpool_driver); | |
2563 | #endif | |
48b4800a | 2564 | zsmalloc_unmount(); |
66cdef66 | 2565 | zs_unregister_cpu_notifier(); |
0f050d99 GM |
2566 | |
2567 | zs_stat_exit(); | |
61989a80 | 2568 | } |
069f101f BH |
2569 | |
2570 | module_init(zs_init); | |
2571 | module_exit(zs_exit); | |
2572 | ||
2573 | MODULE_LICENSE("Dual BSD/GPL"); | |
2574 | MODULE_AUTHOR("Nitin Gupta <ngupta@vflare.org>"); |