Nitin Gupta | 61989a8 | 2012-01-09 16:51:56 -0600 | [diff] [blame] | 1 | /* |
| 2 | * zsmalloc memory allocator |
| 3 | * |
| 4 | * Copyright (C) 2011 Nitin Gupta |
Minchan Kim | 31fc00b | 2014-01-30 15:45:55 -0800 | [diff] [blame] | 5 | * Copyright (C) 2012, 2013 Minchan Kim |
Nitin Gupta | 61989a8 | 2012-01-09 16:51:56 -0600 | [diff] [blame] | 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 | |
Nitin Gupta | 2db51da | 2012-06-09 17:41:14 -0700 | [diff] [blame] | 14 | /* |
Nitin Cupta | c3e3e88 | 2013-12-11 11:04:37 +0900 | [diff] [blame] | 15 | * This allocator is designed for use with zram. Thus, the allocator is |
| 16 | * supposed to work well under low memory conditions. In particular, it |
| 17 | * never attempts higher order page allocation which is very likely to |
| 18 | * fail under memory pressure. On the other hand, if we just use single |
| 19 | * (0-order) pages, it would suffer from very high fragmentation -- |
| 20 | * any object of size PAGE_SIZE/2 or larger would occupy an entire page. |
| 21 | * This was one of the major issues with its predecessor (xvmalloc). |
Nitin Gupta | 2db51da | 2012-06-09 17:41:14 -0700 | [diff] [blame] | 22 | * |
| 23 | * To overcome these issues, zsmalloc allocates a bunch of 0-order pages |
| 24 | * and links them together using various 'struct page' fields. These linked |
| 25 | * pages act as a single higher-order page i.e. an object can span 0-order |
| 26 | * page boundaries. The code refers to these linked pages as a single entity |
| 27 | * called zspage. |
| 28 | * |
Nitin Cupta | c3e3e88 | 2013-12-11 11:04:37 +0900 | [diff] [blame] | 29 | * For simplicity, zsmalloc can only allocate objects of size up to PAGE_SIZE |
| 30 | * since this satisfies the requirements of all its current users (in the |
| 31 | * worst case, page is incompressible and is thus stored "as-is" i.e. in |
| 32 | * uncompressed form). For allocation requests larger than this size, failure |
| 33 | * is returned (see zs_malloc). |
| 34 | * |
| 35 | * Additionally, zs_malloc() does not return a dereferenceable pointer. |
| 36 | * Instead, it returns an opaque handle (unsigned long) which encodes actual |
| 37 | * location of the allocated object. The reason for this indirection is that |
| 38 | * zsmalloc does not keep zspages permanently mapped since that would cause |
| 39 | * issues on 32-bit systems where the VA region for kernel space mappings |
| 40 | * is very small. So, before using the allocating memory, the object has to |
| 41 | * be mapped using zs_map_object() to get a usable pointer and subsequently |
| 42 | * unmapped using zs_unmap_object(). |
| 43 | * |
Nitin Gupta | 2db51da | 2012-06-09 17:41:14 -0700 | [diff] [blame] | 44 | * Following is how we use various fields and flags of underlying |
| 45 | * struct page(s) to form a zspage. |
| 46 | * |
| 47 | * Usage of struct page fields: |
| 48 | * page->first_page: points to the first component (0-order) page |
| 49 | * page->index (union with page->freelist): offset of the first object |
| 50 | * starting in this page. For the first page, this is |
| 51 | * always 0, so we use this field (aka freelist) to point |
| 52 | * to the first free object in zspage. |
| 53 | * page->lru: links together all component pages (except the first page) |
| 54 | * of a zspage |
| 55 | * |
| 56 | * For _first_ page only: |
| 57 | * |
| 58 | * page->private (union with page->first_page): refers to the |
| 59 | * component page after the first page |
| 60 | * page->freelist: points to the first free object in zspage. |
| 61 | * Free objects are linked together using in-place |
| 62 | * metadata. |
| 63 | * page->objects: maximum number of objects we can store in this |
| 64 | * zspage (class->zspage_order * PAGE_SIZE / class->size) |
| 65 | * page->lru: links together first pages of various zspages. |
| 66 | * Basically forming list of zspages in a fullness group. |
| 67 | * page->mapping: class index and fullness group of the zspage |
| 68 | * |
| 69 | * Usage of struct page flags: |
| 70 | * PG_private: identifies the first component page |
| 71 | * PG_private2: identifies the last component page |
| 72 | * |
| 73 | */ |
| 74 | |
Nitin Gupta | 61989a8 | 2012-01-09 16:51:56 -0600 | [diff] [blame] | 75 | #ifdef CONFIG_ZSMALLOC_DEBUG |
| 76 | #define DEBUG |
| 77 | #endif |
| 78 | |
| 79 | #include <linux/module.h> |
| 80 | #include <linux/kernel.h> |
Minchan Kim | 312fcae | 2015-04-15 16:15:30 -0700 | [diff] [blame^] | 81 | #include <linux/sched.h> |
Nitin Gupta | 61989a8 | 2012-01-09 16:51:56 -0600 | [diff] [blame] | 82 | #include <linux/bitops.h> |
| 83 | #include <linux/errno.h> |
| 84 | #include <linux/highmem.h> |
Nitin Gupta | 61989a8 | 2012-01-09 16:51:56 -0600 | [diff] [blame] | 85 | #include <linux/string.h> |
| 86 | #include <linux/slab.h> |
| 87 | #include <asm/tlbflush.h> |
| 88 | #include <asm/pgtable.h> |
| 89 | #include <linux/cpumask.h> |
| 90 | #include <linux/cpu.h> |
Seth Jennings | 0cbb613 | 2012-02-13 08:47:49 -0600 | [diff] [blame] | 91 | #include <linux/vmalloc.h> |
Seth Jennings | c60369f | 2012-07-18 11:55:55 -0500 | [diff] [blame] | 92 | #include <linux/hardirq.h> |
Seth Jennings | 0959c63 | 2012-08-08 15:12:17 +0900 | [diff] [blame] | 93 | #include <linux/spinlock.h> |
| 94 | #include <linux/types.h> |
Ganesh Mahendran | 0f050d9 | 2015-02-12 15:00:54 -0800 | [diff] [blame] | 95 | #include <linux/debugfs.h> |
Minchan Kim | bcf1647 | 2014-01-30 15:45:50 -0800 | [diff] [blame] | 96 | #include <linux/zsmalloc.h> |
Dan Streetman | c795779 | 2014-08-06 16:08:38 -0700 | [diff] [blame] | 97 | #include <linux/zpool.h> |
Seth Jennings | 0959c63 | 2012-08-08 15:12:17 +0900 | [diff] [blame] | 98 | |
| 99 | /* |
| 100 | * This must be power of 2 and greater than of equal to sizeof(link_free). |
| 101 | * These two conditions ensure that any 'struct link_free' itself doesn't |
| 102 | * span more than 1 page which avoids complex case of mapping 2 pages simply |
| 103 | * to restore link_free pointer values. |
| 104 | */ |
| 105 | #define ZS_ALIGN 8 |
| 106 | |
| 107 | /* |
| 108 | * A single 'zspage' is composed of up to 2^N discontiguous 0-order (single) |
| 109 | * pages. ZS_MAX_ZSPAGE_ORDER defines upper limit on N. |
| 110 | */ |
| 111 | #define ZS_MAX_ZSPAGE_ORDER 2 |
| 112 | #define ZS_MAX_PAGES_PER_ZSPAGE (_AC(1, UL) << ZS_MAX_ZSPAGE_ORDER) |
| 113 | |
Minchan Kim | 2e40e16 | 2015-04-15 16:15:23 -0700 | [diff] [blame] | 114 | #define ZS_HANDLE_SIZE (sizeof(unsigned long)) |
| 115 | |
Seth Jennings | 0959c63 | 2012-08-08 15:12:17 +0900 | [diff] [blame] | 116 | /* |
| 117 | * Object location (<PFN>, <obj_idx>) is encoded as |
Nitin Cupta | c3e3e88 | 2013-12-11 11:04:37 +0900 | [diff] [blame] | 118 | * as single (unsigned long) handle value. |
Seth Jennings | 0959c63 | 2012-08-08 15:12:17 +0900 | [diff] [blame] | 119 | * |
| 120 | * Note that object index <obj_idx> is relative to system |
| 121 | * page <PFN> it is stored in, so for each sub-page belonging |
| 122 | * to a zspage, obj_idx starts with 0. |
| 123 | * |
| 124 | * This is made more complicated by various memory models and PAE. |
| 125 | */ |
| 126 | |
| 127 | #ifndef MAX_PHYSMEM_BITS |
| 128 | #ifdef CONFIG_HIGHMEM64G |
| 129 | #define MAX_PHYSMEM_BITS 36 |
| 130 | #else /* !CONFIG_HIGHMEM64G */ |
| 131 | /* |
| 132 | * If this definition of MAX_PHYSMEM_BITS is used, OBJ_INDEX_BITS will just |
| 133 | * be PAGE_SHIFT |
| 134 | */ |
| 135 | #define MAX_PHYSMEM_BITS BITS_PER_LONG |
| 136 | #endif |
| 137 | #endif |
| 138 | #define _PFN_BITS (MAX_PHYSMEM_BITS - PAGE_SHIFT) |
Minchan Kim | 312fcae | 2015-04-15 16:15:30 -0700 | [diff] [blame^] | 139 | |
| 140 | /* |
| 141 | * Memory for allocating for handle keeps object position by |
| 142 | * encoding <page, obj_idx> and the encoded value has a room |
| 143 | * in least bit(ie, look at obj_to_location). |
| 144 | * We use the bit to synchronize between object access by |
| 145 | * user and migration. |
| 146 | */ |
| 147 | #define HANDLE_PIN_BIT 0 |
| 148 | |
| 149 | /* |
| 150 | * Head in allocated object should have OBJ_ALLOCATED_TAG |
| 151 | * to identify the object was allocated or not. |
| 152 | * It's okay to add the status bit in the least bit because |
| 153 | * header keeps handle which is 4byte-aligned address so we |
| 154 | * have room for two bit at least. |
| 155 | */ |
| 156 | #define OBJ_ALLOCATED_TAG 1 |
| 157 | #define OBJ_TAG_BITS 1 |
| 158 | #define OBJ_INDEX_BITS (BITS_PER_LONG - _PFN_BITS - OBJ_TAG_BITS) |
Seth Jennings | 0959c63 | 2012-08-08 15:12:17 +0900 | [diff] [blame] | 159 | #define OBJ_INDEX_MASK ((_AC(1, UL) << OBJ_INDEX_BITS) - 1) |
| 160 | |
| 161 | #define MAX(a, b) ((a) >= (b) ? (a) : (b)) |
| 162 | /* ZS_MIN_ALLOC_SIZE must be multiple of ZS_ALIGN */ |
| 163 | #define ZS_MIN_ALLOC_SIZE \ |
| 164 | MAX(32, (ZS_MAX_PAGES_PER_ZSPAGE << PAGE_SHIFT >> OBJ_INDEX_BITS)) |
Minchan Kim | 2e40e16 | 2015-04-15 16:15:23 -0700 | [diff] [blame] | 165 | /* each chunk includes extra space to keep handle */ |
| 166 | #define ZS_MAX_ALLOC_SIZE (PAGE_SIZE + ZS_HANDLE_SIZE) |
Seth Jennings | 0959c63 | 2012-08-08 15:12:17 +0900 | [diff] [blame] | 167 | |
| 168 | /* |
Weijie Yang | 7eb5251 | 2014-06-04 16:11:08 -0700 | [diff] [blame] | 169 | * On systems with 4K page size, this gives 255 size classes! There is a |
Seth Jennings | 0959c63 | 2012-08-08 15:12:17 +0900 | [diff] [blame] | 170 | * trader-off here: |
| 171 | * - Large number of size classes is potentially wasteful as free page are |
| 172 | * spread across these classes |
| 173 | * - Small number of size classes causes large internal fragmentation |
| 174 | * - Probably its better to use specific size classes (empirically |
| 175 | * determined). NOTE: all those class sizes must be set as multiple of |
| 176 | * ZS_ALIGN to make sure link_free itself never has to span 2 pages. |
| 177 | * |
| 178 | * ZS_MIN_ALLOC_SIZE and ZS_SIZE_CLASS_DELTA must be multiple of ZS_ALIGN |
| 179 | * (reason above) |
| 180 | */ |
Seth Jennings | d662b8e | 2013-01-25 11:46:18 -0600 | [diff] [blame] | 181 | #define ZS_SIZE_CLASS_DELTA (PAGE_SIZE >> 8) |
Seth Jennings | 0959c63 | 2012-08-08 15:12:17 +0900 | [diff] [blame] | 182 | |
| 183 | /* |
| 184 | * We do not maintain any list for completely empty or full pages |
| 185 | */ |
| 186 | enum fullness_group { |
| 187 | ZS_ALMOST_FULL, |
| 188 | ZS_ALMOST_EMPTY, |
| 189 | _ZS_NR_FULLNESS_GROUPS, |
| 190 | |
| 191 | ZS_EMPTY, |
| 192 | ZS_FULL |
| 193 | }; |
| 194 | |
Ganesh Mahendran | 0f050d9 | 2015-02-12 15:00:54 -0800 | [diff] [blame] | 195 | enum zs_stat_type { |
| 196 | OBJ_ALLOCATED, |
| 197 | OBJ_USED, |
| 198 | NR_ZS_STAT_TYPE, |
| 199 | }; |
| 200 | |
| 201 | #ifdef CONFIG_ZSMALLOC_STAT |
| 202 | |
| 203 | static struct dentry *zs_stat_root; |
| 204 | |
| 205 | struct zs_size_stat { |
| 206 | unsigned long objs[NR_ZS_STAT_TYPE]; |
| 207 | }; |
| 208 | |
| 209 | #endif |
| 210 | |
Seth Jennings | 0959c63 | 2012-08-08 15:12:17 +0900 | [diff] [blame] | 211 | /* |
Mahendran Ganesh | 40f9fb8 | 2014-12-12 16:57:01 -0800 | [diff] [blame] | 212 | * number of size_classes |
| 213 | */ |
| 214 | static int zs_size_classes; |
| 215 | |
| 216 | /* |
Seth Jennings | 0959c63 | 2012-08-08 15:12:17 +0900 | [diff] [blame] | 217 | * We assign a page to ZS_ALMOST_EMPTY fullness group when: |
| 218 | * n <= N / f, where |
| 219 | * n = number of allocated objects |
| 220 | * N = total number of objects zspage can store |
Wang Sheng-Hui | 6dd9737 | 2014-10-09 15:29:59 -0700 | [diff] [blame] | 221 | * f = fullness_threshold_frac |
Seth Jennings | 0959c63 | 2012-08-08 15:12:17 +0900 | [diff] [blame] | 222 | * |
| 223 | * Similarly, we assign zspage to: |
| 224 | * ZS_ALMOST_FULL when n > N / f |
| 225 | * ZS_EMPTY when n == 0 |
| 226 | * ZS_FULL when n == N |
| 227 | * |
| 228 | * (see: fix_fullness_group()) |
| 229 | */ |
| 230 | static const int fullness_threshold_frac = 4; |
| 231 | |
| 232 | struct size_class { |
| 233 | /* |
| 234 | * Size of objects stored in this class. Must be multiple |
| 235 | * of ZS_ALIGN. |
| 236 | */ |
| 237 | int size; |
| 238 | unsigned int index; |
| 239 | |
| 240 | /* Number of PAGE_SIZE sized pages to combine to form a 'zspage' */ |
| 241 | int pages_per_zspage; |
| 242 | |
Ganesh Mahendran | 0f050d9 | 2015-02-12 15:00:54 -0800 | [diff] [blame] | 243 | #ifdef CONFIG_ZSMALLOC_STAT |
| 244 | struct zs_size_stat stats; |
| 245 | #endif |
| 246 | |
Seth Jennings | 0959c63 | 2012-08-08 15:12:17 +0900 | [diff] [blame] | 247 | spinlock_t lock; |
| 248 | |
Seth Jennings | 0959c63 | 2012-08-08 15:12:17 +0900 | [diff] [blame] | 249 | struct page *fullness_list[_ZS_NR_FULLNESS_GROUPS]; |
| 250 | }; |
| 251 | |
| 252 | /* |
| 253 | * Placed within free objects to form a singly linked list. |
| 254 | * For every zspage, first_page->freelist gives head of this list. |
| 255 | * |
| 256 | * This must be power of 2 and less than or equal to ZS_ALIGN |
| 257 | */ |
| 258 | struct link_free { |
Minchan Kim | 2e40e16 | 2015-04-15 16:15:23 -0700 | [diff] [blame] | 259 | union { |
| 260 | /* |
| 261 | * Position of next free chunk (encodes <PFN, obj_idx>) |
| 262 | * It's valid for non-allocated object |
| 263 | */ |
| 264 | void *next; |
| 265 | /* |
| 266 | * Handle of allocated object. |
| 267 | */ |
| 268 | unsigned long handle; |
| 269 | }; |
Seth Jennings | 0959c63 | 2012-08-08 15:12:17 +0900 | [diff] [blame] | 270 | }; |
| 271 | |
| 272 | struct zs_pool { |
Ganesh Mahendran | 0f050d9 | 2015-02-12 15:00:54 -0800 | [diff] [blame] | 273 | char *name; |
| 274 | |
Mahendran Ganesh | 40f9fb8 | 2014-12-12 16:57:01 -0800 | [diff] [blame] | 275 | struct size_class **size_class; |
Minchan Kim | 2e40e16 | 2015-04-15 16:15:23 -0700 | [diff] [blame] | 276 | struct kmem_cache *handle_cachep; |
Seth Jennings | 0959c63 | 2012-08-08 15:12:17 +0900 | [diff] [blame] | 277 | |
| 278 | gfp_t flags; /* allocation flags used when growing pool */ |
Minchan Kim | 13de893 | 2014-10-09 15:29:48 -0700 | [diff] [blame] | 279 | atomic_long_t pages_allocated; |
Ganesh Mahendran | 0f050d9 | 2015-02-12 15:00:54 -0800 | [diff] [blame] | 280 | |
| 281 | #ifdef CONFIG_ZSMALLOC_STAT |
| 282 | struct dentry *stat_dentry; |
| 283 | #endif |
Seth Jennings | 0959c63 | 2012-08-08 15:12:17 +0900 | [diff] [blame] | 284 | }; |
Nitin Gupta | 61989a8 | 2012-01-09 16:51:56 -0600 | [diff] [blame] | 285 | |
| 286 | /* |
| 287 | * A zspage's class index and fullness group |
| 288 | * are encoded in its (first)page->mapping |
| 289 | */ |
| 290 | #define CLASS_IDX_BITS 28 |
| 291 | #define FULLNESS_BITS 4 |
| 292 | #define CLASS_IDX_MASK ((1 << CLASS_IDX_BITS) - 1) |
| 293 | #define FULLNESS_MASK ((1 << FULLNESS_BITS) - 1) |
| 294 | |
Seth Jennings | f553646 | 2012-07-18 11:55:56 -0500 | [diff] [blame] | 295 | struct mapping_area { |
Minchan Kim | 1b945ae | 2013-12-11 11:04:36 +0900 | [diff] [blame] | 296 | #ifdef CONFIG_PGTABLE_MAPPING |
Seth Jennings | f553646 | 2012-07-18 11:55:56 -0500 | [diff] [blame] | 297 | struct vm_struct *vm; /* vm area for mapping object that span pages */ |
| 298 | #else |
| 299 | char *vm_buf; /* copy buffer for objects that span pages */ |
| 300 | #endif |
| 301 | char *vm_addr; /* address of kmap_atomic()'ed pages */ |
| 302 | enum zs_mapmode vm_mm; /* mapping mode */ |
| 303 | }; |
| 304 | |
Minchan Kim | 2e40e16 | 2015-04-15 16:15:23 -0700 | [diff] [blame] | 305 | static int create_handle_cache(struct zs_pool *pool) |
| 306 | { |
| 307 | pool->handle_cachep = kmem_cache_create("zs_handle", ZS_HANDLE_SIZE, |
| 308 | 0, 0, NULL); |
| 309 | return pool->handle_cachep ? 0 : 1; |
| 310 | } |
| 311 | |
| 312 | static void destroy_handle_cache(struct zs_pool *pool) |
| 313 | { |
| 314 | kmem_cache_destroy(pool->handle_cachep); |
| 315 | } |
| 316 | |
| 317 | static unsigned long alloc_handle(struct zs_pool *pool) |
| 318 | { |
| 319 | return (unsigned long)kmem_cache_alloc(pool->handle_cachep, |
| 320 | pool->flags & ~__GFP_HIGHMEM); |
| 321 | } |
| 322 | |
| 323 | static void free_handle(struct zs_pool *pool, unsigned long handle) |
| 324 | { |
| 325 | kmem_cache_free(pool->handle_cachep, (void *)handle); |
| 326 | } |
| 327 | |
| 328 | static void record_obj(unsigned long handle, unsigned long obj) |
| 329 | { |
| 330 | *(unsigned long *)handle = obj; |
| 331 | } |
| 332 | |
Dan Streetman | c795779 | 2014-08-06 16:08:38 -0700 | [diff] [blame] | 333 | /* zpool driver */ |
| 334 | |
| 335 | #ifdef CONFIG_ZPOOL |
| 336 | |
Ganesh Mahendran | 3eba0c6 | 2015-02-12 15:00:51 -0800 | [diff] [blame] | 337 | static void *zs_zpool_create(char *name, gfp_t gfp, struct zpool_ops *zpool_ops) |
Dan Streetman | c795779 | 2014-08-06 16:08:38 -0700 | [diff] [blame] | 338 | { |
Ganesh Mahendran | 3eba0c6 | 2015-02-12 15:00:51 -0800 | [diff] [blame] | 339 | return zs_create_pool(name, gfp); |
Dan Streetman | c795779 | 2014-08-06 16:08:38 -0700 | [diff] [blame] | 340 | } |
| 341 | |
| 342 | static void zs_zpool_destroy(void *pool) |
| 343 | { |
| 344 | zs_destroy_pool(pool); |
| 345 | } |
| 346 | |
| 347 | static int zs_zpool_malloc(void *pool, size_t size, gfp_t gfp, |
| 348 | unsigned long *handle) |
| 349 | { |
| 350 | *handle = zs_malloc(pool, size); |
| 351 | return *handle ? 0 : -1; |
| 352 | } |
| 353 | static void zs_zpool_free(void *pool, unsigned long handle) |
| 354 | { |
| 355 | zs_free(pool, handle); |
| 356 | } |
| 357 | |
| 358 | static int zs_zpool_shrink(void *pool, unsigned int pages, |
| 359 | unsigned int *reclaimed) |
| 360 | { |
| 361 | return -EINVAL; |
| 362 | } |
| 363 | |
| 364 | static void *zs_zpool_map(void *pool, unsigned long handle, |
| 365 | enum zpool_mapmode mm) |
| 366 | { |
| 367 | enum zs_mapmode zs_mm; |
| 368 | |
| 369 | switch (mm) { |
| 370 | case ZPOOL_MM_RO: |
| 371 | zs_mm = ZS_MM_RO; |
| 372 | break; |
| 373 | case ZPOOL_MM_WO: |
| 374 | zs_mm = ZS_MM_WO; |
| 375 | break; |
| 376 | case ZPOOL_MM_RW: /* fallthru */ |
| 377 | default: |
| 378 | zs_mm = ZS_MM_RW; |
| 379 | break; |
| 380 | } |
| 381 | |
| 382 | return zs_map_object(pool, handle, zs_mm); |
| 383 | } |
| 384 | static void zs_zpool_unmap(void *pool, unsigned long handle) |
| 385 | { |
| 386 | zs_unmap_object(pool, handle); |
| 387 | } |
| 388 | |
| 389 | static u64 zs_zpool_total_size(void *pool) |
| 390 | { |
Minchan Kim | 722cdc1 | 2014-10-09 15:29:50 -0700 | [diff] [blame] | 391 | return zs_get_total_pages(pool) << PAGE_SHIFT; |
Dan Streetman | c795779 | 2014-08-06 16:08:38 -0700 | [diff] [blame] | 392 | } |
| 393 | |
| 394 | static struct zpool_driver zs_zpool_driver = { |
| 395 | .type = "zsmalloc", |
| 396 | .owner = THIS_MODULE, |
| 397 | .create = zs_zpool_create, |
| 398 | .destroy = zs_zpool_destroy, |
| 399 | .malloc = zs_zpool_malloc, |
| 400 | .free = zs_zpool_free, |
| 401 | .shrink = zs_zpool_shrink, |
| 402 | .map = zs_zpool_map, |
| 403 | .unmap = zs_zpool_unmap, |
| 404 | .total_size = zs_zpool_total_size, |
| 405 | }; |
| 406 | |
Kees Cook | 137f8cf | 2014-08-29 15:18:40 -0700 | [diff] [blame] | 407 | MODULE_ALIAS("zpool-zsmalloc"); |
Dan Streetman | c795779 | 2014-08-06 16:08:38 -0700 | [diff] [blame] | 408 | #endif /* CONFIG_ZPOOL */ |
| 409 | |
Nitin Gupta | 61989a8 | 2012-01-09 16:51:56 -0600 | [diff] [blame] | 410 | /* per-cpu VM mapping areas for zspage accesses that cross page boundaries */ |
| 411 | static DEFINE_PER_CPU(struct mapping_area, zs_map_area); |
| 412 | |
| 413 | static int is_first_page(struct page *page) |
| 414 | { |
Minchan Kim | a27545bf | 2012-04-25 15:23:09 +0900 | [diff] [blame] | 415 | return PagePrivate(page); |
Nitin Gupta | 61989a8 | 2012-01-09 16:51:56 -0600 | [diff] [blame] | 416 | } |
| 417 | |
| 418 | static int is_last_page(struct page *page) |
| 419 | { |
Minchan Kim | a27545bf | 2012-04-25 15:23:09 +0900 | [diff] [blame] | 420 | return PagePrivate2(page); |
Nitin Gupta | 61989a8 | 2012-01-09 16:51:56 -0600 | [diff] [blame] | 421 | } |
| 422 | |
| 423 | static void get_zspage_mapping(struct page *page, unsigned int *class_idx, |
| 424 | enum fullness_group *fullness) |
| 425 | { |
| 426 | unsigned long m; |
| 427 | BUG_ON(!is_first_page(page)); |
| 428 | |
| 429 | m = (unsigned long)page->mapping; |
| 430 | *fullness = m & FULLNESS_MASK; |
| 431 | *class_idx = (m >> FULLNESS_BITS) & CLASS_IDX_MASK; |
| 432 | } |
| 433 | |
| 434 | static void set_zspage_mapping(struct page *page, unsigned int class_idx, |
| 435 | enum fullness_group fullness) |
| 436 | { |
| 437 | unsigned long m; |
| 438 | BUG_ON(!is_first_page(page)); |
| 439 | |
| 440 | m = ((class_idx & CLASS_IDX_MASK) << FULLNESS_BITS) | |
| 441 | (fullness & FULLNESS_MASK); |
| 442 | page->mapping = (struct address_space *)m; |
| 443 | } |
| 444 | |
Nitin Cupta | c3e3e88 | 2013-12-11 11:04:37 +0900 | [diff] [blame] | 445 | /* |
| 446 | * zsmalloc divides the pool into various size classes where each |
| 447 | * class maintains a list of zspages where each zspage is divided |
| 448 | * into equal sized chunks. Each allocation falls into one of these |
| 449 | * classes depending on its size. This function returns index of the |
| 450 | * size class which has chunk size big enough to hold the give size. |
| 451 | */ |
Nitin Gupta | 61989a8 | 2012-01-09 16:51:56 -0600 | [diff] [blame] | 452 | static int get_size_class_index(int size) |
| 453 | { |
| 454 | int idx = 0; |
| 455 | |
| 456 | if (likely(size > ZS_MIN_ALLOC_SIZE)) |
| 457 | idx = DIV_ROUND_UP(size - ZS_MIN_ALLOC_SIZE, |
| 458 | ZS_SIZE_CLASS_DELTA); |
| 459 | |
| 460 | return idx; |
| 461 | } |
| 462 | |
Nitin Cupta | c3e3e88 | 2013-12-11 11:04:37 +0900 | [diff] [blame] | 463 | /* |
| 464 | * For each size class, zspages are divided into different groups |
| 465 | * depending on how "full" they are. This was done so that we could |
| 466 | * easily find empty or nearly empty zspages when we try to shrink |
| 467 | * the pool (not yet implemented). This function returns fullness |
| 468 | * status of the given page. |
| 469 | */ |
Nitin Gupta | 61989a8 | 2012-01-09 16:51:56 -0600 | [diff] [blame] | 470 | static enum fullness_group get_fullness_group(struct page *page) |
| 471 | { |
| 472 | int inuse, max_objects; |
| 473 | enum fullness_group fg; |
| 474 | BUG_ON(!is_first_page(page)); |
| 475 | |
| 476 | inuse = page->inuse; |
| 477 | max_objects = page->objects; |
| 478 | |
| 479 | if (inuse == 0) |
| 480 | fg = ZS_EMPTY; |
| 481 | else if (inuse == max_objects) |
| 482 | fg = ZS_FULL; |
| 483 | else if (inuse <= max_objects / fullness_threshold_frac) |
| 484 | fg = ZS_ALMOST_EMPTY; |
| 485 | else |
| 486 | fg = ZS_ALMOST_FULL; |
| 487 | |
| 488 | return fg; |
| 489 | } |
| 490 | |
Nitin Cupta | c3e3e88 | 2013-12-11 11:04:37 +0900 | [diff] [blame] | 491 | /* |
| 492 | * Each size class maintains various freelists and zspages are assigned |
| 493 | * to one of these freelists based on the number of live objects they |
| 494 | * have. This functions inserts the given zspage into the freelist |
| 495 | * identified by <class, fullness_group>. |
| 496 | */ |
Nitin Gupta | 61989a8 | 2012-01-09 16:51:56 -0600 | [diff] [blame] | 497 | static void insert_zspage(struct page *page, struct size_class *class, |
| 498 | enum fullness_group fullness) |
| 499 | { |
| 500 | struct page **head; |
| 501 | |
| 502 | BUG_ON(!is_first_page(page)); |
| 503 | |
| 504 | if (fullness >= _ZS_NR_FULLNESS_GROUPS) |
| 505 | return; |
| 506 | |
| 507 | head = &class->fullness_list[fullness]; |
| 508 | if (*head) |
| 509 | list_add_tail(&page->lru, &(*head)->lru); |
| 510 | |
| 511 | *head = page; |
| 512 | } |
| 513 | |
Nitin Cupta | c3e3e88 | 2013-12-11 11:04:37 +0900 | [diff] [blame] | 514 | /* |
| 515 | * This function removes the given zspage from the freelist identified |
| 516 | * by <class, fullness_group>. |
| 517 | */ |
Nitin Gupta | 61989a8 | 2012-01-09 16:51:56 -0600 | [diff] [blame] | 518 | static void remove_zspage(struct page *page, struct size_class *class, |
| 519 | enum fullness_group fullness) |
| 520 | { |
| 521 | struct page **head; |
| 522 | |
| 523 | BUG_ON(!is_first_page(page)); |
| 524 | |
| 525 | if (fullness >= _ZS_NR_FULLNESS_GROUPS) |
| 526 | return; |
| 527 | |
| 528 | head = &class->fullness_list[fullness]; |
| 529 | BUG_ON(!*head); |
| 530 | if (list_empty(&(*head)->lru)) |
| 531 | *head = NULL; |
| 532 | else if (*head == page) |
| 533 | *head = (struct page *)list_entry((*head)->lru.next, |
| 534 | struct page, lru); |
| 535 | |
| 536 | list_del_init(&page->lru); |
| 537 | } |
| 538 | |
Nitin Cupta | c3e3e88 | 2013-12-11 11:04:37 +0900 | [diff] [blame] | 539 | /* |
| 540 | * Each size class maintains zspages in different fullness groups depending |
| 541 | * on the number of live objects they contain. When allocating or freeing |
| 542 | * objects, the fullness status of the page can change, say, from ALMOST_FULL |
| 543 | * to ALMOST_EMPTY when freeing an object. This function checks if such |
| 544 | * a status change has occurred for the given page and accordingly moves the |
| 545 | * page from the freelist of the old fullness group to that of the new |
| 546 | * fullness group. |
| 547 | */ |
Minchan Kim | c780626 | 2015-04-15 16:15:26 -0700 | [diff] [blame] | 548 | static enum fullness_group fix_fullness_group(struct size_class *class, |
Nitin Gupta | 61989a8 | 2012-01-09 16:51:56 -0600 | [diff] [blame] | 549 | struct page *page) |
| 550 | { |
| 551 | int class_idx; |
Nitin Gupta | 61989a8 | 2012-01-09 16:51:56 -0600 | [diff] [blame] | 552 | enum fullness_group currfg, newfg; |
| 553 | |
| 554 | BUG_ON(!is_first_page(page)); |
| 555 | |
| 556 | get_zspage_mapping(page, &class_idx, &currfg); |
| 557 | newfg = get_fullness_group(page); |
| 558 | if (newfg == currfg) |
| 559 | goto out; |
| 560 | |
Nitin Gupta | 61989a8 | 2012-01-09 16:51:56 -0600 | [diff] [blame] | 561 | remove_zspage(page, class, currfg); |
| 562 | insert_zspage(page, class, newfg); |
| 563 | set_zspage_mapping(page, class_idx, newfg); |
| 564 | |
| 565 | out: |
| 566 | return newfg; |
| 567 | } |
| 568 | |
| 569 | /* |
| 570 | * We have to decide on how many pages to link together |
| 571 | * to form a zspage for each size class. This is important |
| 572 | * to reduce wastage due to unusable space left at end of |
| 573 | * each zspage which is given as: |
| 574 | * wastage = Zp - Zp % size_class |
| 575 | * where Zp = zspage size = k * PAGE_SIZE where k = 1, 2, ... |
| 576 | * |
| 577 | * For example, for size class of 3/8 * PAGE_SIZE, we should |
| 578 | * link together 3 PAGE_SIZE sized pages to form a zspage |
| 579 | * since then we can perfectly fit in 8 such objects. |
| 580 | */ |
Minchan Kim | 2e3b615 | 2012-05-03 15:40:39 +0900 | [diff] [blame] | 581 | static int get_pages_per_zspage(int class_size) |
Nitin Gupta | 61989a8 | 2012-01-09 16:51:56 -0600 | [diff] [blame] | 582 | { |
| 583 | int i, max_usedpc = 0; |
| 584 | /* zspage order which gives maximum used size per KB */ |
| 585 | int max_usedpc_order = 1; |
| 586 | |
Seth Jennings | 84d4faa | 2012-03-05 11:33:21 -0600 | [diff] [blame] | 587 | for (i = 1; i <= ZS_MAX_PAGES_PER_ZSPAGE; i++) { |
Nitin Gupta | 61989a8 | 2012-01-09 16:51:56 -0600 | [diff] [blame] | 588 | int zspage_size; |
| 589 | int waste, usedpc; |
| 590 | |
| 591 | zspage_size = i * PAGE_SIZE; |
| 592 | waste = zspage_size % class_size; |
| 593 | usedpc = (zspage_size - waste) * 100 / zspage_size; |
| 594 | |
| 595 | if (usedpc > max_usedpc) { |
| 596 | max_usedpc = usedpc; |
| 597 | max_usedpc_order = i; |
| 598 | } |
| 599 | } |
| 600 | |
| 601 | return max_usedpc_order; |
| 602 | } |
| 603 | |
| 604 | /* |
| 605 | * A single 'zspage' is composed of many system pages which are |
| 606 | * linked together using fields in struct page. This function finds |
| 607 | * the first/head page, given any component page of a zspage. |
| 608 | */ |
| 609 | static struct page *get_first_page(struct page *page) |
| 610 | { |
| 611 | if (is_first_page(page)) |
| 612 | return page; |
| 613 | else |
| 614 | return page->first_page; |
| 615 | } |
| 616 | |
| 617 | static struct page *get_next_page(struct page *page) |
| 618 | { |
| 619 | struct page *next; |
| 620 | |
| 621 | if (is_last_page(page)) |
| 622 | next = NULL; |
| 623 | else if (is_first_page(page)) |
Sunghan Suh | e842b97 | 2013-07-12 16:08:13 +0900 | [diff] [blame] | 624 | next = (struct page *)page_private(page); |
Nitin Gupta | 61989a8 | 2012-01-09 16:51:56 -0600 | [diff] [blame] | 625 | else |
| 626 | next = list_entry(page->lru.next, struct page, lru); |
| 627 | |
| 628 | return next; |
| 629 | } |
| 630 | |
Olav Haugan | 6729687 | 2013-11-22 09:30:41 -0800 | [diff] [blame] | 631 | /* |
| 632 | * Encode <page, obj_idx> as a single handle value. |
Minchan Kim | 312fcae | 2015-04-15 16:15:30 -0700 | [diff] [blame^] | 633 | * We use the least bit of handle for tagging. |
Olav Haugan | 6729687 | 2013-11-22 09:30:41 -0800 | [diff] [blame] | 634 | */ |
Minchan Kim | 312fcae | 2015-04-15 16:15:30 -0700 | [diff] [blame^] | 635 | static void *location_to_obj(struct page *page, unsigned long obj_idx) |
Nitin Gupta | 61989a8 | 2012-01-09 16:51:56 -0600 | [diff] [blame] | 636 | { |
Minchan Kim | 312fcae | 2015-04-15 16:15:30 -0700 | [diff] [blame^] | 637 | unsigned long obj; |
Nitin Gupta | 61989a8 | 2012-01-09 16:51:56 -0600 | [diff] [blame] | 638 | |
| 639 | if (!page) { |
| 640 | BUG_ON(obj_idx); |
| 641 | return NULL; |
| 642 | } |
| 643 | |
Minchan Kim | 312fcae | 2015-04-15 16:15:30 -0700 | [diff] [blame^] | 644 | obj = page_to_pfn(page) << OBJ_INDEX_BITS; |
| 645 | obj |= ((obj_idx) & OBJ_INDEX_MASK); |
| 646 | obj <<= OBJ_TAG_BITS; |
Nitin Gupta | 61989a8 | 2012-01-09 16:51:56 -0600 | [diff] [blame] | 647 | |
Minchan Kim | 312fcae | 2015-04-15 16:15:30 -0700 | [diff] [blame^] | 648 | return (void *)obj; |
Nitin Gupta | 61989a8 | 2012-01-09 16:51:56 -0600 | [diff] [blame] | 649 | } |
| 650 | |
Olav Haugan | 6729687 | 2013-11-22 09:30:41 -0800 | [diff] [blame] | 651 | /* |
| 652 | * Decode <page, obj_idx> pair from the given object handle. We adjust the |
| 653 | * decoded obj_idx back to its original value since it was adjusted in |
Minchan Kim | 312fcae | 2015-04-15 16:15:30 -0700 | [diff] [blame^] | 654 | * location_to_obj(). |
Olav Haugan | 6729687 | 2013-11-22 09:30:41 -0800 | [diff] [blame] | 655 | */ |
Minchan Kim | 312fcae | 2015-04-15 16:15:30 -0700 | [diff] [blame^] | 656 | static void obj_to_location(unsigned long obj, struct page **page, |
Nitin Gupta | 61989a8 | 2012-01-09 16:51:56 -0600 | [diff] [blame] | 657 | unsigned long *obj_idx) |
| 658 | { |
Minchan Kim | 312fcae | 2015-04-15 16:15:30 -0700 | [diff] [blame^] | 659 | obj >>= OBJ_TAG_BITS; |
| 660 | *page = pfn_to_page(obj >> OBJ_INDEX_BITS); |
| 661 | *obj_idx = (obj & OBJ_INDEX_MASK); |
Nitin Gupta | 61989a8 | 2012-01-09 16:51:56 -0600 | [diff] [blame] | 662 | } |
| 663 | |
Minchan Kim | 2e40e16 | 2015-04-15 16:15:23 -0700 | [diff] [blame] | 664 | static unsigned long handle_to_obj(unsigned long handle) |
| 665 | { |
| 666 | return *(unsigned long *)handle; |
| 667 | } |
| 668 | |
Minchan Kim | 312fcae | 2015-04-15 16:15:30 -0700 | [diff] [blame^] | 669 | unsigned long obj_to_head(void *obj) |
| 670 | { |
| 671 | return *(unsigned long *)obj; |
| 672 | } |
| 673 | |
Nitin Gupta | 61989a8 | 2012-01-09 16:51:56 -0600 | [diff] [blame] | 674 | static unsigned long obj_idx_to_offset(struct page *page, |
| 675 | unsigned long obj_idx, int class_size) |
| 676 | { |
| 677 | unsigned long off = 0; |
| 678 | |
| 679 | if (!is_first_page(page)) |
| 680 | off = page->index; |
| 681 | |
| 682 | return off + obj_idx * class_size; |
| 683 | } |
| 684 | |
Minchan Kim | 312fcae | 2015-04-15 16:15:30 -0700 | [diff] [blame^] | 685 | static inline int trypin_tag(unsigned long handle) |
| 686 | { |
| 687 | unsigned long *ptr = (unsigned long *)handle; |
| 688 | |
| 689 | return !test_and_set_bit_lock(HANDLE_PIN_BIT, ptr); |
| 690 | } |
| 691 | |
| 692 | static void pin_tag(unsigned long handle) |
| 693 | { |
| 694 | while (!trypin_tag(handle)); |
| 695 | } |
| 696 | |
| 697 | static void unpin_tag(unsigned long handle) |
| 698 | { |
| 699 | unsigned long *ptr = (unsigned long *)handle; |
| 700 | |
| 701 | clear_bit_unlock(HANDLE_PIN_BIT, ptr); |
| 702 | } |
| 703 | |
Nitin Gupta | f4477e9 | 2012-04-02 09:13:56 -0500 | [diff] [blame] | 704 | static void reset_page(struct page *page) |
| 705 | { |
| 706 | clear_bit(PG_private, &page->flags); |
| 707 | clear_bit(PG_private_2, &page->flags); |
| 708 | set_page_private(page, 0); |
| 709 | page->mapping = NULL; |
| 710 | page->freelist = NULL; |
Mel Gorman | 22b751c | 2013-02-22 16:34:59 -0800 | [diff] [blame] | 711 | page_mapcount_reset(page); |
Nitin Gupta | f4477e9 | 2012-04-02 09:13:56 -0500 | [diff] [blame] | 712 | } |
| 713 | |
Nitin Gupta | 61989a8 | 2012-01-09 16:51:56 -0600 | [diff] [blame] | 714 | static void free_zspage(struct page *first_page) |
| 715 | { |
Nitin Gupta | f4477e9 | 2012-04-02 09:13:56 -0500 | [diff] [blame] | 716 | struct page *nextp, *tmp, *head_extra; |
Nitin Gupta | 61989a8 | 2012-01-09 16:51:56 -0600 | [diff] [blame] | 717 | |
| 718 | BUG_ON(!is_first_page(first_page)); |
| 719 | BUG_ON(first_page->inuse); |
| 720 | |
Nitin Gupta | f4477e9 | 2012-04-02 09:13:56 -0500 | [diff] [blame] | 721 | head_extra = (struct page *)page_private(first_page); |
Nitin Gupta | 61989a8 | 2012-01-09 16:51:56 -0600 | [diff] [blame] | 722 | |
Nitin Gupta | f4477e9 | 2012-04-02 09:13:56 -0500 | [diff] [blame] | 723 | reset_page(first_page); |
Nitin Gupta | 61989a8 | 2012-01-09 16:51:56 -0600 | [diff] [blame] | 724 | __free_page(first_page); |
| 725 | |
| 726 | /* zspage with only 1 system page */ |
Nitin Gupta | f4477e9 | 2012-04-02 09:13:56 -0500 | [diff] [blame] | 727 | if (!head_extra) |
Nitin Gupta | 61989a8 | 2012-01-09 16:51:56 -0600 | [diff] [blame] | 728 | return; |
| 729 | |
Nitin Gupta | f4477e9 | 2012-04-02 09:13:56 -0500 | [diff] [blame] | 730 | list_for_each_entry_safe(nextp, tmp, &head_extra->lru, lru) { |
Nitin Gupta | 61989a8 | 2012-01-09 16:51:56 -0600 | [diff] [blame] | 731 | list_del(&nextp->lru); |
Nitin Gupta | f4477e9 | 2012-04-02 09:13:56 -0500 | [diff] [blame] | 732 | reset_page(nextp); |
Nitin Gupta | 61989a8 | 2012-01-09 16:51:56 -0600 | [diff] [blame] | 733 | __free_page(nextp); |
| 734 | } |
Nitin Gupta | f4477e9 | 2012-04-02 09:13:56 -0500 | [diff] [blame] | 735 | reset_page(head_extra); |
| 736 | __free_page(head_extra); |
Nitin Gupta | 61989a8 | 2012-01-09 16:51:56 -0600 | [diff] [blame] | 737 | } |
| 738 | |
| 739 | /* Initialize a newly allocated zspage */ |
| 740 | static void init_zspage(struct page *first_page, struct size_class *class) |
| 741 | { |
| 742 | unsigned long off = 0; |
| 743 | struct page *page = first_page; |
| 744 | |
| 745 | BUG_ON(!is_first_page(first_page)); |
| 746 | while (page) { |
| 747 | struct page *next_page; |
| 748 | struct link_free *link; |
Dan Streetman | 5538c56 | 2014-10-09 15:30:01 -0700 | [diff] [blame] | 749 | unsigned int i = 1; |
Minchan Kim | af4ee5e | 2014-12-12 16:56:58 -0800 | [diff] [blame] | 750 | void *vaddr; |
Nitin Gupta | 61989a8 | 2012-01-09 16:51:56 -0600 | [diff] [blame] | 751 | |
| 752 | /* |
| 753 | * page->index stores offset of first object starting |
| 754 | * in the page. For the first page, this is always 0, |
| 755 | * so we use first_page->index (aka ->freelist) to store |
| 756 | * head of corresponding zspage's freelist. |
| 757 | */ |
| 758 | if (page != first_page) |
| 759 | page->index = off; |
| 760 | |
Minchan Kim | af4ee5e | 2014-12-12 16:56:58 -0800 | [diff] [blame] | 761 | vaddr = kmap_atomic(page); |
| 762 | link = (struct link_free *)vaddr + off / sizeof(*link); |
Nitin Gupta | 61989a8 | 2012-01-09 16:51:56 -0600 | [diff] [blame] | 763 | |
Dan Streetman | 5538c56 | 2014-10-09 15:30:01 -0700 | [diff] [blame] | 764 | while ((off += class->size) < PAGE_SIZE) { |
Minchan Kim | 312fcae | 2015-04-15 16:15:30 -0700 | [diff] [blame^] | 765 | link->next = location_to_obj(page, i++); |
Dan Streetman | 5538c56 | 2014-10-09 15:30:01 -0700 | [diff] [blame] | 766 | link += class->size / sizeof(*link); |
Nitin Gupta | 61989a8 | 2012-01-09 16:51:56 -0600 | [diff] [blame] | 767 | } |
| 768 | |
| 769 | /* |
| 770 | * We now come to the last (full or partial) object on this |
| 771 | * page, which must point to the first object on the next |
| 772 | * page (if present) |
| 773 | */ |
| 774 | next_page = get_next_page(page); |
Minchan Kim | 312fcae | 2015-04-15 16:15:30 -0700 | [diff] [blame^] | 775 | link->next = location_to_obj(next_page, 0); |
Minchan Kim | af4ee5e | 2014-12-12 16:56:58 -0800 | [diff] [blame] | 776 | kunmap_atomic(vaddr); |
Nitin Gupta | 61989a8 | 2012-01-09 16:51:56 -0600 | [diff] [blame] | 777 | page = next_page; |
Dan Streetman | 5538c56 | 2014-10-09 15:30:01 -0700 | [diff] [blame] | 778 | off %= PAGE_SIZE; |
Nitin Gupta | 61989a8 | 2012-01-09 16:51:56 -0600 | [diff] [blame] | 779 | } |
| 780 | } |
| 781 | |
| 782 | /* |
| 783 | * Allocate a zspage for the given size class |
| 784 | */ |
| 785 | static struct page *alloc_zspage(struct size_class *class, gfp_t flags) |
| 786 | { |
| 787 | int i, error; |
Seth Jennings | b4b700c | 2012-06-13 16:03:42 -0500 | [diff] [blame] | 788 | struct page *first_page = NULL, *uninitialized_var(prev_page); |
Nitin Gupta | 61989a8 | 2012-01-09 16:51:56 -0600 | [diff] [blame] | 789 | |
| 790 | /* |
| 791 | * Allocate individual pages and link them together as: |
| 792 | * 1. first page->private = first sub-page |
| 793 | * 2. all sub-pages are linked together using page->lru |
| 794 | * 3. each sub-page is linked to the first page using page->first_page |
| 795 | * |
| 796 | * For each size class, First/Head pages are linked together using |
| 797 | * page->lru. Also, we set PG_private to identify the first page |
| 798 | * (i.e. no other sub-page has this flag set) and PG_private_2 to |
| 799 | * identify the last page. |
| 800 | */ |
| 801 | error = -ENOMEM; |
Minchan Kim | 2e3b615 | 2012-05-03 15:40:39 +0900 | [diff] [blame] | 802 | for (i = 0; i < class->pages_per_zspage; i++) { |
Seth Jennings | b4b700c | 2012-06-13 16:03:42 -0500 | [diff] [blame] | 803 | struct page *page; |
Nitin Gupta | 61989a8 | 2012-01-09 16:51:56 -0600 | [diff] [blame] | 804 | |
| 805 | page = alloc_page(flags); |
| 806 | if (!page) |
| 807 | goto cleanup; |
| 808 | |
| 809 | INIT_LIST_HEAD(&page->lru); |
| 810 | if (i == 0) { /* first page */ |
Minchan Kim | a27545bf | 2012-04-25 15:23:09 +0900 | [diff] [blame] | 811 | SetPagePrivate(page); |
Nitin Gupta | 61989a8 | 2012-01-09 16:51:56 -0600 | [diff] [blame] | 812 | set_page_private(page, 0); |
| 813 | first_page = page; |
| 814 | first_page->inuse = 0; |
| 815 | } |
| 816 | if (i == 1) |
Sunghan Suh | e842b97 | 2013-07-12 16:08:13 +0900 | [diff] [blame] | 817 | set_page_private(first_page, (unsigned long)page); |
Nitin Gupta | 61989a8 | 2012-01-09 16:51:56 -0600 | [diff] [blame] | 818 | if (i >= 1) |
| 819 | page->first_page = first_page; |
| 820 | if (i >= 2) |
| 821 | list_add(&page->lru, &prev_page->lru); |
Minchan Kim | 2e3b615 | 2012-05-03 15:40:39 +0900 | [diff] [blame] | 822 | if (i == class->pages_per_zspage - 1) /* last page */ |
Minchan Kim | a27545bf | 2012-04-25 15:23:09 +0900 | [diff] [blame] | 823 | SetPagePrivate2(page); |
Nitin Gupta | 61989a8 | 2012-01-09 16:51:56 -0600 | [diff] [blame] | 824 | prev_page = page; |
| 825 | } |
| 826 | |
| 827 | init_zspage(first_page, class); |
| 828 | |
Minchan Kim | 312fcae | 2015-04-15 16:15:30 -0700 | [diff] [blame^] | 829 | first_page->freelist = location_to_obj(first_page, 0); |
Nitin Gupta | 61989a8 | 2012-01-09 16:51:56 -0600 | [diff] [blame] | 830 | /* Maximum number of objects we can store in this zspage */ |
Minchan Kim | 2e3b615 | 2012-05-03 15:40:39 +0900 | [diff] [blame] | 831 | first_page->objects = class->pages_per_zspage * PAGE_SIZE / class->size; |
Nitin Gupta | 61989a8 | 2012-01-09 16:51:56 -0600 | [diff] [blame] | 832 | |
| 833 | error = 0; /* Success */ |
| 834 | |
| 835 | cleanup: |
| 836 | if (unlikely(error) && first_page) { |
| 837 | free_zspage(first_page); |
| 838 | first_page = NULL; |
| 839 | } |
| 840 | |
| 841 | return first_page; |
| 842 | } |
| 843 | |
| 844 | static struct page *find_get_zspage(struct size_class *class) |
| 845 | { |
| 846 | int i; |
| 847 | struct page *page; |
| 848 | |
| 849 | for (i = 0; i < _ZS_NR_FULLNESS_GROUPS; i++) { |
| 850 | page = class->fullness_list[i]; |
| 851 | if (page) |
| 852 | break; |
| 853 | } |
| 854 | |
| 855 | return page; |
| 856 | } |
| 857 | |
Minchan Kim | 1b945ae | 2013-12-11 11:04:36 +0900 | [diff] [blame] | 858 | #ifdef CONFIG_PGTABLE_MAPPING |
Seth Jennings | f553646 | 2012-07-18 11:55:56 -0500 | [diff] [blame] | 859 | static inline int __zs_cpu_up(struct mapping_area *area) |
Seth Jennings | 5f60190 | 2012-07-02 16:15:49 -0500 | [diff] [blame] | 860 | { |
Seth Jennings | f553646 | 2012-07-18 11:55:56 -0500 | [diff] [blame] | 861 | /* |
| 862 | * Make sure we don't leak memory if a cpu UP notification |
| 863 | * and zs_init() race and both call zs_cpu_up() on the same cpu |
| 864 | */ |
| 865 | if (area->vm) |
| 866 | return 0; |
| 867 | area->vm = alloc_vm_area(PAGE_SIZE * 2, NULL); |
| 868 | if (!area->vm) |
| 869 | return -ENOMEM; |
| 870 | return 0; |
| 871 | } |
| 872 | |
| 873 | static inline void __zs_cpu_down(struct mapping_area *area) |
| 874 | { |
| 875 | if (area->vm) |
| 876 | free_vm_area(area->vm); |
| 877 | area->vm = NULL; |
| 878 | } |
| 879 | |
| 880 | static inline void *__zs_map_object(struct mapping_area *area, |
| 881 | struct page *pages[2], int off, int size) |
| 882 | { |
WANG Chao | f6f8ed4 | 2014-08-06 16:06:58 -0700 | [diff] [blame] | 883 | BUG_ON(map_vm_area(area->vm, PAGE_KERNEL, pages)); |
Seth Jennings | f553646 | 2012-07-18 11:55:56 -0500 | [diff] [blame] | 884 | area->vm_addr = area->vm->addr; |
| 885 | return area->vm_addr + off; |
| 886 | } |
| 887 | |
| 888 | static inline void __zs_unmap_object(struct mapping_area *area, |
| 889 | struct page *pages[2], int off, int size) |
| 890 | { |
| 891 | unsigned long addr = (unsigned long)area->vm_addr; |
Seth Jennings | f553646 | 2012-07-18 11:55:56 -0500 | [diff] [blame] | 892 | |
Joerg Roedel | d95abbb | 2013-03-27 01:43:14 +0100 | [diff] [blame] | 893 | unmap_kernel_range(addr, PAGE_SIZE * 2); |
Seth Jennings | f553646 | 2012-07-18 11:55:56 -0500 | [diff] [blame] | 894 | } |
| 895 | |
Minchan Kim | 1b945ae | 2013-12-11 11:04:36 +0900 | [diff] [blame] | 896 | #else /* CONFIG_PGTABLE_MAPPING */ |
Seth Jennings | f553646 | 2012-07-18 11:55:56 -0500 | [diff] [blame] | 897 | |
| 898 | static inline int __zs_cpu_up(struct mapping_area *area) |
| 899 | { |
| 900 | /* |
| 901 | * Make sure we don't leak memory if a cpu UP notification |
| 902 | * and zs_init() race and both call zs_cpu_up() on the same cpu |
| 903 | */ |
| 904 | if (area->vm_buf) |
| 905 | return 0; |
Mahendran Ganesh | 40f9fb8 | 2014-12-12 16:57:01 -0800 | [diff] [blame] | 906 | area->vm_buf = kmalloc(ZS_MAX_ALLOC_SIZE, GFP_KERNEL); |
Seth Jennings | f553646 | 2012-07-18 11:55:56 -0500 | [diff] [blame] | 907 | if (!area->vm_buf) |
| 908 | return -ENOMEM; |
| 909 | return 0; |
| 910 | } |
| 911 | |
| 912 | static inline void __zs_cpu_down(struct mapping_area *area) |
| 913 | { |
Mahendran Ganesh | 40f9fb8 | 2014-12-12 16:57:01 -0800 | [diff] [blame] | 914 | kfree(area->vm_buf); |
Seth Jennings | f553646 | 2012-07-18 11:55:56 -0500 | [diff] [blame] | 915 | area->vm_buf = NULL; |
| 916 | } |
| 917 | |
| 918 | static void *__zs_map_object(struct mapping_area *area, |
| 919 | struct page *pages[2], int off, int size) |
| 920 | { |
Seth Jennings | 5f60190 | 2012-07-02 16:15:49 -0500 | [diff] [blame] | 921 | int sizes[2]; |
| 922 | void *addr; |
Seth Jennings | f553646 | 2012-07-18 11:55:56 -0500 | [diff] [blame] | 923 | char *buf = area->vm_buf; |
Seth Jennings | 5f60190 | 2012-07-02 16:15:49 -0500 | [diff] [blame] | 924 | |
Seth Jennings | f553646 | 2012-07-18 11:55:56 -0500 | [diff] [blame] | 925 | /* disable page faults to match kmap_atomic() return conditions */ |
| 926 | pagefault_disable(); |
| 927 | |
| 928 | /* no read fastpath */ |
| 929 | if (area->vm_mm == ZS_MM_WO) |
| 930 | goto out; |
Seth Jennings | 5f60190 | 2012-07-02 16:15:49 -0500 | [diff] [blame] | 931 | |
| 932 | sizes[0] = PAGE_SIZE - off; |
| 933 | sizes[1] = size - sizes[0]; |
| 934 | |
Seth Jennings | 5f60190 | 2012-07-02 16:15:49 -0500 | [diff] [blame] | 935 | /* copy object to per-cpu buffer */ |
| 936 | addr = kmap_atomic(pages[0]); |
| 937 | memcpy(buf, addr + off, sizes[0]); |
| 938 | kunmap_atomic(addr); |
| 939 | addr = kmap_atomic(pages[1]); |
| 940 | memcpy(buf + sizes[0], addr, sizes[1]); |
| 941 | kunmap_atomic(addr); |
Seth Jennings | f553646 | 2012-07-18 11:55:56 -0500 | [diff] [blame] | 942 | out: |
| 943 | return area->vm_buf; |
Seth Jennings | 5f60190 | 2012-07-02 16:15:49 -0500 | [diff] [blame] | 944 | } |
| 945 | |
Seth Jennings | f553646 | 2012-07-18 11:55:56 -0500 | [diff] [blame] | 946 | static void __zs_unmap_object(struct mapping_area *area, |
| 947 | struct page *pages[2], int off, int size) |
Seth Jennings | 5f60190 | 2012-07-02 16:15:49 -0500 | [diff] [blame] | 948 | { |
Seth Jennings | 5f60190 | 2012-07-02 16:15:49 -0500 | [diff] [blame] | 949 | int sizes[2]; |
| 950 | void *addr; |
Minchan Kim | 2e40e16 | 2015-04-15 16:15:23 -0700 | [diff] [blame] | 951 | char *buf; |
Seth Jennings | 5f60190 | 2012-07-02 16:15:49 -0500 | [diff] [blame] | 952 | |
Seth Jennings | f553646 | 2012-07-18 11:55:56 -0500 | [diff] [blame] | 953 | /* no write fastpath */ |
| 954 | if (area->vm_mm == ZS_MM_RO) |
| 955 | goto out; |
Seth Jennings | 5f60190 | 2012-07-02 16:15:49 -0500 | [diff] [blame] | 956 | |
Minchan Kim | 2e40e16 | 2015-04-15 16:15:23 -0700 | [diff] [blame] | 957 | buf = area->vm_buf + ZS_HANDLE_SIZE; |
| 958 | size -= ZS_HANDLE_SIZE; |
| 959 | off += ZS_HANDLE_SIZE; |
| 960 | |
Seth Jennings | 5f60190 | 2012-07-02 16:15:49 -0500 | [diff] [blame] | 961 | sizes[0] = PAGE_SIZE - off; |
| 962 | sizes[1] = size - sizes[0]; |
| 963 | |
| 964 | /* copy per-cpu buffer to object */ |
| 965 | addr = kmap_atomic(pages[0]); |
| 966 | memcpy(addr + off, buf, sizes[0]); |
| 967 | kunmap_atomic(addr); |
| 968 | addr = kmap_atomic(pages[1]); |
| 969 | memcpy(addr, buf + sizes[0], sizes[1]); |
| 970 | kunmap_atomic(addr); |
Seth Jennings | f553646 | 2012-07-18 11:55:56 -0500 | [diff] [blame] | 971 | |
| 972 | out: |
| 973 | /* enable page faults to match kunmap_atomic() return conditions */ |
| 974 | pagefault_enable(); |
Seth Jennings | 5f60190 | 2012-07-02 16:15:49 -0500 | [diff] [blame] | 975 | } |
Nitin Gupta | 61989a8 | 2012-01-09 16:51:56 -0600 | [diff] [blame] | 976 | |
Minchan Kim | 1b945ae | 2013-12-11 11:04:36 +0900 | [diff] [blame] | 977 | #endif /* CONFIG_PGTABLE_MAPPING */ |
Seth Jennings | f553646 | 2012-07-18 11:55:56 -0500 | [diff] [blame] | 978 | |
Nitin Gupta | 61989a8 | 2012-01-09 16:51:56 -0600 | [diff] [blame] | 979 | static int zs_cpu_notifier(struct notifier_block *nb, unsigned long action, |
| 980 | void *pcpu) |
| 981 | { |
Seth Jennings | f553646 | 2012-07-18 11:55:56 -0500 | [diff] [blame] | 982 | int ret, cpu = (long)pcpu; |
Nitin Gupta | 61989a8 | 2012-01-09 16:51:56 -0600 | [diff] [blame] | 983 | struct mapping_area *area; |
| 984 | |
| 985 | switch (action) { |
| 986 | case CPU_UP_PREPARE: |
| 987 | area = &per_cpu(zs_map_area, cpu); |
Seth Jennings | f553646 | 2012-07-18 11:55:56 -0500 | [diff] [blame] | 988 | ret = __zs_cpu_up(area); |
| 989 | if (ret) |
| 990 | return notifier_from_errno(ret); |
Nitin Gupta | 61989a8 | 2012-01-09 16:51:56 -0600 | [diff] [blame] | 991 | break; |
| 992 | case CPU_DEAD: |
| 993 | case CPU_UP_CANCELED: |
| 994 | area = &per_cpu(zs_map_area, cpu); |
Seth Jennings | f553646 | 2012-07-18 11:55:56 -0500 | [diff] [blame] | 995 | __zs_cpu_down(area); |
Nitin Gupta | 61989a8 | 2012-01-09 16:51:56 -0600 | [diff] [blame] | 996 | break; |
| 997 | } |
| 998 | |
| 999 | return NOTIFY_OK; |
| 1000 | } |
| 1001 | |
| 1002 | static struct notifier_block zs_cpu_nb = { |
| 1003 | .notifier_call = zs_cpu_notifier |
| 1004 | }; |
| 1005 | |
Sergey Senozhatsky | b1b00a5 | 2014-12-12 16:56:56 -0800 | [diff] [blame] | 1006 | static int zs_register_cpu_notifier(void) |
Nitin Gupta | 61989a8 | 2012-01-09 16:51:56 -0600 | [diff] [blame] | 1007 | { |
Sergey Senozhatsky | b1b00a5 | 2014-12-12 16:56:56 -0800 | [diff] [blame] | 1008 | int cpu, uninitialized_var(ret); |
Nitin Gupta | 61989a8 | 2012-01-09 16:51:56 -0600 | [diff] [blame] | 1009 | |
Srivatsa S. Bhat | f0e71fc | 2014-03-11 02:09:59 +0530 | [diff] [blame] | 1010 | cpu_notifier_register_begin(); |
| 1011 | |
| 1012 | __register_cpu_notifier(&zs_cpu_nb); |
Nitin Gupta | 61989a8 | 2012-01-09 16:51:56 -0600 | [diff] [blame] | 1013 | for_each_online_cpu(cpu) { |
| 1014 | ret = zs_cpu_notifier(NULL, CPU_UP_PREPARE, (void *)(long)cpu); |
Sergey Senozhatsky | b1b00a5 | 2014-12-12 16:56:56 -0800 | [diff] [blame] | 1015 | if (notifier_to_errno(ret)) |
| 1016 | break; |
Nitin Gupta | 61989a8 | 2012-01-09 16:51:56 -0600 | [diff] [blame] | 1017 | } |
Srivatsa S. Bhat | f0e71fc | 2014-03-11 02:09:59 +0530 | [diff] [blame] | 1018 | |
| 1019 | cpu_notifier_register_done(); |
Sergey Senozhatsky | b1b00a5 | 2014-12-12 16:56:56 -0800 | [diff] [blame] | 1020 | return notifier_to_errno(ret); |
| 1021 | } |
| 1022 | |
Ganesh Mahendran | 66cdef6 | 2014-12-18 16:17:40 -0800 | [diff] [blame] | 1023 | static void zs_unregister_cpu_notifier(void) |
| 1024 | { |
| 1025 | int cpu; |
| 1026 | |
| 1027 | cpu_notifier_register_begin(); |
| 1028 | |
| 1029 | for_each_online_cpu(cpu) |
| 1030 | zs_cpu_notifier(NULL, CPU_DEAD, (void *)(long)cpu); |
| 1031 | __unregister_cpu_notifier(&zs_cpu_nb); |
| 1032 | |
| 1033 | cpu_notifier_register_done(); |
| 1034 | } |
| 1035 | |
Mahendran Ganesh | 40f9fb8 | 2014-12-12 16:57:01 -0800 | [diff] [blame] | 1036 | static void init_zs_size_classes(void) |
| 1037 | { |
| 1038 | int nr; |
| 1039 | |
| 1040 | nr = (ZS_MAX_ALLOC_SIZE - ZS_MIN_ALLOC_SIZE) / ZS_SIZE_CLASS_DELTA + 1; |
| 1041 | if ((ZS_MAX_ALLOC_SIZE - ZS_MIN_ALLOC_SIZE) % ZS_SIZE_CLASS_DELTA) |
| 1042 | nr += 1; |
| 1043 | |
| 1044 | zs_size_classes = nr; |
| 1045 | } |
| 1046 | |
Joonsoo Kim | 9eec4cd | 2014-12-12 16:56:44 -0800 | [diff] [blame] | 1047 | static unsigned int get_maxobj_per_zspage(int size, int pages_per_zspage) |
| 1048 | { |
| 1049 | return pages_per_zspage * PAGE_SIZE / size; |
| 1050 | } |
| 1051 | |
| 1052 | static bool can_merge(struct size_class *prev, int size, int pages_per_zspage) |
| 1053 | { |
| 1054 | if (prev->pages_per_zspage != pages_per_zspage) |
| 1055 | return false; |
| 1056 | |
| 1057 | if (get_maxobj_per_zspage(prev->size, prev->pages_per_zspage) |
| 1058 | != get_maxobj_per_zspage(size, pages_per_zspage)) |
| 1059 | return false; |
| 1060 | |
| 1061 | return true; |
| 1062 | } |
| 1063 | |
Minchan Kim | 312fcae | 2015-04-15 16:15:30 -0700 | [diff] [blame^] | 1064 | static bool zspage_full(struct page *page) |
| 1065 | { |
| 1066 | BUG_ON(!is_first_page(page)); |
| 1067 | |
| 1068 | return page->inuse == page->objects; |
| 1069 | } |
| 1070 | |
Ganesh Mahendran | 0f050d9 | 2015-02-12 15:00:54 -0800 | [diff] [blame] | 1071 | #ifdef CONFIG_ZSMALLOC_STAT |
| 1072 | |
| 1073 | static inline void zs_stat_inc(struct size_class *class, |
| 1074 | enum zs_stat_type type, unsigned long cnt) |
| 1075 | { |
| 1076 | class->stats.objs[type] += cnt; |
| 1077 | } |
| 1078 | |
| 1079 | static inline void zs_stat_dec(struct size_class *class, |
| 1080 | enum zs_stat_type type, unsigned long cnt) |
| 1081 | { |
| 1082 | class->stats.objs[type] -= cnt; |
| 1083 | } |
| 1084 | |
| 1085 | static inline unsigned long zs_stat_get(struct size_class *class, |
| 1086 | enum zs_stat_type type) |
| 1087 | { |
| 1088 | return class->stats.objs[type]; |
| 1089 | } |
| 1090 | |
| 1091 | static int __init zs_stat_init(void) |
| 1092 | { |
| 1093 | if (!debugfs_initialized()) |
| 1094 | return -ENODEV; |
| 1095 | |
| 1096 | zs_stat_root = debugfs_create_dir("zsmalloc", NULL); |
| 1097 | if (!zs_stat_root) |
| 1098 | return -ENOMEM; |
| 1099 | |
| 1100 | return 0; |
| 1101 | } |
| 1102 | |
| 1103 | static void __exit zs_stat_exit(void) |
| 1104 | { |
| 1105 | debugfs_remove_recursive(zs_stat_root); |
| 1106 | } |
| 1107 | |
| 1108 | static int zs_stats_size_show(struct seq_file *s, void *v) |
| 1109 | { |
| 1110 | int i; |
| 1111 | struct zs_pool *pool = s->private; |
| 1112 | struct size_class *class; |
| 1113 | int objs_per_zspage; |
| 1114 | unsigned long obj_allocated, obj_used, pages_used; |
| 1115 | unsigned long total_objs = 0, total_used_objs = 0, total_pages = 0; |
| 1116 | |
| 1117 | seq_printf(s, " %5s %5s %13s %10s %10s\n", "class", "size", |
| 1118 | "obj_allocated", "obj_used", "pages_used"); |
| 1119 | |
| 1120 | for (i = 0; i < zs_size_classes; i++) { |
| 1121 | class = pool->size_class[i]; |
| 1122 | |
| 1123 | if (class->index != i) |
| 1124 | continue; |
| 1125 | |
| 1126 | spin_lock(&class->lock); |
| 1127 | obj_allocated = zs_stat_get(class, OBJ_ALLOCATED); |
| 1128 | obj_used = zs_stat_get(class, OBJ_USED); |
| 1129 | spin_unlock(&class->lock); |
| 1130 | |
| 1131 | objs_per_zspage = get_maxobj_per_zspage(class->size, |
| 1132 | class->pages_per_zspage); |
| 1133 | pages_used = obj_allocated / objs_per_zspage * |
| 1134 | class->pages_per_zspage; |
| 1135 | |
| 1136 | seq_printf(s, " %5u %5u %10lu %10lu %10lu\n", i, |
| 1137 | class->size, obj_allocated, obj_used, pages_used); |
| 1138 | |
| 1139 | total_objs += obj_allocated; |
| 1140 | total_used_objs += obj_used; |
| 1141 | total_pages += pages_used; |
| 1142 | } |
| 1143 | |
| 1144 | seq_puts(s, "\n"); |
| 1145 | seq_printf(s, " %5s %5s %10lu %10lu %10lu\n", "Total", "", |
| 1146 | total_objs, total_used_objs, total_pages); |
| 1147 | |
| 1148 | return 0; |
| 1149 | } |
| 1150 | |
| 1151 | static int zs_stats_size_open(struct inode *inode, struct file *file) |
| 1152 | { |
| 1153 | return single_open(file, zs_stats_size_show, inode->i_private); |
| 1154 | } |
| 1155 | |
| 1156 | static const struct file_operations zs_stat_size_ops = { |
| 1157 | .open = zs_stats_size_open, |
| 1158 | .read = seq_read, |
| 1159 | .llseek = seq_lseek, |
| 1160 | .release = single_release, |
| 1161 | }; |
| 1162 | |
| 1163 | static int zs_pool_stat_create(char *name, struct zs_pool *pool) |
| 1164 | { |
| 1165 | struct dentry *entry; |
| 1166 | |
| 1167 | if (!zs_stat_root) |
| 1168 | return -ENODEV; |
| 1169 | |
| 1170 | entry = debugfs_create_dir(name, zs_stat_root); |
| 1171 | if (!entry) { |
| 1172 | pr_warn("debugfs dir <%s> creation failed\n", name); |
| 1173 | return -ENOMEM; |
| 1174 | } |
| 1175 | pool->stat_dentry = entry; |
| 1176 | |
| 1177 | entry = debugfs_create_file("obj_in_classes", S_IFREG | S_IRUGO, |
| 1178 | pool->stat_dentry, pool, &zs_stat_size_ops); |
| 1179 | if (!entry) { |
| 1180 | pr_warn("%s: debugfs file entry <%s> creation failed\n", |
| 1181 | name, "obj_in_classes"); |
| 1182 | return -ENOMEM; |
| 1183 | } |
| 1184 | |
| 1185 | return 0; |
| 1186 | } |
| 1187 | |
| 1188 | static void zs_pool_stat_destroy(struct zs_pool *pool) |
| 1189 | { |
| 1190 | debugfs_remove_recursive(pool->stat_dentry); |
| 1191 | } |
| 1192 | |
| 1193 | #else /* CONFIG_ZSMALLOC_STAT */ |
| 1194 | |
| 1195 | static inline void zs_stat_inc(struct size_class *class, |
| 1196 | enum zs_stat_type type, unsigned long cnt) |
| 1197 | { |
| 1198 | } |
| 1199 | |
| 1200 | static inline void zs_stat_dec(struct size_class *class, |
| 1201 | enum zs_stat_type type, unsigned long cnt) |
| 1202 | { |
| 1203 | } |
| 1204 | |
| 1205 | static inline unsigned long zs_stat_get(struct size_class *class, |
| 1206 | enum zs_stat_type type) |
| 1207 | { |
| 1208 | return 0; |
| 1209 | } |
| 1210 | |
| 1211 | static int __init zs_stat_init(void) |
| 1212 | { |
| 1213 | return 0; |
| 1214 | } |
| 1215 | |
| 1216 | static void __exit zs_stat_exit(void) |
| 1217 | { |
| 1218 | } |
| 1219 | |
| 1220 | static inline int zs_pool_stat_create(char *name, struct zs_pool *pool) |
| 1221 | { |
| 1222 | return 0; |
| 1223 | } |
| 1224 | |
| 1225 | static inline void zs_pool_stat_destroy(struct zs_pool *pool) |
| 1226 | { |
| 1227 | } |
| 1228 | |
| 1229 | #endif |
| 1230 | |
Ganesh Mahendran | 66cdef6 | 2014-12-18 16:17:40 -0800 | [diff] [blame] | 1231 | unsigned long zs_get_total_pages(struct zs_pool *pool) |
| 1232 | { |
| 1233 | return atomic_long_read(&pool->pages_allocated); |
| 1234 | } |
| 1235 | EXPORT_SYMBOL_GPL(zs_get_total_pages); |
| 1236 | |
| 1237 | /** |
| 1238 | * zs_map_object - get address of allocated object from handle. |
| 1239 | * @pool: pool from which the object was allocated |
| 1240 | * @handle: handle returned from zs_malloc |
| 1241 | * |
| 1242 | * Before using an object allocated from zs_malloc, it must be mapped using |
| 1243 | * this function. When done with the object, it must be unmapped using |
| 1244 | * zs_unmap_object. |
| 1245 | * |
| 1246 | * Only one object can be mapped per cpu at a time. There is no protection |
| 1247 | * against nested mappings. |
| 1248 | * |
| 1249 | * This function returns with preemption and page faults disabled. |
| 1250 | */ |
| 1251 | void *zs_map_object(struct zs_pool *pool, unsigned long handle, |
| 1252 | enum zs_mapmode mm) |
| 1253 | { |
| 1254 | struct page *page; |
Minchan Kim | 2e40e16 | 2015-04-15 16:15:23 -0700 | [diff] [blame] | 1255 | unsigned long obj, obj_idx, off; |
Ganesh Mahendran | 66cdef6 | 2014-12-18 16:17:40 -0800 | [diff] [blame] | 1256 | |
| 1257 | unsigned int class_idx; |
| 1258 | enum fullness_group fg; |
| 1259 | struct size_class *class; |
| 1260 | struct mapping_area *area; |
| 1261 | struct page *pages[2]; |
Minchan Kim | 2e40e16 | 2015-04-15 16:15:23 -0700 | [diff] [blame] | 1262 | void *ret; |
Ganesh Mahendran | 66cdef6 | 2014-12-18 16:17:40 -0800 | [diff] [blame] | 1263 | |
| 1264 | BUG_ON(!handle); |
| 1265 | |
| 1266 | /* |
| 1267 | * Because we use per-cpu mapping areas shared among the |
| 1268 | * pools/users, we can't allow mapping in interrupt context |
| 1269 | * because it can corrupt another users mappings. |
| 1270 | */ |
| 1271 | BUG_ON(in_interrupt()); |
| 1272 | |
Minchan Kim | 312fcae | 2015-04-15 16:15:30 -0700 | [diff] [blame^] | 1273 | /* From now on, migration cannot move the object */ |
| 1274 | pin_tag(handle); |
| 1275 | |
Minchan Kim | 2e40e16 | 2015-04-15 16:15:23 -0700 | [diff] [blame] | 1276 | obj = handle_to_obj(handle); |
| 1277 | obj_to_location(obj, &page, &obj_idx); |
Ganesh Mahendran | 66cdef6 | 2014-12-18 16:17:40 -0800 | [diff] [blame] | 1278 | get_zspage_mapping(get_first_page(page), &class_idx, &fg); |
| 1279 | class = pool->size_class[class_idx]; |
| 1280 | off = obj_idx_to_offset(page, obj_idx, class->size); |
| 1281 | |
| 1282 | area = &get_cpu_var(zs_map_area); |
| 1283 | area->vm_mm = mm; |
| 1284 | if (off + class->size <= PAGE_SIZE) { |
| 1285 | /* this object is contained entirely within a page */ |
| 1286 | area->vm_addr = kmap_atomic(page); |
Minchan Kim | 2e40e16 | 2015-04-15 16:15:23 -0700 | [diff] [blame] | 1287 | ret = area->vm_addr + off; |
| 1288 | goto out; |
Ganesh Mahendran | 66cdef6 | 2014-12-18 16:17:40 -0800 | [diff] [blame] | 1289 | } |
| 1290 | |
| 1291 | /* this object spans two pages */ |
| 1292 | pages[0] = page; |
| 1293 | pages[1] = get_next_page(page); |
| 1294 | BUG_ON(!pages[1]); |
| 1295 | |
Minchan Kim | 2e40e16 | 2015-04-15 16:15:23 -0700 | [diff] [blame] | 1296 | ret = __zs_map_object(area, pages, off, class->size); |
| 1297 | out: |
| 1298 | return ret + ZS_HANDLE_SIZE; |
Ganesh Mahendran | 66cdef6 | 2014-12-18 16:17:40 -0800 | [diff] [blame] | 1299 | } |
| 1300 | EXPORT_SYMBOL_GPL(zs_map_object); |
| 1301 | |
| 1302 | void zs_unmap_object(struct zs_pool *pool, unsigned long handle) |
| 1303 | { |
| 1304 | struct page *page; |
Minchan Kim | 2e40e16 | 2015-04-15 16:15:23 -0700 | [diff] [blame] | 1305 | unsigned long obj, obj_idx, off; |
Ganesh Mahendran | 66cdef6 | 2014-12-18 16:17:40 -0800 | [diff] [blame] | 1306 | |
| 1307 | unsigned int class_idx; |
| 1308 | enum fullness_group fg; |
| 1309 | struct size_class *class; |
| 1310 | struct mapping_area *area; |
| 1311 | |
| 1312 | BUG_ON(!handle); |
| 1313 | |
Minchan Kim | 2e40e16 | 2015-04-15 16:15:23 -0700 | [diff] [blame] | 1314 | obj = handle_to_obj(handle); |
| 1315 | obj_to_location(obj, &page, &obj_idx); |
Ganesh Mahendran | 66cdef6 | 2014-12-18 16:17:40 -0800 | [diff] [blame] | 1316 | get_zspage_mapping(get_first_page(page), &class_idx, &fg); |
| 1317 | class = pool->size_class[class_idx]; |
| 1318 | off = obj_idx_to_offset(page, obj_idx, class->size); |
| 1319 | |
| 1320 | area = this_cpu_ptr(&zs_map_area); |
| 1321 | if (off + class->size <= PAGE_SIZE) |
| 1322 | kunmap_atomic(area->vm_addr); |
| 1323 | else { |
| 1324 | struct page *pages[2]; |
| 1325 | |
| 1326 | pages[0] = page; |
| 1327 | pages[1] = get_next_page(page); |
| 1328 | BUG_ON(!pages[1]); |
| 1329 | |
| 1330 | __zs_unmap_object(area, pages, off, class->size); |
| 1331 | } |
| 1332 | put_cpu_var(zs_map_area); |
Minchan Kim | 312fcae | 2015-04-15 16:15:30 -0700 | [diff] [blame^] | 1333 | unpin_tag(handle); |
Ganesh Mahendran | 66cdef6 | 2014-12-18 16:17:40 -0800 | [diff] [blame] | 1334 | } |
| 1335 | EXPORT_SYMBOL_GPL(zs_unmap_object); |
| 1336 | |
Minchan Kim | c780626 | 2015-04-15 16:15:26 -0700 | [diff] [blame] | 1337 | static unsigned long obj_malloc(struct page *first_page, |
| 1338 | struct size_class *class, unsigned long handle) |
| 1339 | { |
| 1340 | unsigned long obj; |
| 1341 | struct link_free *link; |
| 1342 | |
| 1343 | struct page *m_page; |
| 1344 | unsigned long m_objidx, m_offset; |
| 1345 | void *vaddr; |
| 1346 | |
Minchan Kim | 312fcae | 2015-04-15 16:15:30 -0700 | [diff] [blame^] | 1347 | handle |= OBJ_ALLOCATED_TAG; |
Minchan Kim | c780626 | 2015-04-15 16:15:26 -0700 | [diff] [blame] | 1348 | obj = (unsigned long)first_page->freelist; |
| 1349 | obj_to_location(obj, &m_page, &m_objidx); |
| 1350 | m_offset = obj_idx_to_offset(m_page, m_objidx, class->size); |
| 1351 | |
| 1352 | vaddr = kmap_atomic(m_page); |
| 1353 | link = (struct link_free *)vaddr + m_offset / sizeof(*link); |
| 1354 | first_page->freelist = link->next; |
| 1355 | /* record handle in the header of allocated chunk */ |
| 1356 | link->handle = handle; |
| 1357 | kunmap_atomic(vaddr); |
| 1358 | first_page->inuse++; |
| 1359 | zs_stat_inc(class, OBJ_USED, 1); |
| 1360 | |
| 1361 | return obj; |
| 1362 | } |
| 1363 | |
| 1364 | |
Ganesh Mahendran | 66cdef6 | 2014-12-18 16:17:40 -0800 | [diff] [blame] | 1365 | /** |
| 1366 | * zs_malloc - Allocate block of given size from pool. |
| 1367 | * @pool: pool to allocate from |
| 1368 | * @size: size of block to allocate |
| 1369 | * |
| 1370 | * On success, handle to the allocated object is returned, |
| 1371 | * otherwise 0. |
| 1372 | * Allocation requests with size > ZS_MAX_ALLOC_SIZE will fail. |
| 1373 | */ |
| 1374 | unsigned long zs_malloc(struct zs_pool *pool, size_t size) |
| 1375 | { |
Minchan Kim | 2e40e16 | 2015-04-15 16:15:23 -0700 | [diff] [blame] | 1376 | unsigned long handle, obj; |
Ganesh Mahendran | 66cdef6 | 2014-12-18 16:17:40 -0800 | [diff] [blame] | 1377 | struct size_class *class; |
Minchan Kim | c780626 | 2015-04-15 16:15:26 -0700 | [diff] [blame] | 1378 | struct page *first_page; |
Ganesh Mahendran | 66cdef6 | 2014-12-18 16:17:40 -0800 | [diff] [blame] | 1379 | |
Minchan Kim | 2e40e16 | 2015-04-15 16:15:23 -0700 | [diff] [blame] | 1380 | if (unlikely(!size || (size + ZS_HANDLE_SIZE) > ZS_MAX_ALLOC_SIZE)) |
Ganesh Mahendran | 66cdef6 | 2014-12-18 16:17:40 -0800 | [diff] [blame] | 1381 | return 0; |
| 1382 | |
Minchan Kim | 2e40e16 | 2015-04-15 16:15:23 -0700 | [diff] [blame] | 1383 | handle = alloc_handle(pool); |
| 1384 | if (!handle) |
| 1385 | return 0; |
| 1386 | |
| 1387 | /* extra space in chunk to keep the handle */ |
| 1388 | size += ZS_HANDLE_SIZE; |
Ganesh Mahendran | 66cdef6 | 2014-12-18 16:17:40 -0800 | [diff] [blame] | 1389 | class = pool->size_class[get_size_class_index(size)]; |
| 1390 | |
| 1391 | spin_lock(&class->lock); |
| 1392 | first_page = find_get_zspage(class); |
| 1393 | |
| 1394 | if (!first_page) { |
| 1395 | spin_unlock(&class->lock); |
| 1396 | first_page = alloc_zspage(class, pool->flags); |
Minchan Kim | 2e40e16 | 2015-04-15 16:15:23 -0700 | [diff] [blame] | 1397 | if (unlikely(!first_page)) { |
| 1398 | free_handle(pool, handle); |
Ganesh Mahendran | 66cdef6 | 2014-12-18 16:17:40 -0800 | [diff] [blame] | 1399 | return 0; |
Minchan Kim | 2e40e16 | 2015-04-15 16:15:23 -0700 | [diff] [blame] | 1400 | } |
Ganesh Mahendran | 66cdef6 | 2014-12-18 16:17:40 -0800 | [diff] [blame] | 1401 | |
| 1402 | set_zspage_mapping(first_page, class->index, ZS_EMPTY); |
| 1403 | atomic_long_add(class->pages_per_zspage, |
| 1404 | &pool->pages_allocated); |
Ganesh Mahendran | 0f050d9 | 2015-02-12 15:00:54 -0800 | [diff] [blame] | 1405 | |
Ganesh Mahendran | 66cdef6 | 2014-12-18 16:17:40 -0800 | [diff] [blame] | 1406 | spin_lock(&class->lock); |
Ganesh Mahendran | 0f050d9 | 2015-02-12 15:00:54 -0800 | [diff] [blame] | 1407 | zs_stat_inc(class, OBJ_ALLOCATED, get_maxobj_per_zspage( |
| 1408 | class->size, class->pages_per_zspage)); |
Ganesh Mahendran | 66cdef6 | 2014-12-18 16:17:40 -0800 | [diff] [blame] | 1409 | } |
| 1410 | |
Minchan Kim | c780626 | 2015-04-15 16:15:26 -0700 | [diff] [blame] | 1411 | obj = obj_malloc(first_page, class, handle); |
Ganesh Mahendran | 66cdef6 | 2014-12-18 16:17:40 -0800 | [diff] [blame] | 1412 | /* Now move the zspage to another fullness group, if required */ |
Minchan Kim | c780626 | 2015-04-15 16:15:26 -0700 | [diff] [blame] | 1413 | fix_fullness_group(class, first_page); |
Minchan Kim | 2e40e16 | 2015-04-15 16:15:23 -0700 | [diff] [blame] | 1414 | record_obj(handle, obj); |
Ganesh Mahendran | 66cdef6 | 2014-12-18 16:17:40 -0800 | [diff] [blame] | 1415 | spin_unlock(&class->lock); |
| 1416 | |
Minchan Kim | 2e40e16 | 2015-04-15 16:15:23 -0700 | [diff] [blame] | 1417 | return handle; |
Ganesh Mahendran | 66cdef6 | 2014-12-18 16:17:40 -0800 | [diff] [blame] | 1418 | } |
| 1419 | EXPORT_SYMBOL_GPL(zs_malloc); |
| 1420 | |
Minchan Kim | c780626 | 2015-04-15 16:15:26 -0700 | [diff] [blame] | 1421 | static void obj_free(struct zs_pool *pool, struct size_class *class, |
| 1422 | unsigned long obj) |
Ganesh Mahendran | 66cdef6 | 2014-12-18 16:17:40 -0800 | [diff] [blame] | 1423 | { |
| 1424 | struct link_free *link; |
| 1425 | struct page *first_page, *f_page; |
Minchan Kim | c780626 | 2015-04-15 16:15:26 -0700 | [diff] [blame] | 1426 | unsigned long f_objidx, f_offset; |
Ganesh Mahendran | 66cdef6 | 2014-12-18 16:17:40 -0800 | [diff] [blame] | 1427 | void *vaddr; |
Minchan Kim | c780626 | 2015-04-15 16:15:26 -0700 | [diff] [blame] | 1428 | int class_idx; |
| 1429 | enum fullness_group fullness; |
Ganesh Mahendran | 66cdef6 | 2014-12-18 16:17:40 -0800 | [diff] [blame] | 1430 | |
Minchan Kim | c780626 | 2015-04-15 16:15:26 -0700 | [diff] [blame] | 1431 | BUG_ON(!obj); |
| 1432 | |
Minchan Kim | 312fcae | 2015-04-15 16:15:30 -0700 | [diff] [blame^] | 1433 | obj &= ~OBJ_ALLOCATED_TAG; |
Minchan Kim | c780626 | 2015-04-15 16:15:26 -0700 | [diff] [blame] | 1434 | obj_to_location(obj, &f_page, &f_objidx); |
| 1435 | first_page = get_first_page(f_page); |
| 1436 | |
| 1437 | get_zspage_mapping(first_page, &class_idx, &fullness); |
| 1438 | f_offset = obj_idx_to_offset(f_page, f_objidx, class->size); |
| 1439 | |
| 1440 | vaddr = kmap_atomic(f_page); |
| 1441 | |
| 1442 | /* Insert this object in containing zspage's freelist */ |
| 1443 | link = (struct link_free *)(vaddr + f_offset); |
| 1444 | link->next = first_page->freelist; |
| 1445 | kunmap_atomic(vaddr); |
| 1446 | first_page->freelist = (void *)obj; |
| 1447 | first_page->inuse--; |
| 1448 | zs_stat_dec(class, OBJ_USED, 1); |
| 1449 | } |
| 1450 | |
| 1451 | void zs_free(struct zs_pool *pool, unsigned long handle) |
| 1452 | { |
| 1453 | struct page *first_page, *f_page; |
| 1454 | unsigned long obj, f_objidx; |
Ganesh Mahendran | 66cdef6 | 2014-12-18 16:17:40 -0800 | [diff] [blame] | 1455 | int class_idx; |
| 1456 | struct size_class *class; |
| 1457 | enum fullness_group fullness; |
| 1458 | |
Minchan Kim | 2e40e16 | 2015-04-15 16:15:23 -0700 | [diff] [blame] | 1459 | if (unlikely(!handle)) |
Ganesh Mahendran | 66cdef6 | 2014-12-18 16:17:40 -0800 | [diff] [blame] | 1460 | return; |
| 1461 | |
Minchan Kim | 312fcae | 2015-04-15 16:15:30 -0700 | [diff] [blame^] | 1462 | pin_tag(handle); |
Minchan Kim | 2e40e16 | 2015-04-15 16:15:23 -0700 | [diff] [blame] | 1463 | obj = handle_to_obj(handle); |
Minchan Kim | 2e40e16 | 2015-04-15 16:15:23 -0700 | [diff] [blame] | 1464 | obj_to_location(obj, &f_page, &f_objidx); |
Ganesh Mahendran | 66cdef6 | 2014-12-18 16:17:40 -0800 | [diff] [blame] | 1465 | first_page = get_first_page(f_page); |
| 1466 | |
| 1467 | get_zspage_mapping(first_page, &class_idx, &fullness); |
| 1468 | class = pool->size_class[class_idx]; |
Ganesh Mahendran | 66cdef6 | 2014-12-18 16:17:40 -0800 | [diff] [blame] | 1469 | |
| 1470 | spin_lock(&class->lock); |
Minchan Kim | c780626 | 2015-04-15 16:15:26 -0700 | [diff] [blame] | 1471 | obj_free(pool, class, obj); |
| 1472 | fullness = fix_fullness_group(class, first_page); |
Minchan Kim | 312fcae | 2015-04-15 16:15:30 -0700 | [diff] [blame^] | 1473 | if (fullness == ZS_EMPTY) { |
Ganesh Mahendran | 0f050d9 | 2015-02-12 15:00:54 -0800 | [diff] [blame] | 1474 | zs_stat_dec(class, OBJ_ALLOCATED, get_maxobj_per_zspage( |
| 1475 | class->size, class->pages_per_zspage)); |
Ganesh Mahendran | 66cdef6 | 2014-12-18 16:17:40 -0800 | [diff] [blame] | 1476 | atomic_long_sub(class->pages_per_zspage, |
| 1477 | &pool->pages_allocated); |
| 1478 | free_zspage(first_page); |
| 1479 | } |
Minchan Kim | 312fcae | 2015-04-15 16:15:30 -0700 | [diff] [blame^] | 1480 | spin_unlock(&class->lock); |
| 1481 | unpin_tag(handle); |
| 1482 | |
| 1483 | free_handle(pool, handle); |
Ganesh Mahendran | 66cdef6 | 2014-12-18 16:17:40 -0800 | [diff] [blame] | 1484 | } |
| 1485 | EXPORT_SYMBOL_GPL(zs_free); |
| 1486 | |
Minchan Kim | 312fcae | 2015-04-15 16:15:30 -0700 | [diff] [blame^] | 1487 | static void zs_object_copy(unsigned long src, unsigned long dst, |
| 1488 | struct size_class *class) |
| 1489 | { |
| 1490 | struct page *s_page, *d_page; |
| 1491 | unsigned long s_objidx, d_objidx; |
| 1492 | unsigned long s_off, d_off; |
| 1493 | void *s_addr, *d_addr; |
| 1494 | int s_size, d_size, size; |
| 1495 | int written = 0; |
| 1496 | |
| 1497 | s_size = d_size = class->size; |
| 1498 | |
| 1499 | obj_to_location(src, &s_page, &s_objidx); |
| 1500 | obj_to_location(dst, &d_page, &d_objidx); |
| 1501 | |
| 1502 | s_off = obj_idx_to_offset(s_page, s_objidx, class->size); |
| 1503 | d_off = obj_idx_to_offset(d_page, d_objidx, class->size); |
| 1504 | |
| 1505 | if (s_off + class->size > PAGE_SIZE) |
| 1506 | s_size = PAGE_SIZE - s_off; |
| 1507 | |
| 1508 | if (d_off + class->size > PAGE_SIZE) |
| 1509 | d_size = PAGE_SIZE - d_off; |
| 1510 | |
| 1511 | s_addr = kmap_atomic(s_page); |
| 1512 | d_addr = kmap_atomic(d_page); |
| 1513 | |
| 1514 | while (1) { |
| 1515 | size = min(s_size, d_size); |
| 1516 | memcpy(d_addr + d_off, s_addr + s_off, size); |
| 1517 | written += size; |
| 1518 | |
| 1519 | if (written == class->size) |
| 1520 | break; |
| 1521 | |
| 1522 | if (s_off + size >= PAGE_SIZE) { |
| 1523 | kunmap_atomic(d_addr); |
| 1524 | kunmap_atomic(s_addr); |
| 1525 | s_page = get_next_page(s_page); |
| 1526 | BUG_ON(!s_page); |
| 1527 | s_addr = kmap_atomic(s_page); |
| 1528 | d_addr = kmap_atomic(d_page); |
| 1529 | s_size = class->size - written; |
| 1530 | s_off = 0; |
| 1531 | } else { |
| 1532 | s_off += size; |
| 1533 | s_size -= size; |
| 1534 | } |
| 1535 | |
| 1536 | if (d_off + size >= PAGE_SIZE) { |
| 1537 | kunmap_atomic(d_addr); |
| 1538 | d_page = get_next_page(d_page); |
| 1539 | BUG_ON(!d_page); |
| 1540 | d_addr = kmap_atomic(d_page); |
| 1541 | d_size = class->size - written; |
| 1542 | d_off = 0; |
| 1543 | } else { |
| 1544 | d_off += size; |
| 1545 | d_size -= size; |
| 1546 | } |
| 1547 | } |
| 1548 | |
| 1549 | kunmap_atomic(d_addr); |
| 1550 | kunmap_atomic(s_addr); |
| 1551 | } |
| 1552 | |
| 1553 | /* |
| 1554 | * Find alloced object in zspage from index object and |
| 1555 | * return handle. |
| 1556 | */ |
| 1557 | static unsigned long find_alloced_obj(struct page *page, int index, |
| 1558 | struct size_class *class) |
| 1559 | { |
| 1560 | unsigned long head; |
| 1561 | int offset = 0; |
| 1562 | unsigned long handle = 0; |
| 1563 | void *addr = kmap_atomic(page); |
| 1564 | |
| 1565 | if (!is_first_page(page)) |
| 1566 | offset = page->index; |
| 1567 | offset += class->size * index; |
| 1568 | |
| 1569 | while (offset < PAGE_SIZE) { |
| 1570 | head = obj_to_head(addr + offset); |
| 1571 | if (head & OBJ_ALLOCATED_TAG) { |
| 1572 | handle = head & ~OBJ_ALLOCATED_TAG; |
| 1573 | if (trypin_tag(handle)) |
| 1574 | break; |
| 1575 | handle = 0; |
| 1576 | } |
| 1577 | |
| 1578 | offset += class->size; |
| 1579 | index++; |
| 1580 | } |
| 1581 | |
| 1582 | kunmap_atomic(addr); |
| 1583 | return handle; |
| 1584 | } |
| 1585 | |
| 1586 | struct zs_compact_control { |
| 1587 | /* Source page for migration which could be a subpage of zspage. */ |
| 1588 | struct page *s_page; |
| 1589 | /* Destination page for migration which should be a first page |
| 1590 | * of zspage. */ |
| 1591 | struct page *d_page; |
| 1592 | /* Starting object index within @s_page which used for live object |
| 1593 | * in the subpage. */ |
| 1594 | int index; |
| 1595 | /* how many of objects are migrated */ |
| 1596 | int nr_migrated; |
| 1597 | }; |
| 1598 | |
| 1599 | static int migrate_zspage(struct zs_pool *pool, struct size_class *class, |
| 1600 | struct zs_compact_control *cc) |
| 1601 | { |
| 1602 | unsigned long used_obj, free_obj; |
| 1603 | unsigned long handle; |
| 1604 | struct page *s_page = cc->s_page; |
| 1605 | struct page *d_page = cc->d_page; |
| 1606 | unsigned long index = cc->index; |
| 1607 | int nr_migrated = 0; |
| 1608 | int ret = 0; |
| 1609 | |
| 1610 | while (1) { |
| 1611 | handle = find_alloced_obj(s_page, index, class); |
| 1612 | if (!handle) { |
| 1613 | s_page = get_next_page(s_page); |
| 1614 | if (!s_page) |
| 1615 | break; |
| 1616 | index = 0; |
| 1617 | continue; |
| 1618 | } |
| 1619 | |
| 1620 | /* Stop if there is no more space */ |
| 1621 | if (zspage_full(d_page)) { |
| 1622 | unpin_tag(handle); |
| 1623 | ret = -ENOMEM; |
| 1624 | break; |
| 1625 | } |
| 1626 | |
| 1627 | used_obj = handle_to_obj(handle); |
| 1628 | free_obj = obj_malloc(d_page, class, handle); |
| 1629 | zs_object_copy(used_obj, free_obj, class); |
| 1630 | index++; |
| 1631 | record_obj(handle, free_obj); |
| 1632 | unpin_tag(handle); |
| 1633 | obj_free(pool, class, used_obj); |
| 1634 | nr_migrated++; |
| 1635 | } |
| 1636 | |
| 1637 | /* Remember last position in this iteration */ |
| 1638 | cc->s_page = s_page; |
| 1639 | cc->index = index; |
| 1640 | cc->nr_migrated = nr_migrated; |
| 1641 | |
| 1642 | return ret; |
| 1643 | } |
| 1644 | |
| 1645 | static struct page *alloc_target_page(struct size_class *class) |
| 1646 | { |
| 1647 | int i; |
| 1648 | struct page *page; |
| 1649 | |
| 1650 | for (i = 0; i < _ZS_NR_FULLNESS_GROUPS; i++) { |
| 1651 | page = class->fullness_list[i]; |
| 1652 | if (page) { |
| 1653 | remove_zspage(page, class, i); |
| 1654 | break; |
| 1655 | } |
| 1656 | } |
| 1657 | |
| 1658 | return page; |
| 1659 | } |
| 1660 | |
| 1661 | static void putback_zspage(struct zs_pool *pool, struct size_class *class, |
| 1662 | struct page *first_page) |
| 1663 | { |
| 1664 | int class_idx; |
| 1665 | enum fullness_group fullness; |
| 1666 | |
| 1667 | BUG_ON(!is_first_page(first_page)); |
| 1668 | |
| 1669 | get_zspage_mapping(first_page, &class_idx, &fullness); |
| 1670 | insert_zspage(first_page, class, fullness); |
| 1671 | fullness = fix_fullness_group(class, first_page); |
| 1672 | if (fullness == ZS_EMPTY) { |
| 1673 | zs_stat_dec(class, OBJ_ALLOCATED, get_maxobj_per_zspage( |
| 1674 | class->size, class->pages_per_zspage)); |
| 1675 | atomic_long_sub(class->pages_per_zspage, |
| 1676 | &pool->pages_allocated); |
| 1677 | |
| 1678 | free_zspage(first_page); |
| 1679 | } |
| 1680 | } |
| 1681 | |
| 1682 | static struct page *isolate_source_page(struct size_class *class) |
| 1683 | { |
| 1684 | struct page *page; |
| 1685 | |
| 1686 | page = class->fullness_list[ZS_ALMOST_EMPTY]; |
| 1687 | if (page) |
| 1688 | remove_zspage(page, class, ZS_ALMOST_EMPTY); |
| 1689 | |
| 1690 | return page; |
| 1691 | } |
| 1692 | |
| 1693 | static unsigned long __zs_compact(struct zs_pool *pool, |
| 1694 | struct size_class *class) |
| 1695 | { |
| 1696 | int nr_to_migrate; |
| 1697 | struct zs_compact_control cc; |
| 1698 | struct page *src_page; |
| 1699 | struct page *dst_page = NULL; |
| 1700 | unsigned long nr_total_migrated = 0; |
| 1701 | |
| 1702 | cond_resched(); |
| 1703 | |
| 1704 | spin_lock(&class->lock); |
| 1705 | while ((src_page = isolate_source_page(class))) { |
| 1706 | |
| 1707 | BUG_ON(!is_first_page(src_page)); |
| 1708 | |
| 1709 | /* The goal is to migrate all live objects in source page */ |
| 1710 | nr_to_migrate = src_page->inuse; |
| 1711 | cc.index = 0; |
| 1712 | cc.s_page = src_page; |
| 1713 | |
| 1714 | while ((dst_page = alloc_target_page(class))) { |
| 1715 | cc.d_page = dst_page; |
| 1716 | /* |
| 1717 | * If there is no more space in dst_page, try to |
| 1718 | * allocate another zspage. |
| 1719 | */ |
| 1720 | if (!migrate_zspage(pool, class, &cc)) |
| 1721 | break; |
| 1722 | |
| 1723 | putback_zspage(pool, class, dst_page); |
| 1724 | nr_total_migrated += cc.nr_migrated; |
| 1725 | nr_to_migrate -= cc.nr_migrated; |
| 1726 | } |
| 1727 | |
| 1728 | /* Stop if we couldn't find slot */ |
| 1729 | if (dst_page == NULL) |
| 1730 | break; |
| 1731 | |
| 1732 | putback_zspage(pool, class, dst_page); |
| 1733 | putback_zspage(pool, class, src_page); |
| 1734 | spin_unlock(&class->lock); |
| 1735 | nr_total_migrated += cc.nr_migrated; |
| 1736 | cond_resched(); |
| 1737 | spin_lock(&class->lock); |
| 1738 | } |
| 1739 | |
| 1740 | if (src_page) |
| 1741 | putback_zspage(pool, class, src_page); |
| 1742 | |
| 1743 | spin_unlock(&class->lock); |
| 1744 | |
| 1745 | return nr_total_migrated; |
| 1746 | } |
| 1747 | |
| 1748 | unsigned long zs_compact(struct zs_pool *pool) |
| 1749 | { |
| 1750 | int i; |
| 1751 | unsigned long nr_migrated = 0; |
| 1752 | struct size_class *class; |
| 1753 | |
| 1754 | for (i = zs_size_classes - 1; i >= 0; i--) { |
| 1755 | class = pool->size_class[i]; |
| 1756 | if (!class) |
| 1757 | continue; |
| 1758 | if (class->index != i) |
| 1759 | continue; |
| 1760 | nr_migrated += __zs_compact(pool, class); |
| 1761 | } |
| 1762 | |
| 1763 | synchronize_rcu(); |
| 1764 | |
| 1765 | return nr_migrated; |
| 1766 | } |
| 1767 | EXPORT_SYMBOL_GPL(zs_compact); |
| 1768 | |
Davidlohr Bueso | 4bbc0bc | 2013-01-04 12:14:00 -0800 | [diff] [blame] | 1769 | /** |
| 1770 | * zs_create_pool - Creates an allocation pool to work from. |
Seth Jennings | 0d145a5 | 2013-01-30 09:36:52 -0600 | [diff] [blame] | 1771 | * @flags: allocation flags used to allocate pool metadata |
Davidlohr Bueso | 4bbc0bc | 2013-01-04 12:14:00 -0800 | [diff] [blame] | 1772 | * |
| 1773 | * This function must be called before anything when using |
| 1774 | * the zsmalloc allocator. |
| 1775 | * |
| 1776 | * On success, a pointer to the newly created pool is returned, |
| 1777 | * otherwise NULL. |
| 1778 | */ |
Ganesh Mahendran | 3eba0c6 | 2015-02-12 15:00:51 -0800 | [diff] [blame] | 1779 | struct zs_pool *zs_create_pool(char *name, gfp_t flags) |
Nitin Gupta | 61989a8 | 2012-01-09 16:51:56 -0600 | [diff] [blame] | 1780 | { |
Ganesh Mahendran | 1813665 | 2014-12-12 16:57:10 -0800 | [diff] [blame] | 1781 | int i; |
Nitin Gupta | 61989a8 | 2012-01-09 16:51:56 -0600 | [diff] [blame] | 1782 | struct zs_pool *pool; |
Ganesh Mahendran | df8b5bb | 2014-12-12 16:57:07 -0800 | [diff] [blame] | 1783 | struct size_class *prev_class = NULL; |
Nitin Gupta | 61989a8 | 2012-01-09 16:51:56 -0600 | [diff] [blame] | 1784 | |
Ganesh Mahendran | 1813665 | 2014-12-12 16:57:10 -0800 | [diff] [blame] | 1785 | pool = kzalloc(sizeof(*pool), GFP_KERNEL); |
Nitin Gupta | 61989a8 | 2012-01-09 16:51:56 -0600 | [diff] [blame] | 1786 | if (!pool) |
| 1787 | return NULL; |
| 1788 | |
Minchan Kim | 2e40e16 | 2015-04-15 16:15:23 -0700 | [diff] [blame] | 1789 | pool->size_class = kcalloc(zs_size_classes, sizeof(struct size_class *), |
| 1790 | GFP_KERNEL); |
| 1791 | if (!pool->size_class) { |
Ganesh Mahendran | 0f050d9 | 2015-02-12 15:00:54 -0800 | [diff] [blame] | 1792 | kfree(pool); |
| 1793 | return NULL; |
| 1794 | } |
| 1795 | |
Minchan Kim | 2e40e16 | 2015-04-15 16:15:23 -0700 | [diff] [blame] | 1796 | pool->name = kstrdup(name, GFP_KERNEL); |
| 1797 | if (!pool->name) |
| 1798 | goto err; |
| 1799 | |
| 1800 | if (create_handle_cache(pool)) |
| 1801 | goto err; |
Mahendran Ganesh | 40f9fb8 | 2014-12-12 16:57:01 -0800 | [diff] [blame] | 1802 | |
Joonsoo Kim | 9eec4cd | 2014-12-12 16:56:44 -0800 | [diff] [blame] | 1803 | /* |
| 1804 | * Iterate reversly, because, size of size_class that we want to use |
| 1805 | * for merging should be larger or equal to current size. |
| 1806 | */ |
Mahendran Ganesh | 40f9fb8 | 2014-12-12 16:57:01 -0800 | [diff] [blame] | 1807 | for (i = zs_size_classes - 1; i >= 0; i--) { |
Nitin Gupta | 61989a8 | 2012-01-09 16:51:56 -0600 | [diff] [blame] | 1808 | int size; |
Joonsoo Kim | 9eec4cd | 2014-12-12 16:56:44 -0800 | [diff] [blame] | 1809 | int pages_per_zspage; |
Nitin Gupta | 61989a8 | 2012-01-09 16:51:56 -0600 | [diff] [blame] | 1810 | struct size_class *class; |
| 1811 | |
| 1812 | size = ZS_MIN_ALLOC_SIZE + i * ZS_SIZE_CLASS_DELTA; |
| 1813 | if (size > ZS_MAX_ALLOC_SIZE) |
| 1814 | size = ZS_MAX_ALLOC_SIZE; |
Joonsoo Kim | 9eec4cd | 2014-12-12 16:56:44 -0800 | [diff] [blame] | 1815 | pages_per_zspage = get_pages_per_zspage(size); |
Nitin Gupta | 61989a8 | 2012-01-09 16:51:56 -0600 | [diff] [blame] | 1816 | |
Joonsoo Kim | 9eec4cd | 2014-12-12 16:56:44 -0800 | [diff] [blame] | 1817 | /* |
| 1818 | * size_class is used for normal zsmalloc operation such |
| 1819 | * as alloc/free for that size. Although it is natural that we |
| 1820 | * have one size_class for each size, there is a chance that we |
| 1821 | * can get more memory utilization if we use one size_class for |
| 1822 | * many different sizes whose size_class have same |
| 1823 | * characteristics. So, we makes size_class point to |
| 1824 | * previous size_class if possible. |
| 1825 | */ |
Ganesh Mahendran | df8b5bb | 2014-12-12 16:57:07 -0800 | [diff] [blame] | 1826 | if (prev_class) { |
Joonsoo Kim | 9eec4cd | 2014-12-12 16:56:44 -0800 | [diff] [blame] | 1827 | if (can_merge(prev_class, size, pages_per_zspage)) { |
| 1828 | pool->size_class[i] = prev_class; |
| 1829 | continue; |
| 1830 | } |
| 1831 | } |
| 1832 | |
| 1833 | class = kzalloc(sizeof(struct size_class), GFP_KERNEL); |
| 1834 | if (!class) |
| 1835 | goto err; |
| 1836 | |
Nitin Gupta | 61989a8 | 2012-01-09 16:51:56 -0600 | [diff] [blame] | 1837 | class->size = size; |
| 1838 | class->index = i; |
Joonsoo Kim | 9eec4cd | 2014-12-12 16:56:44 -0800 | [diff] [blame] | 1839 | class->pages_per_zspage = pages_per_zspage; |
Nitin Gupta | 61989a8 | 2012-01-09 16:51:56 -0600 | [diff] [blame] | 1840 | spin_lock_init(&class->lock); |
Joonsoo Kim | 9eec4cd | 2014-12-12 16:56:44 -0800 | [diff] [blame] | 1841 | pool->size_class[i] = class; |
Ganesh Mahendran | df8b5bb | 2014-12-12 16:57:07 -0800 | [diff] [blame] | 1842 | |
| 1843 | prev_class = class; |
Nitin Gupta | 61989a8 | 2012-01-09 16:51:56 -0600 | [diff] [blame] | 1844 | } |
| 1845 | |
Nitin Gupta | 61989a8 | 2012-01-09 16:51:56 -0600 | [diff] [blame] | 1846 | pool->flags = flags; |
Nitin Gupta | 61989a8 | 2012-01-09 16:51:56 -0600 | [diff] [blame] | 1847 | |
Ganesh Mahendran | 0f050d9 | 2015-02-12 15:00:54 -0800 | [diff] [blame] | 1848 | if (zs_pool_stat_create(name, pool)) |
| 1849 | goto err; |
| 1850 | |
Nitin Gupta | 61989a8 | 2012-01-09 16:51:56 -0600 | [diff] [blame] | 1851 | return pool; |
Joonsoo Kim | 9eec4cd | 2014-12-12 16:56:44 -0800 | [diff] [blame] | 1852 | |
| 1853 | err: |
| 1854 | zs_destroy_pool(pool); |
| 1855 | return NULL; |
Nitin Gupta | 61989a8 | 2012-01-09 16:51:56 -0600 | [diff] [blame] | 1856 | } |
| 1857 | EXPORT_SYMBOL_GPL(zs_create_pool); |
| 1858 | |
| 1859 | void zs_destroy_pool(struct zs_pool *pool) |
| 1860 | { |
| 1861 | int i; |
| 1862 | |
Ganesh Mahendran | 0f050d9 | 2015-02-12 15:00:54 -0800 | [diff] [blame] | 1863 | zs_pool_stat_destroy(pool); |
| 1864 | |
Mahendran Ganesh | 40f9fb8 | 2014-12-12 16:57:01 -0800 | [diff] [blame] | 1865 | for (i = 0; i < zs_size_classes; i++) { |
Nitin Gupta | 61989a8 | 2012-01-09 16:51:56 -0600 | [diff] [blame] | 1866 | int fg; |
Joonsoo Kim | 9eec4cd | 2014-12-12 16:56:44 -0800 | [diff] [blame] | 1867 | struct size_class *class = pool->size_class[i]; |
| 1868 | |
| 1869 | if (!class) |
| 1870 | continue; |
| 1871 | |
| 1872 | if (class->index != i) |
| 1873 | continue; |
Nitin Gupta | 61989a8 | 2012-01-09 16:51:56 -0600 | [diff] [blame] | 1874 | |
| 1875 | for (fg = 0; fg < _ZS_NR_FULLNESS_GROUPS; fg++) { |
| 1876 | if (class->fullness_list[fg]) { |
Marlies Ruck | 93ad5ab | 2013-05-15 16:56:49 -0400 | [diff] [blame] | 1877 | pr_info("Freeing non-empty class with size %db, fullness group %d\n", |
Nitin Gupta | 61989a8 | 2012-01-09 16:51:56 -0600 | [diff] [blame] | 1878 | class->size, fg); |
| 1879 | } |
| 1880 | } |
Joonsoo Kim | 9eec4cd | 2014-12-12 16:56:44 -0800 | [diff] [blame] | 1881 | kfree(class); |
Nitin Gupta | 61989a8 | 2012-01-09 16:51:56 -0600 | [diff] [blame] | 1882 | } |
Mahendran Ganesh | 40f9fb8 | 2014-12-12 16:57:01 -0800 | [diff] [blame] | 1883 | |
Minchan Kim | 2e40e16 | 2015-04-15 16:15:23 -0700 | [diff] [blame] | 1884 | destroy_handle_cache(pool); |
Mahendran Ganesh | 40f9fb8 | 2014-12-12 16:57:01 -0800 | [diff] [blame] | 1885 | kfree(pool->size_class); |
Ganesh Mahendran | 0f050d9 | 2015-02-12 15:00:54 -0800 | [diff] [blame] | 1886 | kfree(pool->name); |
Nitin Gupta | 61989a8 | 2012-01-09 16:51:56 -0600 | [diff] [blame] | 1887 | kfree(pool); |
| 1888 | } |
| 1889 | EXPORT_SYMBOL_GPL(zs_destroy_pool); |
| 1890 | |
Ganesh Mahendran | 66cdef6 | 2014-12-18 16:17:40 -0800 | [diff] [blame] | 1891 | static int __init zs_init(void) |
Nitin Gupta | 61989a8 | 2012-01-09 16:51:56 -0600 | [diff] [blame] | 1892 | { |
Ganesh Mahendran | 66cdef6 | 2014-12-18 16:17:40 -0800 | [diff] [blame] | 1893 | int ret = zs_register_cpu_notifier(); |
Nitin Gupta | 61989a8 | 2012-01-09 16:51:56 -0600 | [diff] [blame] | 1894 | |
Ganesh Mahendran | 0f050d9 | 2015-02-12 15:00:54 -0800 | [diff] [blame] | 1895 | if (ret) |
| 1896 | goto notifier_fail; |
Nitin Gupta | 61989a8 | 2012-01-09 16:51:56 -0600 | [diff] [blame] | 1897 | |
Ganesh Mahendran | 66cdef6 | 2014-12-18 16:17:40 -0800 | [diff] [blame] | 1898 | init_zs_size_classes(); |
Nitin Gupta | 61989a8 | 2012-01-09 16:51:56 -0600 | [diff] [blame] | 1899 | |
Ganesh Mahendran | 66cdef6 | 2014-12-18 16:17:40 -0800 | [diff] [blame] | 1900 | #ifdef CONFIG_ZPOOL |
| 1901 | zpool_register_driver(&zs_zpool_driver); |
| 1902 | #endif |
Ganesh Mahendran | 0f050d9 | 2015-02-12 15:00:54 -0800 | [diff] [blame] | 1903 | |
| 1904 | ret = zs_stat_init(); |
| 1905 | if (ret) { |
| 1906 | pr_err("zs stat initialization failed\n"); |
| 1907 | goto stat_fail; |
| 1908 | } |
Ganesh Mahendran | 66cdef6 | 2014-12-18 16:17:40 -0800 | [diff] [blame] | 1909 | return 0; |
Ganesh Mahendran | 0f050d9 | 2015-02-12 15:00:54 -0800 | [diff] [blame] | 1910 | |
| 1911 | stat_fail: |
| 1912 | #ifdef CONFIG_ZPOOL |
| 1913 | zpool_unregister_driver(&zs_zpool_driver); |
| 1914 | #endif |
| 1915 | notifier_fail: |
| 1916 | zs_unregister_cpu_notifier(); |
| 1917 | |
| 1918 | return ret; |
Nitin Gupta | 61989a8 | 2012-01-09 16:51:56 -0600 | [diff] [blame] | 1919 | } |
Nitin Gupta | 61989a8 | 2012-01-09 16:51:56 -0600 | [diff] [blame] | 1920 | |
Ganesh Mahendran | 66cdef6 | 2014-12-18 16:17:40 -0800 | [diff] [blame] | 1921 | static void __exit zs_exit(void) |
Nitin Gupta | 61989a8 | 2012-01-09 16:51:56 -0600 | [diff] [blame] | 1922 | { |
Ganesh Mahendran | 66cdef6 | 2014-12-18 16:17:40 -0800 | [diff] [blame] | 1923 | #ifdef CONFIG_ZPOOL |
| 1924 | zpool_unregister_driver(&zs_zpool_driver); |
| 1925 | #endif |
| 1926 | zs_unregister_cpu_notifier(); |
Ganesh Mahendran | 0f050d9 | 2015-02-12 15:00:54 -0800 | [diff] [blame] | 1927 | |
| 1928 | zs_stat_exit(); |
Nitin Gupta | 61989a8 | 2012-01-09 16:51:56 -0600 | [diff] [blame] | 1929 | } |
Ben Hutchings | 069f101 | 2012-06-20 02:31:11 +0100 | [diff] [blame] | 1930 | |
| 1931 | module_init(zs_init); |
| 1932 | module_exit(zs_exit); |
| 1933 | |
| 1934 | MODULE_LICENSE("Dual BSD/GPL"); |
| 1935 | MODULE_AUTHOR("Nitin Gupta <ngupta@vflare.org>"); |