diff options
Diffstat (limited to 'mm/memcontrol.c')
| -rw-r--r-- | mm/memcontrol.c | 739 |
1 files changed, 654 insertions, 85 deletions
diff --git a/mm/memcontrol.c b/mm/memcontrol.c index fd4529d86de5..e2b98a6875c0 100644 --- a/mm/memcontrol.c +++ b/mm/memcontrol.c @@ -29,6 +29,7 @@ #include <linux/rcupdate.h> #include <linux/limits.h> #include <linux/mutex.h> +#include <linux/rbtree.h> #include <linux/slab.h> #include <linux/swap.h> #include <linux/spinlock.h> @@ -43,6 +44,7 @@ struct cgroup_subsys mem_cgroup_subsys __read_mostly; #define MEM_CGROUP_RECLAIM_RETRIES 5 +struct mem_cgroup *root_mem_cgroup __read_mostly; #ifdef CONFIG_CGROUP_MEM_RES_CTLR_SWAP /* Turned on only when memory cgroup is enabled && really_do_swap_account = 1 */ @@ -53,6 +55,7 @@ static int really_do_swap_account __initdata = 1; /* for remember boot option*/ #endif static DEFINE_MUTEX(memcg_tasklist); /* can be hold under cgroup_mutex */ +#define SOFTLIMIT_EVENTS_THRESH (1000) /* * Statistics for memory cgroup. @@ -66,6 +69,8 @@ enum mem_cgroup_stat_index { MEM_CGROUP_STAT_MAPPED_FILE, /* # of pages charged as file rss */ MEM_CGROUP_STAT_PGPGIN_COUNT, /* # of pages paged in */ MEM_CGROUP_STAT_PGPGOUT_COUNT, /* # of pages paged out */ + MEM_CGROUP_STAT_EVENTS, /* sum of pagein + pageout for internal use */ + MEM_CGROUP_STAT_SWAPOUT, /* # of pages, swapped out */ MEM_CGROUP_STAT_NSTATS, }; @@ -78,6 +83,20 @@ struct mem_cgroup_stat { struct mem_cgroup_stat_cpu cpustat[0]; }; +static inline void +__mem_cgroup_stat_reset_safe(struct mem_cgroup_stat_cpu *stat, + enum mem_cgroup_stat_index idx) +{ + stat->count[idx] = 0; +} + +static inline s64 +__mem_cgroup_stat_read_local(struct mem_cgroup_stat_cpu *stat, + enum mem_cgroup_stat_index idx) +{ + return stat->count[idx]; +} + /* * For accounting under irq disable, no need for increment preempt count. */ @@ -117,6 +136,12 @@ struct mem_cgroup_per_zone { unsigned long count[NR_LRU_LISTS]; struct zone_reclaim_stat reclaim_stat; + struct rb_node tree_node; /* RB tree node */ + unsigned long long usage_in_excess;/* Set to the value by which */ + /* the soft limit is exceeded*/ + bool on_tree; + struct mem_cgroup *mem; /* Back pointer, we cannot */ + /* use container_of */ }; /* Macro for accessing counter */ #define MEM_CGROUP_ZSTAT(mz, idx) ((mz)->count[(idx)]) @@ -130,6 +155,26 @@ struct mem_cgroup_lru_info { }; /* + * Cgroups above their limits are maintained in a RB-Tree, independent of + * their hierarchy representation + */ + +struct mem_cgroup_tree_per_zone { + struct rb_root rb_root; + spinlock_t lock; +}; + +struct mem_cgroup_tree_per_node { + struct mem_cgroup_tree_per_zone rb_tree_per_zone[MAX_NR_ZONES]; +}; + +struct mem_cgroup_tree { + struct mem_cgroup_tree_per_node *rb_tree_per_node[MAX_NUMNODES]; +}; + +static struct mem_cgroup_tree soft_limit_tree __read_mostly; + +/* * 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, @@ -186,6 +231,13 @@ struct mem_cgroup { struct mem_cgroup_stat stat; }; +/* + * Maximum loops in mem_cgroup_hierarchical_reclaim(), used for soft + * limit reclaim to prevent infinite loops, if they ever occur. + */ +#define MEM_CGROUP_MAX_RECLAIM_LOOPS (100) +#define MEM_CGROUP_MAX_SOFT_LIMIT_RECLAIM_LOOPS (2) + enum charge_type { MEM_CGROUP_CHARGE_TYPE_CACHE = 0, MEM_CGROUP_CHARGE_TYPE_MAPPED, @@ -200,13 +252,8 @@ enum charge_type { #define PCGF_CACHE (1UL << PCG_CACHE) #define PCGF_USED (1UL << PCG_USED) #define PCGF_LOCK (1UL << PCG_LOCK) -static const unsigned long -pcg_default_flags[NR_CHARGE_TYPE] = { - PCGF_CACHE | PCGF_USED | PCGF_LOCK, /* File Cache */ - PCGF_USED | PCGF_LOCK, /* Anon */ - PCGF_CACHE | PCGF_USED | PCGF_LOCK, /* Shmem */ - 0, /* FORCE */ -}; +/* Not used, but added here for completeness */ +#define PCGF_ACCT (1UL << PCG_ACCT) /* for encoding cft->private value on file */ #define _MEM (0) @@ -215,15 +262,241 @@ pcg_default_flags[NR_CHARGE_TYPE] = { #define MEMFILE_TYPE(val) (((val) >> 16) & 0xffff) #define MEMFILE_ATTR(val) ((val) & 0xffff) +/* + * Reclaim flags for mem_cgroup_hierarchical_reclaim + */ +#define MEM_CGROUP_RECLAIM_NOSWAP_BIT 0x0 +#define MEM_CGROUP_RECLAIM_NOSWAP (1 << MEM_CGROUP_RECLAIM_NOSWAP_BIT) +#define MEM_CGROUP_RECLAIM_SHRINK_BIT 0x1 +#define MEM_CGROUP_RECLAIM_SHRINK (1 << MEM_CGROUP_RECLAIM_SHRINK_BIT) +#define MEM_CGROUP_RECLAIM_SOFT_BIT 0x2 +#define MEM_CGROUP_RECLAIM_SOFT (1 << MEM_CGROUP_RECLAIM_SOFT_BIT) + static void mem_cgroup_get(struct mem_cgroup *mem); static void mem_cgroup_put(struct mem_cgroup *mem); static struct mem_cgroup *parent_mem_cgroup(struct mem_cgroup *mem); +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); + + if (!mem) + return NULL; + + return mem_cgroup_zoneinfo(mem, nid, zid); +} + +static struct mem_cgroup_tree_per_zone * +soft_limit_tree_node_zone(int nid, int zid) +{ + return &soft_limit_tree.rb_tree_per_node[nid]->rb_tree_per_zone[zid]; +} + +static struct mem_cgroup_tree_per_zone * +soft_limit_tree_from_page(struct page *page) +{ + int nid = page_to_nid(page); + int zid = page_zonenum(page); + + return &soft_limit_tree.rb_tree_per_node[nid]->rb_tree_per_zone[zid]; +} + +static void +__mem_cgroup_insert_exceeded(struct mem_cgroup *mem, + struct mem_cgroup_per_zone *mz, + struct mem_cgroup_tree_per_zone *mctz) +{ + struct rb_node **p = &mctz->rb_root.rb_node; + struct rb_node *parent = NULL; + struct mem_cgroup_per_zone *mz_node; + + if (mz->on_tree) + return; + + mz->usage_in_excess = res_counter_soft_limit_excess(&mem->res); + while (*p) { + parent = *p; + mz_node = rb_entry(parent, struct mem_cgroup_per_zone, + tree_node); + if (mz->usage_in_excess < mz_node->usage_in_excess) + p = &(*p)->rb_left; + /* + * We can't avoid mem cgroups that are over their soft + * limit by the same amount + */ + else if (mz->usage_in_excess >= mz_node->usage_in_excess) + p = &(*p)->rb_right; + } + rb_link_node(&mz->tree_node, parent, p); + rb_insert_color(&mz->tree_node, &mctz->rb_root); + mz->on_tree = true; +} + +static void +__mem_cgroup_remove_exceeded(struct mem_cgroup *mem, + struct mem_cgroup_per_zone *mz, + struct mem_cgroup_tree_per_zone *mctz) +{ + if (!mz->on_tree) + return; + rb_erase(&mz->tree_node, &mctz->rb_root); + mz->on_tree = false; +} + +static void +mem_cgroup_insert_exceeded(struct mem_cgroup *mem, + struct mem_cgroup_per_zone *mz, + struct mem_cgroup_tree_per_zone *mctz) +{ + spin_lock(&mctz->lock); + __mem_cgroup_insert_exceeded(mem, mz, mctz); + spin_unlock(&mctz->lock); +} + +static void +mem_cgroup_remove_exceeded(struct mem_cgroup *mem, + struct mem_cgroup_per_zone *mz, + struct mem_cgroup_tree_per_zone *mctz) +{ + spin_lock(&mctz->lock); + __mem_cgroup_remove_exceeded(mem, mz, mctz); + spin_unlock(&mctz->lock); +} + +static bool mem_cgroup_soft_limit_check(struct mem_cgroup *mem) +{ + bool ret = false; + int cpu; + s64 val; + struct mem_cgroup_stat_cpu *cpustat; + + cpu = get_cpu(); + cpustat = &mem->stat.cpustat[cpu]; + val = __mem_cgroup_stat_read_local(cpustat, MEM_CGROUP_STAT_EVENTS); + if (unlikely(val > SOFTLIMIT_EVENTS_THRESH)) { + __mem_cgroup_stat_reset_safe(cpustat, MEM_CGROUP_STAT_EVENTS); + ret = true; + } + put_cpu(); + return ret; +} + +static void mem_cgroup_update_tree(struct mem_cgroup *mem, struct page *page) +{ + unsigned long long prev_usage_in_excess, new_usage_in_excess; + bool updated_tree = false; + struct mem_cgroup_per_zone *mz; + struct mem_cgroup_tree_per_zone *mctz; + + mz = mem_cgroup_zoneinfo(mem, page_to_nid(page), page_zonenum(page)); + mctz = soft_limit_tree_from_page(page); + + /* + * We do updates in lazy mode, mem's are removed + * lazily from the per-zone, per-node rb tree + */ + prev_usage_in_excess = mz->usage_in_excess; + + new_usage_in_excess = res_counter_soft_limit_excess(&mem->res); + if (prev_usage_in_excess) { + mem_cgroup_remove_exceeded(mem, mz, mctz); + updated_tree = true; + } + if (!new_usage_in_excess) + goto done; + mem_cgroup_insert_exceeded(mem, mz, mctz); + +done: + if (updated_tree) { + spin_lock(&mctz->lock); + mz->usage_in_excess = new_usage_in_excess; + spin_unlock(&mctz->lock); + } +} + +static void mem_cgroup_remove_from_trees(struct mem_cgroup *mem) +{ + int node, zone; + struct mem_cgroup_per_zone *mz; + struct mem_cgroup_tree_per_zone *mctz; + + for_each_node_state(node, N_POSSIBLE) { + for (zone = 0; zone < MAX_NR_ZONES; zone++) { + mz = mem_cgroup_zoneinfo(mem, node, zone); + mctz = soft_limit_tree_node_zone(node, zone); + mem_cgroup_remove_exceeded(mem, mz, mctz); + } + } +} + +static inline unsigned long mem_cgroup_get_excess(struct mem_cgroup *mem) +{ + return res_counter_soft_limit_excess(&mem->res) >> PAGE_SHIFT; +} + +static struct mem_cgroup_per_zone * +__mem_cgroup_largest_soft_limit_node(struct mem_cgroup_tree_per_zone *mctz) +{ + struct rb_node *rightmost = NULL; + struct mem_cgroup_per_zone *mz = NULL; + +retry: + rightmost = rb_last(&mctz->rb_root); + if (!rightmost) + goto done; /* Nothing to reclaim from */ + + mz = rb_entry(rightmost, struct mem_cgroup_per_zone, tree_node); + /* + * Remove the node now but someone else can add it back, + * we will to add it back at the end of reclaim to its correct + * position in the tree. + */ + __mem_cgroup_remove_exceeded(mz->mem, mz, mctz); + if (!res_counter_soft_limit_excess(&mz->mem->res) || + !css_tryget(&mz->mem->css)) + goto retry; +done: + return mz; +} + +static struct mem_cgroup_per_zone * +mem_cgroup_largest_soft_limit_node(struct mem_cgroup_tree_per_zone *mctz) +{ + struct mem_cgroup_per_zone *mz; + + spin_lock(&mctz->lock); + mz = __mem_cgroup_largest_soft_limit_node(mctz); + spin_unlock(&mctz->lock); + return mz; +} + +static void mem_cgroup_swap_statistics(struct mem_cgroup *mem, + bool charge) +{ + int val = (charge) ? 1 : -1; + struct mem_cgroup_stat *stat = &mem->stat; + struct mem_cgroup_stat_cpu *cpustat; + int cpu = get_cpu(); + + cpustat = &stat->cpustat[cpu]; + __mem_cgroup_stat_add_safe(cpustat, MEM_CGROUP_STAT_SWAPOUT, val); + put_cpu(); +} + static void mem_cgroup_charge_statistics(struct mem_cgroup *mem, struct page_cgroup *pc, bool charge) { - int val = (charge)? 1 : -1; + int val = (charge) ? 1 : -1; struct mem_cgroup_stat *stat = &mem->stat; struct mem_cgroup_stat_cpu *cpustat; int cpu = get_cpu(); @@ -240,28 +513,10 @@ static void mem_cgroup_charge_statistics(struct mem_cgroup *mem, else __mem_cgroup_stat_add_safe(cpustat, MEM_CGROUP_STAT_PGPGOUT_COUNT, 1); + __mem_cgroup_stat_add_safe(cpustat, MEM_CGROUP_STAT_EVENTS, 1); put_cpu(); } -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); - - if (!mem) - return NULL; - - return mem_cgroup_zoneinfo(mem, nid, zid); -} - static unsigned long mem_cgroup_get_local_zonestat(struct mem_cgroup *mem, enum lru_list idx) { @@ -354,6 +609,11 @@ static int mem_cgroup_walk_tree(struct mem_cgroup *root, void *data, return ret; } +static inline bool mem_cgroup_is_root(struct mem_cgroup *mem) +{ + return (mem == root_mem_cgroup); +} + /* * Following LRU functions are allowed to be used without PCG_LOCK. * Operations are called by routine of global LRU independently from memcg. @@ -371,22 +631,24 @@ static int mem_cgroup_walk_tree(struct mem_cgroup *root, void *data, void mem_cgroup_del_lru_list(struct page *page, enum lru_list lru) { struct page_cgroup *pc; - struct mem_cgroup *mem; struct mem_cgroup_per_zone *mz; if (mem_cgroup_disabled()) return; pc = lookup_page_cgroup(page); /* can happen while we handle swapcache. */ - if (list_empty(&pc->lru) || !pc->mem_cgroup) + if (!TestClearPageCgroupAcctLRU(pc)) return; + VM_BUG_ON(!pc->mem_cgroup); /* * We don't check PCG_USED bit. It's cleared when the "page" is finally * removed from global LRU. */ mz = page_cgroup_zoneinfo(pc); - mem = pc->mem_cgroup; MEM_CGROUP_ZSTAT(mz, lru) -= 1; + if (mem_cgroup_is_root(pc->mem_cgroup)) + return; + VM_BUG_ON(list_empty(&pc->lru)); list_del_init(&pc->lru); return; } @@ -410,8 +672,8 @@ void mem_cgroup_rotate_lru_list(struct page *page, enum lru_list lru) * For making pc->mem_cgroup visible, insert smp_rmb() here. */ smp_rmb(); - /* unused page is not rotated. */ - if (!PageCgroupUsed(pc)) + /* unused or root page is not rotated. */ + if (!PageCgroupUsed(pc) || mem_cgroup_is_root(pc->mem_cgroup)) return; mz = page_cgroup_zoneinfo(pc); list_move(&pc->lru, &mz->lists[lru]); @@ -425,6 +687,7 @@ void mem_cgroup_add_lru_list(struct page *page, enum lru_list lru) if (mem_cgroup_disabled()) return; pc = lookup_page_cgroup(page); + VM_BUG_ON(PageCgroupAcctLRU(pc)); /* * Used bit is set without atomic ops but after smp_wmb(). * For making pc->mem_cgroup visible, insert smp_rmb() here. @@ -435,6 +698,9 @@ void mem_cgroup_add_lru_list(struct page *page, enum lru_list lru) mz = page_cgroup_zoneinfo(pc); MEM_CGROUP_ZSTAT(mz, lru) += 1; + SetPageCgroupAcctLRU(pc); + if (mem_cgroup_is_root(pc->mem_cgroup)) + return; list_add(&pc->lru, &mz->lists[lru]); } @@ -469,7 +735,7 @@ static void mem_cgroup_lru_add_after_commit_swapcache(struct page *page) spin_lock_irqsave(&zone->lru_lock, flags); /* link when the page is linked to LRU but page_cgroup isn't */ - if (PageLRU(page) && list_empty(&pc->lru)) + if (PageLRU(page) && !PageCgroupAcctLRU(pc)) mem_cgroup_add_lru_list(page, page_lru(page)); spin_unlock_irqrestore(&zone->lru_lock, flags); } @@ -648,7 +914,7 @@ unsigned long mem_cgroup_isolate_pages(unsigned long nr_to_scan, int nid = z->zone_pgdat->node_id; int zid = zone_idx(z); struct mem_cgroup_per_zone *mz; - int lru = LRU_FILE * !!file + !!active; + int lru = LRU_FILE * file + active; int ret; BUG_ON(!mem_cont); @@ -855,28 +1121,62 @@ mem_cgroup_select_victim(struct mem_cgroup *root_mem) * If shrink==true, for avoiding to free too much, this returns immedieately. */ static int mem_cgroup_hierarchical_reclaim(struct mem_cgroup *root_mem, - gfp_t gfp_mask, bool noswap, bool shrink) + struct zone *zone, + gfp_t gfp_mask, + unsigned long reclaim_options) { struct mem_cgroup *victim; int ret, total = 0; int loop = 0; + bool noswap = reclaim_options & MEM_CGROUP_RECLAIM_NOSWAP; + bool shrink = reclaim_options & MEM_CGROUP_RECLAIM_SHRINK; + bool check_soft = reclaim_options & MEM_CGROUP_RECLAIM_SOFT; + unsigned long excess = mem_cgroup_get_excess(root_mem); /* If memsw_is_minimum==1, swap-out is of-no-use. */ if (root_mem->memsw_is_minimum) noswap = true; - while (loop < 2) { + while (1) { victim = mem_cgroup_select_victim(root_mem); - if (victim == root_mem) + if (victim == root_mem) { loop++; + if (loop >= 2) { + /* + * If we have not been able to reclaim + * anything, it might because there are + * no reclaimable pages under this hierarchy + */ + if (!check_soft || !total) { + css_put(&victim->css); + break; + } + /* + * We want to do more targetted reclaim. + * excess >> 2 is not to excessive so as to + * reclaim too much, nor too less that we keep + * coming back to reclaim from this cgroup + */ + if (total >= (excess >> 2) || + (loop > MEM_CGROUP_MAX_RECLAIM_LOOPS)) { + css_put(&victim->css); + break; + } + } + } if (!mem_cgroup_local_usage(&victim->stat)) { /* this cgroup's local usage == 0 */ css_put(&victim->css); continue; } /* we use swappiness of local cgroup */ - ret = try_to_free_mem_cgroup_pages(victim, gfp_mask, noswap, - get_swappiness(victim)); + if (check_soft) + ret = mem_cgroup_shrink_node_zone(victim, gfp_mask, + noswap, get_swappiness(victim), zone, + zone->zone_pgdat->node_id); + else + ret = try_to_free_mem_cgroup_pages(victim, gfp_mask, + noswap, get_swappiness(victim)); css_put(&victim->css); /* * At shrinking usage, we can't check we should stop here or @@ -886,7 +1186,10 @@ static int mem_cgroup_hierarchical_reclaim(struct mem_cgroup *root_mem, if (shrink) return ret; total += ret; - if (mem_cgroup_check_under_limit(root_mem)) + if (check_soft) { + if (res_counter_check_under_soft_limit(&root_mem->res)) + return total; + } else if (mem_cgroup_check_under_limit(root_mem)) return 1 + total; } return total; @@ -965,11 +1268,11 @@ done: */ static int __mem_cgroup_try_charge(struct mm_struct *mm, gfp_t gfp_mask, struct mem_cgroup **memcg, - bool oom) + bool oom, struct page *page) { - struct mem_cgroup *mem, *mem_over_limit; + struct mem_cgroup *mem, *mem_over_limit, *mem_over_soft_limit; int nr_retries = MEM_CGROUP_RECLAIM_RETRIES; - struct res_counter *fail_res; + struct res_counter *fail_res, *soft_fail_res = NULL; if (unlikely(test_thread_flag(TIF_MEMDIE))) { /* Don't account this! */ @@ -996,20 +1299,23 @@ static int __mem_cgroup_try_charge(struct mm_struct *mm, VM_BUG_ON(css_is_removed(&mem->css)); while (1) { - int ret; - bool noswap = false; + int ret = 0; + unsigned long flags = 0; - ret = res_counter_charge(&mem->res, PAGE_SIZE, &fail_res); + if (mem_cgroup_is_root(mem)) + goto done; + ret = res_counter_charge(&mem->res, PAGE_SIZE, &fail_res, + &soft_fail_res); if (likely(!ret)) { if (!do_swap_account) break; ret = res_counter_charge(&mem->memsw, PAGE_SIZE, - &fail_res); + &fail_res, NULL); if (likely(!ret)) break; /* mem+swap counter fails */ - res_counter_uncharge(&mem->res, PAGE_SIZE); - noswap = true; + res_counter_uncharge(&mem->res, PAGE_SIZE, NULL); + flags |= MEM_CGROUP_RECLAIM_NOSWAP; mem_over_limit = mem_cgroup_from_res_counter(fail_res, memsw); } else @@ -1020,8 +1326,8 @@ static int __mem_cgroup_try_charge(struct mm_struct *mm, if (!(gfp_mask & __GFP_WAIT)) goto nomem; - ret = mem_cgroup_hierarchical_reclaim(mem_over_limit, gfp_mask, - noswap, false); + ret = mem_cgroup_hierarchical_reclaim(mem_over_limit, NULL, + gfp_mask, flags); if (ret) continue; @@ -1046,13 +1352,24 @@ static int __mem_cgroup_try_charge(struct mm_struct *mm, goto nomem; } } + /* + * Insert just the ancestor, we should trickle down to the correct + * cgroup for reclaim, since the other nodes will be below their + * soft limit + */ + if (soft_fail_res) { + mem_over_soft_limit = + mem_cgroup_from_res_counter(soft_fail_res, res); + if (mem_cgroup_soft_limit_check(mem_over_soft_limit)) + mem_cgroup_update_tree(mem_over_soft_limit, page); + } +done: return 0; nomem: css_put(&mem->css); return -ENOMEM; } - /* * A helper function to get mem_cgroup from ID. must be called under * rcu_read_lock(). The caller must check css_is_removed() or some if @@ -1119,15 +1436,38 @@ static void __mem_cgroup_commit_charge(struct mem_cgroup *mem, lock_page_cgroup(pc); if (unlikely(PageCgroupUsed(pc))) { unlock_page_cgroup(pc); - res_counter_uncharge(&mem->res, PAGE_SIZE); - if (do_swap_account) - res_counter_uncharge(&mem->memsw, PAGE_SIZE); + if (!mem_cgroup_is_root(mem)) { + res_counter_uncharge(&mem->res, PAGE_SIZE, NULL); + if (do_swap_account) + res_counter_uncharge(&mem->memsw, PAGE_SIZE, + NULL); + } css_put(&mem->css); return; } + pc->mem_cgroup = mem; + /* + * We access a page_cgroup asynchronously without lock_page_cgroup(). + * Especially when a page_cgroup is taken from a page, pc->mem_cgroup + * is accessed after testing USED bit. To make pc->mem_cgroup visible + * before USED bit, we need memory barrier here. + * See mem_cgroup_add_lru_list(), etc. + */ smp_wmb(); - pc->flags = pcg_default_flags[ctype]; + switch (ctype) { + case MEM_CGROUP_CHARGE_TYPE_CACHE: + case MEM_CGROUP_CHARGE_TYPE_SHMEM: + SetPageCgroupCache(pc); + SetPageCgroupUsed(pc); + break; + case MEM_CGROUP_CHARGE_TYPE_MAPPED: + ClearPageCgroupCache(pc); + SetPageCgroupUsed(pc); + break; + default: + break; + } mem_cgroup_charge_statistics(mem, pc, true); @@ -1178,7 +1518,8 @@ static int mem_cgroup_move_account(struct page_cgroup *pc, if (pc->mem_cgroup != from) goto out; - res_counter_uncharge(&from->res, PAGE_SIZE); + if (!mem_cgroup_is_root(from)) + res_counter_uncharge(&from->res, PAGE_SIZE, NULL); mem_cgroup_charge_statistics(from, pc, false); page = pc->page; @@ -1197,8 +1538,8 @@ static int mem_cgroup_move_account(struct page_cgroup *pc, 1); } - if (do_swap_account) - res_counter_uncharge(&from->memsw, PAGE_SIZE); + if (do_swap_account && !mem_cgroup_is_root(from)) + res_counter_uncharge(&from->memsw, PAGE_SIZE, NULL); css_put(&from->css); css_get(&to->css); @@ -1238,7 +1579,7 @@ static int mem_cgroup_move_parent(struct page_cgroup *pc, parent = mem_cgroup_from_cont(pcg); - ret = __mem_cgroup_try_charge(NULL, gfp_mask, &parent, false); + ret = __mem_cgroup_try_charge(NULL, gfp_mask, &parent, false, page); if (ret || !parent) return ret; @@ -1268,9 +1609,11 @@ uncharge: /* drop extra refcnt by try_charge() */ css_put(&parent->css); /* uncharge if move fails */ - res_counter_uncharge(&parent->res, PAGE_SIZE); - if (do_swap_account) - res_counter_uncharge(&parent->memsw, PAGE_SIZE); + if (!mem_cgroup_is_root(parent)) { + res_counter_uncharge(&parent->res, PAGE_SIZE, NULL); + if (do_swap_account) + res_counter_uncharge(&parent->memsw, PAGE_SIZE, NULL); + } return ret; } @@ -1295,7 +1638,7 @@ static int mem_cgroup_charge_common(struct page *page, struct mm_struct *mm, prefetchw(pc); mem = memcg; - ret = __mem_cgroup_try_charge(mm, gfp_mask, &mem, true); + ret = __mem_cgroup_try_charge(mm, gfp_mask, &mem, true, page); if (ret || !mem) return ret; @@ -1414,14 +1757,14 @@ int mem_cgroup_try_charge_swapin(struct mm_struct *mm, if (!mem) goto charge_cur_mm; *ptr = mem; - ret = __mem_cgroup_try_charge(NULL, mask, ptr, true); + ret = __mem_cgroup_try_charge(NULL, mask, ptr, true, page); /* drop extra refcnt from tryget */ css_put(&mem->css); return ret; charge_cur_mm: if (unlikely(!mm)) mm = &init_mm; - return __mem_cgroup_try_charge(mm, mask, ptr, true); + return __mem_cgroup_try_charge(mm, mask, ptr, true, page); } static void @@ -1459,7 +1802,10 @@ __mem_cgroup_commit_charge_swapin(struct page *page, struct mem_cgroup *ptr, * This recorded memcg can be obsolete one. So, avoid * calling css_tryget */ - res_counter_uncharge(&memcg->memsw, PAGE_SIZE); + if (!mem_cgroup_is_root(memcg)) + res_counter_uncharge(&memcg->memsw, PAGE_SIZE, + NULL); + mem_cgroup_swap_statistics(memcg, false); mem_cgroup_put(memcg); } rcu_read_unlock(); @@ -1484,9 +1830,11 @@ void mem_cgroup_cancel_charge_swapin(struct mem_cgroup *mem) return; if (!mem) return; - res_counter_uncharge(&mem->res, PAGE_SIZE); - if (do_swap_account) - res_counter_uncharge(&mem->memsw, PAGE_SIZE); + if (!mem_cgroup_is_root(mem)) { + res_counter_uncharge(&mem->res, PAGE_SIZE, NULL); + if (do_swap_account) + res_counter_uncharge(&mem->memsw, PAGE_SIZE, NULL); + } css_put(&mem->css); } @@ -1500,6 +1848,7 @@ __mem_cgroup_uncharge_common(struct page *page, enum charge_type ctype) struct page_cgroup *pc; struct mem_cgroup *mem = NULL; struct mem_cgroup_per_zone *mz; + bool soft_limit_excess = false; if (mem_cgroup_disabled()) return NULL; @@ -1538,9 +1887,14 @@ __mem_cgroup_uncharge_common(struct page *page, enum charge_type ctype) break; } - res_counter_uncharge(&mem->res, PAGE_SIZE); - if (do_swap_account && (ctype != MEM_CGROUP_CHARGE_TYPE_SWAPOUT)) - res_counter_uncharge(&mem->memsw, PAGE_SIZE); + if (!mem_cgroup_is_root(mem)) { + res_counter_uncharge(&mem->res, PAGE_SIZE, &soft_limit_excess); + if (do_swap_account && + (ctype != MEM_CGROUP_CHARGE_TYPE_SWAPOUT)) + res_counter_uncharge(&mem->memsw, PAGE_SIZE, NULL); + } + if (ctype == MEM_CGROUP_CHARGE_TYPE_SWAPOUT) + mem_cgroup_swap_statistics(mem, true); mem_cgroup_charge_statistics(mem, pc, false); ClearPageCgroupUsed(pc); @@ -1554,6 +1908,8 @@ __mem_cgroup_uncharge_common(struct page *page, enum charge_type ctype) mz = page_cgroup_zoneinfo(pc); unlock_page_cgroup(pc); + if (soft_limit_excess && mem_cgroup_soft_limit_check(mem)) + mem_cgroup_update_tree(mem, page); /* at swapout, this memcg will be accessed to record to swap */ if (ctype != MEM_CGROUP_CHARGE_TYPE_SWAPOUT) css_put(&mem->css); @@ -1629,7 +1985,9 @@ void mem_cgroup_uncharge_swap(swp_entry_t ent) * We uncharge this because swap is freed. * This memcg can be obsolete one. We avoid calling css_tryget */ - res_counter_uncharge(&memcg->memsw, PAGE_SIZE); + if (!mem_cgroup_is_root(memcg)) + res_counter_uncharge(&memcg->memsw, PAGE_SIZE, NULL); + mem_cgroup_swap_statistics(memcg, false); mem_cgroup_put(memcg); } rcu_read_unlock(); @@ -1658,7 +2016,8 @@ int mem_cgroup_prepare_migration(struct page *page, struct mem_cgroup **ptr) unlock_page_cgroup(pc); if (mem) { - ret = __mem_cgroup_try_charge(NULL, GFP_KERNEL, &mem, false); + ret = __mem_cgroup_try_charge(NULL, GFP_KERNEL, &mem, false, + page); css_put(&mem->css); } *ptr = mem; @@ -1798,8 +2157,9 @@ static int mem_cgroup_resize_limit(struct mem_cgroup *memcg, if (!ret) break; - progress = mem_cgroup_hierarchical_reclaim(memcg, GFP_KERNEL, - false, true); + progress = mem_cgroup_hierarchical_reclaim(memcg, NULL, + GFP_KERNEL, + MEM_CGROUP_RECLAIM_SHRINK); curusage = res_counter_read_u64(&memcg->res, RES_USAGE); /* Usage is reduced ? */ if (curusage >= oldusage) @@ -1851,7 +2211,9 @@ static int mem_cgroup_resize_memsw_limit(struct mem_cgroup *memcg, if (!ret) break; - mem_cgroup_hierarchical_reclaim(memcg, GFP_KERNEL, true, true); + mem_cgroup_hierarchical_reclaim(memcg, NULL, GFP_KERNEL, + MEM_CGROUP_RECLAIM_NOSWAP | + MEM_CGROUP_RECLAIM_SHRINK); curusage = res_counter_read_u64(&memcg->memsw, RES_USAGE); /* Usage is reduced ? */ if (curusage >= oldusage) @@ -1862,6 +2224,97 @@ static int mem_cgroup_resize_memsw_limit(struct mem_cgroup *memcg, return ret; } +unsigned long mem_cgroup_soft_limit_reclaim(struct zone *zone, int order, + gfp_t gfp_mask, int nid, + int zid) +{ + unsigned long nr_reclaimed = 0; + struct mem_cgroup_per_zone *mz, *next_mz = NULL; + unsigned long reclaimed; + int loop = 0; + struct mem_cgroup_tree_per_zone *mctz; + + if (order > 0) + return 0; + + mctz = soft_limit_tree_node_zone(nid, zid); + /* + * This loop can run a while, specially if mem_cgroup's continuously + * keep exceeding their soft limit and putting the system under + * pressure + */ + do { + if (next_mz) + mz = next_mz; + else + mz = mem_cgroup_largest_soft_limit_node(mctz); + if (!mz) + break; + + reclaimed = mem_cgroup_hierarchical_reclaim(mz->mem, zone, + gfp_mask, + MEM_CGROUP_RECLAIM_SOFT); + nr_reclaimed += reclaimed; + spin_lock(&mctz->lock); + + /* + * If we failed to reclaim anything from this memory cgroup + * it is time to move on to the next cgroup + */ + next_mz = NULL; + if (!reclaimed) { + do { + /* + * Loop until we find yet another one. + * + * By the time we get the soft_limit lock + * again, someone might have aded the + * group back on the RB tree. Iterate to + * make sure we get a different mem. + * mem_cgroup_largest_soft_limit_node returns + * NULL if no other cgroup is present on + * the tree + */ + next_mz = + __mem_cgroup_largest_soft_limit_node(mctz); + if (next_mz == mz) { + css_put(&next_mz->mem->css); + next_mz = NULL; + } else /* next_mz == NULL or other memcg */ + break; + } while (1); + } + mz->usage_in_excess = + res_counter_soft_limit_excess(&mz->mem->res); + __mem_cgroup_remove_exceeded(mz->mem, mz, mctz); + /* + * One school of thought says that we should not add + * back the node to the tree if reclaim returns 0. + * But our reclaim could return 0, simply because due + * to priority we are exposing a smaller subset of + * memory to reclaim from. Consider this as a longer + * term TODO. + */ + if (mz->usage_in_excess) + __mem_cgroup_insert_exceeded(mz->mem, mz, mctz); + spin_unlock(&mctz->lock); + css_put(&mz->mem->css); + loop++; + /* + * Could not reclaim anything and there are no more + * mem cgroups to try or we seem to be looping without + * reclaiming anything. + */ + if (!nr_reclaimed && + (next_mz == NULL || + loop > MEM_CGROUP_MAX_SOFT_LIMIT_RECLAIM_LOOPS)) + break; + } while (!nr_reclaimed); + if (next_mz) + css_put(&next_mz->mem->css); + return nr_reclaimed; +} + /* * This routine traverse page_cgroup in given list and drop them all. * *And* this routine doesn't reclaim page itself, just removes page_cgroup. @@ -2046,20 +2499,64 @@ static int mem_cgroup_hierarchy_write(struct cgroup *cont, struct cftype *cft, return retval; } +struct mem_cgroup_idx_data { + s64 val; + enum mem_cgroup_stat_index idx; +}; + +static int +mem_cgroup_get_idx_stat(struct mem_cgroup *mem, void *data) +{ + struct mem_cgroup_idx_data *d = data; + d->val += mem_cgroup_read_stat(&mem->stat, d->idx); + return 0; +} + +static void +mem_cgroup_get_recursive_idx_stat(struct mem_cgroup *mem, + enum mem_cgroup_stat_index idx, s64 *val) +{ + struct mem_cgroup_idx_data d; + d.idx = idx; + d.val = 0; + mem_cgroup_walk_tree(mem, &d, mem_cgroup_get_idx_stat); + *val = d.val; +} + static u64 mem_cgroup_read(struct cgroup *cont, struct cftype *cft) { struct mem_cgroup *mem = mem_cgroup_from_cont(cont); - u64 val = 0; + u64 idx_val, val; int type, name; type = MEMFILE_TYPE(cft->private); name = MEMFILE_ATTR(cft->private); switch (type) { case _MEM: - val = res_counter_read_u64(&mem->res, name); + if (name == RES_USAGE && mem_cgroup_is_root(mem)) { + mem_cgroup_get_recursive_idx_stat(mem, + MEM_CGROUP_STAT_CACHE, &idx_val); + val = idx_val; + mem_cgroup_get_recursive_idx_stat(mem, + MEM_CGROUP_STAT_RSS, &idx_val); + val += idx_val; + val <<= PAGE_SHIFT; + } else + val = res_counter_read_u64(&mem->res, name); break; case _MEMSWAP: - val = res_counter_read_u64(&mem->memsw, name); + if (name == RES_USAGE && mem_cgroup_is_root(mem)) { + mem_cgroup_get_recursive_idx_stat(mem, + MEM_CGROUP_STAT_CACHE, &idx_val); + val = idx_val; + mem_cgroup_get_recursive_idx_stat(mem, + MEM_CGROUP_STAT_RSS, &idx_val); + val += idx_val; + mem_cgroup_get_recursive_idx_stat(mem, + MEM_CGROUP_STAT_SWAPOUT, &idx_val); + val <<= PAGE_SHIFT; + } else + val = res_counter_read_u64(&mem->memsw, name); break; default: BUG(); @@ -2083,6 +2580,10 @@ static int mem_cgroup_write(struct cgroup *cont, struct cftype *cft, name = MEMFILE_ATTR(cft->private); switch (name) { case RES_LIMIT: + if (mem_cgroup_is_root(memcg)) { /* Can't set limit on root */ + ret = -EINVAL; + break; + } /* This function does all necessary parse...reuse it */ ret = res_counter_memparse_write_strategy(buffer, &val); if (ret) @@ -2092,6 +2593,20 @@ static int mem_cgroup_write(struct cgroup *cont, struct cftype *cft, else ret = mem_cgroup_resize_memsw_limit(memcg, val); break; + case RES_SOFT_LIMIT: + ret = res_counter_memparse_write_strategy(buffer, &val); + if (ret) + break; + /* + * For memsw, soft limits are hard to implement in terms + * of semantics, for now, we support soft limits for + * control without swap + */ + if (type == _MEM) + ret = res_counter_set_soft_limit(&memcg->res, val); + else + ret = -EINVAL; + break; default: ret = -EINVAL; /* should be BUG() ? */ break; @@ -2149,6 +2664,7 @@ static int mem_cgroup_reset(struct cgroup *cont, unsigned int event) res_counter_reset_failcnt(&mem->memsw); break; } + return 0; } @@ -2160,6 +2676,7 @@ enum { MCS_MAPPED_FILE, MCS_PGPGIN, MCS_PGPGOUT, + MCS_SWAP, MCS_INACTIVE_ANON, MCS_ACTIVE_ANON, MCS_INACTIVE_FILE, @@ -2181,6 +2698,7 @@ struct { {"mapped_file", "total_mapped_file"}, {"pgpgin", "total_pgpgin"}, {"pgpgout", "total_pgpgout"}, + {"swap", "total_swap"}, {"inactive_anon", "total_inactive_anon"}, {"active_anon", "total_active_anon"}, {"inactive_file", "total_inactive_file"}, @@ -2205,6 +2723,10 @@ static int mem_cgroup_get_local_stat(struct mem_cgroup *mem, void *data) s->stat[MCS_PGPGIN] += val; val = mem_cgroup_read_stat(&mem->stat, MEM_CGROUP_STAT_PGPGOUT_COUNT); s->stat[MCS_PGPGOUT] += val; + if (do_swap_account) { + val = mem_cgroup_read_stat(&mem->stat, MEM_CGROUP_STAT_SWAPOUT); + s->stat[MCS_SWAP] += val * PAGE_SIZE; + } /* per zone stat */ val = mem_cgroup_get_local_zonestat(mem, LRU_INACTIVE_ANON); @@ -2236,8 +2758,11 @@ static int mem_control_stat_show(struct cgroup *cont, struct cftype *cft, memset(&mystat, 0, sizeof(mystat)); mem_cgroup_get_local_stat(mem_cont, &mystat); - for (i = 0; i < NR_MCS_STAT; i++) + for (i = 0; i < NR_MCS_STAT; i++) { + if (i == MCS_SWAP && !do_swap_account) + continue; cb->fill(cb, memcg_stat_strings[i].local_name, mystat.stat[i]); + } /* Hierarchical information */ { @@ -2250,9 +2775,11 @@ static int mem_control_stat_show(struct cgroup *cont, struct cftype *cft, memset(&mystat, 0, sizeof(mystat)); mem_cgroup_get_total_stat(mem_cont, &mystat); - for (i = 0; i < NR_MCS_STAT; i++) + for (i = 0; i < NR_MCS_STAT; i++) { + if (i == MCS_SWAP && !do_swap_account) + continue; cb->fill(cb, memcg_stat_strings[i].total_name, mystat.stat[i]); - + } #ifdef CONFIG_DEBUG_VM cb->fill(cb, "inactive_ratio", calc_inactive_ratio(mem_cont, NULL)); @@ -2345,6 +2872,12 @@ static struct cftype mem_cgroup_files[] = { .read_u64 = mem_cgroup_read, }, { + .name = "soft_limit_in_bytes", + .private = MEMFILE_PRIVATE(_MEM, RES_SOFT_LIMIT), + .write_string = mem_cgroup_write, + .read_u64 = mem_cgroup_read, + }, + { .name = "failcnt", .private = MEMFILE_PRIVATE(_MEM, RES_FAILCNT), .trigger = mem_cgroup_reset, @@ -2438,6 +2971,9 @@ static int alloc_mem_cgroup_per_zone_info(struct mem_cgroup *mem, int node) mz = &pn->zoneinfo[zone]; for_each_lru(l) INIT_LIST_HEAD(&mz->lists[l]); + mz->usage_in_excess = 0; + mz->on_tree = false; + mz->mem = mem; } return 0; } @@ -2483,6 +3019,7 @@ static void __mem_cgroup_free(struct mem_cgroup *mem) { int node; + mem_cgroup_remove_from_trees(mem); free_css_id(&mem_cgroup_subsys, &mem->css); for_each_node_state(node, N_POSSIBLE) @@ -2531,6 +3068,31 @@ static void __init enable_swap_cgroup(void) } #endif +static int mem_cgroup_soft_limit_tree_init(void) +{ + struct mem_cgroup_tree_per_node *rtpn; + struct mem_cgroup_tree_per_zone *rtpz; + int tmp, node, zone; + + for_each_node_state(node, N_POSSIBLE) { + tmp = node; + if (!node_state(node, N_NORMAL_MEMORY)) + tmp = -1; + rtpn = kzalloc_node(sizeof(*rtpn), GFP_KERNEL, tmp); + if (!rtpn) + return 1; + + soft_limit_tree.rb_tree_per_node[node] = rtpn; + + for (zone = 0; zone < MAX_NR_ZONES; zone++) { + rtpz = &rtpn->rb_tree_per_zone[zone]; + rtpz->rb_root = RB_ROOT; + spin_lock_init(&rtpz->lock); + } + } + return 0; +} + static struct cgroup_subsys_state * __ref mem_cgroup_create(struct cgroup_subsys *ss, struct cgroup *cont) { @@ -2545,10 +3107,15 @@ mem_cgroup_create(struct cgroup_subsys *ss, struct cgroup *cont) for_each_node_state(node, N_POSSIBLE) if (alloc_mem_cgroup_per_zone_info(mem, node)) goto free_out; + /* root ? */ if (cont->parent == NULL) { enable_swap_cgroup(); parent = NULL; + root_mem_cgroup = mem; + if (mem_cgroup_soft_limit_tree_init()) + goto free_out; + } else { parent = mem_cgroup_from_cont(cont->parent); mem->use_hierarchy = parent->use_hierarchy; @@ -2577,6 +3144,7 @@ mem_cgroup_create(struct cgroup_subsys *ss, struct cgroup *cont) return &mem->css; free_out: __mem_cgroup_free(mem); + root_mem_cgroup = NULL; return ERR_PTR(error); } @@ -2612,7 +3180,8 @@ static int mem_cgroup_populate(struct cgroup_subsys *ss, static void mem_cgroup_move_task(struct cgroup_subsys *ss, struct cgroup *cont, struct cgroup *old_cont, - struct task_struct *p) + struct task_struct *p, + bool threadgroup) { mutex_lock(&memcg_tasklist); /* |