| 1 | /* memcontrol.c - Memory Controller |
| 2 | * |
| 3 | * Copyright IBM Corporation, 2007 |
| 4 | * Author Balbir Singh <balbir@linux.vnet.ibm.com> |
| 5 | * |
| 6 | * Copyright 2007 OpenVZ SWsoft Inc |
| 7 | * Author: Pavel Emelianov <xemul@openvz.org> |
| 8 | * |
| 9 | * This program is free software; you can redistribute it and/or modify |
| 10 | * it under the terms of the GNU General Public License as published by |
| 11 | * the Free Software Foundation; either version 2 of the License, or |
| 12 | * (at your option) any later version. |
| 13 | * |
| 14 | * This program is distributed in the hope that it will be useful, |
| 15 | * but WITHOUT ANY WARRANTY; without even the implied warranty of |
| 16 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
| 17 | * GNU General Public License for more details. |
| 18 | */ |
| 19 | |
| 20 | #include <linux/res_counter.h> |
| 21 | #include <linux/memcontrol.h> |
| 22 | #include <linux/cgroup.h> |
| 23 | #include <linux/mm.h> |
| 24 | #include <linux/pagemap.h> |
| 25 | #include <linux/smp.h> |
| 26 | #include <linux/page-flags.h> |
| 27 | #include <linux/backing-dev.h> |
| 28 | #include <linux/bit_spinlock.h> |
| 29 | #include <linux/rcupdate.h> |
| 30 | #include <linux/mutex.h> |
| 31 | #include <linux/slab.h> |
| 32 | #include <linux/swap.h> |
| 33 | #include <linux/spinlock.h> |
| 34 | #include <linux/fs.h> |
| 35 | #include <linux/seq_file.h> |
| 36 | #include <linux/vmalloc.h> |
| 37 | #include <linux/mm_inline.h> |
| 38 | #include <linux/page_cgroup.h> |
| 39 | #include "internal.h" |
| 40 | |
| 41 | #include <asm/uaccess.h> |
| 42 | |
| 43 | struct cgroup_subsys mem_cgroup_subsys __read_mostly; |
| 44 | #define MEM_CGROUP_RECLAIM_RETRIES 5 |
| 45 | |
| 46 | #ifdef CONFIG_CGROUP_MEM_RES_CTLR_SWAP |
| 47 | /* Turned on only when memory cgroup is enabled && really_do_swap_account = 0 */ |
| 48 | int do_swap_account __read_mostly; |
| 49 | static int really_do_swap_account __initdata = 1; /* for remember boot option*/ |
| 50 | #else |
| 51 | #define do_swap_account (0) |
| 52 | #endif |
| 53 | |
| 54 | static DEFINE_MUTEX(memcg_tasklist); /* can be hold under cgroup_mutex */ |
| 55 | |
| 56 | /* |
| 57 | * Statistics for memory cgroup. |
| 58 | */ |
| 59 | enum mem_cgroup_stat_index { |
| 60 | /* |
| 61 | * For MEM_CONTAINER_TYPE_ALL, usage = pagecache + rss. |
| 62 | */ |
| 63 | MEM_CGROUP_STAT_CACHE, /* # of pages charged as cache */ |
| 64 | MEM_CGROUP_STAT_RSS, /* # of pages charged as rss */ |
| 65 | MEM_CGROUP_STAT_PGPGIN_COUNT, /* # of pages paged in */ |
| 66 | MEM_CGROUP_STAT_PGPGOUT_COUNT, /* # of pages paged out */ |
| 67 | |
| 68 | MEM_CGROUP_STAT_NSTATS, |
| 69 | }; |
| 70 | |
| 71 | struct mem_cgroup_stat_cpu { |
| 72 | s64 count[MEM_CGROUP_STAT_NSTATS]; |
| 73 | } ____cacheline_aligned_in_smp; |
| 74 | |
| 75 | struct mem_cgroup_stat { |
| 76 | struct mem_cgroup_stat_cpu cpustat[0]; |
| 77 | }; |
| 78 | |
| 79 | /* |
| 80 | * For accounting under irq disable, no need for increment preempt count. |
| 81 | */ |
| 82 | static inline void __mem_cgroup_stat_add_safe(struct mem_cgroup_stat_cpu *stat, |
| 83 | enum mem_cgroup_stat_index idx, int val) |
| 84 | { |
| 85 | stat->count[idx] += val; |
| 86 | } |
| 87 | |
| 88 | static s64 mem_cgroup_read_stat(struct mem_cgroup_stat *stat, |
| 89 | enum mem_cgroup_stat_index idx) |
| 90 | { |
| 91 | int cpu; |
| 92 | s64 ret = 0; |
| 93 | for_each_possible_cpu(cpu) |
| 94 | ret += stat->cpustat[cpu].count[idx]; |
| 95 | return ret; |
| 96 | } |
| 97 | |
| 98 | /* |
| 99 | * per-zone information in memory controller. |
| 100 | */ |
| 101 | struct mem_cgroup_per_zone { |
| 102 | /* |
| 103 | * spin_lock to protect the per cgroup LRU |
| 104 | */ |
| 105 | struct list_head lists[NR_LRU_LISTS]; |
| 106 | unsigned long count[NR_LRU_LISTS]; |
| 107 | |
| 108 | struct zone_reclaim_stat reclaim_stat; |
| 109 | }; |
| 110 | /* Macro for accessing counter */ |
| 111 | #define MEM_CGROUP_ZSTAT(mz, idx) ((mz)->count[(idx)]) |
| 112 | |
| 113 | struct mem_cgroup_per_node { |
| 114 | struct mem_cgroup_per_zone zoneinfo[MAX_NR_ZONES]; |
| 115 | }; |
| 116 | |
| 117 | struct mem_cgroup_lru_info { |
| 118 | struct mem_cgroup_per_node *nodeinfo[MAX_NUMNODES]; |
| 119 | }; |
| 120 | |
| 121 | /* |
| 122 | * The memory controller data structure. The memory controller controls both |
| 123 | * page cache and RSS per cgroup. We would eventually like to provide |
| 124 | * statistics based on the statistics developed by Rik Van Riel for clock-pro, |
| 125 | * to help the administrator determine what knobs to tune. |
| 126 | * |
| 127 | * TODO: Add a water mark for the memory controller. Reclaim will begin when |
| 128 | * we hit the water mark. May be even add a low water mark, such that |
| 129 | * no reclaim occurs from a cgroup at it's low water mark, this is |
| 130 | * a feature that will be implemented much later in the future. |
| 131 | */ |
| 132 | struct mem_cgroup { |
| 133 | struct cgroup_subsys_state css; |
| 134 | /* |
| 135 | * the counter to account for memory usage |
| 136 | */ |
| 137 | struct res_counter res; |
| 138 | /* |
| 139 | * the counter to account for mem+swap usage. |
| 140 | */ |
| 141 | struct res_counter memsw; |
| 142 | /* |
| 143 | * Per cgroup active and inactive list, similar to the |
| 144 | * per zone LRU lists. |
| 145 | */ |
| 146 | struct mem_cgroup_lru_info info; |
| 147 | |
| 148 | /* |
| 149 | protect against reclaim related member. |
| 150 | */ |
| 151 | spinlock_t reclaim_param_lock; |
| 152 | |
| 153 | int prev_priority; /* for recording reclaim priority */ |
| 154 | |
| 155 | /* |
| 156 | * While reclaiming in a hiearchy, we cache the last child we |
| 157 | * reclaimed from. Protected by hierarchy_mutex |
| 158 | */ |
| 159 | struct mem_cgroup *last_scanned_child; |
| 160 | /* |
| 161 | * Should the accounting and control be hierarchical, per subtree? |
| 162 | */ |
| 163 | bool use_hierarchy; |
| 164 | unsigned long last_oom_jiffies; |
| 165 | atomic_t refcnt; |
| 166 | |
| 167 | unsigned int swappiness; |
| 168 | |
| 169 | /* |
| 170 | * statistics. This must be placed at the end of memcg. |
| 171 | */ |
| 172 | struct mem_cgroup_stat stat; |
| 173 | }; |
| 174 | |
| 175 | enum charge_type { |
| 176 | MEM_CGROUP_CHARGE_TYPE_CACHE = 0, |
| 177 | MEM_CGROUP_CHARGE_TYPE_MAPPED, |
| 178 | MEM_CGROUP_CHARGE_TYPE_SHMEM, /* used by page migration of shmem */ |
| 179 | MEM_CGROUP_CHARGE_TYPE_FORCE, /* used by force_empty */ |
| 180 | MEM_CGROUP_CHARGE_TYPE_SWAPOUT, /* for accounting swapcache */ |
| 181 | NR_CHARGE_TYPE, |
| 182 | }; |
| 183 | |
| 184 | /* only for here (for easy reading.) */ |
| 185 | #define PCGF_CACHE (1UL << PCG_CACHE) |
| 186 | #define PCGF_USED (1UL << PCG_USED) |
| 187 | #define PCGF_LOCK (1UL << PCG_LOCK) |
| 188 | static const unsigned long |
| 189 | pcg_default_flags[NR_CHARGE_TYPE] = { |
| 190 | PCGF_CACHE | PCGF_USED | PCGF_LOCK, /* File Cache */ |
| 191 | PCGF_USED | PCGF_LOCK, /* Anon */ |
| 192 | PCGF_CACHE | PCGF_USED | PCGF_LOCK, /* Shmem */ |
| 193 | 0, /* FORCE */ |
| 194 | }; |
| 195 | |
| 196 | /* for encoding cft->private value on file */ |
| 197 | #define _MEM (0) |
| 198 | #define _MEMSWAP (1) |
| 199 | #define MEMFILE_PRIVATE(x, val) (((x) << 16) | (val)) |
| 200 | #define MEMFILE_TYPE(val) (((val) >> 16) & 0xffff) |
| 201 | #define MEMFILE_ATTR(val) ((val) & 0xffff) |
| 202 | |
| 203 | static void mem_cgroup_get(struct mem_cgroup *mem); |
| 204 | static void mem_cgroup_put(struct mem_cgroup *mem); |
| 205 | |
| 206 | static void mem_cgroup_charge_statistics(struct mem_cgroup *mem, |
| 207 | struct page_cgroup *pc, |
| 208 | bool charge) |
| 209 | { |
| 210 | int val = (charge)? 1 : -1; |
| 211 | struct mem_cgroup_stat *stat = &mem->stat; |
| 212 | struct mem_cgroup_stat_cpu *cpustat; |
| 213 | int cpu = get_cpu(); |
| 214 | |
| 215 | cpustat = &stat->cpustat[cpu]; |
| 216 | if (PageCgroupCache(pc)) |
| 217 | __mem_cgroup_stat_add_safe(cpustat, MEM_CGROUP_STAT_CACHE, val); |
| 218 | else |
| 219 | __mem_cgroup_stat_add_safe(cpustat, MEM_CGROUP_STAT_RSS, val); |
| 220 | |
| 221 | if (charge) |
| 222 | __mem_cgroup_stat_add_safe(cpustat, |
| 223 | MEM_CGROUP_STAT_PGPGIN_COUNT, 1); |
| 224 | else |
| 225 | __mem_cgroup_stat_add_safe(cpustat, |
| 226 | MEM_CGROUP_STAT_PGPGOUT_COUNT, 1); |
| 227 | put_cpu(); |
| 228 | } |
| 229 | |
| 230 | static struct mem_cgroup_per_zone * |
| 231 | mem_cgroup_zoneinfo(struct mem_cgroup *mem, int nid, int zid) |
| 232 | { |
| 233 | return &mem->info.nodeinfo[nid]->zoneinfo[zid]; |
| 234 | } |
| 235 | |
| 236 | static struct mem_cgroup_per_zone * |
| 237 | page_cgroup_zoneinfo(struct page_cgroup *pc) |
| 238 | { |
| 239 | struct mem_cgroup *mem = pc->mem_cgroup; |
| 240 | int nid = page_cgroup_nid(pc); |
| 241 | int zid = page_cgroup_zid(pc); |
| 242 | |
| 243 | if (!mem) |
| 244 | return NULL; |
| 245 | |
| 246 | return mem_cgroup_zoneinfo(mem, nid, zid); |
| 247 | } |
| 248 | |
| 249 | static unsigned long mem_cgroup_get_all_zonestat(struct mem_cgroup *mem, |
| 250 | enum lru_list idx) |
| 251 | { |
| 252 | int nid, zid; |
| 253 | struct mem_cgroup_per_zone *mz; |
| 254 | u64 total = 0; |
| 255 | |
| 256 | for_each_online_node(nid) |
| 257 | for (zid = 0; zid < MAX_NR_ZONES; zid++) { |
| 258 | mz = mem_cgroup_zoneinfo(mem, nid, zid); |
| 259 | total += MEM_CGROUP_ZSTAT(mz, idx); |
| 260 | } |
| 261 | return total; |
| 262 | } |
| 263 | |
| 264 | static struct mem_cgroup *mem_cgroup_from_cont(struct cgroup *cont) |
| 265 | { |
| 266 | return container_of(cgroup_subsys_state(cont, |
| 267 | mem_cgroup_subsys_id), struct mem_cgroup, |
| 268 | css); |
| 269 | } |
| 270 | |
| 271 | struct mem_cgroup *mem_cgroup_from_task(struct task_struct *p) |
| 272 | { |
| 273 | /* |
| 274 | * mm_update_next_owner() may clear mm->owner to NULL |
| 275 | * if it races with swapoff, page migration, etc. |
| 276 | * So this can be called with p == NULL. |
| 277 | */ |
| 278 | if (unlikely(!p)) |
| 279 | return NULL; |
| 280 | |
| 281 | return container_of(task_subsys_state(p, mem_cgroup_subsys_id), |
| 282 | struct mem_cgroup, css); |
| 283 | } |
| 284 | |
| 285 | static struct mem_cgroup *try_get_mem_cgroup_from_mm(struct mm_struct *mm) |
| 286 | { |
| 287 | struct mem_cgroup *mem = NULL; |
| 288 | /* |
| 289 | * Because we have no locks, mm->owner's may be being moved to other |
| 290 | * cgroup. We use css_tryget() here even if this looks |
| 291 | * pessimistic (rather than adding locks here). |
| 292 | */ |
| 293 | rcu_read_lock(); |
| 294 | do { |
| 295 | mem = mem_cgroup_from_task(rcu_dereference(mm->owner)); |
| 296 | if (unlikely(!mem)) |
| 297 | break; |
| 298 | } while (!css_tryget(&mem->css)); |
| 299 | rcu_read_unlock(); |
| 300 | return mem; |
| 301 | } |
| 302 | |
| 303 | static bool mem_cgroup_is_obsolete(struct mem_cgroup *mem) |
| 304 | { |
| 305 | if (!mem) |
| 306 | return true; |
| 307 | return css_is_removed(&mem->css); |
| 308 | } |
| 309 | |
| 310 | /* |
| 311 | * Following LRU functions are allowed to be used without PCG_LOCK. |
| 312 | * Operations are called by routine of global LRU independently from memcg. |
| 313 | * What we have to take care of here is validness of pc->mem_cgroup. |
| 314 | * |
| 315 | * Changes to pc->mem_cgroup happens when |
| 316 | * 1. charge |
| 317 | * 2. moving account |
| 318 | * In typical case, "charge" is done before add-to-lru. Exception is SwapCache. |
| 319 | * It is added to LRU before charge. |
| 320 | * If PCG_USED bit is not set, page_cgroup is not added to this private LRU. |
| 321 | * When moving account, the page is not on LRU. It's isolated. |
| 322 | */ |
| 323 | |
| 324 | void mem_cgroup_del_lru_list(struct page *page, enum lru_list lru) |
| 325 | { |
| 326 | struct page_cgroup *pc; |
| 327 | struct mem_cgroup *mem; |
| 328 | struct mem_cgroup_per_zone *mz; |
| 329 | |
| 330 | if (mem_cgroup_disabled()) |
| 331 | return; |
| 332 | pc = lookup_page_cgroup(page); |
| 333 | /* can happen while we handle swapcache. */ |
| 334 | if (list_empty(&pc->lru) || !pc->mem_cgroup) |
| 335 | return; |
| 336 | /* |
| 337 | * We don't check PCG_USED bit. It's cleared when the "page" is finally |
| 338 | * removed from global LRU. |
| 339 | */ |
| 340 | mz = page_cgroup_zoneinfo(pc); |
| 341 | mem = pc->mem_cgroup; |
| 342 | MEM_CGROUP_ZSTAT(mz, lru) -= 1; |
| 343 | list_del_init(&pc->lru); |
| 344 | return; |
| 345 | } |
| 346 | |
| 347 | void mem_cgroup_del_lru(struct page *page) |
| 348 | { |
| 349 | mem_cgroup_del_lru_list(page, page_lru(page)); |
| 350 | } |
| 351 | |
| 352 | void mem_cgroup_rotate_lru_list(struct page *page, enum lru_list lru) |
| 353 | { |
| 354 | struct mem_cgroup_per_zone *mz; |
| 355 | struct page_cgroup *pc; |
| 356 | |
| 357 | if (mem_cgroup_disabled()) |
| 358 | return; |
| 359 | |
| 360 | pc = lookup_page_cgroup(page); |
| 361 | /* |
| 362 | * Used bit is set without atomic ops but after smp_wmb(). |
| 363 | * For making pc->mem_cgroup visible, insert smp_rmb() here. |
| 364 | */ |
| 365 | smp_rmb(); |
| 366 | /* unused page is not rotated. */ |
| 367 | if (!PageCgroupUsed(pc)) |
| 368 | return; |
| 369 | mz = page_cgroup_zoneinfo(pc); |
| 370 | list_move(&pc->lru, &mz->lists[lru]); |
| 371 | } |
| 372 | |
| 373 | void mem_cgroup_add_lru_list(struct page *page, enum lru_list lru) |
| 374 | { |
| 375 | struct page_cgroup *pc; |
| 376 | struct mem_cgroup_per_zone *mz; |
| 377 | |
| 378 | if (mem_cgroup_disabled()) |
| 379 | return; |
| 380 | pc = lookup_page_cgroup(page); |
| 381 | /* |
| 382 | * Used bit is set without atomic ops but after smp_wmb(). |
| 383 | * For making pc->mem_cgroup visible, insert smp_rmb() here. |
| 384 | */ |
| 385 | smp_rmb(); |
| 386 | if (!PageCgroupUsed(pc)) |
| 387 | return; |
| 388 | |
| 389 | mz = page_cgroup_zoneinfo(pc); |
| 390 | MEM_CGROUP_ZSTAT(mz, lru) += 1; |
| 391 | list_add(&pc->lru, &mz->lists[lru]); |
| 392 | } |
| 393 | |
| 394 | /* |
| 395 | * At handling SwapCache, pc->mem_cgroup may be changed while it's linked to |
| 396 | * lru because the page may.be reused after it's fully uncharged (because of |
| 397 | * SwapCache behavior).To handle that, unlink page_cgroup from LRU when charge |
| 398 | * it again. This function is only used to charge SwapCache. It's done under |
| 399 | * lock_page and expected that zone->lru_lock is never held. |
| 400 | */ |
| 401 | static void mem_cgroup_lru_del_before_commit_swapcache(struct page *page) |
| 402 | { |
| 403 | unsigned long flags; |
| 404 | struct zone *zone = page_zone(page); |
| 405 | struct page_cgroup *pc = lookup_page_cgroup(page); |
| 406 | |
| 407 | spin_lock_irqsave(&zone->lru_lock, flags); |
| 408 | /* |
| 409 | * Forget old LRU when this page_cgroup is *not* used. This Used bit |
| 410 | * is guarded by lock_page() because the page is SwapCache. |
| 411 | */ |
| 412 | if (!PageCgroupUsed(pc)) |
| 413 | mem_cgroup_del_lru_list(page, page_lru(page)); |
| 414 | spin_unlock_irqrestore(&zone->lru_lock, flags); |
| 415 | } |
| 416 | |
| 417 | static void mem_cgroup_lru_add_after_commit_swapcache(struct page *page) |
| 418 | { |
| 419 | unsigned long flags; |
| 420 | struct zone *zone = page_zone(page); |
| 421 | struct page_cgroup *pc = lookup_page_cgroup(page); |
| 422 | |
| 423 | spin_lock_irqsave(&zone->lru_lock, flags); |
| 424 | /* link when the page is linked to LRU but page_cgroup isn't */ |
| 425 | if (PageLRU(page) && list_empty(&pc->lru)) |
| 426 | mem_cgroup_add_lru_list(page, page_lru(page)); |
| 427 | spin_unlock_irqrestore(&zone->lru_lock, flags); |
| 428 | } |
| 429 | |
| 430 | |
| 431 | void mem_cgroup_move_lists(struct page *page, |
| 432 | enum lru_list from, enum lru_list to) |
| 433 | { |
| 434 | if (mem_cgroup_disabled()) |
| 435 | return; |
| 436 | mem_cgroup_del_lru_list(page, from); |
| 437 | mem_cgroup_add_lru_list(page, to); |
| 438 | } |
| 439 | |
| 440 | int task_in_mem_cgroup(struct task_struct *task, const struct mem_cgroup *mem) |
| 441 | { |
| 442 | int ret; |
| 443 | |
| 444 | task_lock(task); |
| 445 | ret = task->mm && mm_match_cgroup(task->mm, mem); |
| 446 | task_unlock(task); |
| 447 | return ret; |
| 448 | } |
| 449 | |
| 450 | /* |
| 451 | * Calculate mapped_ratio under memory controller. This will be used in |
| 452 | * vmscan.c for deteremining we have to reclaim mapped pages. |
| 453 | */ |
| 454 | int mem_cgroup_calc_mapped_ratio(struct mem_cgroup *mem) |
| 455 | { |
| 456 | long total, rss; |
| 457 | |
| 458 | /* |
| 459 | * usage is recorded in bytes. But, here, we assume the number of |
| 460 | * physical pages can be represented by "long" on any arch. |
| 461 | */ |
| 462 | total = (long) (mem->res.usage >> PAGE_SHIFT) + 1L; |
| 463 | rss = (long)mem_cgroup_read_stat(&mem->stat, MEM_CGROUP_STAT_RSS); |
| 464 | return (int)((rss * 100L) / total); |
| 465 | } |
| 466 | |
| 467 | /* |
| 468 | * prev_priority control...this will be used in memory reclaim path. |
| 469 | */ |
| 470 | int mem_cgroup_get_reclaim_priority(struct mem_cgroup *mem) |
| 471 | { |
| 472 | int prev_priority; |
| 473 | |
| 474 | spin_lock(&mem->reclaim_param_lock); |
| 475 | prev_priority = mem->prev_priority; |
| 476 | spin_unlock(&mem->reclaim_param_lock); |
| 477 | |
| 478 | return prev_priority; |
| 479 | } |
| 480 | |
| 481 | void mem_cgroup_note_reclaim_priority(struct mem_cgroup *mem, int priority) |
| 482 | { |
| 483 | spin_lock(&mem->reclaim_param_lock); |
| 484 | if (priority < mem->prev_priority) |
| 485 | mem->prev_priority = priority; |
| 486 | spin_unlock(&mem->reclaim_param_lock); |
| 487 | } |
| 488 | |
| 489 | void mem_cgroup_record_reclaim_priority(struct mem_cgroup *mem, int priority) |
| 490 | { |
| 491 | spin_lock(&mem->reclaim_param_lock); |
| 492 | mem->prev_priority = priority; |
| 493 | spin_unlock(&mem->reclaim_param_lock); |
| 494 | } |
| 495 | |
| 496 | static int calc_inactive_ratio(struct mem_cgroup *memcg, unsigned long *present_pages) |
| 497 | { |
| 498 | unsigned long active; |
| 499 | unsigned long inactive; |
| 500 | unsigned long gb; |
| 501 | unsigned long inactive_ratio; |
| 502 | |
| 503 | inactive = mem_cgroup_get_all_zonestat(memcg, LRU_INACTIVE_ANON); |
| 504 | active = mem_cgroup_get_all_zonestat(memcg, LRU_ACTIVE_ANON); |
| 505 | |
| 506 | gb = (inactive + active) >> (30 - PAGE_SHIFT); |
| 507 | if (gb) |
| 508 | inactive_ratio = int_sqrt(10 * gb); |
| 509 | else |
| 510 | inactive_ratio = 1; |
| 511 | |
| 512 | if (present_pages) { |
| 513 | present_pages[0] = inactive; |
| 514 | present_pages[1] = active; |
| 515 | } |
| 516 | |
| 517 | return inactive_ratio; |
| 518 | } |
| 519 | |
| 520 | int mem_cgroup_inactive_anon_is_low(struct mem_cgroup *memcg) |
| 521 | { |
| 522 | unsigned long active; |
| 523 | unsigned long inactive; |
| 524 | unsigned long present_pages[2]; |
| 525 | unsigned long inactive_ratio; |
| 526 | |
| 527 | inactive_ratio = calc_inactive_ratio(memcg, present_pages); |
| 528 | |
| 529 | inactive = present_pages[0]; |
| 530 | active = present_pages[1]; |
| 531 | |
| 532 | if (inactive * inactive_ratio < active) |
| 533 | return 1; |
| 534 | |
| 535 | return 0; |
| 536 | } |
| 537 | |
| 538 | unsigned long mem_cgroup_zone_nr_pages(struct mem_cgroup *memcg, |
| 539 | struct zone *zone, |
| 540 | enum lru_list lru) |
| 541 | { |
| 542 | int nid = zone->zone_pgdat->node_id; |
| 543 | int zid = zone_idx(zone); |
| 544 | struct mem_cgroup_per_zone *mz = mem_cgroup_zoneinfo(memcg, nid, zid); |
| 545 | |
| 546 | return MEM_CGROUP_ZSTAT(mz, lru); |
| 547 | } |
| 548 | |
| 549 | struct zone_reclaim_stat *mem_cgroup_get_reclaim_stat(struct mem_cgroup *memcg, |
| 550 | struct zone *zone) |
| 551 | { |
| 552 | int nid = zone->zone_pgdat->node_id; |
| 553 | int zid = zone_idx(zone); |
| 554 | struct mem_cgroup_per_zone *mz = mem_cgroup_zoneinfo(memcg, nid, zid); |
| 555 | |
| 556 | return &mz->reclaim_stat; |
| 557 | } |
| 558 | |
| 559 | struct zone_reclaim_stat * |
| 560 | mem_cgroup_get_reclaim_stat_from_page(struct page *page) |
| 561 | { |
| 562 | struct page_cgroup *pc; |
| 563 | struct mem_cgroup_per_zone *mz; |
| 564 | |
| 565 | if (mem_cgroup_disabled()) |
| 566 | return NULL; |
| 567 | |
| 568 | pc = lookup_page_cgroup(page); |
| 569 | /* |
| 570 | * Used bit is set without atomic ops but after smp_wmb(). |
| 571 | * For making pc->mem_cgroup visible, insert smp_rmb() here. |
| 572 | */ |
| 573 | smp_rmb(); |
| 574 | if (!PageCgroupUsed(pc)) |
| 575 | return NULL; |
| 576 | |
| 577 | mz = page_cgroup_zoneinfo(pc); |
| 578 | if (!mz) |
| 579 | return NULL; |
| 580 | |
| 581 | return &mz->reclaim_stat; |
| 582 | } |
| 583 | |
| 584 | unsigned long mem_cgroup_isolate_pages(unsigned long nr_to_scan, |
| 585 | struct list_head *dst, |
| 586 | unsigned long *scanned, int order, |
| 587 | int mode, struct zone *z, |
| 588 | struct mem_cgroup *mem_cont, |
| 589 | int active, int file) |
| 590 | { |
| 591 | unsigned long nr_taken = 0; |
| 592 | struct page *page; |
| 593 | unsigned long scan; |
| 594 | LIST_HEAD(pc_list); |
| 595 | struct list_head *src; |
| 596 | struct page_cgroup *pc, *tmp; |
| 597 | int nid = z->zone_pgdat->node_id; |
| 598 | int zid = zone_idx(z); |
| 599 | struct mem_cgroup_per_zone *mz; |
| 600 | int lru = LRU_FILE * !!file + !!active; |
| 601 | |
| 602 | BUG_ON(!mem_cont); |
| 603 | mz = mem_cgroup_zoneinfo(mem_cont, nid, zid); |
| 604 | src = &mz->lists[lru]; |
| 605 | |
| 606 | scan = 0; |
| 607 | list_for_each_entry_safe_reverse(pc, tmp, src, lru) { |
| 608 | if (scan >= nr_to_scan) |
| 609 | break; |
| 610 | |
| 611 | page = pc->page; |
| 612 | if (unlikely(!PageCgroupUsed(pc))) |
| 613 | continue; |
| 614 | if (unlikely(!PageLRU(page))) |
| 615 | continue; |
| 616 | |
| 617 | scan++; |
| 618 | if (__isolate_lru_page(page, mode, file) == 0) { |
| 619 | list_move(&page->lru, dst); |
| 620 | nr_taken++; |
| 621 | } |
| 622 | } |
| 623 | |
| 624 | *scanned = scan; |
| 625 | return nr_taken; |
| 626 | } |
| 627 | |
| 628 | #define mem_cgroup_from_res_counter(counter, member) \ |
| 629 | container_of(counter, struct mem_cgroup, member) |
| 630 | |
| 631 | /* |
| 632 | * This routine finds the DFS walk successor. This routine should be |
| 633 | * called with hierarchy_mutex held |
| 634 | */ |
| 635 | static struct mem_cgroup * |
| 636 | __mem_cgroup_get_next_node(struct mem_cgroup *curr, struct mem_cgroup *root_mem) |
| 637 | { |
| 638 | struct cgroup *cgroup, *curr_cgroup, *root_cgroup; |
| 639 | |
| 640 | curr_cgroup = curr->css.cgroup; |
| 641 | root_cgroup = root_mem->css.cgroup; |
| 642 | |
| 643 | if (!list_empty(&curr_cgroup->children)) { |
| 644 | /* |
| 645 | * Walk down to children |
| 646 | */ |
| 647 | cgroup = list_entry(curr_cgroup->children.next, |
| 648 | struct cgroup, sibling); |
| 649 | curr = mem_cgroup_from_cont(cgroup); |
| 650 | goto done; |
| 651 | } |
| 652 | |
| 653 | visit_parent: |
| 654 | if (curr_cgroup == root_cgroup) { |
| 655 | /* caller handles NULL case */ |
| 656 | curr = NULL; |
| 657 | goto done; |
| 658 | } |
| 659 | |
| 660 | /* |
| 661 | * Goto next sibling |
| 662 | */ |
| 663 | if (curr_cgroup->sibling.next != &curr_cgroup->parent->children) { |
| 664 | cgroup = list_entry(curr_cgroup->sibling.next, struct cgroup, |
| 665 | sibling); |
| 666 | curr = mem_cgroup_from_cont(cgroup); |
| 667 | goto done; |
| 668 | } |
| 669 | |
| 670 | /* |
| 671 | * Go up to next parent and next parent's sibling if need be |
| 672 | */ |
| 673 | curr_cgroup = curr_cgroup->parent; |
| 674 | goto visit_parent; |
| 675 | |
| 676 | done: |
| 677 | return curr; |
| 678 | } |
| 679 | |
| 680 | /* |
| 681 | * Visit the first child (need not be the first child as per the ordering |
| 682 | * of the cgroup list, since we track last_scanned_child) of @mem and use |
| 683 | * that to reclaim free pages from. |
| 684 | */ |
| 685 | static struct mem_cgroup * |
| 686 | mem_cgroup_get_next_node(struct mem_cgroup *root_mem) |
| 687 | { |
| 688 | struct cgroup *cgroup; |
| 689 | struct mem_cgroup *orig, *next; |
| 690 | bool obsolete; |
| 691 | |
| 692 | /* |
| 693 | * Scan all children under the mem_cgroup mem |
| 694 | */ |
| 695 | mutex_lock(&mem_cgroup_subsys.hierarchy_mutex); |
| 696 | |
| 697 | orig = root_mem->last_scanned_child; |
| 698 | obsolete = mem_cgroup_is_obsolete(orig); |
| 699 | |
| 700 | if (list_empty(&root_mem->css.cgroup->children)) { |
| 701 | /* |
| 702 | * root_mem might have children before and last_scanned_child |
| 703 | * may point to one of them. We put it later. |
| 704 | */ |
| 705 | if (orig) |
| 706 | VM_BUG_ON(!obsolete); |
| 707 | next = NULL; |
| 708 | goto done; |
| 709 | } |
| 710 | |
| 711 | if (!orig || obsolete) { |
| 712 | cgroup = list_first_entry(&root_mem->css.cgroup->children, |
| 713 | struct cgroup, sibling); |
| 714 | next = mem_cgroup_from_cont(cgroup); |
| 715 | } else |
| 716 | next = __mem_cgroup_get_next_node(orig, root_mem); |
| 717 | |
| 718 | done: |
| 719 | if (next) |
| 720 | mem_cgroup_get(next); |
| 721 | root_mem->last_scanned_child = next; |
| 722 | if (orig) |
| 723 | mem_cgroup_put(orig); |
| 724 | mutex_unlock(&mem_cgroup_subsys.hierarchy_mutex); |
| 725 | return (next) ? next : root_mem; |
| 726 | } |
| 727 | |
| 728 | static bool mem_cgroup_check_under_limit(struct mem_cgroup *mem) |
| 729 | { |
| 730 | if (do_swap_account) { |
| 731 | if (res_counter_check_under_limit(&mem->res) && |
| 732 | res_counter_check_under_limit(&mem->memsw)) |
| 733 | return true; |
| 734 | } else |
| 735 | if (res_counter_check_under_limit(&mem->res)) |
| 736 | return true; |
| 737 | return false; |
| 738 | } |
| 739 | |
| 740 | static unsigned int get_swappiness(struct mem_cgroup *memcg) |
| 741 | { |
| 742 | struct cgroup *cgrp = memcg->css.cgroup; |
| 743 | unsigned int swappiness; |
| 744 | |
| 745 | /* root ? */ |
| 746 | if (cgrp->parent == NULL) |
| 747 | return vm_swappiness; |
| 748 | |
| 749 | spin_lock(&memcg->reclaim_param_lock); |
| 750 | swappiness = memcg->swappiness; |
| 751 | spin_unlock(&memcg->reclaim_param_lock); |
| 752 | |
| 753 | return swappiness; |
| 754 | } |
| 755 | |
| 756 | /* |
| 757 | * Dance down the hierarchy if needed to reclaim memory. We remember the |
| 758 | * last child we reclaimed from, so that we don't end up penalizing |
| 759 | * one child extensively based on its position in the children list. |
| 760 | * |
| 761 | * root_mem is the original ancestor that we've been reclaim from. |
| 762 | */ |
| 763 | static int mem_cgroup_hierarchical_reclaim(struct mem_cgroup *root_mem, |
| 764 | gfp_t gfp_mask, bool noswap) |
| 765 | { |
| 766 | struct mem_cgroup *next_mem; |
| 767 | int ret = 0; |
| 768 | |
| 769 | /* |
| 770 | * Reclaim unconditionally and don't check for return value. |
| 771 | * We need to reclaim in the current group and down the tree. |
| 772 | * One might think about checking for children before reclaiming, |
| 773 | * but there might be left over accounting, even after children |
| 774 | * have left. |
| 775 | */ |
| 776 | ret = try_to_free_mem_cgroup_pages(root_mem, gfp_mask, noswap, |
| 777 | get_swappiness(root_mem)); |
| 778 | if (mem_cgroup_check_under_limit(root_mem)) |
| 779 | return 0; |
| 780 | if (!root_mem->use_hierarchy) |
| 781 | return ret; |
| 782 | |
| 783 | next_mem = mem_cgroup_get_next_node(root_mem); |
| 784 | |
| 785 | while (next_mem != root_mem) { |
| 786 | if (mem_cgroup_is_obsolete(next_mem)) { |
| 787 | next_mem = mem_cgroup_get_next_node(root_mem); |
| 788 | continue; |
| 789 | } |
| 790 | ret = try_to_free_mem_cgroup_pages(next_mem, gfp_mask, noswap, |
| 791 | get_swappiness(next_mem)); |
| 792 | if (mem_cgroup_check_under_limit(root_mem)) |
| 793 | return 0; |
| 794 | next_mem = mem_cgroup_get_next_node(root_mem); |
| 795 | } |
| 796 | return ret; |
| 797 | } |
| 798 | |
| 799 | bool mem_cgroup_oom_called(struct task_struct *task) |
| 800 | { |
| 801 | bool ret = false; |
| 802 | struct mem_cgroup *mem; |
| 803 | struct mm_struct *mm; |
| 804 | |
| 805 | rcu_read_lock(); |
| 806 | mm = task->mm; |
| 807 | if (!mm) |
| 808 | mm = &init_mm; |
| 809 | mem = mem_cgroup_from_task(rcu_dereference(mm->owner)); |
| 810 | if (mem && time_before(jiffies, mem->last_oom_jiffies + HZ/10)) |
| 811 | ret = true; |
| 812 | rcu_read_unlock(); |
| 813 | return ret; |
| 814 | } |
| 815 | /* |
| 816 | * Unlike exported interface, "oom" parameter is added. if oom==true, |
| 817 | * oom-killer can be invoked. |
| 818 | */ |
| 819 | static int __mem_cgroup_try_charge(struct mm_struct *mm, |
| 820 | gfp_t gfp_mask, struct mem_cgroup **memcg, |
| 821 | bool oom) |
| 822 | { |
| 823 | struct mem_cgroup *mem, *mem_over_limit; |
| 824 | int nr_retries = MEM_CGROUP_RECLAIM_RETRIES; |
| 825 | struct res_counter *fail_res; |
| 826 | |
| 827 | if (unlikely(test_thread_flag(TIF_MEMDIE))) { |
| 828 | /* Don't account this! */ |
| 829 | *memcg = NULL; |
| 830 | return 0; |
| 831 | } |
| 832 | |
| 833 | /* |
| 834 | * We always charge the cgroup the mm_struct belongs to. |
| 835 | * The mm_struct's mem_cgroup changes on task migration if the |
| 836 | * thread group leader migrates. It's possible that mm is not |
| 837 | * set, if so charge the init_mm (happens for pagecache usage). |
| 838 | */ |
| 839 | mem = *memcg; |
| 840 | if (likely(!mem)) { |
| 841 | mem = try_get_mem_cgroup_from_mm(mm); |
| 842 | *memcg = mem; |
| 843 | } else { |
| 844 | css_get(&mem->css); |
| 845 | } |
| 846 | if (unlikely(!mem)) |
| 847 | return 0; |
| 848 | |
| 849 | VM_BUG_ON(mem_cgroup_is_obsolete(mem)); |
| 850 | |
| 851 | while (1) { |
| 852 | int ret; |
| 853 | bool noswap = false; |
| 854 | |
| 855 | ret = res_counter_charge(&mem->res, PAGE_SIZE, &fail_res); |
| 856 | if (likely(!ret)) { |
| 857 | if (!do_swap_account) |
| 858 | break; |
| 859 | ret = res_counter_charge(&mem->memsw, PAGE_SIZE, |
| 860 | &fail_res); |
| 861 | if (likely(!ret)) |
| 862 | break; |
| 863 | /* mem+swap counter fails */ |
| 864 | res_counter_uncharge(&mem->res, PAGE_SIZE); |
| 865 | noswap = true; |
| 866 | mem_over_limit = mem_cgroup_from_res_counter(fail_res, |
| 867 | memsw); |
| 868 | } else |
| 869 | /* mem counter fails */ |
| 870 | mem_over_limit = mem_cgroup_from_res_counter(fail_res, |
| 871 | res); |
| 872 | |
| 873 | if (!(gfp_mask & __GFP_WAIT)) |
| 874 | goto nomem; |
| 875 | |
| 876 | ret = mem_cgroup_hierarchical_reclaim(mem_over_limit, gfp_mask, |
| 877 | noswap); |
| 878 | |
| 879 | /* |
| 880 | * try_to_free_mem_cgroup_pages() might not give us a full |
| 881 | * picture of reclaim. Some pages are reclaimed and might be |
| 882 | * moved to swap cache or just unmapped from the cgroup. |
| 883 | * Check the limit again to see if the reclaim reduced the |
| 884 | * current usage of the cgroup before giving up |
| 885 | * |
| 886 | */ |
| 887 | if (mem_cgroup_check_under_limit(mem_over_limit)) |
| 888 | continue; |
| 889 | |
| 890 | if (!nr_retries--) { |
| 891 | if (oom) { |
| 892 | mutex_lock(&memcg_tasklist); |
| 893 | mem_cgroup_out_of_memory(mem_over_limit, gfp_mask); |
| 894 | mutex_unlock(&memcg_tasklist); |
| 895 | mem_over_limit->last_oom_jiffies = jiffies; |
| 896 | } |
| 897 | goto nomem; |
| 898 | } |
| 899 | } |
| 900 | return 0; |
| 901 | nomem: |
| 902 | css_put(&mem->css); |
| 903 | return -ENOMEM; |
| 904 | } |
| 905 | |
| 906 | static struct mem_cgroup *try_get_mem_cgroup_from_swapcache(struct page *page) |
| 907 | { |
| 908 | struct mem_cgroup *mem; |
| 909 | swp_entry_t ent; |
| 910 | |
| 911 | if (!PageSwapCache(page)) |
| 912 | return NULL; |
| 913 | |
| 914 | ent.val = page_private(page); |
| 915 | mem = lookup_swap_cgroup(ent); |
| 916 | if (!mem) |
| 917 | return NULL; |
| 918 | if (!css_tryget(&mem->css)) |
| 919 | return NULL; |
| 920 | return mem; |
| 921 | } |
| 922 | |
| 923 | /* |
| 924 | * commit a charge got by __mem_cgroup_try_charge() and makes page_cgroup to be |
| 925 | * USED state. If already USED, uncharge and return. |
| 926 | */ |
| 927 | |
| 928 | static void __mem_cgroup_commit_charge(struct mem_cgroup *mem, |
| 929 | struct page_cgroup *pc, |
| 930 | enum charge_type ctype) |
| 931 | { |
| 932 | /* try_charge() can return NULL to *memcg, taking care of it. */ |
| 933 | if (!mem) |
| 934 | return; |
| 935 | |
| 936 | lock_page_cgroup(pc); |
| 937 | if (unlikely(PageCgroupUsed(pc))) { |
| 938 | unlock_page_cgroup(pc); |
| 939 | res_counter_uncharge(&mem->res, PAGE_SIZE); |
| 940 | if (do_swap_account) |
| 941 | res_counter_uncharge(&mem->memsw, PAGE_SIZE); |
| 942 | css_put(&mem->css); |
| 943 | return; |
| 944 | } |
| 945 | pc->mem_cgroup = mem; |
| 946 | smp_wmb(); |
| 947 | pc->flags = pcg_default_flags[ctype]; |
| 948 | |
| 949 | mem_cgroup_charge_statistics(mem, pc, true); |
| 950 | |
| 951 | unlock_page_cgroup(pc); |
| 952 | } |
| 953 | |
| 954 | /** |
| 955 | * mem_cgroup_move_account - move account of the page |
| 956 | * @pc: page_cgroup of the page. |
| 957 | * @from: mem_cgroup which the page is moved from. |
| 958 | * @to: mem_cgroup which the page is moved to. @from != @to. |
| 959 | * |
| 960 | * The caller must confirm following. |
| 961 | * - page is not on LRU (isolate_page() is useful.) |
| 962 | * |
| 963 | * returns 0 at success, |
| 964 | * returns -EBUSY when lock is busy or "pc" is unstable. |
| 965 | * |
| 966 | * This function does "uncharge" from old cgroup but doesn't do "charge" to |
| 967 | * new cgroup. It should be done by a caller. |
| 968 | */ |
| 969 | |
| 970 | static int mem_cgroup_move_account(struct page_cgroup *pc, |
| 971 | struct mem_cgroup *from, struct mem_cgroup *to) |
| 972 | { |
| 973 | struct mem_cgroup_per_zone *from_mz, *to_mz; |
| 974 | int nid, zid; |
| 975 | int ret = -EBUSY; |
| 976 | |
| 977 | VM_BUG_ON(from == to); |
| 978 | VM_BUG_ON(PageLRU(pc->page)); |
| 979 | |
| 980 | nid = page_cgroup_nid(pc); |
| 981 | zid = page_cgroup_zid(pc); |
| 982 | from_mz = mem_cgroup_zoneinfo(from, nid, zid); |
| 983 | to_mz = mem_cgroup_zoneinfo(to, nid, zid); |
| 984 | |
| 985 | if (!trylock_page_cgroup(pc)) |
| 986 | return ret; |
| 987 | |
| 988 | if (!PageCgroupUsed(pc)) |
| 989 | goto out; |
| 990 | |
| 991 | if (pc->mem_cgroup != from) |
| 992 | goto out; |
| 993 | |
| 994 | res_counter_uncharge(&from->res, PAGE_SIZE); |
| 995 | mem_cgroup_charge_statistics(from, pc, false); |
| 996 | if (do_swap_account) |
| 997 | res_counter_uncharge(&from->memsw, PAGE_SIZE); |
| 998 | css_put(&from->css); |
| 999 | |
| 1000 | css_get(&to->css); |
| 1001 | pc->mem_cgroup = to; |
| 1002 | mem_cgroup_charge_statistics(to, pc, true); |
| 1003 | ret = 0; |
| 1004 | out: |
| 1005 | unlock_page_cgroup(pc); |
| 1006 | return ret; |
| 1007 | } |
| 1008 | |
| 1009 | /* |
| 1010 | * move charges to its parent. |
| 1011 | */ |
| 1012 | |
| 1013 | static int mem_cgroup_move_parent(struct page_cgroup *pc, |
| 1014 | struct mem_cgroup *child, |
| 1015 | gfp_t gfp_mask) |
| 1016 | { |
| 1017 | struct page *page = pc->page; |
| 1018 | struct cgroup *cg = child->css.cgroup; |
| 1019 | struct cgroup *pcg = cg->parent; |
| 1020 | struct mem_cgroup *parent; |
| 1021 | int ret; |
| 1022 | |
| 1023 | /* Is ROOT ? */ |
| 1024 | if (!pcg) |
| 1025 | return -EINVAL; |
| 1026 | |
| 1027 | |
| 1028 | parent = mem_cgroup_from_cont(pcg); |
| 1029 | |
| 1030 | |
| 1031 | ret = __mem_cgroup_try_charge(NULL, gfp_mask, &parent, false); |
| 1032 | if (ret || !parent) |
| 1033 | return ret; |
| 1034 | |
| 1035 | if (!get_page_unless_zero(page)) { |
| 1036 | ret = -EBUSY; |
| 1037 | goto uncharge; |
| 1038 | } |
| 1039 | |
| 1040 | ret = isolate_lru_page(page); |
| 1041 | |
| 1042 | if (ret) |
| 1043 | goto cancel; |
| 1044 | |
| 1045 | ret = mem_cgroup_move_account(pc, child, parent); |
| 1046 | |
| 1047 | putback_lru_page(page); |
| 1048 | if (!ret) { |
| 1049 | put_page(page); |
| 1050 | /* drop extra refcnt by try_charge() */ |
| 1051 | css_put(&parent->css); |
| 1052 | return 0; |
| 1053 | } |
| 1054 | |
| 1055 | cancel: |
| 1056 | put_page(page); |
| 1057 | uncharge: |
| 1058 | /* drop extra refcnt by try_charge() */ |
| 1059 | css_put(&parent->css); |
| 1060 | /* uncharge if move fails */ |
| 1061 | res_counter_uncharge(&parent->res, PAGE_SIZE); |
| 1062 | if (do_swap_account) |
| 1063 | res_counter_uncharge(&parent->memsw, PAGE_SIZE); |
| 1064 | return ret; |
| 1065 | } |
| 1066 | |
| 1067 | /* |
| 1068 | * Charge the memory controller for page usage. |
| 1069 | * Return |
| 1070 | * 0 if the charge was successful |
| 1071 | * < 0 if the cgroup is over its limit |
| 1072 | */ |
| 1073 | static int mem_cgroup_charge_common(struct page *page, struct mm_struct *mm, |
| 1074 | gfp_t gfp_mask, enum charge_type ctype, |
| 1075 | struct mem_cgroup *memcg) |
| 1076 | { |
| 1077 | struct mem_cgroup *mem; |
| 1078 | struct page_cgroup *pc; |
| 1079 | int ret; |
| 1080 | |
| 1081 | pc = lookup_page_cgroup(page); |
| 1082 | /* can happen at boot */ |
| 1083 | if (unlikely(!pc)) |
| 1084 | return 0; |
| 1085 | prefetchw(pc); |
| 1086 | |
| 1087 | mem = memcg; |
| 1088 | ret = __mem_cgroup_try_charge(mm, gfp_mask, &mem, true); |
| 1089 | if (ret || !mem) |
| 1090 | return ret; |
| 1091 | |
| 1092 | __mem_cgroup_commit_charge(mem, pc, ctype); |
| 1093 | return 0; |
| 1094 | } |
| 1095 | |
| 1096 | int mem_cgroup_newpage_charge(struct page *page, |
| 1097 | struct mm_struct *mm, gfp_t gfp_mask) |
| 1098 | { |
| 1099 | if (mem_cgroup_disabled()) |
| 1100 | return 0; |
| 1101 | if (PageCompound(page)) |
| 1102 | return 0; |
| 1103 | /* |
| 1104 | * If already mapped, we don't have to account. |
| 1105 | * If page cache, page->mapping has address_space. |
| 1106 | * But page->mapping may have out-of-use anon_vma pointer, |
| 1107 | * detecit it by PageAnon() check. newly-mapped-anon's page->mapping |
| 1108 | * is NULL. |
| 1109 | */ |
| 1110 | if (page_mapped(page) || (page->mapping && !PageAnon(page))) |
| 1111 | return 0; |
| 1112 | if (unlikely(!mm)) |
| 1113 | mm = &init_mm; |
| 1114 | return mem_cgroup_charge_common(page, mm, gfp_mask, |
| 1115 | MEM_CGROUP_CHARGE_TYPE_MAPPED, NULL); |
| 1116 | } |
| 1117 | |
| 1118 | int mem_cgroup_cache_charge(struct page *page, struct mm_struct *mm, |
| 1119 | gfp_t gfp_mask) |
| 1120 | { |
| 1121 | struct mem_cgroup *mem = NULL; |
| 1122 | int ret; |
| 1123 | |
| 1124 | if (mem_cgroup_disabled()) |
| 1125 | return 0; |
| 1126 | if (PageCompound(page)) |
| 1127 | return 0; |
| 1128 | /* |
| 1129 | * Corner case handling. This is called from add_to_page_cache() |
| 1130 | * in usual. But some FS (shmem) precharges this page before calling it |
| 1131 | * and call add_to_page_cache() with GFP_NOWAIT. |
| 1132 | * |
| 1133 | * For GFP_NOWAIT case, the page may be pre-charged before calling |
| 1134 | * add_to_page_cache(). (See shmem.c) check it here and avoid to call |
| 1135 | * charge twice. (It works but has to pay a bit larger cost.) |
| 1136 | * And when the page is SwapCache, it should take swap information |
| 1137 | * into account. This is under lock_page() now. |
| 1138 | */ |
| 1139 | if (!(gfp_mask & __GFP_WAIT)) { |
| 1140 | struct page_cgroup *pc; |
| 1141 | |
| 1142 | |
| 1143 | pc = lookup_page_cgroup(page); |
| 1144 | if (!pc) |
| 1145 | return 0; |
| 1146 | lock_page_cgroup(pc); |
| 1147 | if (PageCgroupUsed(pc)) { |
| 1148 | unlock_page_cgroup(pc); |
| 1149 | return 0; |
| 1150 | } |
| 1151 | unlock_page_cgroup(pc); |
| 1152 | } |
| 1153 | |
| 1154 | if (do_swap_account && PageSwapCache(page)) { |
| 1155 | mem = try_get_mem_cgroup_from_swapcache(page); |
| 1156 | if (mem) |
| 1157 | mm = NULL; |
| 1158 | else |
| 1159 | mem = NULL; |
| 1160 | /* SwapCache may be still linked to LRU now. */ |
| 1161 | mem_cgroup_lru_del_before_commit_swapcache(page); |
| 1162 | } |
| 1163 | |
| 1164 | if (unlikely(!mm && !mem)) |
| 1165 | mm = &init_mm; |
| 1166 | |
| 1167 | if (page_is_file_cache(page)) |
| 1168 | return mem_cgroup_charge_common(page, mm, gfp_mask, |
| 1169 | MEM_CGROUP_CHARGE_TYPE_CACHE, NULL); |
| 1170 | |
| 1171 | ret = mem_cgroup_charge_common(page, mm, gfp_mask, |
| 1172 | MEM_CGROUP_CHARGE_TYPE_SHMEM, mem); |
| 1173 | if (mem) |
| 1174 | css_put(&mem->css); |
| 1175 | if (PageSwapCache(page)) |
| 1176 | mem_cgroup_lru_add_after_commit_swapcache(page); |
| 1177 | |
| 1178 | if (do_swap_account && !ret && PageSwapCache(page)) { |
| 1179 | swp_entry_t ent = {.val = page_private(page)}; |
| 1180 | /* avoid double counting */ |
| 1181 | mem = swap_cgroup_record(ent, NULL); |
| 1182 | if (mem) { |
| 1183 | res_counter_uncharge(&mem->memsw, PAGE_SIZE); |
| 1184 | mem_cgroup_put(mem); |
| 1185 | } |
| 1186 | } |
| 1187 | return ret; |
| 1188 | } |
| 1189 | |
| 1190 | /* |
| 1191 | * While swap-in, try_charge -> commit or cancel, the page is locked. |
| 1192 | * And when try_charge() successfully returns, one refcnt to memcg without |
| 1193 | * struct page_cgroup is aquired. This refcnt will be cumsumed by |
| 1194 | * "commit()" or removed by "cancel()" |
| 1195 | */ |
| 1196 | int mem_cgroup_try_charge_swapin(struct mm_struct *mm, |
| 1197 | struct page *page, |
| 1198 | gfp_t mask, struct mem_cgroup **ptr) |
| 1199 | { |
| 1200 | struct mem_cgroup *mem; |
| 1201 | int ret; |
| 1202 | |
| 1203 | if (mem_cgroup_disabled()) |
| 1204 | return 0; |
| 1205 | |
| 1206 | if (!do_swap_account) |
| 1207 | goto charge_cur_mm; |
| 1208 | /* |
| 1209 | * A racing thread's fault, or swapoff, may have already updated |
| 1210 | * the pte, and even removed page from swap cache: return success |
| 1211 | * to go on to do_swap_page()'s pte_same() test, which should fail. |
| 1212 | */ |
| 1213 | if (!PageSwapCache(page)) |
| 1214 | return 0; |
| 1215 | mem = try_get_mem_cgroup_from_swapcache(page); |
| 1216 | if (!mem) |
| 1217 | goto charge_cur_mm; |
| 1218 | *ptr = mem; |
| 1219 | ret = __mem_cgroup_try_charge(NULL, mask, ptr, true); |
| 1220 | /* drop extra refcnt from tryget */ |
| 1221 | css_put(&mem->css); |
| 1222 | return ret; |
| 1223 | charge_cur_mm: |
| 1224 | if (unlikely(!mm)) |
| 1225 | mm = &init_mm; |
| 1226 | return __mem_cgroup_try_charge(mm, mask, ptr, true); |
| 1227 | } |
| 1228 | |
| 1229 | void mem_cgroup_commit_charge_swapin(struct page *page, struct mem_cgroup *ptr) |
| 1230 | { |
| 1231 | struct page_cgroup *pc; |
| 1232 | |
| 1233 | if (mem_cgroup_disabled()) |
| 1234 | return; |
| 1235 | if (!ptr) |
| 1236 | return; |
| 1237 | pc = lookup_page_cgroup(page); |
| 1238 | mem_cgroup_lru_del_before_commit_swapcache(page); |
| 1239 | __mem_cgroup_commit_charge(ptr, pc, MEM_CGROUP_CHARGE_TYPE_MAPPED); |
| 1240 | mem_cgroup_lru_add_after_commit_swapcache(page); |
| 1241 | /* |
| 1242 | * Now swap is on-memory. This means this page may be |
| 1243 | * counted both as mem and swap....double count. |
| 1244 | * Fix it by uncharging from memsw. Basically, this SwapCache is stable |
| 1245 | * under lock_page(). But in do_swap_page()::memory.c, reuse_swap_page() |
| 1246 | * may call delete_from_swap_cache() before reach here. |
| 1247 | */ |
| 1248 | if (do_swap_account && PageSwapCache(page)) { |
| 1249 | swp_entry_t ent = {.val = page_private(page)}; |
| 1250 | struct mem_cgroup *memcg; |
| 1251 | memcg = swap_cgroup_record(ent, NULL); |
| 1252 | if (memcg) { |
| 1253 | res_counter_uncharge(&memcg->memsw, PAGE_SIZE); |
| 1254 | mem_cgroup_put(memcg); |
| 1255 | } |
| 1256 | |
| 1257 | } |
| 1258 | /* add this page(page_cgroup) to the LRU we want. */ |
| 1259 | |
| 1260 | } |
| 1261 | |
| 1262 | void mem_cgroup_cancel_charge_swapin(struct mem_cgroup *mem) |
| 1263 | { |
| 1264 | if (mem_cgroup_disabled()) |
| 1265 | return; |
| 1266 | if (!mem) |
| 1267 | return; |
| 1268 | res_counter_uncharge(&mem->res, PAGE_SIZE); |
| 1269 | if (do_swap_account) |
| 1270 | res_counter_uncharge(&mem->memsw, PAGE_SIZE); |
| 1271 | css_put(&mem->css); |
| 1272 | } |
| 1273 | |
| 1274 | |
| 1275 | /* |
| 1276 | * uncharge if !page_mapped(page) |
| 1277 | */ |
| 1278 | static struct mem_cgroup * |
| 1279 | __mem_cgroup_uncharge_common(struct page *page, enum charge_type ctype) |
| 1280 | { |
| 1281 | struct page_cgroup *pc; |
| 1282 | struct mem_cgroup *mem = NULL; |
| 1283 | struct mem_cgroup_per_zone *mz; |
| 1284 | |
| 1285 | if (mem_cgroup_disabled()) |
| 1286 | return NULL; |
| 1287 | |
| 1288 | if (PageSwapCache(page)) |
| 1289 | return NULL; |
| 1290 | |
| 1291 | /* |
| 1292 | * Check if our page_cgroup is valid |
| 1293 | */ |
| 1294 | pc = lookup_page_cgroup(page); |
| 1295 | if (unlikely(!pc || !PageCgroupUsed(pc))) |
| 1296 | return NULL; |
| 1297 | |
| 1298 | lock_page_cgroup(pc); |
| 1299 | |
| 1300 | mem = pc->mem_cgroup; |
| 1301 | |
| 1302 | if (!PageCgroupUsed(pc)) |
| 1303 | goto unlock_out; |
| 1304 | |
| 1305 | switch (ctype) { |
| 1306 | case MEM_CGROUP_CHARGE_TYPE_MAPPED: |
| 1307 | if (page_mapped(page)) |
| 1308 | goto unlock_out; |
| 1309 | break; |
| 1310 | case MEM_CGROUP_CHARGE_TYPE_SWAPOUT: |
| 1311 | if (!PageAnon(page)) { /* Shared memory */ |
| 1312 | if (page->mapping && !page_is_file_cache(page)) |
| 1313 | goto unlock_out; |
| 1314 | } else if (page_mapped(page)) /* Anon */ |
| 1315 | goto unlock_out; |
| 1316 | break; |
| 1317 | default: |
| 1318 | break; |
| 1319 | } |
| 1320 | |
| 1321 | res_counter_uncharge(&mem->res, PAGE_SIZE); |
| 1322 | if (do_swap_account && (ctype != MEM_CGROUP_CHARGE_TYPE_SWAPOUT)) |
| 1323 | res_counter_uncharge(&mem->memsw, PAGE_SIZE); |
| 1324 | |
| 1325 | mem_cgroup_charge_statistics(mem, pc, false); |
| 1326 | ClearPageCgroupUsed(pc); |
| 1327 | /* |
| 1328 | * pc->mem_cgroup is not cleared here. It will be accessed when it's |
| 1329 | * freed from LRU. This is safe because uncharged page is expected not |
| 1330 | * to be reused (freed soon). Exception is SwapCache, it's handled by |
| 1331 | * special functions. |
| 1332 | */ |
| 1333 | |
| 1334 | mz = page_cgroup_zoneinfo(pc); |
| 1335 | unlock_page_cgroup(pc); |
| 1336 | |
| 1337 | /* at swapout, this memcg will be accessed to record to swap */ |
| 1338 | if (ctype != MEM_CGROUP_CHARGE_TYPE_SWAPOUT) |
| 1339 | css_put(&mem->css); |
| 1340 | |
| 1341 | return mem; |
| 1342 | |
| 1343 | unlock_out: |
| 1344 | unlock_page_cgroup(pc); |
| 1345 | return NULL; |
| 1346 | } |
| 1347 | |
| 1348 | void mem_cgroup_uncharge_page(struct page *page) |
| 1349 | { |
| 1350 | /* early check. */ |
| 1351 | if (page_mapped(page)) |
| 1352 | return; |
| 1353 | if (page->mapping && !PageAnon(page)) |
| 1354 | return; |
| 1355 | __mem_cgroup_uncharge_common(page, MEM_CGROUP_CHARGE_TYPE_MAPPED); |
| 1356 | } |
| 1357 | |
| 1358 | void mem_cgroup_uncharge_cache_page(struct page *page) |
| 1359 | { |
| 1360 | VM_BUG_ON(page_mapped(page)); |
| 1361 | VM_BUG_ON(page->mapping); |
| 1362 | __mem_cgroup_uncharge_common(page, MEM_CGROUP_CHARGE_TYPE_CACHE); |
| 1363 | } |
| 1364 | |
| 1365 | /* |
| 1366 | * called from __delete_from_swap_cache() and drop "page" account. |
| 1367 | * memcg information is recorded to swap_cgroup of "ent" |
| 1368 | */ |
| 1369 | void mem_cgroup_uncharge_swapcache(struct page *page, swp_entry_t ent) |
| 1370 | { |
| 1371 | struct mem_cgroup *memcg; |
| 1372 | |
| 1373 | memcg = __mem_cgroup_uncharge_common(page, |
| 1374 | MEM_CGROUP_CHARGE_TYPE_SWAPOUT); |
| 1375 | /* record memcg information */ |
| 1376 | if (do_swap_account && memcg) { |
| 1377 | swap_cgroup_record(ent, memcg); |
| 1378 | mem_cgroup_get(memcg); |
| 1379 | } |
| 1380 | if (memcg) |
| 1381 | css_put(&memcg->css); |
| 1382 | } |
| 1383 | |
| 1384 | #ifdef CONFIG_CGROUP_MEM_RES_CTLR_SWAP |
| 1385 | /* |
| 1386 | * called from swap_entry_free(). remove record in swap_cgroup and |
| 1387 | * uncharge "memsw" account. |
| 1388 | */ |
| 1389 | void mem_cgroup_uncharge_swap(swp_entry_t ent) |
| 1390 | { |
| 1391 | struct mem_cgroup *memcg; |
| 1392 | |
| 1393 | if (!do_swap_account) |
| 1394 | return; |
| 1395 | |
| 1396 | memcg = swap_cgroup_record(ent, NULL); |
| 1397 | if (memcg) { |
| 1398 | res_counter_uncharge(&memcg->memsw, PAGE_SIZE); |
| 1399 | mem_cgroup_put(memcg); |
| 1400 | } |
| 1401 | } |
| 1402 | #endif |
| 1403 | |
| 1404 | /* |
| 1405 | * Before starting migration, account PAGE_SIZE to mem_cgroup that the old |
| 1406 | * page belongs to. |
| 1407 | */ |
| 1408 | int mem_cgroup_prepare_migration(struct page *page, struct mem_cgroup **ptr) |
| 1409 | { |
| 1410 | struct page_cgroup *pc; |
| 1411 | struct mem_cgroup *mem = NULL; |
| 1412 | int ret = 0; |
| 1413 | |
| 1414 | if (mem_cgroup_disabled()) |
| 1415 | return 0; |
| 1416 | |
| 1417 | pc = lookup_page_cgroup(page); |
| 1418 | lock_page_cgroup(pc); |
| 1419 | if (PageCgroupUsed(pc)) { |
| 1420 | mem = pc->mem_cgroup; |
| 1421 | css_get(&mem->css); |
| 1422 | } |
| 1423 | unlock_page_cgroup(pc); |
| 1424 | |
| 1425 | if (mem) { |
| 1426 | ret = __mem_cgroup_try_charge(NULL, GFP_KERNEL, &mem, false); |
| 1427 | css_put(&mem->css); |
| 1428 | } |
| 1429 | *ptr = mem; |
| 1430 | return ret; |
| 1431 | } |
| 1432 | |
| 1433 | /* remove redundant charge if migration failed*/ |
| 1434 | void mem_cgroup_end_migration(struct mem_cgroup *mem, |
| 1435 | struct page *oldpage, struct page *newpage) |
| 1436 | { |
| 1437 | struct page *target, *unused; |
| 1438 | struct page_cgroup *pc; |
| 1439 | enum charge_type ctype; |
| 1440 | |
| 1441 | if (!mem) |
| 1442 | return; |
| 1443 | |
| 1444 | /* at migration success, oldpage->mapping is NULL. */ |
| 1445 | if (oldpage->mapping) { |
| 1446 | target = oldpage; |
| 1447 | unused = NULL; |
| 1448 | } else { |
| 1449 | target = newpage; |
| 1450 | unused = oldpage; |
| 1451 | } |
| 1452 | |
| 1453 | if (PageAnon(target)) |
| 1454 | ctype = MEM_CGROUP_CHARGE_TYPE_MAPPED; |
| 1455 | else if (page_is_file_cache(target)) |
| 1456 | ctype = MEM_CGROUP_CHARGE_TYPE_CACHE; |
| 1457 | else |
| 1458 | ctype = MEM_CGROUP_CHARGE_TYPE_SHMEM; |
| 1459 | |
| 1460 | /* unused page is not on radix-tree now. */ |
| 1461 | if (unused) |
| 1462 | __mem_cgroup_uncharge_common(unused, ctype); |
| 1463 | |
| 1464 | pc = lookup_page_cgroup(target); |
| 1465 | /* |
| 1466 | * __mem_cgroup_commit_charge() check PCG_USED bit of page_cgroup. |
| 1467 | * So, double-counting is effectively avoided. |
| 1468 | */ |
| 1469 | __mem_cgroup_commit_charge(mem, pc, ctype); |
| 1470 | |
| 1471 | /* |
| 1472 | * Both of oldpage and newpage are still under lock_page(). |
| 1473 | * Then, we don't have to care about race in radix-tree. |
| 1474 | * But we have to be careful that this page is unmapped or not. |
| 1475 | * |
| 1476 | * There is a case for !page_mapped(). At the start of |
| 1477 | * migration, oldpage was mapped. But now, it's zapped. |
| 1478 | * But we know *target* page is not freed/reused under us. |
| 1479 | * mem_cgroup_uncharge_page() does all necessary checks. |
| 1480 | */ |
| 1481 | if (ctype == MEM_CGROUP_CHARGE_TYPE_MAPPED) |
| 1482 | mem_cgroup_uncharge_page(target); |
| 1483 | } |
| 1484 | |
| 1485 | /* |
| 1486 | * A call to try to shrink memory usage under specified resource controller. |
| 1487 | * This is typically used for page reclaiming for shmem for reducing side |
| 1488 | * effect of page allocation from shmem, which is used by some mem_cgroup. |
| 1489 | */ |
| 1490 | int mem_cgroup_shrink_usage(struct page *page, |
| 1491 | struct mm_struct *mm, |
| 1492 | gfp_t gfp_mask) |
| 1493 | { |
| 1494 | struct mem_cgroup *mem = NULL; |
| 1495 | int progress = 0; |
| 1496 | int retry = MEM_CGROUP_RECLAIM_RETRIES; |
| 1497 | |
| 1498 | if (mem_cgroup_disabled()) |
| 1499 | return 0; |
| 1500 | if (page) |
| 1501 | mem = try_get_mem_cgroup_from_swapcache(page); |
| 1502 | if (!mem && mm) |
| 1503 | mem = try_get_mem_cgroup_from_mm(mm); |
| 1504 | if (unlikely(!mem)) |
| 1505 | return 0; |
| 1506 | |
| 1507 | do { |
| 1508 | progress = mem_cgroup_hierarchical_reclaim(mem, gfp_mask, true); |
| 1509 | progress += mem_cgroup_check_under_limit(mem); |
| 1510 | } while (!progress && --retry); |
| 1511 | |
| 1512 | css_put(&mem->css); |
| 1513 | if (!retry) |
| 1514 | return -ENOMEM; |
| 1515 | return 0; |
| 1516 | } |
| 1517 | |
| 1518 | static DEFINE_MUTEX(set_limit_mutex); |
| 1519 | |
| 1520 | static int mem_cgroup_resize_limit(struct mem_cgroup *memcg, |
| 1521 | unsigned long long val) |
| 1522 | { |
| 1523 | |
| 1524 | int retry_count = MEM_CGROUP_RECLAIM_RETRIES; |
| 1525 | int progress; |
| 1526 | u64 memswlimit; |
| 1527 | int ret = 0; |
| 1528 | |
| 1529 | while (retry_count) { |
| 1530 | if (signal_pending(current)) { |
| 1531 | ret = -EINTR; |
| 1532 | break; |
| 1533 | } |
| 1534 | /* |
| 1535 | * Rather than hide all in some function, I do this in |
| 1536 | * open coded manner. You see what this really does. |
| 1537 | * We have to guarantee mem->res.limit < mem->memsw.limit. |
| 1538 | */ |
| 1539 | mutex_lock(&set_limit_mutex); |
| 1540 | memswlimit = res_counter_read_u64(&memcg->memsw, RES_LIMIT); |
| 1541 | if (memswlimit < val) { |
| 1542 | ret = -EINVAL; |
| 1543 | mutex_unlock(&set_limit_mutex); |
| 1544 | break; |
| 1545 | } |
| 1546 | ret = res_counter_set_limit(&memcg->res, val); |
| 1547 | mutex_unlock(&set_limit_mutex); |
| 1548 | |
| 1549 | if (!ret) |
| 1550 | break; |
| 1551 | |
| 1552 | progress = mem_cgroup_hierarchical_reclaim(memcg, GFP_KERNEL, |
| 1553 | false); |
| 1554 | if (!progress) retry_count--; |
| 1555 | } |
| 1556 | |
| 1557 | return ret; |
| 1558 | } |
| 1559 | |
| 1560 | int mem_cgroup_resize_memsw_limit(struct mem_cgroup *memcg, |
| 1561 | unsigned long long val) |
| 1562 | { |
| 1563 | int retry_count = MEM_CGROUP_RECLAIM_RETRIES; |
| 1564 | u64 memlimit, oldusage, curusage; |
| 1565 | int ret; |
| 1566 | |
| 1567 | if (!do_swap_account) |
| 1568 | return -EINVAL; |
| 1569 | |
| 1570 | while (retry_count) { |
| 1571 | if (signal_pending(current)) { |
| 1572 | ret = -EINTR; |
| 1573 | break; |
| 1574 | } |
| 1575 | /* |
| 1576 | * Rather than hide all in some function, I do this in |
| 1577 | * open coded manner. You see what this really does. |
| 1578 | * We have to guarantee mem->res.limit < mem->memsw.limit. |
| 1579 | */ |
| 1580 | mutex_lock(&set_limit_mutex); |
| 1581 | memlimit = res_counter_read_u64(&memcg->res, RES_LIMIT); |
| 1582 | if (memlimit > val) { |
| 1583 | ret = -EINVAL; |
| 1584 | mutex_unlock(&set_limit_mutex); |
| 1585 | break; |
| 1586 | } |
| 1587 | ret = res_counter_set_limit(&memcg->memsw, val); |
| 1588 | mutex_unlock(&set_limit_mutex); |
| 1589 | |
| 1590 | if (!ret) |
| 1591 | break; |
| 1592 | |
| 1593 | oldusage = res_counter_read_u64(&memcg->memsw, RES_USAGE); |
| 1594 | mem_cgroup_hierarchical_reclaim(memcg, GFP_KERNEL, true); |
| 1595 | curusage = res_counter_read_u64(&memcg->memsw, RES_USAGE); |
| 1596 | if (curusage >= oldusage) |
| 1597 | retry_count--; |
| 1598 | } |
| 1599 | return ret; |
| 1600 | } |
| 1601 | |
| 1602 | /* |
| 1603 | * This routine traverse page_cgroup in given list and drop them all. |
| 1604 | * *And* this routine doesn't reclaim page itself, just removes page_cgroup. |
| 1605 | */ |
| 1606 | static int mem_cgroup_force_empty_list(struct mem_cgroup *mem, |
| 1607 | int node, int zid, enum lru_list lru) |
| 1608 | { |
| 1609 | struct zone *zone; |
| 1610 | struct mem_cgroup_per_zone *mz; |
| 1611 | struct page_cgroup *pc, *busy; |
| 1612 | unsigned long flags, loop; |
| 1613 | struct list_head *list; |
| 1614 | int ret = 0; |
| 1615 | |
| 1616 | zone = &NODE_DATA(node)->node_zones[zid]; |
| 1617 | mz = mem_cgroup_zoneinfo(mem, node, zid); |
| 1618 | list = &mz->lists[lru]; |
| 1619 | |
| 1620 | loop = MEM_CGROUP_ZSTAT(mz, lru); |
| 1621 | /* give some margin against EBUSY etc...*/ |
| 1622 | loop += 256; |
| 1623 | busy = NULL; |
| 1624 | while (loop--) { |
| 1625 | ret = 0; |
| 1626 | spin_lock_irqsave(&zone->lru_lock, flags); |
| 1627 | if (list_empty(list)) { |
| 1628 | spin_unlock_irqrestore(&zone->lru_lock, flags); |
| 1629 | break; |
| 1630 | } |
| 1631 | pc = list_entry(list->prev, struct page_cgroup, lru); |
| 1632 | if (busy == pc) { |
| 1633 | list_move(&pc->lru, list); |
| 1634 | busy = 0; |
| 1635 | spin_unlock_irqrestore(&zone->lru_lock, flags); |
| 1636 | continue; |
| 1637 | } |
| 1638 | spin_unlock_irqrestore(&zone->lru_lock, flags); |
| 1639 | |
| 1640 | ret = mem_cgroup_move_parent(pc, mem, GFP_KERNEL); |
| 1641 | if (ret == -ENOMEM) |
| 1642 | break; |
| 1643 | |
| 1644 | if (ret == -EBUSY || ret == -EINVAL) { |
| 1645 | /* found lock contention or "pc" is obsolete. */ |
| 1646 | busy = pc; |
| 1647 | cond_resched(); |
| 1648 | } else |
| 1649 | busy = NULL; |
| 1650 | } |
| 1651 | |
| 1652 | if (!ret && !list_empty(list)) |
| 1653 | return -EBUSY; |
| 1654 | return ret; |
| 1655 | } |
| 1656 | |
| 1657 | /* |
| 1658 | * make mem_cgroup's charge to be 0 if there is no task. |
| 1659 | * This enables deleting this mem_cgroup. |
| 1660 | */ |
| 1661 | static int mem_cgroup_force_empty(struct mem_cgroup *mem, bool free_all) |
| 1662 | { |
| 1663 | int ret; |
| 1664 | int node, zid, shrink; |
| 1665 | int nr_retries = MEM_CGROUP_RECLAIM_RETRIES; |
| 1666 | struct cgroup *cgrp = mem->css.cgroup; |
| 1667 | |
| 1668 | css_get(&mem->css); |
| 1669 | |
| 1670 | shrink = 0; |
| 1671 | /* should free all ? */ |
| 1672 | if (free_all) |
| 1673 | goto try_to_free; |
| 1674 | move_account: |
| 1675 | while (mem->res.usage > 0) { |
| 1676 | ret = -EBUSY; |
| 1677 | if (cgroup_task_count(cgrp) || !list_empty(&cgrp->children)) |
| 1678 | goto out; |
| 1679 | ret = -EINTR; |
| 1680 | if (signal_pending(current)) |
| 1681 | goto out; |
| 1682 | /* This is for making all *used* pages to be on LRU. */ |
| 1683 | lru_add_drain_all(); |
| 1684 | ret = 0; |
| 1685 | for_each_node_state(node, N_POSSIBLE) { |
| 1686 | for (zid = 0; !ret && zid < MAX_NR_ZONES; zid++) { |
| 1687 | enum lru_list l; |
| 1688 | for_each_lru(l) { |
| 1689 | ret = mem_cgroup_force_empty_list(mem, |
| 1690 | node, zid, l); |
| 1691 | if (ret) |
| 1692 | break; |
| 1693 | } |
| 1694 | } |
| 1695 | if (ret) |
| 1696 | break; |
| 1697 | } |
| 1698 | /* it seems parent cgroup doesn't have enough mem */ |
| 1699 | if (ret == -ENOMEM) |
| 1700 | goto try_to_free; |
| 1701 | cond_resched(); |
| 1702 | } |
| 1703 | ret = 0; |
| 1704 | out: |
| 1705 | css_put(&mem->css); |
| 1706 | return ret; |
| 1707 | |
| 1708 | try_to_free: |
| 1709 | /* returns EBUSY if there is a task or if we come here twice. */ |
| 1710 | if (cgroup_task_count(cgrp) || !list_empty(&cgrp->children) || shrink) { |
| 1711 | ret = -EBUSY; |
| 1712 | goto out; |
| 1713 | } |
| 1714 | /* we call try-to-free pages for make this cgroup empty */ |
| 1715 | lru_add_drain_all(); |
| 1716 | /* try to free all pages in this cgroup */ |
| 1717 | shrink = 1; |
| 1718 | while (nr_retries && mem->res.usage > 0) { |
| 1719 | int progress; |
| 1720 | |
| 1721 | if (signal_pending(current)) { |
| 1722 | ret = -EINTR; |
| 1723 | goto out; |
| 1724 | } |
| 1725 | progress = try_to_free_mem_cgroup_pages(mem, GFP_KERNEL, |
| 1726 | false, get_swappiness(mem)); |
| 1727 | if (!progress) { |
| 1728 | nr_retries--; |
| 1729 | /* maybe some writeback is necessary */ |
| 1730 | congestion_wait(WRITE, HZ/10); |
| 1731 | } |
| 1732 | |
| 1733 | } |
| 1734 | lru_add_drain(); |
| 1735 | /* try move_account...there may be some *locked* pages. */ |
| 1736 | if (mem->res.usage) |
| 1737 | goto move_account; |
| 1738 | ret = 0; |
| 1739 | goto out; |
| 1740 | } |
| 1741 | |
| 1742 | int mem_cgroup_force_empty_write(struct cgroup *cont, unsigned int event) |
| 1743 | { |
| 1744 | return mem_cgroup_force_empty(mem_cgroup_from_cont(cont), true); |
| 1745 | } |
| 1746 | |
| 1747 | |
| 1748 | static u64 mem_cgroup_hierarchy_read(struct cgroup *cont, struct cftype *cft) |
| 1749 | { |
| 1750 | return mem_cgroup_from_cont(cont)->use_hierarchy; |
| 1751 | } |
| 1752 | |
| 1753 | static int mem_cgroup_hierarchy_write(struct cgroup *cont, struct cftype *cft, |
| 1754 | u64 val) |
| 1755 | { |
| 1756 | int retval = 0; |
| 1757 | struct mem_cgroup *mem = mem_cgroup_from_cont(cont); |
| 1758 | struct cgroup *parent = cont->parent; |
| 1759 | struct mem_cgroup *parent_mem = NULL; |
| 1760 | |
| 1761 | if (parent) |
| 1762 | parent_mem = mem_cgroup_from_cont(parent); |
| 1763 | |
| 1764 | cgroup_lock(); |
| 1765 | /* |
| 1766 | * If parent's use_hiearchy is set, we can't make any modifications |
| 1767 | * in the child subtrees. If it is unset, then the change can |
| 1768 | * occur, provided the current cgroup has no children. |
| 1769 | * |
| 1770 | * For the root cgroup, parent_mem is NULL, we allow value to be |
| 1771 | * set if there are no children. |
| 1772 | */ |
| 1773 | if ((!parent_mem || !parent_mem->use_hierarchy) && |
| 1774 | (val == 1 || val == 0)) { |
| 1775 | if (list_empty(&cont->children)) |
| 1776 | mem->use_hierarchy = val; |
| 1777 | else |
| 1778 | retval = -EBUSY; |
| 1779 | } else |
| 1780 | retval = -EINVAL; |
| 1781 | cgroup_unlock(); |
| 1782 | |
| 1783 | return retval; |
| 1784 | } |
| 1785 | |
| 1786 | static u64 mem_cgroup_read(struct cgroup *cont, struct cftype *cft) |
| 1787 | { |
| 1788 | struct mem_cgroup *mem = mem_cgroup_from_cont(cont); |
| 1789 | u64 val = 0; |
| 1790 | int type, name; |
| 1791 | |
| 1792 | type = MEMFILE_TYPE(cft->private); |
| 1793 | name = MEMFILE_ATTR(cft->private); |
| 1794 | switch (type) { |
| 1795 | case _MEM: |
| 1796 | val = res_counter_read_u64(&mem->res, name); |
| 1797 | break; |
| 1798 | case _MEMSWAP: |
| 1799 | if (do_swap_account) |
| 1800 | val = res_counter_read_u64(&mem->memsw, name); |
| 1801 | break; |
| 1802 | default: |
| 1803 | BUG(); |
| 1804 | break; |
| 1805 | } |
| 1806 | return val; |
| 1807 | } |
| 1808 | /* |
| 1809 | * The user of this function is... |
| 1810 | * RES_LIMIT. |
| 1811 | */ |
| 1812 | static int mem_cgroup_write(struct cgroup *cont, struct cftype *cft, |
| 1813 | const char *buffer) |
| 1814 | { |
| 1815 | struct mem_cgroup *memcg = mem_cgroup_from_cont(cont); |
| 1816 | int type, name; |
| 1817 | unsigned long long val; |
| 1818 | int ret; |
| 1819 | |
| 1820 | type = MEMFILE_TYPE(cft->private); |
| 1821 | name = MEMFILE_ATTR(cft->private); |
| 1822 | switch (name) { |
| 1823 | case RES_LIMIT: |
| 1824 | /* This function does all necessary parse...reuse it */ |
| 1825 | ret = res_counter_memparse_write_strategy(buffer, &val); |
| 1826 | if (ret) |
| 1827 | break; |
| 1828 | if (type == _MEM) |
| 1829 | ret = mem_cgroup_resize_limit(memcg, val); |
| 1830 | else |
| 1831 | ret = mem_cgroup_resize_memsw_limit(memcg, val); |
| 1832 | break; |
| 1833 | default: |
| 1834 | ret = -EINVAL; /* should be BUG() ? */ |
| 1835 | break; |
| 1836 | } |
| 1837 | return ret; |
| 1838 | } |
| 1839 | |
| 1840 | static void memcg_get_hierarchical_limit(struct mem_cgroup *memcg, |
| 1841 | unsigned long long *mem_limit, unsigned long long *memsw_limit) |
| 1842 | { |
| 1843 | struct cgroup *cgroup; |
| 1844 | unsigned long long min_limit, min_memsw_limit, tmp; |
| 1845 | |
| 1846 | min_limit = res_counter_read_u64(&memcg->res, RES_LIMIT); |
| 1847 | min_memsw_limit = res_counter_read_u64(&memcg->memsw, RES_LIMIT); |
| 1848 | cgroup = memcg->css.cgroup; |
| 1849 | if (!memcg->use_hierarchy) |
| 1850 | goto out; |
| 1851 | |
| 1852 | while (cgroup->parent) { |
| 1853 | cgroup = cgroup->parent; |
| 1854 | memcg = mem_cgroup_from_cont(cgroup); |
| 1855 | if (!memcg->use_hierarchy) |
| 1856 | break; |
| 1857 | tmp = res_counter_read_u64(&memcg->res, RES_LIMIT); |
| 1858 | min_limit = min(min_limit, tmp); |
| 1859 | tmp = res_counter_read_u64(&memcg->memsw, RES_LIMIT); |
| 1860 | min_memsw_limit = min(min_memsw_limit, tmp); |
| 1861 | } |
| 1862 | out: |
| 1863 | *mem_limit = min_limit; |
| 1864 | *memsw_limit = min_memsw_limit; |
| 1865 | return; |
| 1866 | } |
| 1867 | |
| 1868 | static int mem_cgroup_reset(struct cgroup *cont, unsigned int event) |
| 1869 | { |
| 1870 | struct mem_cgroup *mem; |
| 1871 | int type, name; |
| 1872 | |
| 1873 | mem = mem_cgroup_from_cont(cont); |
| 1874 | type = MEMFILE_TYPE(event); |
| 1875 | name = MEMFILE_ATTR(event); |
| 1876 | switch (name) { |
| 1877 | case RES_MAX_USAGE: |
| 1878 | if (type == _MEM) |
| 1879 | res_counter_reset_max(&mem->res); |
| 1880 | else |
| 1881 | res_counter_reset_max(&mem->memsw); |
| 1882 | break; |
| 1883 | case RES_FAILCNT: |
| 1884 | if (type == _MEM) |
| 1885 | res_counter_reset_failcnt(&mem->res); |
| 1886 | else |
| 1887 | res_counter_reset_failcnt(&mem->memsw); |
| 1888 | break; |
| 1889 | } |
| 1890 | return 0; |
| 1891 | } |
| 1892 | |
| 1893 | static const struct mem_cgroup_stat_desc { |
| 1894 | const char *msg; |
| 1895 | u64 unit; |
| 1896 | } mem_cgroup_stat_desc[] = { |
| 1897 | [MEM_CGROUP_STAT_CACHE] = { "cache", PAGE_SIZE, }, |
| 1898 | [MEM_CGROUP_STAT_RSS] = { "rss", PAGE_SIZE, }, |
| 1899 | [MEM_CGROUP_STAT_PGPGIN_COUNT] = {"pgpgin", 1, }, |
| 1900 | [MEM_CGROUP_STAT_PGPGOUT_COUNT] = {"pgpgout", 1, }, |
| 1901 | }; |
| 1902 | |
| 1903 | static int mem_control_stat_show(struct cgroup *cont, struct cftype *cft, |
| 1904 | struct cgroup_map_cb *cb) |
| 1905 | { |
| 1906 | struct mem_cgroup *mem_cont = mem_cgroup_from_cont(cont); |
| 1907 | struct mem_cgroup_stat *stat = &mem_cont->stat; |
| 1908 | int i; |
| 1909 | |
| 1910 | for (i = 0; i < ARRAY_SIZE(stat->cpustat[0].count); i++) { |
| 1911 | s64 val; |
| 1912 | |
| 1913 | val = mem_cgroup_read_stat(stat, i); |
| 1914 | val *= mem_cgroup_stat_desc[i].unit; |
| 1915 | cb->fill(cb, mem_cgroup_stat_desc[i].msg, val); |
| 1916 | } |
| 1917 | /* showing # of active pages */ |
| 1918 | { |
| 1919 | unsigned long active_anon, inactive_anon; |
| 1920 | unsigned long active_file, inactive_file; |
| 1921 | unsigned long unevictable; |
| 1922 | |
| 1923 | inactive_anon = mem_cgroup_get_all_zonestat(mem_cont, |
| 1924 | LRU_INACTIVE_ANON); |
| 1925 | active_anon = mem_cgroup_get_all_zonestat(mem_cont, |
| 1926 | LRU_ACTIVE_ANON); |
| 1927 | inactive_file = mem_cgroup_get_all_zonestat(mem_cont, |
| 1928 | LRU_INACTIVE_FILE); |
| 1929 | active_file = mem_cgroup_get_all_zonestat(mem_cont, |
| 1930 | LRU_ACTIVE_FILE); |
| 1931 | unevictable = mem_cgroup_get_all_zonestat(mem_cont, |
| 1932 | LRU_UNEVICTABLE); |
| 1933 | |
| 1934 | cb->fill(cb, "active_anon", (active_anon) * PAGE_SIZE); |
| 1935 | cb->fill(cb, "inactive_anon", (inactive_anon) * PAGE_SIZE); |
| 1936 | cb->fill(cb, "active_file", (active_file) * PAGE_SIZE); |
| 1937 | cb->fill(cb, "inactive_file", (inactive_file) * PAGE_SIZE); |
| 1938 | cb->fill(cb, "unevictable", unevictable * PAGE_SIZE); |
| 1939 | |
| 1940 | } |
| 1941 | { |
| 1942 | unsigned long long limit, memsw_limit; |
| 1943 | memcg_get_hierarchical_limit(mem_cont, &limit, &memsw_limit); |
| 1944 | cb->fill(cb, "hierarchical_memory_limit", limit); |
| 1945 | if (do_swap_account) |
| 1946 | cb->fill(cb, "hierarchical_memsw_limit", memsw_limit); |
| 1947 | } |
| 1948 | |
| 1949 | #ifdef CONFIG_DEBUG_VM |
| 1950 | cb->fill(cb, "inactive_ratio", calc_inactive_ratio(mem_cont, NULL)); |
| 1951 | |
| 1952 | { |
| 1953 | int nid, zid; |
| 1954 | struct mem_cgroup_per_zone *mz; |
| 1955 | unsigned long recent_rotated[2] = {0, 0}; |
| 1956 | unsigned long recent_scanned[2] = {0, 0}; |
| 1957 | |
| 1958 | for_each_online_node(nid) |
| 1959 | for (zid = 0; zid < MAX_NR_ZONES; zid++) { |
| 1960 | mz = mem_cgroup_zoneinfo(mem_cont, nid, zid); |
| 1961 | |
| 1962 | recent_rotated[0] += |
| 1963 | mz->reclaim_stat.recent_rotated[0]; |
| 1964 | recent_rotated[1] += |
| 1965 | mz->reclaim_stat.recent_rotated[1]; |
| 1966 | recent_scanned[0] += |
| 1967 | mz->reclaim_stat.recent_scanned[0]; |
| 1968 | recent_scanned[1] += |
| 1969 | mz->reclaim_stat.recent_scanned[1]; |
| 1970 | } |
| 1971 | cb->fill(cb, "recent_rotated_anon", recent_rotated[0]); |
| 1972 | cb->fill(cb, "recent_rotated_file", recent_rotated[1]); |
| 1973 | cb->fill(cb, "recent_scanned_anon", recent_scanned[0]); |
| 1974 | cb->fill(cb, "recent_scanned_file", recent_scanned[1]); |
| 1975 | } |
| 1976 | #endif |
| 1977 | |
| 1978 | return 0; |
| 1979 | } |
| 1980 | |
| 1981 | static u64 mem_cgroup_swappiness_read(struct cgroup *cgrp, struct cftype *cft) |
| 1982 | { |
| 1983 | struct mem_cgroup *memcg = mem_cgroup_from_cont(cgrp); |
| 1984 | |
| 1985 | return get_swappiness(memcg); |
| 1986 | } |
| 1987 | |
| 1988 | static int mem_cgroup_swappiness_write(struct cgroup *cgrp, struct cftype *cft, |
| 1989 | u64 val) |
| 1990 | { |
| 1991 | struct mem_cgroup *memcg = mem_cgroup_from_cont(cgrp); |
| 1992 | struct mem_cgroup *parent; |
| 1993 | if (val > 100) |
| 1994 | return -EINVAL; |
| 1995 | |
| 1996 | if (cgrp->parent == NULL) |
| 1997 | return -EINVAL; |
| 1998 | |
| 1999 | parent = mem_cgroup_from_cont(cgrp->parent); |
| 2000 | /* If under hierarchy, only empty-root can set this value */ |
| 2001 | if ((parent->use_hierarchy) || |
| 2002 | (memcg->use_hierarchy && !list_empty(&cgrp->children))) |
| 2003 | return -EINVAL; |
| 2004 | |
| 2005 | spin_lock(&memcg->reclaim_param_lock); |
| 2006 | memcg->swappiness = val; |
| 2007 | spin_unlock(&memcg->reclaim_param_lock); |
| 2008 | |
| 2009 | return 0; |
| 2010 | } |
| 2011 | |
| 2012 | |
| 2013 | static struct cftype mem_cgroup_files[] = { |
| 2014 | { |
| 2015 | .name = "usage_in_bytes", |
| 2016 | .private = MEMFILE_PRIVATE(_MEM, RES_USAGE), |
| 2017 | .read_u64 = mem_cgroup_read, |
| 2018 | }, |
| 2019 | { |
| 2020 | .name = "max_usage_in_bytes", |
| 2021 | .private = MEMFILE_PRIVATE(_MEM, RES_MAX_USAGE), |
| 2022 | .trigger = mem_cgroup_reset, |
| 2023 | .read_u64 = mem_cgroup_read, |
| 2024 | }, |
| 2025 | { |
| 2026 | .name = "limit_in_bytes", |
| 2027 | .private = MEMFILE_PRIVATE(_MEM, RES_LIMIT), |
| 2028 | .write_string = mem_cgroup_write, |
| 2029 | .read_u64 = mem_cgroup_read, |
| 2030 | }, |
| 2031 | { |
| 2032 | .name = "failcnt", |
| 2033 | .private = MEMFILE_PRIVATE(_MEM, RES_FAILCNT), |
| 2034 | .trigger = mem_cgroup_reset, |
| 2035 | .read_u64 = mem_cgroup_read, |
| 2036 | }, |
| 2037 | { |
| 2038 | .name = "stat", |
| 2039 | .read_map = mem_control_stat_show, |
| 2040 | }, |
| 2041 | { |
| 2042 | .name = "force_empty", |
| 2043 | .trigger = mem_cgroup_force_empty_write, |
| 2044 | }, |
| 2045 | { |
| 2046 | .name = "use_hierarchy", |
| 2047 | .write_u64 = mem_cgroup_hierarchy_write, |
| 2048 | .read_u64 = mem_cgroup_hierarchy_read, |
| 2049 | }, |
| 2050 | { |
| 2051 | .name = "swappiness", |
| 2052 | .read_u64 = mem_cgroup_swappiness_read, |
| 2053 | .write_u64 = mem_cgroup_swappiness_write, |
| 2054 | }, |
| 2055 | }; |
| 2056 | |
| 2057 | #ifdef CONFIG_CGROUP_MEM_RES_CTLR_SWAP |
| 2058 | static struct cftype memsw_cgroup_files[] = { |
| 2059 | { |
| 2060 | .name = "memsw.usage_in_bytes", |
| 2061 | .private = MEMFILE_PRIVATE(_MEMSWAP, RES_USAGE), |
| 2062 | .read_u64 = mem_cgroup_read, |
| 2063 | }, |
| 2064 | { |
| 2065 | .name = "memsw.max_usage_in_bytes", |
| 2066 | .private = MEMFILE_PRIVATE(_MEMSWAP, RES_MAX_USAGE), |
| 2067 | .trigger = mem_cgroup_reset, |
| 2068 | .read_u64 = mem_cgroup_read, |
| 2069 | }, |
| 2070 | { |
| 2071 | .name = "memsw.limit_in_bytes", |
| 2072 | .private = MEMFILE_PRIVATE(_MEMSWAP, RES_LIMIT), |
| 2073 | .write_string = mem_cgroup_write, |
| 2074 | .read_u64 = mem_cgroup_read, |
| 2075 | }, |
| 2076 | { |
| 2077 | .name = "memsw.failcnt", |
| 2078 | .private = MEMFILE_PRIVATE(_MEMSWAP, RES_FAILCNT), |
| 2079 | .trigger = mem_cgroup_reset, |
| 2080 | .read_u64 = mem_cgroup_read, |
| 2081 | }, |
| 2082 | }; |
| 2083 | |
| 2084 | static int register_memsw_files(struct cgroup *cont, struct cgroup_subsys *ss) |
| 2085 | { |
| 2086 | if (!do_swap_account) |
| 2087 | return 0; |
| 2088 | return cgroup_add_files(cont, ss, memsw_cgroup_files, |
| 2089 | ARRAY_SIZE(memsw_cgroup_files)); |
| 2090 | }; |
| 2091 | #else |
| 2092 | static int register_memsw_files(struct cgroup *cont, struct cgroup_subsys *ss) |
| 2093 | { |
| 2094 | return 0; |
| 2095 | } |
| 2096 | #endif |
| 2097 | |
| 2098 | static int alloc_mem_cgroup_per_zone_info(struct mem_cgroup *mem, int node) |
| 2099 | { |
| 2100 | struct mem_cgroup_per_node *pn; |
| 2101 | struct mem_cgroup_per_zone *mz; |
| 2102 | enum lru_list l; |
| 2103 | int zone, tmp = node; |
| 2104 | /* |
| 2105 | * This routine is called against possible nodes. |
| 2106 | * But it's BUG to call kmalloc() against offline node. |
| 2107 | * |
| 2108 | * TODO: this routine can waste much memory for nodes which will |
| 2109 | * never be onlined. It's better to use memory hotplug callback |
| 2110 | * function. |
| 2111 | */ |
| 2112 | if (!node_state(node, N_NORMAL_MEMORY)) |
| 2113 | tmp = -1; |
| 2114 | pn = kmalloc_node(sizeof(*pn), GFP_KERNEL, tmp); |
| 2115 | if (!pn) |
| 2116 | return 1; |
| 2117 | |
| 2118 | mem->info.nodeinfo[node] = pn; |
| 2119 | memset(pn, 0, sizeof(*pn)); |
| 2120 | |
| 2121 | for (zone = 0; zone < MAX_NR_ZONES; zone++) { |
| 2122 | mz = &pn->zoneinfo[zone]; |
| 2123 | for_each_lru(l) |
| 2124 | INIT_LIST_HEAD(&mz->lists[l]); |
| 2125 | } |
| 2126 | return 0; |
| 2127 | } |
| 2128 | |
| 2129 | static void free_mem_cgroup_per_zone_info(struct mem_cgroup *mem, int node) |
| 2130 | { |
| 2131 | kfree(mem->info.nodeinfo[node]); |
| 2132 | } |
| 2133 | |
| 2134 | static int mem_cgroup_size(void) |
| 2135 | { |
| 2136 | int cpustat_size = nr_cpu_ids * sizeof(struct mem_cgroup_stat_cpu); |
| 2137 | return sizeof(struct mem_cgroup) + cpustat_size; |
| 2138 | } |
| 2139 | |
| 2140 | static struct mem_cgroup *mem_cgroup_alloc(void) |
| 2141 | { |
| 2142 | struct mem_cgroup *mem; |
| 2143 | int size = mem_cgroup_size(); |
| 2144 | |
| 2145 | if (size < PAGE_SIZE) |
| 2146 | mem = kmalloc(size, GFP_KERNEL); |
| 2147 | else |
| 2148 | mem = vmalloc(size); |
| 2149 | |
| 2150 | if (mem) |
| 2151 | memset(mem, 0, size); |
| 2152 | return mem; |
| 2153 | } |
| 2154 | |
| 2155 | /* |
| 2156 | * At destroying mem_cgroup, references from swap_cgroup can remain. |
| 2157 | * (scanning all at force_empty is too costly...) |
| 2158 | * |
| 2159 | * Instead of clearing all references at force_empty, we remember |
| 2160 | * the number of reference from swap_cgroup and free mem_cgroup when |
| 2161 | * it goes down to 0. |
| 2162 | * |
| 2163 | * Removal of cgroup itself succeeds regardless of refs from swap. |
| 2164 | */ |
| 2165 | |
| 2166 | static void __mem_cgroup_free(struct mem_cgroup *mem) |
| 2167 | { |
| 2168 | int node; |
| 2169 | |
| 2170 | for_each_node_state(node, N_POSSIBLE) |
| 2171 | free_mem_cgroup_per_zone_info(mem, node); |
| 2172 | |
| 2173 | if (mem_cgroup_size() < PAGE_SIZE) |
| 2174 | kfree(mem); |
| 2175 | else |
| 2176 | vfree(mem); |
| 2177 | } |
| 2178 | |
| 2179 | static void mem_cgroup_get(struct mem_cgroup *mem) |
| 2180 | { |
| 2181 | atomic_inc(&mem->refcnt); |
| 2182 | } |
| 2183 | |
| 2184 | static void mem_cgroup_put(struct mem_cgroup *mem) |
| 2185 | { |
| 2186 | if (atomic_dec_and_test(&mem->refcnt)) |
| 2187 | __mem_cgroup_free(mem); |
| 2188 | } |
| 2189 | |
| 2190 | |
| 2191 | #ifdef CONFIG_CGROUP_MEM_RES_CTLR_SWAP |
| 2192 | static void __init enable_swap_cgroup(void) |
| 2193 | { |
| 2194 | if (!mem_cgroup_disabled() && really_do_swap_account) |
| 2195 | do_swap_account = 1; |
| 2196 | } |
| 2197 | #else |
| 2198 | static void __init enable_swap_cgroup(void) |
| 2199 | { |
| 2200 | } |
| 2201 | #endif |
| 2202 | |
| 2203 | static struct cgroup_subsys_state * |
| 2204 | mem_cgroup_create(struct cgroup_subsys *ss, struct cgroup *cont) |
| 2205 | { |
| 2206 | struct mem_cgroup *mem, *parent; |
| 2207 | int node; |
| 2208 | |
| 2209 | mem = mem_cgroup_alloc(); |
| 2210 | if (!mem) |
| 2211 | return ERR_PTR(-ENOMEM); |
| 2212 | |
| 2213 | for_each_node_state(node, N_POSSIBLE) |
| 2214 | if (alloc_mem_cgroup_per_zone_info(mem, node)) |
| 2215 | goto free_out; |
| 2216 | /* root ? */ |
| 2217 | if (cont->parent == NULL) { |
| 2218 | enable_swap_cgroup(); |
| 2219 | parent = NULL; |
| 2220 | } else { |
| 2221 | parent = mem_cgroup_from_cont(cont->parent); |
| 2222 | mem->use_hierarchy = parent->use_hierarchy; |
| 2223 | } |
| 2224 | |
| 2225 | if (parent && parent->use_hierarchy) { |
| 2226 | res_counter_init(&mem->res, &parent->res); |
| 2227 | res_counter_init(&mem->memsw, &parent->memsw); |
| 2228 | } else { |
| 2229 | res_counter_init(&mem->res, NULL); |
| 2230 | res_counter_init(&mem->memsw, NULL); |
| 2231 | } |
| 2232 | mem->last_scanned_child = NULL; |
| 2233 | spin_lock_init(&mem->reclaim_param_lock); |
| 2234 | |
| 2235 | if (parent) |
| 2236 | mem->swappiness = get_swappiness(parent); |
| 2237 | atomic_set(&mem->refcnt, 1); |
| 2238 | return &mem->css; |
| 2239 | free_out: |
| 2240 | __mem_cgroup_free(mem); |
| 2241 | return ERR_PTR(-ENOMEM); |
| 2242 | } |
| 2243 | |
| 2244 | static void mem_cgroup_pre_destroy(struct cgroup_subsys *ss, |
| 2245 | struct cgroup *cont) |
| 2246 | { |
| 2247 | struct mem_cgroup *mem = mem_cgroup_from_cont(cont); |
| 2248 | mem_cgroup_force_empty(mem, false); |
| 2249 | } |
| 2250 | |
| 2251 | static void mem_cgroup_destroy(struct cgroup_subsys *ss, |
| 2252 | struct cgroup *cont) |
| 2253 | { |
| 2254 | struct mem_cgroup *mem = mem_cgroup_from_cont(cont); |
| 2255 | struct mem_cgroup *last_scanned_child = mem->last_scanned_child; |
| 2256 | |
| 2257 | if (last_scanned_child) { |
| 2258 | VM_BUG_ON(!mem_cgroup_is_obsolete(last_scanned_child)); |
| 2259 | mem_cgroup_put(last_scanned_child); |
| 2260 | } |
| 2261 | mem_cgroup_put(mem); |
| 2262 | } |
| 2263 | |
| 2264 | static int mem_cgroup_populate(struct cgroup_subsys *ss, |
| 2265 | struct cgroup *cont) |
| 2266 | { |
| 2267 | int ret; |
| 2268 | |
| 2269 | ret = cgroup_add_files(cont, ss, mem_cgroup_files, |
| 2270 | ARRAY_SIZE(mem_cgroup_files)); |
| 2271 | |
| 2272 | if (!ret) |
| 2273 | ret = register_memsw_files(cont, ss); |
| 2274 | return ret; |
| 2275 | } |
| 2276 | |
| 2277 | static void mem_cgroup_move_task(struct cgroup_subsys *ss, |
| 2278 | struct cgroup *cont, |
| 2279 | struct cgroup *old_cont, |
| 2280 | struct task_struct *p) |
| 2281 | { |
| 2282 | mutex_lock(&memcg_tasklist); |
| 2283 | /* |
| 2284 | * FIXME: It's better to move charges of this process from old |
| 2285 | * memcg to new memcg. But it's just on TODO-List now. |
| 2286 | */ |
| 2287 | mutex_unlock(&memcg_tasklist); |
| 2288 | } |
| 2289 | |
| 2290 | struct cgroup_subsys mem_cgroup_subsys = { |
| 2291 | .name = "memory", |
| 2292 | .subsys_id = mem_cgroup_subsys_id, |
| 2293 | .create = mem_cgroup_create, |
| 2294 | .pre_destroy = mem_cgroup_pre_destroy, |
| 2295 | .destroy = mem_cgroup_destroy, |
| 2296 | .populate = mem_cgroup_populate, |
| 2297 | .attach = mem_cgroup_move_task, |
| 2298 | .early_init = 0, |
| 2299 | }; |
| 2300 | |
| 2301 | #ifdef CONFIG_CGROUP_MEM_RES_CTLR_SWAP |
| 2302 | |
| 2303 | static int __init disable_swap_account(char *s) |
| 2304 | { |
| 2305 | really_do_swap_account = 0; |
| 2306 | return 1; |
| 2307 | } |
| 2308 | __setup("noswapaccount", disable_swap_account); |
| 2309 | #endif |