/* memcontrol.c - Memory Controller * * Copyright IBM Corporation, 2007 * Author Balbir Singh <balbir@linux.vnet.ibm.com> * * Copyright 2007 OpenVZ SWsoft Inc * Author: Pavel Emelianov <xemul@openvz.org> * * This program is free software; you can redistribute it and/or modify * it under the terms of the GNU General Public License as published by * the Free Software Foundation; either version 2 of the License, or * (at your option) any later version. * * This program is distributed in the hope that it will be useful, * but WITHOUT ANY WARRANTY; without even the implied warranty of * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the * GNU General Public License for more details. */ #include <linux/res_counter.h> #include <linux/memcontrol.h> #include <linux/cgroup.h> #include <linux/mm.h> #include <linux/smp.h> #include <linux/page-flags.h> #include <linux/backing-dev.h> #include <linux/bit_spinlock.h> #include <linux/rcupdate.h> #include <linux/slab.h> #include <linux/swap.h> #include <linux/spinlock.h> #include <linux/fs.h> #include <linux/seq_file.h> #include <linux/vmalloc.h> #include <linux/mm_inline.h> #include <linux/page_cgroup.h> #include <asm/uaccess.h> struct cgroup_subsys mem_cgroup_subsys __read_mostly; #define MEM_CGROUP_RECLAIM_RETRIES 5 /* * Statistics for memory cgroup. */ enum mem_cgroup_stat_index { /* * For MEM_CONTAINER_TYPE_ALL, usage = pagecache + rss. */ MEM_CGROUP_STAT_CACHE, /* # of pages charged as cache */ MEM_CGROUP_STAT_RSS, /* # of pages charged as rss */ MEM_CGROUP_STAT_PGPGIN_COUNT, /* # of pages paged in */ MEM_CGROUP_STAT_PGPGOUT_COUNT, /* # of pages paged out */ MEM_CGROUP_STAT_NSTATS, }; struct mem_cgroup_stat_cpu { s64 count[MEM_CGROUP_STAT_NSTATS]; } ____cacheline_aligned_in_smp; struct mem_cgroup_stat { struct mem_cgroup_stat_cpu cpustat[NR_CPUS]; }; /* * For accounting under irq disable, no need for increment preempt count. */ static inline void __mem_cgroup_stat_add_safe(struct mem_cgroup_stat_cpu *stat, enum mem_cgroup_stat_index idx, int val) { stat->count[idx] += val; } static s64 mem_cgroup_read_stat(struct mem_cgroup_stat *stat, enum mem_cgroup_stat_index idx) { int cpu; s64 ret = 0; for_each_possible_cpu(cpu) ret += stat->cpustat[cpu].count[idx]; return ret; } /* * per-zone information in memory controller. */ struct mem_cgroup_per_zone { /* * spin_lock to protect the per cgroup LRU */ spinlock_t lru_lock; struct list_head lists[NR_LRU_LISTS]; unsigned long count[NR_LRU_LISTS]; }; /* Macro for accessing counter */ #define MEM_CGROUP_ZSTAT(mz, idx) ((mz)->count[(idx)]) struct mem_cgroup_per_node { struct mem_cgroup_per_zone zoneinfo[MAX_NR_ZONES]; }; struct mem_cgroup_lru_info { struct mem_cgroup_per_node *nodeinfo[MAX_NUMNODES]; }; /* * The memory controller data structure. The memory controller controls both * page cache and RSS per cgroup. We would eventually like to provide * statistics based on the statistics developed by Rik Van Riel for clock-pro, * to help the administrator determine what knobs to tune. * * TODO: Add a water mark for the memory controller. Reclaim will begin when * we hit the water mark. May be even add a low water mark, such that * no reclaim occurs from a cgroup at it's low water mark, this is * a feature that will be implemented much later in the future. */ struct mem_cgroup { struct cgroup_subsys_state css; /* * the counter to account for memory usage */ struct res_counter res; /* * Per cgroup active and inactive list, similar to the * per zone LRU lists. */ struct mem_cgroup_lru_info info; int prev_priority; /* for recording reclaim priority */ /* * statistics. */ struct mem_cgroup_stat stat; }; static struct mem_cgroup init_mem_cgroup; enum charge_type { MEM_CGROUP_CHARGE_TYPE_CACHE = 0, MEM_CGROUP_CHARGE_TYPE_MAPPED, MEM_CGROUP_CHARGE_TYPE_SHMEM, /* used by page migration of shmem */ MEM_CGROUP_CHARGE_TYPE_FORCE, /* used by force_empty */ NR_CHARGE_TYPE, }; /* only for here (for easy reading.) */ #define PCGF_CACHE (1UL << PCG_CACHE) #define PCGF_USED (1UL << PCG_USED) #define PCGF_ACTIVE (1UL << PCG_ACTIVE) #define PCGF_LOCK (1UL << PCG_LOCK) #define PCGF_FILE (1UL << PCG_FILE) static const unsigned long pcg_default_flags[NR_CHARGE_TYPE] = { PCGF_CACHE | PCGF_FILE | PCGF_USED | PCGF_LOCK, /* File Cache */ PCGF_ACTIVE | PCGF_USED | PCGF_LOCK, /* Anon */ PCGF_ACTIVE | PCGF_CACHE | PCGF_USED | PCGF_LOCK, /* Shmem */ 0, /* FORCE */ }; /* * Always modified under lru lock. Then, not necessary to preempt_disable() */ static void mem_cgroup_charge_statistics(struct mem_cgroup *mem, struct page_cgroup *pc, bool charge) { int val = (charge)? 1 : -1; struct mem_cgroup_stat *stat = &mem->stat; struct mem_cgroup_stat_cpu *cpustat; VM_BUG_ON(!irqs_disabled()); cpustat = &stat->cpustat[smp_processor_id()]; if (PageCgroupCache(pc)) __mem_cgroup_stat_add_safe(cpustat, MEM_CGROUP_STAT_CACHE, val); else __mem_cgroup_stat_add_safe(cpustat, MEM_CGROUP_STAT_RSS, val); if (charge) __mem_cgroup_stat_add_safe(cpustat, MEM_CGROUP_STAT_PGPGIN_COUNT, 1); else __mem_cgroup_stat_add_safe(cpustat, MEM_CGROUP_STAT_PGPGOUT_COUNT, 1); } static struct mem_cgroup_per_zone * mem_cgroup_zoneinfo(struct mem_cgroup *mem, int nid, int zid) { return &mem->info.nodeinfo[nid]->zoneinfo[zid]; } static struct mem_cgroup_per_zone * page_cgroup_zoneinfo(struct page_cgroup *pc) { struct mem_cgroup *mem = pc->mem_cgroup; int nid = page_cgroup_nid(pc); int zid = page_cgroup_zid(pc); return mem_cgroup_zoneinfo(mem, nid, zid); } static unsigned long mem_cgroup_get_all_zonestat(struct mem_cgroup *mem, enum lru_list idx) { int nid, zid; struct mem_cgroup_per_zone *mz; u64 total = 0; for_each_online_node(nid) for (zid = 0; zid < MAX_NR_ZONES; zid++) { mz = mem_cgroup_zoneinfo(mem, nid, zid); total += MEM_CGROUP_ZSTAT(mz, idx); } return total; } static struct mem_cgroup *mem_cgroup_from_cont(struct cgroup *cont) { return container_of(cgroup_subsys_state(cont, mem_cgroup_subsys_id), struct mem_cgroup, css); } struct mem_cgroup *mem_cgroup_from_task(struct task_struct *p) { /* * mm_update_next_owner() may clear mm->owner to NULL * if it races with swapoff, page migration, etc. * So this can be called with p == NULL. */ if (unlikely(!p)) return NULL; return container_of(task_subsys_state(p, mem_cgroup_subsys_id), struct mem_cgroup, css); } static void __mem_cgroup_remove_list(struct mem_cgroup_per_zone *mz, struct page_cgroup *pc) { int lru = LRU_BASE; if (PageCgroupUnevictable(pc)) lru = LRU_UNEVICTABLE; else { if (PageCgroupActive(pc)) lru += LRU_ACTIVE; if (PageCgroupFile(pc)) lru += LRU_FILE; } MEM_CGROUP_ZSTAT(mz, lru) -= 1; mem_cgroup_charge_statistics(pc->mem_cgroup, pc, false); list_del(&pc->lru); } static void __mem_cgroup_add_list(struct mem_cgroup_per_zone *mz, struct page_cgroup *pc) { int lru = LRU_BASE; if (PageCgroupUnevictable(pc)) lru = LRU_UNEVICTABLE; else { if (PageCgroupActive(pc)) lru += LRU_ACTIVE; if (PageCgroupFile(pc)) lru += LRU_FILE; } MEM_CGROUP_ZSTAT(mz, lru) += 1; list_add(&pc->lru, &mz->lists[lru]); mem_cgroup_charge_statistics(pc->mem_cgroup, pc, true); } static void __mem_cgroup_move_lists(struct page_cgroup *pc, enum lru_list lru) { struct mem_cgroup_per_zone *mz = page_cgroup_zoneinfo(pc); int active = PageCgroupActive(pc); int file = PageCgroupFile(pc); int unevictable = PageCgroupUnevictable(pc); enum lru_list from = unevictable ? LRU_UNEVICTABLE : (LRU_FILE * !!file + !!active); if (lru == from) return; MEM_CGROUP_ZSTAT(mz, from) -= 1; /* * However this is done under mz->lru_lock, another flags, which * are not related to LRU, will be modified from out-of-lock. * We have to use atomic set/clear flags. */ if (is_unevictable_lru(lru)) { ClearPageCgroupActive(pc); SetPageCgroupUnevictable(pc); } else { if (is_active_lru(lru)) SetPageCgroupActive(pc); else ClearPageCgroupActive(pc); ClearPageCgroupUnevictable(pc); } MEM_CGROUP_ZSTAT(mz, lru) += 1; list_move(&pc->lru, &mz->lists[lru]); } int task_in_mem_cgroup(struct task_struct *task, const struct mem_cgroup *mem) { int ret; task_lock(task); ret = task->mm && mm_match_cgroup(task->mm, mem); task_unlock(task); return ret; } /* * This routine assumes that the appropriate zone's lru lock is already held */ void mem_cgroup_move_lists(struct page *page, enum lru_list lru) { struct page_cgroup *pc; struct mem_cgroup_per_zone *mz; unsigned long flags; if (mem_cgroup_subsys.disabled) return; /* * We cannot lock_page_cgroup while holding zone's lru_lock, * because other holders of lock_page_cgroup can be interrupted * with an attempt to rotate_reclaimable_page. But we cannot * safely get to page_cgroup without it, so just try_lock it: * mem_cgroup_isolate_pages allows for page left on wrong list. */ pc = lookup_page_cgroup(page); if (!trylock_page_cgroup(pc)) return; if (pc && PageCgroupUsed(pc)) { mz = page_cgroup_zoneinfo(pc); spin_lock_irqsave(&mz->lru_lock, flags); __mem_cgroup_move_lists(pc, lru); spin_unlock_irqrestore(&mz->lru_lock, flags); } unlock_page_cgroup(pc); } /* * Calculate mapped_ratio under memory controller. This will be used in * vmscan.c for deteremining we have to reclaim mapped pages. */ int mem_cgroup_calc_mapped_ratio(struct mem_cgroup *mem) { long total, rss; /* * usage is recorded in bytes. But, here, we assume the number of * physical pages can be represented by "long" on any arch. */ total = (long) (mem->res.usage >> PAGE_SHIFT) + 1L; rss = (long)mem_cgroup_read_stat(&mem->stat, MEM_CGROUP_STAT_RSS); return (int)((rss * 100L) / total); } /* * prev_priority control...this will be used in memory reclaim path. */ int mem_cgroup_get_reclaim_priority(struct mem_cgroup *mem) { return mem->prev_priority; } void mem_cgroup_note_reclaim_priority(struct mem_cgroup *mem, int priority) { if (priority < mem->prev_priority) mem->prev_priority = priority; } void mem_cgroup_record_reclaim_priority(struct mem_cgroup *mem, int priority) { mem->prev_priority = priority; } /* * Calculate # of pages to be scanned in this priority/zone. * See also vmscan.c * * priority starts from "DEF_PRIORITY" and decremented in each loop. * (see include/linux/mmzone.h) */ long mem_cgroup_calc_reclaim(struct mem_cgroup *mem, struct zone *zone, int priority, enum lru_list lru) { long nr_pages; int nid = zone->zone_pgdat->node_id; int zid = zone_idx(zone); struct mem_cgroup_per_zone *mz = mem_cgroup_zoneinfo(mem, nid, zid); nr_pages = MEM_CGROUP_ZSTAT(mz, lru); return (nr_pages >> priority); } unsigned long mem_cgroup_isolate_pages(unsigned long nr_to_scan, struct list_head *dst, unsigned long *scanned, int order, int mode, struct zone *z, struct mem_cgroup *mem_cont, int active, int file) { unsigned long nr_taken = 0; struct page *page; unsigned long scan; LIST_HEAD(pc_list); struct list_head *src; struct page_cgroup *pc, *tmp; int nid = z->zone_pgdat->node_id; int zid = zone_idx(z); struct mem_cgroup_per_zone *mz; int lru = LRU_FILE * !!file + !!active; BUG_ON(!mem_cont); mz = mem_cgroup_zoneinfo(mem_cont, nid, zid); src = &mz->lists[lru]; spin_lock(&mz->lru_lock); scan = 0; list_for_each_entry_safe_reverse(pc, tmp, src, lru) { if (scan >= nr_to_scan) break; if (unlikely(!PageCgroupUsed(pc))) continue; page = pc->page; if (unlikely(!PageLRU(page))) continue; /* * TODO: play better with lumpy reclaim, grabbing anything. */ if (PageUnevictable(page) || (PageActive(page) && !active) || (!PageActive(page) && active)) { __mem_cgroup_move_lists(pc, page_lru(page)); continue; } scan++; list_move(&pc->lru, &pc_list); if (__isolate_lru_page(page, mode, file) == 0) { list_move(&page->lru, dst); nr_taken++; } } list_splice(&pc_list, src); spin_unlock(&mz->lru_lock); *scanned = scan; return nr_taken; } /* * Charge the memory controller for page usage. * Return * 0 if the charge was successful * < 0 if the cgroup is over its limit */ static int mem_cgroup_charge_common(struct page *page, struct mm_struct *mm, gfp_t gfp_mask, enum charge_type ctype, struct mem_cgroup *memcg) { struct mem_cgroup *mem; struct page_cgroup *pc; unsigned long nr_retries = MEM_CGROUP_RECLAIM_RETRIES; struct mem_cgroup_per_zone *mz; unsigned long flags; pc = lookup_page_cgroup(page); /* can happen at boot */ if (unlikely(!pc)) return 0; prefetchw(pc); /* * We always charge the cgroup the mm_struct belongs to. * The mm_struct's mem_cgroup changes on task migration if the * thread group leader migrates. It's possible that mm is not * set, if so charge the init_mm (happens for pagecache usage). */ if (likely(!memcg)) { rcu_read_lock(); mem = mem_cgroup_from_task(rcu_dereference(mm->owner)); if (unlikely(!mem)) { rcu_read_unlock(); return 0; } /* * For every charge from the cgroup, increment reference count */ css_get(&mem->css); rcu_read_unlock(); } else { mem = memcg; css_get(&memcg->css); } while (unlikely(res_counter_charge(&mem->res, PAGE_SIZE))) { if (!(gfp_mask & __GFP_WAIT)) goto out; if (try_to_free_mem_cgroup_pages(mem, gfp_mask)) continue; /* * try_to_free_mem_cgroup_pages() might not give us a full * picture of reclaim. Some pages are reclaimed and might be * moved to swap cache or just unmapped from the cgroup. * Check the limit again to see if the reclaim reduced the * current usage of the cgroup before giving up */ if (res_counter_check_under_limit(&mem->res)) continue; if (!nr_retries--) { mem_cgroup_out_of_memory(mem, gfp_mask); goto out; } } lock_page_cgroup(pc); if (unlikely(PageCgroupUsed(pc))) { unlock_page_cgroup(pc); res_counter_uncharge(&mem->res, PAGE_SIZE); css_put(&mem->css); goto done; } pc->mem_cgroup = mem; /* * If a page is accounted as a page cache, insert to inactive list. * If anon, insert to active list. */ pc->flags = pcg_default_flags[ctype]; mz = page_cgroup_zoneinfo(pc); spin_lock_irqsave(&mz->lru_lock, flags); __mem_cgroup_add_list(mz, pc); spin_unlock_irqrestore(&mz->lru_lock, flags); unlock_page_cgroup(pc); done: return 0; out: css_put(&mem->css); return -ENOMEM; } int mem_cgroup_charge(struct page *page, struct mm_struct *mm, gfp_t gfp_mask) { if (mem_cgroup_subsys.disabled) return 0; if (PageCompound(page)) return 0; /* * If already mapped, we don't have to account. * If page cache, page->mapping has address_space. * But page->mapping may have out-of-use anon_vma pointer, * detecit it by PageAnon() check. newly-mapped-anon's page->mapping * is NULL. */ if (page_mapped(page) || (page->mapping && !PageAnon(page))) return 0; if (unlikely(!mm)) mm = &init_mm; return mem_cgroup_charge_common(page, mm, gfp_mask, MEM_CGROUP_CHARGE_TYPE_MAPPED, NULL); } int mem_cgroup_cache_charge(struct page *page, struct mm_struct *mm, gfp_t gfp_mask) { if (mem_cgroup_subsys.disabled) return 0; if (PageCompound(page)) return 0; /* * Corner case handling. This is called from add_to_page_cache() * in usual. But some FS (shmem) precharges this page before calling it * and call add_to_page_cache() with GFP_NOWAIT. * * For GFP_NOWAIT case, the page may be pre-charged before calling * add_to_page_cache(). (See shmem.c) check it here and avoid to call * charge twice. (It works but has to pay a bit larger cost.) */ if (!(gfp_mask & __GFP_WAIT)) { struct page_cgroup *pc; pc = lookup_page_cgroup(page); if (!pc) return 0; lock_page_cgroup(pc); if (PageCgroupUsed(pc)) { unlock_page_cgroup(pc); return 0; } unlock_page_cgroup(pc); } if (unlikely(!mm)) mm = &init_mm; if (page_is_file_cache(page)) return mem_cgroup_charge_common(page, mm, gfp_mask, MEM_CGROUP_CHARGE_TYPE_CACHE, NULL); else return mem_cgroup_charge_common(page, mm, gfp_mask, MEM_CGROUP_CHARGE_TYPE_SHMEM, NULL); } /* * uncharge if !page_mapped(page) */ static void __mem_cgroup_uncharge_common(struct page *page, enum charge_type ctype) { struct page_cgroup *pc; struct mem_cgroup *mem; struct mem_cgroup_per_zone *mz; unsigned long flags; if (mem_cgroup_subsys.disabled) return; /* * Check if our page_cgroup is valid */ pc = lookup_page_cgroup(page); if (unlikely(!pc || !PageCgroupUsed(pc))) return; lock_page_cgroup(pc); if ((ctype == MEM_CGROUP_CHARGE_TYPE_MAPPED && page_mapped(page)) || !PageCgroupUsed(pc)) { /* This happens at race in zap_pte_range() and do_swap_page()*/ unlock_page_cgroup(pc); return; } ClearPageCgroupUsed(pc); mem = pc->mem_cgroup; mz = page_cgroup_zoneinfo(pc); spin_lock_irqsave(&mz->lru_lock, flags); __mem_cgroup_remove_list(mz, pc); spin_unlock_irqrestore(&mz->lru_lock, flags); unlock_page_cgroup(pc); res_counter_uncharge(&mem->res, PAGE_SIZE); css_put(&mem->css); return; } void mem_cgroup_uncharge_page(struct page *page) { /* early check. */ if (page_mapped(page)) return; if (page->mapping && !PageAnon(page)) return; __mem_cgroup_uncharge_common(page, MEM_CGROUP_CHARGE_TYPE_MAPPED); } void mem_cgroup_uncharge_cache_page(struct page *page) { VM_BUG_ON(page_mapped(page)); VM_BUG_ON(page->mapping); __mem_cgroup_uncharge_common(page, MEM_CGROUP_CHARGE_TYPE_CACHE); } /* * Before starting migration, account against new page. */ int mem_cgroup_prepare_migration(struct page *page, struct page *newpage) { struct page_cgroup *pc; struct mem_cgroup *mem = NULL; enum charge_type ctype = MEM_CGROUP_CHARGE_TYPE_MAPPED; int ret = 0; if (mem_cgroup_subsys.disabled) return 0; pc = lookup_page_cgroup(page); lock_page_cgroup(pc); if (PageCgroupUsed(pc)) { mem = pc->mem_cgroup; css_get(&mem->css); if (PageCgroupCache(pc)) { if (page_is_file_cache(page)) ctype = MEM_CGROUP_CHARGE_TYPE_CACHE; else ctype = MEM_CGROUP_CHARGE_TYPE_SHMEM; } } unlock_page_cgroup(pc); if (mem) { ret = mem_cgroup_charge_common(newpage, NULL, GFP_KERNEL, ctype, mem); css_put(&mem->css); } return ret; } /* remove redundant charge if migration failed*/ void mem_cgroup_end_migration(struct page *newpage) { /* * At success, page->mapping is not NULL. * special rollback care is necessary when * 1. at migration failure. (newpage->mapping is cleared in this case) * 2. the newpage was moved but not remapped again because the task * exits and the newpage is obsolete. In this case, the new page * may be a swapcache. So, we just call mem_cgroup_uncharge_page() * always for avoiding mess. The page_cgroup will be removed if * unnecessary. File cache pages is still on radix-tree. Don't * care it. */ if (!newpage->mapping) __mem_cgroup_uncharge_common(newpage, MEM_CGROUP_CHARGE_TYPE_FORCE); else if (PageAnon(newpage)) mem_cgroup_uncharge_page(newpage); } /* * A call to try to shrink memory usage under specified resource controller. * This is typically used for page reclaiming for shmem for reducing side * effect of page allocation from shmem, which is used by some mem_cgroup. */ int mem_cgroup_shrink_usage(struct mm_struct *mm, gfp_t gfp_mask) { struct mem_cgroup *mem; int progress = 0; int retry = MEM_CGROUP_RECLAIM_RETRIES; if (mem_cgroup_subsys.disabled) return 0; if (!mm) return 0; rcu_read_lock(); mem = mem_cgroup_from_task(rcu_dereference(mm->owner)); if (unlikely(!mem)) { rcu_read_unlock(); return 0; } css_get(&mem->css); rcu_read_unlock(); do { progress = try_to_free_mem_cgroup_pages(mem, gfp_mask); progress += res_counter_check_under_limit(&mem->res); } while (!progress && --retry); css_put(&mem->css); if (!retry) return -ENOMEM; return 0; } int mem_cgroup_resize_limit(struct mem_cgroup *memcg, unsigned long long val) { int retry_count = MEM_CGROUP_RECLAIM_RETRIES; int progress; int ret = 0; while (res_counter_set_limit(&memcg->res, val)) { if (signal_pending(current)) { ret = -EINTR; break; } if (!retry_count) { ret = -EBUSY; break; } progress = try_to_free_mem_cgroup_pages(memcg, GFP_KERNEL); if (!progress) retry_count--; } return ret; } /* * This routine traverse page_cgroup in given list and drop them all. * *And* this routine doesn't reclaim page itself, just removes page_cgroup. */ #define FORCE_UNCHARGE_BATCH (128) static void mem_cgroup_force_empty_list(struct mem_cgroup *mem, struct mem_cgroup_per_zone *mz, enum lru_list lru) { struct page_cgroup *pc; struct page *page; int count = FORCE_UNCHARGE_BATCH; unsigned long flags; struct list_head *list; list = &mz->lists[lru]; spin_lock_irqsave(&mz->lru_lock, flags); while (!list_empty(list)) { pc = list_entry(list->prev, struct page_cgroup, lru); page = pc->page; if (!PageCgroupUsed(pc)) break; get_page(page); spin_unlock_irqrestore(&mz->lru_lock, flags); /* * Check if this page is on LRU. !LRU page can be found * if it's under page migration. */ if (PageLRU(page)) { __mem_cgroup_uncharge_common(page, MEM_CGROUP_CHARGE_TYPE_FORCE); put_page(page); if (--count <= 0) { count = FORCE_UNCHARGE_BATCH; cond_resched(); } } else { spin_lock_irqsave(&mz->lru_lock, flags); break; } spin_lock_irqsave(&mz->lru_lock, flags); } spin_unlock_irqrestore(&mz->lru_lock, flags); } /* * make mem_cgroup's charge to be 0 if there is no task. * This enables deleting this mem_cgroup. */ static int mem_cgroup_force_empty(struct mem_cgroup *mem) { int ret = -EBUSY; int node, zid; css_get(&mem->css); /* * page reclaim code (kswapd etc..) will move pages between * active_list <-> inactive_list while we don't take a lock. * So, we have to do loop here until all lists are empty. */ while (mem->res.usage > 0) { if (atomic_read(&mem->css.cgroup->count) > 0) goto out; /* This is for making all *used* pages to be on LRU. */ lru_add_drain_all(); for_each_node_state(node, N_POSSIBLE) for (zid = 0; zid < MAX_NR_ZONES; zid++) { struct mem_cgroup_per_zone *mz; enum lru_list l; mz = mem_cgroup_zoneinfo(mem, node, zid); for_each_lru(l) mem_cgroup_force_empty_list(mem, mz, l); } cond_resched(); } ret = 0; out: css_put(&mem->css); return ret; } static u64 mem_cgroup_read(struct cgroup *cont, struct cftype *cft) { return res_counter_read_u64(&mem_cgroup_from_cont(cont)->res, cft->private); } /* * The user of this function is... * RES_LIMIT. */ static int mem_cgroup_write(struct cgroup *cont, struct cftype *cft, const char *buffer) { struct mem_cgroup *memcg = mem_cgroup_from_cont(cont); unsigned long long val; int ret; switch (cft->private) { case RES_LIMIT: /* This function does all necessary parse...reuse it */ ret = res_counter_memparse_write_strategy(buffer, &val); if (!ret) ret = mem_cgroup_resize_limit(memcg, val); break; default: ret = -EINVAL; /* should be BUG() ? */ break; } return ret; } static int mem_cgroup_reset(struct cgroup *cont, unsigned int event) { struct mem_cgroup *mem; mem = mem_cgroup_from_cont(cont); switch (event) { case RES_MAX_USAGE: res_counter_reset_max(&mem->res); break; case RES_FAILCNT: res_counter_reset_failcnt(&mem->res); break; } return 0; } static int mem_force_empty_write(struct cgroup *cont, unsigned int event) { return mem_cgroup_force_empty(mem_cgroup_from_cont(cont)); } static const struct mem_cgroup_stat_desc { const char *msg; u64 unit; } mem_cgroup_stat_desc[] = { [MEM_CGROUP_STAT_CACHE] = { "cache", PAGE_SIZE, }, [MEM_CGROUP_STAT_RSS] = { "rss", PAGE_SIZE, }, [MEM_CGROUP_STAT_PGPGIN_COUNT] = {"pgpgin", 1, }, [MEM_CGROUP_STAT_PGPGOUT_COUNT] = {"pgpgout", 1, }, }; static int mem_control_stat_show(struct cgroup *cont, struct cftype *cft, struct cgroup_map_cb *cb) { struct mem_cgroup *mem_cont = mem_cgroup_from_cont(cont); struct mem_cgroup_stat *stat = &mem_cont->stat; int i; for (i = 0; i < ARRAY_SIZE(stat->cpustat[0].count); i++) { s64 val; val = mem_cgroup_read_stat(stat, i); val *= mem_cgroup_stat_desc[i].unit; cb->fill(cb, mem_cgroup_stat_desc[i].msg, val); } /* showing # of active pages */ { unsigned long active_anon, inactive_anon; unsigned long active_file, inactive_file; unsigned long unevictable; inactive_anon = mem_cgroup_get_all_zonestat(mem_cont, LRU_INACTIVE_ANON); active_anon = mem_cgroup_get_all_zonestat(mem_cont, LRU_ACTIVE_ANON); inactive_file = mem_cgroup_get_all_zonestat(mem_cont, LRU_INACTIVE_FILE); active_file = mem_cgroup_get_all_zonestat(mem_cont, LRU_ACTIVE_FILE); unevictable = mem_cgroup_get_all_zonestat(mem_cont, LRU_UNEVICTABLE); cb->fill(cb, "active_anon", (active_anon) * PAGE_SIZE); cb->fill(cb, "inactive_anon", (inactive_anon) * PAGE_SIZE); cb->fill(cb, "active_file", (active_file) * PAGE_SIZE); cb->fill(cb, "inactive_file", (inactive_file) * PAGE_SIZE); cb->fill(cb, "unevictable", unevictable * PAGE_SIZE); } return 0; } static struct cftype mem_cgroup_files[] = { { .name = "usage_in_bytes", .private = RES_USAGE, .read_u64 = mem_cgroup_read, }, { .name = "max_usage_in_bytes", .private = RES_MAX_USAGE, .trigger = mem_cgroup_reset, .read_u64 = mem_cgroup_read, }, { .name = "limit_in_bytes", .private = RES_LIMIT, .write_string = mem_cgroup_write, .read_u64 = mem_cgroup_read, }, { .name = "failcnt", .private = RES_FAILCNT, .trigger = mem_cgroup_reset, .read_u64 = mem_cgroup_read, }, { .name = "force_empty", .trigger = mem_force_empty_write, }, { .name = "stat", .read_map = mem_control_stat_show, }, }; static int alloc_mem_cgroup_per_zone_info(struct mem_cgroup *mem, int node) { struct mem_cgroup_per_node *pn; struct mem_cgroup_per_zone *mz; enum lru_list l; int zone, tmp = node; /* * This routine is called against possible nodes. * But it's BUG to call kmalloc() against offline node. * * TODO: this routine can waste much memory for nodes which will * never be onlined. It's better to use memory hotplug callback * function. */ if (!node_state(node, N_NORMAL_MEMORY)) tmp = -1; pn = kmalloc_node(sizeof(*pn), GFP_KERNEL, tmp); if (!pn) return 1; mem->info.nodeinfo[node] = pn; memset(pn, 0, sizeof(*pn)); for (zone = 0; zone < MAX_NR_ZONES; zone++) { mz = &pn->zoneinfo[zone]; spin_lock_init(&mz->lru_lock); for_each_lru(l) INIT_LIST_HEAD(&mz->lists[l]); } return 0; } static void free_mem_cgroup_per_zone_info(struct mem_cgroup *mem, int node) { kfree(mem->info.nodeinfo[node]); } static struct mem_cgroup *mem_cgroup_alloc(void) { struct mem_cgroup *mem; if (sizeof(*mem) < PAGE_SIZE) mem = kmalloc(sizeof(*mem), GFP_KERNEL); else mem = vmalloc(sizeof(*mem)); if (mem) memset(mem, 0, sizeof(*mem)); return mem; } static void mem_cgroup_free(struct mem_cgroup *mem) { if (sizeof(*mem) < PAGE_SIZE) kfree(mem); else vfree(mem); } static struct cgroup_subsys_state * mem_cgroup_create(struct cgroup_subsys *ss, struct cgroup *cont) { struct mem_cgroup *mem; int node; if (unlikely((cont->parent) == NULL)) { mem = &init_mem_cgroup; } else { mem = mem_cgroup_alloc(); if (!mem) return ERR_PTR(-ENOMEM); } res_counter_init(&mem->res); for_each_node_state(node, N_POSSIBLE) if (alloc_mem_cgroup_per_zone_info(mem, node)) goto free_out; return &mem->css; free_out: for_each_node_state(node, N_POSSIBLE) free_mem_cgroup_per_zone_info(mem, node); if (cont->parent != NULL) mem_cgroup_free(mem); return ERR_PTR(-ENOMEM); } static void mem_cgroup_pre_destroy(struct cgroup_subsys *ss, struct cgroup *cont) { struct mem_cgroup *mem = mem_cgroup_from_cont(cont); mem_cgroup_force_empty(mem); } static void mem_cgroup_destroy(struct cgroup_subsys *ss, struct cgroup *cont) { int node; struct mem_cgroup *mem = mem_cgroup_from_cont(cont); for_each_node_state(node, N_POSSIBLE) free_mem_cgroup_per_zone_info(mem, node); mem_cgroup_free(mem_cgroup_from_cont(cont)); } static int mem_cgroup_populate(struct cgroup_subsys *ss, struct cgroup *cont) { return cgroup_add_files(cont, ss, mem_cgroup_files, ARRAY_SIZE(mem_cgroup_files)); } static void mem_cgroup_move_task(struct cgroup_subsys *ss, struct cgroup *cont, struct cgroup *old_cont, struct task_struct *p) { struct mm_struct *mm; struct mem_cgroup *mem, *old_mem; mm = get_task_mm(p); if (mm == NULL) return; mem = mem_cgroup_from_cont(cont); old_mem = mem_cgroup_from_cont(old_cont); /* * Only thread group leaders are allowed to migrate, the mm_struct is * in effect owned by the leader */ if (!thread_group_leader(p)) goto out; out: mmput(mm); } struct cgroup_subsys mem_cgroup_subsys = { .name = "memory", .subsys_id = mem_cgroup_subsys_id, .create = mem_cgroup_create, .pre_destroy = mem_cgroup_pre_destroy, .destroy = mem_cgroup_destroy, .populate = mem_cgroup_populate, .attach = mem_cgroup_move_task, .early_init = 0, };