diff options
Diffstat (limited to '')
| -rw-r--r-- | mm/memcontrol.c | 4467 |
1 files changed, 2540 insertions, 1927 deletions
diff --git a/mm/memcontrol.c b/mm/memcontrol.c index 7a4bd8b9adc2..2d8549ae1b30 100644 --- a/mm/memcontrol.c +++ b/mm/memcontrol.c @@ -20,6 +20,9 @@ * Lockless page tracking & accounting * Unified hierarchy configuration model * Copyright (C) 2015 Red Hat, Inc., Johannes Weiner + * + * Per memcg lru locking + * Copyright (C) 2020 Alibaba, Inc, Alex Shi */ #include <linux/page_counter.h> @@ -50,19 +53,21 @@ #include <linux/fs.h> #include <linux/seq_file.h> #include <linux/vmpressure.h> +#include <linux/memremap.h> #include <linux/mm_inline.h> #include <linux/swap_cgroup.h> #include <linux/cpu.h> #include <linux/oom.h> #include <linux/lockdep.h> #include <linux/file.h> -#include <linux/tracehook.h> +#include <linux/resume_user_mode.h> #include <linux/psi.h> #include <linux/seq_buf.h> #include "internal.h" #include <net/sock.h> #include <net/ip.h> #include "slab.h" +#include "swap.h" #include <linux/uaccess.h> @@ -73,20 +78,15 @@ EXPORT_SYMBOL(memory_cgrp_subsys); struct mem_cgroup *root_mem_cgroup __read_mostly; -#define MEM_CGROUP_RECLAIM_RETRIES 5 +/* Active memory cgroup to use from an interrupt context */ +DEFINE_PER_CPU(struct mem_cgroup *, int_active_memcg); +EXPORT_PER_CPU_SYMBOL_GPL(int_active_memcg); /* Socket memory accounting disabled? */ -static bool cgroup_memory_nosocket; +static bool cgroup_memory_nosocket __ro_after_init; /* Kernel memory accounting disabled? */ -static bool cgroup_memory_nokmem; - -/* Whether the swap controller is active */ -#ifdef CONFIG_MEMCG_SWAP -int do_swap_account __read_mostly; -#else -#define do_swap_account 0 -#endif +static bool cgroup_memory_nokmem __ro_after_init; #ifdef CONFIG_CGROUP_WRITEBACK static DECLARE_WAIT_QUEUE_HEAD(memcg_cgwb_frn_waitq); @@ -95,7 +95,7 @@ static DECLARE_WAIT_QUEUE_HEAD(memcg_cgwb_frn_waitq); /* Whether legacy memory+swap accounting is active */ static bool do_memsw_account(void) { - return !cgroup_subsys_on_dfl(memory_cgrp_subsys) && do_swap_account; + return !cgroup_subsys_on_dfl(memory_cgrp_subsys); } #define THRESHOLDS_EVENTS_TARGET 128 @@ -199,19 +199,10 @@ static struct move_charge_struct { #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_ANON, - MEM_CGROUP_CHARGE_TYPE_SWAPOUT, /* for accounting swapcache */ - MEM_CGROUP_CHARGE_TYPE_DROP, /* a page was unused swap cache */ - NR_CHARGE_TYPE, -}; - /* for encoding cft->private value on file */ enum res_type { _MEM, _MEMSWAP, - _OOM_TYPE, _KMEM, _TCP, }; @@ -219,8 +210,6 @@ enum res_type { #define MEMFILE_PRIVATE(x, val) ((x) << 16 | (val)) #define MEMFILE_TYPE(val) ((val) >> 16 & 0xffff) #define MEMFILE_ATTR(val) ((val) & 0xffff) -/* Used for OOM nofiier */ -#define OOM_CONTROL (0) /* * Iteration constructs for visiting all cgroups (under a tree). If @@ -237,7 +226,7 @@ enum res_type { iter != NULL; \ iter = mem_cgroup_iter(NULL, iter, NULL)) -static inline bool should_force_charge(void) +static inline bool task_is_dying(void) { return tsk_is_oom_victim(current) || fatal_signal_pending(current) || (current->flags & PF_EXITING); @@ -251,189 +240,114 @@ struct vmpressure *memcg_to_vmpressure(struct mem_cgroup *memcg) return &memcg->vmpressure; } -struct cgroup_subsys_state *vmpressure_to_css(struct vmpressure *vmpr) +struct mem_cgroup *vmpressure_to_memcg(struct vmpressure *vmpr) { - return &container_of(vmpr, struct mem_cgroup, vmpressure)->css; + return container_of(vmpr, struct mem_cgroup, vmpressure); } #ifdef CONFIG_MEMCG_KMEM -/* - * This will be the memcg's index in each cache's ->memcg_params.memcg_caches. - * The main reason for not using cgroup id for this: - * this works better in sparse environments, where we have a lot of memcgs, - * but only a few kmem-limited. Or also, if we have, for instance, 200 - * memcgs, and none but the 200th is kmem-limited, we'd have to have a - * 200 entry array for that. - * - * The current size of the caches array is stored in memcg_nr_cache_ids. It - * will double each time we have to increase it. - */ -static DEFINE_IDA(memcg_cache_ida); -int memcg_nr_cache_ids; - -/* Protects memcg_nr_cache_ids */ -static DECLARE_RWSEM(memcg_cache_ids_sem); - -void memcg_get_cache_ids(void) -{ - down_read(&memcg_cache_ids_sem); -} +static DEFINE_SPINLOCK(objcg_lock); -void memcg_put_cache_ids(void) +bool mem_cgroup_kmem_disabled(void) { - up_read(&memcg_cache_ids_sem); + return cgroup_memory_nokmem; } -/* - * MIN_SIZE is different than 1, because we would like to avoid going through - * the alloc/free process all the time. In a small machine, 4 kmem-limited - * cgroups is a reasonable guess. In the future, it could be a parameter or - * tunable, but that is strictly not necessary. - * - * MAX_SIZE should be as large as the number of cgrp_ids. Ideally, we could get - * this constant directly from cgroup, but it is understandable that this is - * better kept as an internal representation in cgroup.c. In any case, the - * cgrp_id space is not getting any smaller, and we don't have to necessarily - * increase ours as well if it increases. - */ -#define MEMCG_CACHES_MIN_SIZE 4 -#define MEMCG_CACHES_MAX_SIZE MEM_CGROUP_ID_MAX - -/* - * A lot of the calls to the cache allocation functions are expected to be - * inlined by the compiler. Since the calls to memcg_kmem_get_cache are - * conditional to this static branch, we'll have to allow modules that does - * kmem_cache_alloc and the such to see this symbol as well - */ -DEFINE_STATIC_KEY_FALSE(memcg_kmem_enabled_key); -EXPORT_SYMBOL(memcg_kmem_enabled_key); - -struct workqueue_struct *memcg_kmem_cache_wq; -#endif - -static int memcg_shrinker_map_size; -static DEFINE_MUTEX(memcg_shrinker_map_mutex); - -static void memcg_free_shrinker_map_rcu(struct rcu_head *head) -{ - kvfree(container_of(head, struct memcg_shrinker_map, rcu)); -} +static void obj_cgroup_uncharge_pages(struct obj_cgroup *objcg, + unsigned int nr_pages); -static int memcg_expand_one_shrinker_map(struct mem_cgroup *memcg, - int size, int old_size) +static void obj_cgroup_release(struct percpu_ref *ref) { - struct memcg_shrinker_map *new, *old; - int nid; - - lockdep_assert_held(&memcg_shrinker_map_mutex); - - for_each_node(nid) { - old = rcu_dereference_protected( - mem_cgroup_nodeinfo(memcg, nid)->shrinker_map, true); - /* Not yet online memcg */ - if (!old) - return 0; + struct obj_cgroup *objcg = container_of(ref, struct obj_cgroup, refcnt); + unsigned int nr_bytes; + unsigned int nr_pages; + unsigned long flags; - new = kvmalloc(sizeof(*new) + size, GFP_KERNEL); - if (!new) - return -ENOMEM; + /* + * At this point all allocated objects are freed, and + * objcg->nr_charged_bytes can't have an arbitrary byte value. + * However, it can be PAGE_SIZE or (x * PAGE_SIZE). + * + * The following sequence can lead to it: + * 1) CPU0: objcg == stock->cached_objcg + * 2) CPU1: we do a small allocation (e.g. 92 bytes), + * PAGE_SIZE bytes are charged + * 3) CPU1: a process from another memcg is allocating something, + * the stock if flushed, + * objcg->nr_charged_bytes = PAGE_SIZE - 92 + * 5) CPU0: we do release this object, + * 92 bytes are added to stock->nr_bytes + * 6) CPU0: stock is flushed, + * 92 bytes are added to objcg->nr_charged_bytes + * + * In the result, nr_charged_bytes == PAGE_SIZE. + * This page will be uncharged in obj_cgroup_release(). + */ + nr_bytes = atomic_read(&objcg->nr_charged_bytes); + WARN_ON_ONCE(nr_bytes & (PAGE_SIZE - 1)); + nr_pages = nr_bytes >> PAGE_SHIFT; - /* Set all old bits, clear all new bits */ - memset(new->map, (int)0xff, old_size); - memset((void *)new->map + old_size, 0, size - old_size); + if (nr_pages) + obj_cgroup_uncharge_pages(objcg, nr_pages); - rcu_assign_pointer(memcg->nodeinfo[nid]->shrinker_map, new); - call_rcu(&old->rcu, memcg_free_shrinker_map_rcu); - } + spin_lock_irqsave(&objcg_lock, flags); + list_del(&objcg->list); + spin_unlock_irqrestore(&objcg_lock, flags); - return 0; + percpu_ref_exit(ref); + kfree_rcu(objcg, rcu); } -static void memcg_free_shrinker_maps(struct mem_cgroup *memcg) +static struct obj_cgroup *obj_cgroup_alloc(void) { - struct mem_cgroup_per_node *pn; - struct memcg_shrinker_map *map; - int nid; + struct obj_cgroup *objcg; + int ret; - if (mem_cgroup_is_root(memcg)) - return; + objcg = kzalloc(sizeof(struct obj_cgroup), GFP_KERNEL); + if (!objcg) + return NULL; - for_each_node(nid) { - pn = mem_cgroup_nodeinfo(memcg, nid); - map = rcu_dereference_protected(pn->shrinker_map, true); - if (map) - kvfree(map); - rcu_assign_pointer(pn->shrinker_map, NULL); + ret = percpu_ref_init(&objcg->refcnt, obj_cgroup_release, 0, + GFP_KERNEL); + if (ret) { + kfree(objcg); + return NULL; } + INIT_LIST_HEAD(&objcg->list); + return objcg; } -static int memcg_alloc_shrinker_maps(struct mem_cgroup *memcg) +static void memcg_reparent_objcgs(struct mem_cgroup *memcg, + struct mem_cgroup *parent) { - struct memcg_shrinker_map *map; - int nid, size, ret = 0; - - if (mem_cgroup_is_root(memcg)) - return 0; + struct obj_cgroup *objcg, *iter; - mutex_lock(&memcg_shrinker_map_mutex); - size = memcg_shrinker_map_size; - for_each_node(nid) { - map = kvzalloc(sizeof(*map) + size, GFP_KERNEL); - if (!map) { - memcg_free_shrinker_maps(memcg); - ret = -ENOMEM; - break; - } - rcu_assign_pointer(memcg->nodeinfo[nid]->shrinker_map, map); - } - mutex_unlock(&memcg_shrinker_map_mutex); - - return ret; -} + objcg = rcu_replace_pointer(memcg->objcg, NULL, true); -int memcg_expand_shrinker_maps(int new_id) -{ - int size, old_size, ret = 0; - struct mem_cgroup *memcg; + spin_lock_irq(&objcg_lock); - size = DIV_ROUND_UP(new_id + 1, BITS_PER_LONG) * sizeof(unsigned long); - old_size = memcg_shrinker_map_size; - if (size <= old_size) - return 0; + /* 1) Ready to reparent active objcg. */ + list_add(&objcg->list, &memcg->objcg_list); + /* 2) Reparent active objcg and already reparented objcgs to parent. */ + list_for_each_entry(iter, &memcg->objcg_list, list) + WRITE_ONCE(iter->memcg, parent); + /* 3) Move already reparented objcgs to the parent's list */ + list_splice(&memcg->objcg_list, &parent->objcg_list); - mutex_lock(&memcg_shrinker_map_mutex); - if (!root_mem_cgroup) - goto unlock; + spin_unlock_irq(&objcg_lock); - for_each_mem_cgroup(memcg) { - if (mem_cgroup_is_root(memcg)) - continue; - ret = memcg_expand_one_shrinker_map(memcg, size, old_size); - if (ret) { - mem_cgroup_iter_break(NULL, memcg); - goto unlock; - } - } -unlock: - if (!ret) - memcg_shrinker_map_size = size; - mutex_unlock(&memcg_shrinker_map_mutex); - return ret; + percpu_ref_kill(&objcg->refcnt); } -void memcg_set_shrinker_bit(struct mem_cgroup *memcg, int nid, int shrinker_id) -{ - if (shrinker_id >= 0 && memcg && !mem_cgroup_is_root(memcg)) { - struct memcg_shrinker_map *map; - - rcu_read_lock(); - map = rcu_dereference(memcg->nodeinfo[nid]->shrinker_map); - /* Pairs with smp mb in shrink_slab() */ - smp_mb__before_atomic(); - set_bit(shrinker_id, map->map); - rcu_read_unlock(); - } -} +/* + * A lot of the calls to the cache allocation functions are expected to be + * inlined by the compiler. Since the calls to memcg_slab_pre_alloc_hook() are + * conditional to this static branch, we'll have to allow modules that does + * kmem_cache_alloc and the such to see this symbol as well + */ +DEFINE_STATIC_KEY_FALSE(memcg_kmem_enabled_key); +EXPORT_SYMBOL(memcg_kmem_enabled_key); +#endif /** * mem_cgroup_css_from_page - css of the memcg associated with a page @@ -450,7 +364,7 @@ struct cgroup_subsys_state *mem_cgroup_css_from_page(struct page *page) { struct mem_cgroup *memcg; - memcg = page->mem_cgroup; + memcg = page_memcg(page); if (!memcg || !cgroup_subsys_on_dfl(memory_cgrp_subsys)) memcg = root_mem_cgroup; @@ -477,10 +391,8 @@ ino_t page_cgroup_ino(struct page *page) unsigned long ino = 0; rcu_read_lock(); - if (PageSlab(page) && !PageTail(page)) - memcg = memcg_from_slab_page(page); - else - memcg = READ_ONCE(page->mem_cgroup); + memcg = page_memcg_check(page); + while (memcg && !(memcg->css.flags & CSS_ONLINE)) memcg = parent_mem_cgroup(memcg); if (memcg) @@ -489,28 +401,6 @@ ino_t page_cgroup_ino(struct page *page) return ino; } -static struct mem_cgroup_per_node * -mem_cgroup_page_nodeinfo(struct mem_cgroup *memcg, struct page *page) -{ - int nid = page_to_nid(page); - - return memcg->nodeinfo[nid]; -} - -static struct mem_cgroup_tree_per_node * -soft_limit_tree_node(int nid) -{ - return soft_limit_tree.rb_tree_per_node[nid]; -} - -static struct mem_cgroup_tree_per_node * -soft_limit_tree_from_page(struct page *page) -{ - int nid = page_to_nid(page); - - return soft_limit_tree.rb_tree_per_node[nid]; -} - static void __mem_cgroup_insert_exceeded(struct mem_cgroup_per_node *mz, struct mem_cgroup_tree_per_node *mctz, unsigned long new_usage_in_excess) @@ -533,14 +423,9 @@ static void __mem_cgroup_insert_exceeded(struct mem_cgroup_per_node *mz, if (mz->usage_in_excess < mz_node->usage_in_excess) { p = &(*p)->rb_left; rightmost = false; - } - - /* - * 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) + } else { p = &(*p)->rb_right; + } } if (rightmost) @@ -586,13 +471,13 @@ static unsigned long soft_limit_excess(struct mem_cgroup *memcg) return excess; } -static void mem_cgroup_update_tree(struct mem_cgroup *memcg, struct page *page) +static void mem_cgroup_update_tree(struct mem_cgroup *memcg, int nid) { unsigned long excess; struct mem_cgroup_per_node *mz; struct mem_cgroup_tree_per_node *mctz; - mctz = soft_limit_tree_from_page(page); + mctz = soft_limit_tree.rb_tree_per_node[nid]; if (!mctz) return; /* @@ -600,7 +485,7 @@ static void mem_cgroup_update_tree(struct mem_cgroup *memcg, struct page *page) * because their event counter is not touched. */ for (; memcg; memcg = parent_mem_cgroup(memcg)) { - mz = mem_cgroup_page_nodeinfo(memcg, page); + mz = memcg->nodeinfo[nid]; excess = soft_limit_excess(memcg); /* * We have to update the tree if mz is on RB-tree or @@ -630,8 +515,8 @@ static void mem_cgroup_remove_from_trees(struct mem_cgroup *memcg) int nid; for_each_node(nid) { - mz = mem_cgroup_nodeinfo(memcg, nid); - mctz = soft_limit_tree_node(nid); + mz = memcg->nodeinfo[nid]; + mctz = soft_limit_tree.rb_tree_per_node[nid]; if (mctz) mem_cgroup_remove_exceeded(mz, mctz); } @@ -656,7 +541,7 @@ retry: */ __mem_cgroup_remove_exceeded(mz, mctz); if (!soft_limit_excess(mz->memcg) || - !css_tryget_online(&mz->memcg->css)) + !css_tryget(&mz->memcg->css)) goto retry; done: return mz; @@ -673,6 +558,178 @@ mem_cgroup_largest_soft_limit_node(struct mem_cgroup_tree_per_node *mctz) return mz; } +/* + * memcg and lruvec stats flushing + * + * Many codepaths leading to stats update or read are performance sensitive and + * adding stats flushing in such codepaths is not desirable. So, to optimize the + * flushing the kernel does: + * + * 1) Periodically and asynchronously flush the stats every 2 seconds to not let + * rstat update tree grow unbounded. + * + * 2) Flush the stats synchronously on reader side only when there are more than + * (MEMCG_CHARGE_BATCH * nr_cpus) update events. Though this optimization + * will let stats be out of sync by atmost (MEMCG_CHARGE_BATCH * nr_cpus) but + * only for 2 seconds due to (1). + */ +static void flush_memcg_stats_dwork(struct work_struct *w); +static DECLARE_DEFERRABLE_WORK(stats_flush_dwork, flush_memcg_stats_dwork); +static DEFINE_SPINLOCK(stats_flush_lock); +static DEFINE_PER_CPU(unsigned int, stats_updates); +static atomic_t stats_flush_threshold = ATOMIC_INIT(0); +static u64 flush_next_time; + +#define FLUSH_TIME (2UL*HZ) + +/* + * Accessors to ensure that preemption is disabled on PREEMPT_RT because it can + * not rely on this as part of an acquired spinlock_t lock. These functions are + * never used in hardirq context on PREEMPT_RT and therefore disabling preemtion + * is sufficient. + */ +static void memcg_stats_lock(void) +{ + preempt_disable_nested(); + VM_WARN_ON_IRQS_ENABLED(); +} + +static void __memcg_stats_lock(void) +{ + preempt_disable_nested(); +} + +static void memcg_stats_unlock(void) +{ + preempt_enable_nested(); +} + +static inline void memcg_rstat_updated(struct mem_cgroup *memcg, int val) +{ + unsigned int x; + + cgroup_rstat_updated(memcg->css.cgroup, smp_processor_id()); + + x = __this_cpu_add_return(stats_updates, abs(val)); + if (x > MEMCG_CHARGE_BATCH) { + /* + * If stats_flush_threshold exceeds the threshold + * (>num_online_cpus()), cgroup stats update will be triggered + * in __mem_cgroup_flush_stats(). Increasing this var further + * is redundant and simply adds overhead in atomic update. + */ + if (atomic_read(&stats_flush_threshold) <= num_online_cpus()) + atomic_add(x / MEMCG_CHARGE_BATCH, &stats_flush_threshold); + __this_cpu_write(stats_updates, 0); + } +} + +static void __mem_cgroup_flush_stats(void) +{ + unsigned long flag; + + if (!spin_trylock_irqsave(&stats_flush_lock, flag)) + return; + + flush_next_time = jiffies_64 + 2*FLUSH_TIME; + cgroup_rstat_flush_irqsafe(root_mem_cgroup->css.cgroup); + atomic_set(&stats_flush_threshold, 0); + spin_unlock_irqrestore(&stats_flush_lock, flag); +} + +void mem_cgroup_flush_stats(void) +{ + if (atomic_read(&stats_flush_threshold) > num_online_cpus()) + __mem_cgroup_flush_stats(); +} + +void mem_cgroup_flush_stats_delayed(void) +{ + if (time_after64(jiffies_64, flush_next_time)) + mem_cgroup_flush_stats(); +} + +static void flush_memcg_stats_dwork(struct work_struct *w) +{ + __mem_cgroup_flush_stats(); + queue_delayed_work(system_unbound_wq, &stats_flush_dwork, FLUSH_TIME); +} + +/* Subset of vm_event_item to report for memcg event stats */ +static const unsigned int memcg_vm_event_stat[] = { + PGPGIN, + PGPGOUT, + PGSCAN_KSWAPD, + PGSCAN_DIRECT, + PGSTEAL_KSWAPD, + PGSTEAL_DIRECT, + PGFAULT, + PGMAJFAULT, + PGREFILL, + PGACTIVATE, + PGDEACTIVATE, + PGLAZYFREE, + PGLAZYFREED, +#if defined(CONFIG_MEMCG_KMEM) && defined(CONFIG_ZSWAP) + ZSWPIN, + ZSWPOUT, +#endif +#ifdef CONFIG_TRANSPARENT_HUGEPAGE + THP_FAULT_ALLOC, + THP_COLLAPSE_ALLOC, +#endif +}; + +#define NR_MEMCG_EVENTS ARRAY_SIZE(memcg_vm_event_stat) +static int mem_cgroup_events_index[NR_VM_EVENT_ITEMS] __read_mostly; + +static void init_memcg_events(void) +{ + int i; + + for (i = 0; i < NR_MEMCG_EVENTS; ++i) + mem_cgroup_events_index[memcg_vm_event_stat[i]] = i + 1; +} + +static inline int memcg_events_index(enum vm_event_item idx) +{ + return mem_cgroup_events_index[idx] - 1; +} + +struct memcg_vmstats_percpu { + /* Local (CPU and cgroup) page state & events */ + long state[MEMCG_NR_STAT]; + unsigned long events[NR_MEMCG_EVENTS]; + + /* Delta calculation for lockless upward propagation */ + long state_prev[MEMCG_NR_STAT]; + unsigned long events_prev[NR_MEMCG_EVENTS]; + + /* Cgroup1: threshold notifications & softlimit tree updates */ + unsigned long nr_page_events; + unsigned long targets[MEM_CGROUP_NTARGETS]; +}; + +struct memcg_vmstats { + /* Aggregated (CPU and subtree) page state & events */ + long state[MEMCG_NR_STAT]; + unsigned long events[NR_MEMCG_EVENTS]; + + /* Pending child counts during tree propagation */ + long state_pending[MEMCG_NR_STAT]; + unsigned long events_pending[NR_MEMCG_EVENTS]; +}; + +unsigned long memcg_page_state(struct mem_cgroup *memcg, int idx) +{ + long x = READ_ONCE(memcg->vmstats->state[idx]); +#ifdef CONFIG_SMP + if (x < 0) + x = 0; +#endif + return x; +} + /** * __mod_memcg_state - update cgroup memory statistics * @memcg: the memory cgroup @@ -681,36 +738,66 @@ mem_cgroup_largest_soft_limit_node(struct mem_cgroup_tree_per_node *mctz) */ void __mod_memcg_state(struct mem_cgroup *memcg, int idx, int val) { - long x; - if (mem_cgroup_disabled()) return; - x = val + __this_cpu_read(memcg->vmstats_percpu->stat[idx]); - if (unlikely(abs(x) > MEMCG_CHARGE_BATCH)) { - struct mem_cgroup *mi; + __this_cpu_add(memcg->vmstats_percpu->state[idx], val); + memcg_rstat_updated(memcg, val); +} - /* - * Batch local counters to keep them in sync with - * the hierarchical ones. - */ - __this_cpu_add(memcg->vmstats_local->stat[idx], x); - for (mi = memcg; mi; mi = parent_mem_cgroup(mi)) - atomic_long_add(x, &mi->vmstats[idx]); +/* idx can be of type enum memcg_stat_item or node_stat_item. */ +static unsigned long memcg_page_state_local(struct mem_cgroup *memcg, int idx) +{ + long x = 0; + int cpu; + + for_each_possible_cpu(cpu) + x += per_cpu(memcg->vmstats_percpu->state[idx], cpu); +#ifdef CONFIG_SMP + if (x < 0) x = 0; - } - __this_cpu_write(memcg->vmstats_percpu->stat[idx], x); +#endif + return x; } -static struct mem_cgroup_per_node * -parent_nodeinfo(struct mem_cgroup_per_node *pn, int nid) +void __mod_memcg_lruvec_state(struct lruvec *lruvec, enum node_stat_item idx, + int val) { - struct mem_cgroup *parent; + struct mem_cgroup_per_node *pn; + struct mem_cgroup *memcg; - parent = parent_mem_cgroup(pn->memcg); - if (!parent) - return NULL; - return mem_cgroup_nodeinfo(parent, nid); + pn = container_of(lruvec, struct mem_cgroup_per_node, lruvec); + memcg = pn->memcg; + + /* + * The caller from rmap relay on disabled preemption becase they never + * update their counter from in-interrupt context. For these two + * counters we check that the update is never performed from an + * interrupt context while other caller need to have disabled interrupt. + */ + __memcg_stats_lock(); + if (IS_ENABLED(CONFIG_DEBUG_VM)) { + switch (idx) { + case NR_ANON_MAPPED: + case NR_FILE_MAPPED: + case NR_ANON_THPS: + case NR_SHMEM_PMDMAPPED: + case NR_FILE_PMDMAPPED: + WARN_ON_ONCE(!in_task()); + break; + default: + VM_WARN_ON_IRQS_ENABLED(); + } + } + + /* Update memcg */ + __this_cpu_add(memcg->vmstats_percpu->state[idx], val); + + /* Update lruvec */ + __this_cpu_add(pn->lruvec_stats_percpu->state[idx], val); + + memcg_rstat_updated(memcg, val); + memcg_stats_unlock(); } /** @@ -726,49 +813,53 @@ parent_nodeinfo(struct mem_cgroup_per_node *pn, int nid) void __mod_lruvec_state(struct lruvec *lruvec, enum node_stat_item idx, int val) { - pg_data_t *pgdat = lruvec_pgdat(lruvec); - struct mem_cgroup_per_node *pn; - struct mem_cgroup *memcg; - long x; - /* Update node */ - __mod_node_page_state(pgdat, idx, val); + __mod_node_page_state(lruvec_pgdat(lruvec), idx, val); - if (mem_cgroup_disabled()) - return; - - pn = container_of(lruvec, struct mem_cgroup_per_node, lruvec); - memcg = pn->memcg; - - /* Update memcg */ - __mod_memcg_state(memcg, idx, val); - - /* Update lruvec */ - __this_cpu_add(pn->lruvec_stat_local->count[idx], val); + /* Update memcg and lruvec */ + if (!mem_cgroup_disabled()) + __mod_memcg_lruvec_state(lruvec, idx, val); +} - x = val + __this_cpu_read(pn->lruvec_stat_cpu->count[idx]); - if (unlikely(abs(x) > MEMCG_CHARGE_BATCH)) { - struct mem_cgroup_per_node *pi; +void __mod_lruvec_page_state(struct page *page, enum node_stat_item idx, + int val) +{ + struct page *head = compound_head(page); /* rmap on tail pages */ + struct mem_cgroup *memcg; + pg_data_t *pgdat = page_pgdat(page); + struct lruvec *lruvec; - for (pi = pn; pi; pi = parent_nodeinfo(pi, pgdat->node_id)) - atomic_long_add(x, &pi->lruvec_stat[idx]); - x = 0; + rcu_read_lock(); + memcg = page_memcg(head); + /* Untracked pages have no memcg, no lruvec. Update only the node */ + if (!memcg) { + rcu_read_unlock(); + __mod_node_page_state(pgdat, idx, val); + return; } - __this_cpu_write(pn->lruvec_stat_cpu->count[idx], x); + + lruvec = mem_cgroup_lruvec(memcg, pgdat); + __mod_lruvec_state(lruvec, idx, val); + rcu_read_unlock(); } +EXPORT_SYMBOL(__mod_lruvec_page_state); -void __mod_lruvec_slab_state(void *p, enum node_stat_item idx, int val) +void __mod_lruvec_kmem_state(void *p, enum node_stat_item idx, int val) { - struct page *page = virt_to_head_page(p); - pg_data_t *pgdat = page_pgdat(page); + pg_data_t *pgdat = page_pgdat(virt_to_page(p)); struct mem_cgroup *memcg; struct lruvec *lruvec; rcu_read_lock(); - memcg = memcg_from_slab_page(page); + memcg = mem_cgroup_from_slab_obj(p); - /* Untracked pages have no memcg, no lruvec. Update only the node */ - if (!memcg || memcg == root_mem_cgroup) { + /* + * Untracked pages have no memcg, no lruvec. Update only the + * node. If we reparent the slab objects to the root memcg, + * when we free the slab object, we need to update the per-memcg + * vmstats to keep it correct for the root memcg. + */ + if (!memcg) { __mod_node_page_state(pgdat, idx, val); } else { lruvec = mem_cgroup_lruvec(memcg, pgdat); @@ -781,68 +872,48 @@ void __mod_lruvec_slab_state(void *p, enum node_stat_item idx, int val) * __count_memcg_events - account VM events in a cgroup * @memcg: the memory cgroup * @idx: the event item - * @count: the number of events that occured + * @count: the number of events that occurred */ void __count_memcg_events(struct mem_cgroup *memcg, enum vm_event_item idx, unsigned long count) { - unsigned long x; + int index = memcg_events_index(idx); - if (mem_cgroup_disabled()) + if (mem_cgroup_disabled() || index < 0) return; - x = count + __this_cpu_read(memcg->vmstats_percpu->events[idx]); - if (unlikely(x > MEMCG_CHARGE_BATCH)) { - struct mem_cgroup *mi; - - /* - * Batch local counters to keep them in sync with - * the hierarchical ones. - */ - __this_cpu_add(memcg->vmstats_local->events[idx], x); - for (mi = memcg; mi; mi = parent_mem_cgroup(mi)) - atomic_long_add(x, &mi->vmevents[idx]); - x = 0; - } - __this_cpu_write(memcg->vmstats_percpu->events[idx], x); + memcg_stats_lock(); + __this_cpu_add(memcg->vmstats_percpu->events[index], count); + memcg_rstat_updated(memcg, count); + memcg_stats_unlock(); } static unsigned long memcg_events(struct mem_cgroup *memcg, int event) { - return atomic_long_read(&memcg->vmevents[event]); + int index = memcg_events_index(event); + + if (index < 0) + return 0; + return READ_ONCE(memcg->vmstats->events[index]); } static unsigned long memcg_events_local(struct mem_cgroup *memcg, int event) { long x = 0; int cpu; + int index = memcg_events_index(event); + + if (index < 0) + return 0; for_each_possible_cpu(cpu) - x += per_cpu(memcg->vmstats_local->events[event], cpu); + x += per_cpu(memcg->vmstats_percpu->events[index], cpu); return x; } static void mem_cgroup_charge_statistics(struct mem_cgroup *memcg, - struct page *page, - bool compound, int nr_pages) + int nr_pages) { - /* - * Here, RSS means 'mapped anon' and anon's SwapCache. Shmem/tmpfs is - * counted as CACHE even if it's on ANON LRU. - */ - if (PageAnon(page)) - __mod_memcg_state(memcg, MEMCG_RSS, nr_pages); - else { - __mod_memcg_state(memcg, MEMCG_CACHE, nr_pages); - if (PageSwapBacked(page)) - __mod_memcg_state(memcg, NR_SHMEM, nr_pages); - } - - if (compound) { - VM_BUG_ON_PAGE(!PageTransHuge(page), page); - __mod_memcg_state(memcg, MEMCG_RSS_HUGE, nr_pages); - } - /* pagein of a big page is an event. So, ignore page size */ if (nr_pages > 0) __count_memcg_events(memcg, PGPGIN, 1); @@ -883,8 +954,11 @@ static bool mem_cgroup_event_ratelimit(struct mem_cgroup *memcg, * Check events in order. * */ -static void memcg_check_events(struct mem_cgroup *memcg, struct page *page) +static void memcg_check_events(struct mem_cgroup *memcg, int nid) { + if (IS_ENABLED(CONFIG_PREEMPT_RT)) + return; + /* threshold event is triggered in finer grain than soft limit */ if (unlikely(mem_cgroup_event_ratelimit(memcg, MEM_CGROUP_TARGET_THRESH))) { @@ -894,7 +968,7 @@ static void memcg_check_events(struct mem_cgroup *memcg, struct page *page) MEM_CGROUP_TARGET_SOFTLIMIT); mem_cgroup_threshold(memcg); if (unlikely(do_softlimit)) - mem_cgroup_update_tree(memcg, page); + mem_cgroup_update_tree(memcg, nid); } } @@ -912,13 +986,24 @@ struct mem_cgroup *mem_cgroup_from_task(struct task_struct *p) } EXPORT_SYMBOL(mem_cgroup_from_task); +static __always_inline struct mem_cgroup *active_memcg(void) +{ + if (!in_task()) + return this_cpu_read(int_active_memcg); + else + return current->active_memcg; +} + /** * get_mem_cgroup_from_mm: Obtain a reference on given mm_struct's memcg. * @mm: mm from which memcg should be extracted. It can be NULL. * - * Obtain a reference on mm->memcg and returns it if successful. Otherwise - * root_mem_cgroup is returned. However if mem_cgroup is disabled, NULL is - * returned. + * Obtain a reference on mm->memcg and returns it if successful. If mm + * is NULL, then the memcg is chosen as follows: + * 1) The active memcg, if set. + * 2) current->mm->memcg, if available + * 3) root memcg + * If mem_cgroup is disabled, NULL is returned. */ struct mem_cgroup *get_mem_cgroup_from_mm(struct mm_struct *mm) { @@ -927,63 +1012,49 @@ struct mem_cgroup *get_mem_cgroup_from_mm(struct mm_struct *mm) if (mem_cgroup_disabled()) return NULL; + /* + * Page cache insertions can happen without an + * actual mm context, e.g. during disk probing + * on boot, loopback IO, acct() writes etc. + * + * No need to css_get on root memcg as the reference + * counting is disabled on the root level in the + * cgroup core. See CSS_NO_REF. + */ + if (unlikely(!mm)) { + memcg = active_memcg(); + if (unlikely(memcg)) { + /* remote memcg must hold a ref */ + css_get(&memcg->css); + return memcg; + } + mm = current->mm; + if (unlikely(!mm)) + return root_mem_cgroup; + } + rcu_read_lock(); do { - /* - * Page cache insertions can happen withou an - * actual mm context, e.g. during disk probing - * on boot, loopback IO, acct() writes etc. - */ - if (unlikely(!mm)) + memcg = mem_cgroup_from_task(rcu_dereference(mm->owner)); + if (unlikely(!memcg)) memcg = root_mem_cgroup; - else { - memcg = mem_cgroup_from_task(rcu_dereference(mm->owner)); - if (unlikely(!memcg)) - memcg = root_mem_cgroup; - } } while (!css_tryget(&memcg->css)); rcu_read_unlock(); return memcg; } EXPORT_SYMBOL(get_mem_cgroup_from_mm); -/** - * get_mem_cgroup_from_page: Obtain a reference on given page's memcg. - * @page: page from which memcg should be extracted. - * - * Obtain a reference on page->memcg and returns it if successful. Otherwise - * root_mem_cgroup is returned. - */ -struct mem_cgroup *get_mem_cgroup_from_page(struct page *page) +static __always_inline bool memcg_kmem_bypass(void) { - struct mem_cgroup *memcg = page->mem_cgroup; - - if (mem_cgroup_disabled()) - return NULL; - - rcu_read_lock(); - if (!memcg || !css_tryget_online(&memcg->css)) - memcg = root_mem_cgroup; - rcu_read_unlock(); - return memcg; -} -EXPORT_SYMBOL(get_mem_cgroup_from_page); + /* Allow remote memcg charging from any context. */ + if (unlikely(active_memcg())) + return false; -/** - * If current->active_memcg is non-NULL, do not fallback to current->mm->memcg. - */ -static __always_inline struct mem_cgroup *get_mem_cgroup_from_current(void) -{ - if (unlikely(current->active_memcg)) { - struct mem_cgroup *memcg = root_mem_cgroup; + /* Memcg to charge can't be determined. */ + if (!in_task() || !current->mm || (current->flags & PF_KTHREAD)) + return true; - rcu_read_lock(); - if (css_tryget_online(¤t->active_memcg->css)) - memcg = current->active_memcg; - rcu_read_unlock(); - return memcg; - } - return get_mem_cgroup_from_mm(current->mm); + return false; } /** @@ -999,15 +1070,15 @@ static __always_inline struct mem_cgroup *get_mem_cgroup_from_current(void) * invocations for reference counting, or use mem_cgroup_iter_break() * to cancel a hierarchy walk before the round-trip is complete. * - * Reclaimers can specify a node and a priority level in @reclaim to - * divide up the memcgs in the hierarchy among all concurrent - * reclaimers operating on the same node and priority. + * Reclaimers can specify a node in @reclaim to divide up the memcgs + * in the hierarchy among all concurrent reclaimers operating on the + * same node. */ struct mem_cgroup *mem_cgroup_iter(struct mem_cgroup *root, struct mem_cgroup *prev, struct mem_cgroup_reclaim_cookie *reclaim) { - struct mem_cgroup_reclaim_iter *uninitialized_var(iter); + struct mem_cgroup_reclaim_iter *iter; struct cgroup_subsys_state *css = NULL; struct mem_cgroup *memcg = NULL; struct mem_cgroup *pos = NULL; @@ -1018,24 +1089,21 @@ struct mem_cgroup *mem_cgroup_iter(struct mem_cgroup *root, if (!root) root = root_mem_cgroup; - if (prev && !reclaim) - pos = prev; - - if (!root->use_hierarchy && root != root_mem_cgroup) { - if (prev) - goto out; - return root; - } - rcu_read_lock(); if (reclaim) { struct mem_cgroup_per_node *mz; - mz = mem_cgroup_nodeinfo(root, reclaim->pgdat->node_id); + mz = root->nodeinfo[reclaim->pgdat->node_id]; iter = &mz->iter; - if (prev && reclaim->generation != iter->generation) + /* + * On start, join the current reclaim iteration cycle. + * Exit when a concurrent walker completes it. + */ + if (!prev) + reclaim->generation = iter->generation; + else if (reclaim->generation != iter->generation) goto out_unlock; while (1) { @@ -1052,6 +1120,8 @@ struct mem_cgroup *mem_cgroup_iter(struct mem_cgroup *root, */ (void)cmpxchg(&iter->position, pos, NULL); } + } else if (prev) { + pos = prev; } if (pos) @@ -1076,15 +1146,10 @@ struct mem_cgroup *mem_cgroup_iter(struct mem_cgroup *root, * is provided by the caller, so we know it's alive * and kicking, and don't take an extra reference. */ - memcg = mem_cgroup_from_css(css); - - if (css == &root->css) - break; - - if (css_tryget(css)) + if (css == &root->css || css_tryget(css)) { + memcg = mem_cgroup_from_css(css); break; - - memcg = NULL; + } } if (reclaim) { @@ -1100,13 +1165,10 @@ struct mem_cgroup *mem_cgroup_iter(struct mem_cgroup *root, if (!memcg) iter->generation++; - else if (!prev) - reclaim->generation = iter->generation; } out_unlock: rcu_read_unlock(); -out: if (prev && prev != root) css_put(&prev->css); @@ -1135,7 +1197,7 @@ static void __invalidate_reclaim_iterators(struct mem_cgroup *from, int nid; for_each_node(nid) { - mz = mem_cgroup_nodeinfo(from, nid); + mz = from->nodeinfo[nid]; iter = &mz->iter; cmpxchg(&iter->position, dead_memcg, NULL); } @@ -1152,7 +1214,7 @@ static void invalidate_reclaim_iterators(struct mem_cgroup *dead_memcg) } while ((memcg = parent_mem_cgroup(memcg))); /* - * When cgruop1 non-hierarchy mode is used, + * When cgroup1 non-hierarchy mode is used, * parent_mem_cgroup() does not walk all the way up to the * cgroup root (root_mem_cgroup). So we have to handle * dead_memcg from cgroup root separately. @@ -1199,44 +1261,90 @@ int mem_cgroup_scan_tasks(struct mem_cgroup *memcg, return ret; } +#ifdef CONFIG_DEBUG_VM +void lruvec_memcg_debug(struct lruvec *lruvec, struct folio *folio) +{ + struct mem_cgroup *memcg; + + if (mem_cgroup_disabled()) + return; + + memcg = folio_memcg(folio); + + if (!memcg) + VM_BUG_ON_FOLIO(lruvec_memcg(lruvec) != root_mem_cgroup, folio); + else + VM_BUG_ON_FOLIO(lruvec_memcg(lruvec) != memcg, folio); +} +#endif + /** - * mem_cgroup_page_lruvec - return lruvec for isolating/putting an LRU page - * @page: the page - * @pgdat: pgdat of the page + * folio_lruvec_lock - Lock the lruvec for a folio. + * @folio: Pointer to the folio. * - * This function is only safe when following the LRU page isolation - * and putback protocol: the LRU lock must be held, and the page must - * either be PageLRU() or the caller must have isolated/allocated it. + * These functions are safe to use under any of the following conditions: + * - folio locked + * - folio_test_lru false + * - folio_memcg_lock() + * - folio frozen (refcount of 0) + * + * Return: The lruvec this folio is on with its lock held. */ -struct lruvec *mem_cgroup_page_lruvec(struct page *page, struct pglist_data *pgdat) +struct lruvec *folio_lruvec_lock(struct folio *folio) { - struct mem_cgroup_per_node *mz; - struct mem_cgroup *memcg; - struct lruvec *lruvec; + struct lruvec *lruvec = folio_lruvec(folio); - if (mem_cgroup_disabled()) { - lruvec = &pgdat->__lruvec; - goto out; - } + spin_lock(&lruvec->lru_lock); + lruvec_memcg_debug(lruvec, folio); - memcg = page->mem_cgroup; - /* - * Swapcache readahead pages are added to the LRU - and - * possibly migrated - before they are charged. - */ - if (!memcg) - memcg = root_mem_cgroup; + return lruvec; +} + +/** + * folio_lruvec_lock_irq - Lock the lruvec for a folio. + * @folio: Pointer to the folio. + * + * These functions are safe to use under any of the following conditions: + * - folio locked + * - folio_test_lru false + * - folio_memcg_lock() + * - folio frozen (refcount of 0) + * + * Return: The lruvec this folio is on with its lock held and interrupts + * disabled. + */ +struct lruvec *folio_lruvec_lock_irq(struct folio *folio) +{ + struct lruvec *lruvec = folio_lruvec(folio); + + spin_lock_irq(&lruvec->lru_lock); + lruvec_memcg_debug(lruvec, folio); + + return lruvec; +} + +/** + * folio_lruvec_lock_irqsave - Lock the lruvec for a folio. + * @folio: Pointer to the folio. + * @flags: Pointer to irqsave flags. + * + * These functions are safe to use under any of the following conditions: + * - folio locked + * - folio_test_lru false + * - folio_memcg_lock() + * - folio frozen (refcount of 0) + * + * Return: The lruvec this folio is on with its lock held and interrupts + * disabled. + */ +struct lruvec *folio_lruvec_lock_irqsave(struct folio *folio, + unsigned long *flags) +{ + struct lruvec *lruvec = folio_lruvec(folio); + + spin_lock_irqsave(&lruvec->lru_lock, *flags); + lruvec_memcg_debug(lruvec, folio); - mz = mem_cgroup_page_nodeinfo(memcg, page); - lruvec = &mz->lruvec; -out: - /* - * Since a node can be onlined after the mem_cgroup was created, - * we have to be prepared to initialize lruvec->zone here; - * and if offlined then reonlined, we need to reinitialize it. - */ - if (unlikely(lruvec->pgdat != pgdat)) - lruvec->pgdat = pgdat; return lruvec; } @@ -1248,8 +1356,7 @@ out: * @nr_pages: positive when adding or negative when removing * * This function must be called under lru_lock, just before a page is added - * to or just after a page is removed from an lru list (that ordering being - * so as to allow it to check that lru_size 0 is consistent with list_empty). + * to or just after a page is removed from an lru list. */ void mem_cgroup_update_lru_size(struct lruvec *lruvec, enum lru_list lru, int zid, int nr_pages) @@ -1300,7 +1407,7 @@ static unsigned long mem_cgroup_margin(struct mem_cgroup *memcg) if (do_memsw_account()) { count = page_counter_read(&memcg->memsw); limit = READ_ONCE(memcg->memsw.max); - if (count <= limit) + if (count < limit) margin = min(margin, limit - count); else margin = 0; @@ -1354,14 +1461,90 @@ static bool mem_cgroup_wait_acct_move(struct mem_cgroup *memcg) return false; } -static char *memory_stat_format(struct mem_cgroup *memcg) +struct memory_stat { + const char *name; + unsigned int idx; +}; + +static const struct memory_stat memory_stats[] = { + { "anon", NR_ANON_MAPPED }, + { "file", NR_FILE_PAGES }, + { "kernel", MEMCG_KMEM }, + { "kernel_stack", NR_KERNEL_STACK_KB }, + { "pagetables", NR_PAGETABLE }, + { "sec_pagetables", NR_SECONDARY_PAGETABLE }, + { "percpu", MEMCG_PERCPU_B }, + { "sock", MEMCG_SOCK }, + { "vmalloc", MEMCG_VMALLOC }, + { "shmem", NR_SHMEM }, +#if defined(CONFIG_MEMCG_KMEM) && defined(CONFIG_ZSWAP) + { "zswap", MEMCG_ZSWAP_B }, + { "zswapped", MEMCG_ZSWAPPED }, +#endif + { "file_mapped", NR_FILE_MAPPED }, + { "file_dirty", NR_FILE_DIRTY }, + { "file_writeback", NR_WRITEBACK }, +#ifdef CONFIG_SWAP + { "swapcached", NR_SWAPCACHE }, +#endif +#ifdef CONFIG_TRANSPARENT_HUGEPAGE + { "anon_thp", NR_ANON_THPS }, + { "file_thp", NR_FILE_THPS }, + { "shmem_thp", NR_SHMEM_THPS }, +#endif + { "inactive_anon", NR_INACTIVE_ANON }, + { "active_anon", NR_ACTIVE_ANON }, + { "inactive_file", NR_INACTIVE_FILE }, + { "active_file", NR_ACTIVE_FILE }, + { "unevictable", NR_UNEVICTABLE }, + { "slab_reclaimable", NR_SLAB_RECLAIMABLE_B }, + { "slab_unreclaimable", NR_SLAB_UNRECLAIMABLE_B }, + + /* The memory events */ + { "workingset_refault_anon", WORKINGSET_REFAULT_ANON }, + { "workingset_refault_file", WORKINGSET_REFAULT_FILE }, + { "workingset_activate_anon", WORKINGSET_ACTIVATE_ANON }, + { "workingset_activate_file", WORKINGSET_ACTIVATE_FILE }, + { "workingset_restore_anon", WORKINGSET_RESTORE_ANON }, + { "workingset_restore_file", WORKINGSET_RESTORE_FILE }, + { "workingset_nodereclaim", WORKINGSET_NODERECLAIM }, +}; + +/* Translate stat items to the correct unit for memory.stat output */ +static int memcg_page_state_unit(int item) +{ + switch (item) { + case MEMCG_PERCPU_B: + case MEMCG_ZSWAP_B: + case NR_SLAB_RECLAIMABLE_B: + case NR_SLAB_UNRECLAIMABLE_B: + case WORKINGSET_REFAULT_ANON: + case WORKINGSET_REFAULT_FILE: + case WORKINGSET_ACTIVATE_ANON: + case WORKINGSET_ACTIVATE_FILE: + case WORKINGSET_RESTORE_ANON: + case WORKINGSET_RESTORE_FILE: + case WORKINGSET_NODERECLAIM: + return 1; + case NR_KERNEL_STACK_KB: + return SZ_1K; + default: + return PAGE_SIZE; + } +} + +static inline unsigned long memcg_page_state_output(struct mem_cgroup *memcg, + int item) +{ + return memcg_page_state(memcg, item) * memcg_page_state_unit(item); +} + +static void memory_stat_format(struct mem_cgroup *memcg, char *buf, int bufsize) { struct seq_buf s; int i; - seq_buf_init(&s, kmalloc(PAGE_SIZE, GFP_KERNEL), PAGE_SIZE); - if (!s.buffer) - return NULL; + seq_buf_init(&s, buf, bufsize); /* * Provide statistics on the state of the memory subsystem as @@ -1373,101 +1556,41 @@ static char *memory_stat_format(struct mem_cgroup *memcg) * * Current memory state: */ + mem_cgroup_flush_stats(); - seq_buf_printf(&s, "anon %llu\n", - (u64)memcg_page_state(memcg, MEMCG_RSS) * - PAGE_SIZE); - seq_buf_printf(&s, "file %llu\n", - (u64)memcg_page_state(memcg, MEMCG_CACHE) * - PAGE_SIZE); - seq_buf_printf(&s, "kernel_stack %llu\n", - (u64)memcg_page_state(memcg, MEMCG_KERNEL_STACK_KB) * - 1024); - seq_buf_printf(&s, "slab %llu\n", - (u64)(memcg_page_state(memcg, NR_SLAB_RECLAIMABLE) + - memcg_page_state(memcg, NR_SLAB_UNRECLAIMABLE)) * - PAGE_SIZE); - seq_buf_printf(&s, "sock %llu\n", - (u64)memcg_page_state(memcg, MEMCG_SOCK) * - PAGE_SIZE); - - seq_buf_printf(&s, "shmem %llu\n", - (u64)memcg_page_state(memcg, NR_SHMEM) * - PAGE_SIZE); - seq_buf_printf(&s, "file_mapped %llu\n", - (u64)memcg_page_state(memcg, NR_FILE_MAPPED) * - PAGE_SIZE); - seq_buf_printf(&s, "file_dirty %llu\n", - (u64)memcg_page_state(memcg, NR_FILE_DIRTY) * - PAGE_SIZE); - seq_buf_printf(&s, "file_writeback %llu\n", - (u64)memcg_page_state(memcg, NR_WRITEBACK) * - PAGE_SIZE); - - /* - * TODO: We should eventually replace our own MEMCG_RSS_HUGE counter - * with the NR_ANON_THP vm counter, but right now it's a pain in the - * arse because it requires migrating the work out of rmap to a place - * where the page->mem_cgroup is set up and stable. - */ - seq_buf_printf(&s, "anon_thp %llu\n", - (u64)memcg_page_state(memcg, MEMCG_RSS_HUGE) * - PAGE_SIZE); + for (i = 0; i < ARRAY_SIZE(memory_stats); i++) { + u64 size; - for (i = 0; i < NR_LRU_LISTS; i++) - seq_buf_printf(&s, "%s %llu\n", lru_list_name(i), - (u64)memcg_page_state(memcg, NR_LRU_BASE + i) * - PAGE_SIZE); + size = memcg_page_state_output(memcg, memory_stats[i].idx); + seq_buf_printf(&s, "%s %llu\n", memory_stats[i].name, size); - seq_buf_printf(&s, "slab_reclaimable %llu\n", - (u64)memcg_page_state(memcg, NR_SLAB_RECLAIMABLE) * - PAGE_SIZE); - seq_buf_printf(&s, "slab_unreclaimable %llu\n", - (u64)memcg_page_state(memcg, NR_SLAB_UNRECLAIMABLE) * - PAGE_SIZE); + if (unlikely(memory_stats[i].idx == NR_SLAB_UNRECLAIMABLE_B)) { + size += memcg_page_state_output(memcg, + NR_SLAB_RECLAIMABLE_B); + seq_buf_printf(&s, "slab %llu\n", size); + } + } /* Accumulated memory events */ - - seq_buf_printf(&s, "%s %lu\n", vm_event_name(PGFAULT), - memcg_events(memcg, PGFAULT)); - seq_buf_printf(&s, "%s %lu\n", vm_event_name(PGMAJFAULT), - memcg_events(memcg, PGMAJFAULT)); - - seq_buf_printf(&s, "workingset_refault %lu\n", - memcg_page_state(memcg, WORKINGSET_REFAULT)); - seq_buf_printf(&s, "workingset_activate %lu\n", - memcg_page_state(memcg, WORKINGSET_ACTIVATE)); - seq_buf_printf(&s, "workingset_nodereclaim %lu\n", - memcg_page_state(memcg, WORKINGSET_NODERECLAIM)); - - seq_buf_printf(&s, "%s %lu\n", vm_event_name(PGREFILL), - memcg_events(memcg, PGREFILL)); seq_buf_printf(&s, "pgscan %lu\n", memcg_events(memcg, PGSCAN_KSWAPD) + memcg_events(memcg, PGSCAN_DIRECT)); seq_buf_printf(&s, "pgsteal %lu\n", memcg_events(memcg, PGSTEAL_KSWAPD) + memcg_events(memcg, PGSTEAL_DIRECT)); - seq_buf_printf(&s, "%s %lu\n", vm_event_name(PGACTIVATE), - memcg_events(memcg, PGACTIVATE)); - seq_buf_printf(&s, "%s %lu\n", vm_event_name(PGDEACTIVATE), - memcg_events(memcg, PGDEACTIVATE)); - seq_buf_printf(&s, "%s %lu\n", vm_event_name(PGLAZYFREE), - memcg_events(memcg, PGLAZYFREE)); - seq_buf_printf(&s, "%s %lu\n", vm_event_name(PGLAZYFREED), - memcg_events(memcg, PGLAZYFREED)); -#ifdef CONFIG_TRANSPARENT_HUGEPAGE - seq_buf_printf(&s, "%s %lu\n", vm_event_name(THP_FAULT_ALLOC), - memcg_events(memcg, THP_FAULT_ALLOC)); - seq_buf_printf(&s, "%s %lu\n", vm_event_name(THP_COLLAPSE_ALLOC), - memcg_events(memcg, THP_COLLAPSE_ALLOC)); -#endif /* CONFIG_TRANSPARENT_HUGEPAGE */ + for (i = 0; i < ARRAY_SIZE(memcg_vm_event_stat); i++) { + if (memcg_vm_event_stat[i] == PGPGIN || + memcg_vm_event_stat[i] == PGPGOUT) + continue; + + seq_buf_printf(&s, "%s %lu\n", + vm_event_name(memcg_vm_event_stat[i]), + memcg_events(memcg, memcg_vm_event_stat[i])); + } /* The above should easily fit into one page */ WARN_ON_ONCE(seq_buf_has_overflowed(&s)); - - return s.buffer; } #define K(x) ((x) << (PAGE_SHIFT-10)) @@ -1503,15 +1626,18 @@ void mem_cgroup_print_oom_context(struct mem_cgroup *memcg, struct task_struct * */ void mem_cgroup_print_oom_meminfo(struct mem_cgroup *memcg) { - char *buf; + /* Use static buffer, for the caller is holding oom_lock. */ + static char buf[PAGE_SIZE]; + + lockdep_assert_held(&oom_lock); pr_info("memory: usage %llukB, limit %llukB, failcnt %lu\n", K((u64)page_counter_read(&memcg->memory)), - K((u64)memcg->memory.max), memcg->memory.failcnt); + K((u64)READ_ONCE(memcg->memory.max)), memcg->memory.failcnt); if (cgroup_subsys_on_dfl(memory_cgrp_subsys)) pr_info("swap: usage %llukB, limit %llukB, failcnt %lu\n", K((u64)page_counter_read(&memcg->swap)), - K((u64)memcg->swap.max), memcg->swap.failcnt); + K((u64)READ_ONCE(memcg->swap.max)), memcg->swap.failcnt); else { pr_info("memory+swap: usage %llukB, limit %llukB, failcnt %lu\n", K((u64)page_counter_read(&memcg->memsw)), @@ -1524,11 +1650,8 @@ void mem_cgroup_print_oom_meminfo(struct mem_cgroup *memcg) pr_info("Memory cgroup stats for "); pr_cont_cgroup_path(memcg->css.cgroup); pr_cont(":"); - buf = memory_stat_format(memcg); - if (!buf) - return; + memory_stat_format(memcg, buf, sizeof(buf)); pr_info("%s", buf); - kfree(buf); } /* @@ -1536,17 +1659,19 @@ void mem_cgroup_print_oom_meminfo(struct mem_cgroup *memcg) */ unsigned long mem_cgroup_get_max(struct mem_cgroup *memcg) { - unsigned long max; + unsigned long max = READ_ONCE(memcg->memory.max); - max = memcg->memory.max; - if (mem_cgroup_swappiness(memcg)) { - unsigned long memsw_max; - unsigned long swap_max; + if (do_memsw_account()) { + if (mem_cgroup_swappiness(memcg)) { + /* Calculate swap excess capacity from memsw limit */ + unsigned long swap = READ_ONCE(memcg->memsw.max) - max; - memsw_max = memcg->memsw.max; - swap_max = memcg->swap.max; - swap_max = min(swap_max, (unsigned long)total_swap_pages); - max = min(max + swap_max, memsw_max); + max += min(swap, (unsigned long)total_swap_pages); + } + } else { + if (mem_cgroup_swappiness(memcg)) + max += min(READ_ONCE(memcg->swap.max), + (unsigned long)total_swap_pages); } return max; } @@ -1566,15 +1691,21 @@ static bool mem_cgroup_out_of_memory(struct mem_cgroup *memcg, gfp_t gfp_mask, .gfp_mask = gfp_mask, .order = order, }; - bool ret; + bool ret = true; if (mutex_lock_killable(&oom_lock)) return true; + + if (mem_cgroup_margin(memcg) >= (1 << order)) + goto unlock; + /* * A few threads which were not waiting at mutex_lock_killable() can * fail to bail out. Therefore, check again after holding oom_lock. */ - ret = should_force_charge() || out_of_memory(&oc); + ret = task_is_dying() || out_of_memory(&oc); + +unlock: mutex_unlock(&oom_lock); return ret; } @@ -1706,8 +1837,8 @@ static void mem_cgroup_unmark_under_oom(struct mem_cgroup *memcg) struct mem_cgroup *iter; /* - * When a new child is created while the hierarchy is under oom, - * mem_cgroup_oom_lock() may not be called. Watch for underflow. + * Be careful about under_oom underflows because a child memcg + * could have been added after mem_cgroup_mark_under_oom. */ spin_lock(&memcg_oom_lock); for_each_mem_cgroup_tree(iter, memcg) @@ -1753,20 +1884,16 @@ static void memcg_oom_recover(struct mem_cgroup *memcg) __wake_up(&memcg_oom_waitq, TASK_NORMAL, 0, memcg); } -enum oom_status { - OOM_SUCCESS, - OOM_FAILED, - OOM_ASYNC, - OOM_SKIPPED -}; - -static enum oom_status mem_cgroup_oom(struct mem_cgroup *memcg, gfp_t mask, int order) +/* + * Returns true if successfully killed one or more processes. Though in some + * corner cases it can return true even without killing any process. + */ +static bool mem_cgroup_oom(struct mem_cgroup *memcg, gfp_t mask, int order) { - enum oom_status ret; - bool locked; + bool locked, ret; if (order > PAGE_ALLOC_COSTLY_ORDER) - return OOM_SKIPPED; + return false; memcg_memory_event(memcg, MEMCG_OOM); @@ -1789,14 +1916,13 @@ static enum oom_status mem_cgroup_oom(struct mem_cgroup *memcg, gfp_t mask, int * victim and then we have to bail out from the charge path. */ if (memcg->oom_kill_disable) { - if (!current->in_user_fault) - return OOM_SKIPPED; - css_get(&memcg->css); - current->memcg_in_oom = memcg; - current->memcg_oom_gfp_mask = mask; - current->memcg_oom_order = order; - - return OOM_ASYNC; + if (current->in_user_fault) { + css_get(&memcg->css); + current->memcg_in_oom = memcg; + current->memcg_oom_gfp_mask = mask; + current->memcg_oom_order = order; + } + return false; } mem_cgroup_mark_under_oom(memcg); @@ -1807,10 +1933,7 @@ static enum oom_status mem_cgroup_oom(struct mem_cgroup *memcg, gfp_t mask, int mem_cgroup_oom_notify(memcg); mem_cgroup_unmark_under_oom(memcg); - if (mem_cgroup_out_of_memory(memcg, mask, order)) - ret = OOM_SUCCESS; - else - ret = OOM_FAILED; + ret = mem_cgroup_out_of_memory(memcg, mask, order); if (locked) mem_cgroup_oom_unlock(memcg); @@ -1878,7 +2001,7 @@ bool mem_cgroup_oom_synchronize(bool handle) /* * There is no guarantee that an OOM-lock contender * sees the wakeups triggered by the OOM kill - * uncharges. Wake any sleepers explicitely. + * uncharges. Wake any sleepers explicitly. */ memcg_oom_recover(memcg); } @@ -1917,6 +2040,14 @@ struct mem_cgroup *mem_cgroup_get_oom_group(struct task_struct *victim, goto out; /* + * If the victim task has been asynchronously moved to a different + * memory cgroup, we might end up killing tasks outside oom_domain. + * In this case it's better to ignore memory.group.oom. + */ + if (unlikely(!mem_cgroup_is_descendant(memcg, oom_domain))) + goto out; + + /* * Traverse the memory cgroup hierarchy from the victim task's * cgroup up to the OOMing cgroup (or root) to find the * highest-level memory cgroup with oom.group set. @@ -1945,17 +2076,16 @@ void mem_cgroup_print_oom_group(struct mem_cgroup *memcg) } /** - * lock_page_memcg - lock a page->mem_cgroup binding - * @page: the page + * folio_memcg_lock - Bind a folio to its memcg. + * @folio: The folio. * - * This function protects unlocked LRU pages from being moved to + * This function prevents unlocked LRU folios from being moved to * another cgroup. * - * It ensures lifetime of the returned memcg. Caller is responsible - * for the lifetime of the page; __unlock_page_memcg() is available - * when @page might get freed inside the locked section. + * It ensures lifetime of the bound memcg. The caller is responsible + * for the lifetime of the folio. */ -struct mem_cgroup *lock_page_memcg(struct page *page) +void folio_memcg_lock(struct folio *folio) { struct mem_cgroup *memcg; unsigned long flags; @@ -1964,50 +2094,47 @@ struct mem_cgroup *lock_page_memcg(struct page *page) * The RCU lock is held throughout the transaction. The fast * path can get away without acquiring the memcg->move_lock * because page moving starts with an RCU grace period. - * - * The RCU lock also protects the memcg from being freed when - * the page state that is going to change is the only thing - * preventing the page itself from being freed. E.g. writeback - * doesn't hold a page reference and relies on PG_writeback to - * keep off truncation, migration and so forth. */ rcu_read_lock(); if (mem_cgroup_disabled()) - return NULL; + return; again: - memcg = page->mem_cgroup; + memcg = folio_memcg(folio); if (unlikely(!memcg)) - return NULL; + return; + +#ifdef CONFIG_PROVE_LOCKING + local_irq_save(flags); + might_lock(&memcg->move_lock); + local_irq_restore(flags); +#endif if (atomic_read(&memcg->moving_account) <= 0) - return memcg; + return; spin_lock_irqsave(&memcg->move_lock, flags); - if (memcg != page->mem_cgroup) { + if (memcg != folio_memcg(folio)) { spin_unlock_irqrestore(&memcg->move_lock, flags); goto again; } /* - * When charge migration first begins, we can have locked and - * unlocked page stat updates happening concurrently. Track - * the task who has the lock for unlock_page_memcg(). + * When charge migration first begins, we can have multiple + * critical sections holding the fast-path RCU lock and one + * holding the slowpath move_lock. Track the task who has the + * move_lock for unlock_page_memcg(). */ memcg->move_lock_task = current; memcg->move_lock_flags = flags; +} - return memcg; +void lock_page_memcg(struct page *page) +{ + folio_memcg_lock(page_folio(page)); } -EXPORT_SYMBOL(lock_page_memcg); -/** - * __unlock_page_memcg - unlock and unpin a memcg - * @memcg: the memcg - * - * Unlock and unpin a memcg returned by lock_page_memcg(). - */ -void __unlock_page_memcg(struct mem_cgroup *memcg) +static void __folio_memcg_unlock(struct mem_cgroup *memcg) { if (memcg && memcg->move_lock_task == current) { unsigned long flags = memcg->move_lock_flags; @@ -2022,25 +2149,66 @@ void __unlock_page_memcg(struct mem_cgroup *memcg) } /** - * unlock_page_memcg - unlock a page->mem_cgroup binding - * @page: the page + * folio_memcg_unlock - Release the binding between a folio and its memcg. + * @folio: The folio. + * + * This releases the binding created by folio_memcg_lock(). This does + * not change the accounting of this folio to its memcg, but it does + * permit others to change it. */ +void folio_memcg_unlock(struct folio *folio) +{ + __folio_memcg_unlock(folio_memcg(folio)); +} + void unlock_page_memcg(struct page *page) { - __unlock_page_memcg(page->mem_cgroup); + folio_memcg_unlock(page_folio(page)); } -EXPORT_SYMBOL(unlock_page_memcg); struct memcg_stock_pcp { + local_lock_t stock_lock; struct mem_cgroup *cached; /* this never be root cgroup */ unsigned int nr_pages; + +#ifdef CONFIG_MEMCG_KMEM + struct obj_cgroup *cached_objcg; + struct pglist_data *cached_pgdat; + unsigned int nr_bytes; + int nr_slab_reclaimable_b; + int nr_slab_unreclaimable_b; +#endif + struct work_struct work; unsigned long flags; #define FLUSHING_CACHED_CHARGE 0 }; -static DEFINE_PER_CPU(struct memcg_stock_pcp, memcg_stock); +static DEFINE_PER_CPU(struct memcg_stock_pcp, memcg_stock) = { + .stock_lock = INIT_LOCAL_LOCK(stock_lock), +}; static DEFINE_MUTEX(percpu_charge_mutex); +#ifdef CONFIG_MEMCG_KMEM +static struct obj_cgroup *drain_obj_stock(struct memcg_stock_pcp *stock); +static bool obj_stock_flush_required(struct memcg_stock_pcp *stock, + struct mem_cgroup *root_memcg); +static void memcg_account_kmem(struct mem_cgroup *memcg, int nr_pages); + +#else +static inline struct obj_cgroup *drain_obj_stock(struct memcg_stock_pcp *stock) +{ + return NULL; +} +static bool obj_stock_flush_required(struct memcg_stock_pcp *stock, + struct mem_cgroup *root_memcg) +{ + return false; +} +static void memcg_account_kmem(struct mem_cgroup *memcg, int nr_pages) +{ +} +#endif + /** * consume_stock: Try to consume stocked charge on this cpu. * @memcg: memcg to consume from. @@ -2061,7 +2229,7 @@ static bool consume_stock(struct mem_cgroup *memcg, unsigned int nr_pages) if (nr_pages > MEMCG_CHARGE_BATCH) return ret; - local_irq_save(flags); + local_lock_irqsave(&memcg_stock.stock_lock, flags); stock = this_cpu_ptr(&memcg_stock); if (memcg == stock->cached && stock->nr_pages >= nr_pages) { @@ -2069,7 +2237,7 @@ static bool consume_stock(struct mem_cgroup *memcg, unsigned int nr_pages) ret = true; } - local_irq_restore(flags); + local_unlock_irqrestore(&memcg_stock.stock_lock, flags); return ret; } @@ -2081,56 +2249,70 @@ static void drain_stock(struct memcg_stock_pcp *stock) { struct mem_cgroup *old = stock->cached; + if (!old) + return; + if (stock->nr_pages) { page_counter_uncharge(&old->memory, stock->nr_pages); if (do_memsw_account()) page_counter_uncharge(&old->memsw, stock->nr_pages); - css_put_many(&old->css, stock->nr_pages); stock->nr_pages = 0; } + + css_put(&old->css); stock->cached = NULL; } static void drain_local_stock(struct work_struct *dummy) { struct memcg_stock_pcp *stock; + struct obj_cgroup *old = NULL; unsigned long flags; /* - * The only protection from memory hotplug vs. drain_stock races is - * that we always operate on local CPU stock here with IRQ disabled + * The only protection from cpu hotplug (memcg_hotplug_cpu_dead) vs. + * drain_stock races is that we always operate on local CPU stock + * here with IRQ disabled */ - local_irq_save(flags); + local_lock_irqsave(&memcg_stock.stock_lock, flags); stock = this_cpu_ptr(&memcg_stock); + old = drain_obj_stock(stock); drain_stock(stock); clear_bit(FLUSHING_CACHED_CHARGE, &stock->flags); - local_irq_restore(flags); + local_unlock_irqrestore(&memcg_stock.stock_lock, flags); + if (old) + obj_cgroup_put(old); } /* * Cache charges(val) to local per_cpu area. * This will be consumed by consume_stock() function, later. */ -static void refill_stock(struct mem_cgroup *memcg, unsigned int nr_pages) +static void __refill_stock(struct mem_cgroup *memcg, unsigned int nr_pages) { struct memcg_stock_pcp *stock; - unsigned long flags; - - local_irq_save(flags); stock = this_cpu_ptr(&memcg_stock); if (stock->cached != memcg) { /* reset if necessary */ drain_stock(stock); + css_get(&memcg->css); stock->cached = memcg; } stock->nr_pages += nr_pages; if (stock->nr_pages > MEMCG_CHARGE_BATCH) drain_stock(stock); +} - local_irq_restore(flags); +static void refill_stock(struct mem_cgroup *memcg, unsigned int nr_pages) +{ + unsigned long flags; + + local_lock_irqsave(&memcg_stock.stock_lock, flags); + __refill_stock(memcg, nr_pages); + local_unlock_irqrestore(&memcg_stock.stock_lock, flags); } /* @@ -2150,7 +2332,8 @@ static void drain_all_stock(struct mem_cgroup *root_memcg) * as well as workers from this path always operate on the local * per-cpu data. CPU up doesn't touch memcg_stock at all. */ - curcpu = get_cpu(); + migrate_disable(); + curcpu = smp_processor_id(); for_each_online_cpu(cpu) { struct memcg_stock_pcp *stock = &per_cpu(memcg_stock, cpu); struct mem_cgroup *memcg; @@ -2161,6 +2344,8 @@ static void drain_all_stock(struct mem_cgroup *root_memcg) if (memcg && stock->nr_pages && mem_cgroup_is_descendant(memcg, root_memcg)) flush = true; + else if (obj_stock_flush_required(stock, root_memcg)) + flush = true; rcu_read_unlock(); if (flush && @@ -2171,68 +2356,44 @@ static void drain_all_stock(struct mem_cgroup *root_memcg) schedule_work_on(cpu, &stock->work); } } - put_cpu(); + migrate_enable(); mutex_unlock(&percpu_charge_mutex); } static int memcg_hotplug_cpu_dead(unsigned int cpu) { struct memcg_stock_pcp *stock; - struct mem_cgroup *memcg, *mi; stock = &per_cpu(memcg_stock, cpu); drain_stock(stock); - for_each_mem_cgroup(memcg) { - int i; - - for (i = 0; i < MEMCG_NR_STAT; i++) { - int nid; - long x; - - x = this_cpu_xchg(memcg->vmstats_percpu->stat[i], 0); - if (x) - for (mi = memcg; mi; mi = parent_mem_cgroup(mi)) - atomic_long_add(x, &memcg->vmstats[i]); - - if (i >= NR_VM_NODE_STAT_ITEMS) - continue; - - for_each_node(nid) { - struct mem_cgroup_per_node *pn; - - pn = mem_cgroup_nodeinfo(memcg, nid); - x = this_cpu_xchg(pn->lruvec_stat_cpu->count[i], 0); - if (x) - do { - atomic_long_add(x, &pn->lruvec_stat[i]); - } while ((pn = parent_nodeinfo(pn, nid))); - } - } - - for (i = 0; i < NR_VM_EVENT_ITEMS; i++) { - long x; - - x = this_cpu_xchg(memcg->vmstats_percpu->events[i], 0); - if (x) - for (mi = memcg; mi; mi = parent_mem_cgroup(mi)) - atomic_long_add(x, &memcg->vmevents[i]); - } - } - return 0; } -static void reclaim_high(struct mem_cgroup *memcg, - unsigned int nr_pages, - gfp_t gfp_mask) +static unsigned long reclaim_high(struct mem_cgroup *memcg, + unsigned int nr_pages, + gfp_t gfp_mask) { + unsigned long nr_reclaimed = 0; + do { - if (page_counter_read(&memcg->memory) <= memcg->high) + unsigned long pflags; + + if (page_counter_read(&memcg->memory) <= + READ_ONCE(memcg->memory.high)) continue; + memcg_memory_event(memcg, MEMCG_HIGH); - try_to_free_mem_cgroup_pages(memcg, nr_pages, gfp_mask, true); - } while ((memcg = parent_mem_cgroup(memcg))); + + psi_memstall_enter(&pflags); + nr_reclaimed += try_to_free_mem_cgroup_pages(memcg, nr_pages, + gfp_mask, + MEMCG_RECLAIM_MAY_SWAP); + psi_memstall_leave(&pflags); + } while ((memcg = parent_mem_cgroup(memcg)) && + !mem_cgroup_is_root(memcg)); + + return nr_reclaimed; } static void high_work_func(struct work_struct *work) @@ -2257,7 +2418,7 @@ static void high_work_func(struct work_struct *work) * * - MEMCG_DELAY_PRECISION_SHIFT: Extra precision bits while translating the * overage ratio to a delay. - * - MEMCG_DELAY_SCALING_SHIFT: The number of bits to scale down down the + * - MEMCG_DELAY_SCALING_SHIFT: The number of bits to scale down the * proposed penalty in order to reduce to a reasonable number of jiffies, and * to produce a reasonable delay curve. * @@ -2296,38 +2457,64 @@ static void high_work_func(struct work_struct *work) #define MEMCG_DELAY_PRECISION_SHIFT 20 #define MEMCG_DELAY_SCALING_SHIFT 14 -/* - * Get the number of jiffies that we should penalise a mischievous cgroup which - * is exceeding its memory.high by checking both it and its ancestors. - */ -static unsigned long calculate_high_delay(struct mem_cgroup *memcg, - unsigned int nr_pages) +static u64 calculate_overage(unsigned long usage, unsigned long high) { - unsigned long penalty_jiffies; - u64 max_overage = 0; + u64 overage; - do { - unsigned long usage, high; - u64 overage; + if (usage <= high) + return 0; - usage = page_counter_read(&memcg->memory); - high = READ_ONCE(memcg->high); + /* + * Prevent division by 0 in overage calculation by acting as if + * it was a threshold of 1 page + */ + high = max(high, 1UL); - /* - * Prevent division by 0 in overage calculation by acting as if - * it was a threshold of 1 page - */ - high = max(high, 1UL); + overage = usage - high; + overage <<= MEMCG_DELAY_PRECISION_SHIFT; + return div64_u64(overage, high); +} + +static u64 mem_find_max_overage(struct mem_cgroup *memcg) +{ + u64 overage, max_overage = 0; + + do { + overage = calculate_overage(page_counter_read(&memcg->memory), + READ_ONCE(memcg->memory.high)); + max_overage = max(overage, max_overage); + } while ((memcg = parent_mem_cgroup(memcg)) && + !mem_cgroup_is_root(memcg)); - overage = usage - high; - overage <<= MEMCG_DELAY_PRECISION_SHIFT; - overage = div64_u64(overage, high); + return max_overage; +} + +static u64 swap_find_max_overage(struct mem_cgroup *memcg) +{ + u64 overage, max_overage = 0; - if (overage > max_overage) - max_overage = overage; + do { + overage = calculate_overage(page_counter_read(&memcg->swap), + READ_ONCE(memcg->swap.high)); + if (overage) + memcg_memory_event(memcg, MEMCG_SWAP_HIGH); + max_overage = max(overage, max_overage); } while ((memcg = parent_mem_cgroup(memcg)) && !mem_cgroup_is_root(memcg)); + return max_overage; +} + +/* + * Get the number of jiffies that we should penalise a mischievous cgroup which + * is exceeding its memory.high by checking both it and its ancestors. + */ +static unsigned long calculate_high_delay(struct mem_cgroup *memcg, + unsigned int nr_pages, + u64 max_overage) +{ + unsigned long penalty_jiffies; + if (!max_overage) return 0; @@ -2351,14 +2538,7 @@ static unsigned long calculate_high_delay(struct mem_cgroup *memcg, * MEMCG_CHARGE_BATCH pages is nominal, so work out how much smaller or * larger the current charge patch is than that. */ - penalty_jiffies = penalty_jiffies * nr_pages / MEMCG_CHARGE_BATCH; - - /* - * Clamp the max delay per usermode return so as to still keep the - * application moving forwards and also permit diagnostics, albeit - * extremely slowly. - */ - return min(penalty_jiffies, MEMCG_MAX_HIGH_DELAY_JIFFIES); + return penalty_jiffies * nr_pages / MEMCG_CHARGE_BATCH; } /* @@ -2369,21 +2549,48 @@ void mem_cgroup_handle_over_high(void) { unsigned long penalty_jiffies; unsigned long pflags; + unsigned long nr_reclaimed; unsigned int nr_pages = current->memcg_nr_pages_over_high; + int nr_retries = MAX_RECLAIM_RETRIES; struct mem_cgroup *memcg; + bool in_retry = false; if (likely(!nr_pages)) return; memcg = get_mem_cgroup_from_mm(current->mm); - reclaim_high(memcg, nr_pages, GFP_KERNEL); current->memcg_nr_pages_over_high = 0; +retry_reclaim: + /* + * The allocating task should reclaim at least the batch size, but for + * subsequent retries we only want to do what's necessary to prevent oom + * or breaching resource isolation. + * + * This is distinct from memory.max or page allocator behaviour because + * memory.high is currently batched, whereas memory.max and the page + * allocator run every time an allocation is made. + */ + nr_reclaimed = reclaim_high(memcg, + in_retry ? SWAP_CLUSTER_MAX : nr_pages, + GFP_KERNEL); + /* * memory.high is breached and reclaim is unable to keep up. Throttle * allocators proactively to slow down excessive growth. */ - penalty_jiffies = calculate_high_delay(memcg, nr_pages); + penalty_jiffies = calculate_high_delay(memcg, nr_pages, + mem_find_max_overage(memcg)); + + penalty_jiffies += calculate_high_delay(memcg, nr_pages, + swap_find_max_overage(memcg)); + + /* + * Clamp the max delay per usermode return so as to still keep the + * application moving forwards and also permit diagnostics, albeit + * extremely slowly. + */ + penalty_jiffies = min(penalty_jiffies, MEMCG_MAX_HIGH_DELAY_JIFFIES); /* * Don't sleep if the amount of jiffies this memcg owes us is so low @@ -2395,6 +2602,16 @@ void mem_cgroup_handle_over_high(void) goto out; /* + * If reclaim is making forward progress but we're still over + * memory.high, we want to encourage that rather than doing allocator + * throttling. + */ + if (nr_reclaimed || nr_retries--) { + in_retry = true; + goto retry_reclaim; + } + + /* * If we exit early, we're guaranteed to die (since * schedule_timeout_killable sets TASK_KILLABLE). This means we don't * need to account for any ill-begotten jiffies to pay them off later. @@ -2407,20 +2624,20 @@ out: css_put(&memcg->css); } -static int try_charge(struct mem_cgroup *memcg, gfp_t gfp_mask, - unsigned int nr_pages) +static int try_charge_memcg(struct mem_cgroup *memcg, gfp_t gfp_mask, + unsigned int nr_pages) { unsigned int batch = max(MEMCG_CHARGE_BATCH, nr_pages); - int nr_retries = MEM_CGROUP_RECLAIM_RETRIES; + int nr_retries = MAX_RECLAIM_RETRIES; struct mem_cgroup *mem_over_limit; struct page_counter *counter; unsigned long nr_reclaimed; - bool may_swap = true; + bool passed_oom = false; + unsigned int reclaim_options = MEMCG_RECLAIM_MAY_SWAP; bool drained = false; - enum oom_status oom_status; + bool raised_max_event = false; + unsigned long pflags; - if (mem_cgroup_is_root(memcg)) - return 0; retry: if (consume_stock(memcg, nr_pages)) return 0; @@ -2434,7 +2651,7 @@ retry: mem_over_limit = mem_cgroup_from_counter(counter, memory); } else { mem_over_limit = mem_cgroup_from_counter(counter, memsw); - may_swap = false; + reclaim_options &= ~MEMCG_RECLAIM_MAY_SWAP; } if (batch > nr_pages) { @@ -2443,24 +2660,6 @@ retry: } /* - * Memcg doesn't have a dedicated reserve for atomic - * allocations. But like the global atomic pool, we need to - * put the burden of reclaim on regular allocation requests - * and let these go through as privileged allocations. - */ - if (gfp_mask & __GFP_ATOMIC) - goto force; - - /* - * Unlike in global OOM situations, memcg is not in a physical - * memory shortage. Allow dying and OOM-killed tasks to - * bypass the last charges so that they can exit quickly and - * free their memory. - */ - if (unlikely(should_force_charge())) - goto force; - - /* * Prevent unbounded recursion when reclaim operations need to * allocate memory. This might exceed the limits temporarily, * but we prefer facilitating memory reclaim and getting back @@ -2476,9 +2675,12 @@ retry: goto nomem; memcg_memory_event(mem_over_limit, MEMCG_MAX); + raised_max_event = true; + psi_memstall_enter(&pflags); nr_reclaimed = try_to_free_mem_cgroup_pages(mem_over_limit, nr_pages, - gfp_mask, may_swap); + gfp_mask, reclaim_options); + psi_memstall_leave(&pflags); if (mem_cgroup_margin(mem_over_limit) >= nr_pages) goto retry; @@ -2515,33 +2717,39 @@ retry: if (gfp_mask & __GFP_RETRY_MAYFAIL) goto nomem; - if (gfp_mask & __GFP_NOFAIL) - goto force; - - if (fatal_signal_pending(current)) - goto force; + /* Avoid endless loop for tasks bypassed by the oom killer */ + if (passed_oom && task_is_dying()) + goto nomem; /* * keep retrying as long as the memcg oom killer is able to make * a forward progress or bypass the charge if the oom killer * couldn't make any progress. */ - oom_status = mem_cgroup_oom(mem_over_limit, gfp_mask, - get_order(nr_pages * PAGE_SIZE)); - switch (oom_status) { - case OOM_SUCCESS: - nr_retries = MEM_CGROUP_RECLAIM_RETRIES; + if (mem_cgroup_oom(mem_over_limit, gfp_mask, + get_order(nr_pages * PAGE_SIZE))) { + passed_oom = true; + nr_retries = MAX_RECLAIM_RETRIES; goto retry; - case OOM_FAILED: - goto force; - default: - goto nomem; } nomem: - if (!(gfp_mask & __GFP_NOFAIL)) + /* + * Memcg doesn't have a dedicated reserve for atomic + * allocations. But like the global atomic pool, we need to + * put the burden of reclaim on regular allocation requests + * and let these go through as privileged allocations. + */ + if (!(gfp_mask & (__GFP_NOFAIL | __GFP_HIGH))) return -ENOMEM; force: /* + * If the allocation has to be enforced, don't forget to raise + * a MEMCG_MAX event. + */ + if (!raised_max_event) + memcg_memory_event(mem_over_limit, MEMCG_MAX); + + /* * The allocation either can't fail or will lead to more memory * being freed very soon. Allow memory usage go over the limit * temporarily by force charging it. @@ -2549,12 +2757,10 @@ force: page_counter_charge(&memcg->memory, nr_pages); if (do_memsw_account()) page_counter_charge(&memcg->memsw, nr_pages); - css_get_many(&memcg->css, nr_pages); return 0; done_restock: - css_get_many(&memcg->css, batch); if (batch > nr_pages) refill_stock(memcg, batch - nr_pages); @@ -2568,22 +2774,56 @@ done_restock: * reclaim, the cost of mismatch is negligible. */ do { - if (page_counter_read(&memcg->memory) > memcg->high) { - /* Don't bother a random interrupted task */ - if (in_interrupt()) { + bool mem_high, swap_high; + + mem_high = page_counter_read(&memcg->memory) > + READ_ONCE(memcg->memory.high); + swap_high = page_counter_read(&memcg->swap) > + READ_ONCE(memcg->swap.high); + + /* Don't bother a random interrupted task */ + if (!in_task()) { + if (mem_high) { schedule_work(&memcg->high_work); break; } + continue; + } + + if (mem_high || swap_high) { + /* + * The allocating tasks in this cgroup will need to do + * reclaim or be throttled to prevent further growth + * of the memory or swap footprints. + * + * Target some best-effort fairness between the tasks, + * and distribute reclaim work and delay penalties + * based on how much each task is actually allocating. + */ current->memcg_nr_pages_over_high += batch; set_notify_resume(current); break; } } while ((memcg = parent_mem_cgroup(memcg))); + if (current->memcg_nr_pages_over_high > MEMCG_CHARGE_BATCH && + !(current->flags & PF_MEMALLOC) && + gfpflags_allow_blocking(gfp_mask)) { + mem_cgroup_handle_over_high(); + } return 0; } -static void cancel_charge(struct mem_cgroup *memcg, unsigned int nr_pages) +static inline int try_charge(struct mem_cgroup *memcg, gfp_t gfp_mask, + unsigned int nr_pages) +{ + if (mem_cgroup_is_root(memcg)) + return 0; + + return try_charge_memcg(memcg, gfp_mask, nr_pages); +} + +static inline void cancel_charge(struct mem_cgroup *memcg, unsigned int nr_pages) { if (mem_cgroup_is_root(memcg)) return; @@ -2591,385 +2831,593 @@ static void cancel_charge(struct mem_cgroup *memcg, unsigned int nr_pages) page_counter_uncharge(&memcg->memory, nr_pages); if (do_memsw_account()) page_counter_uncharge(&memcg->memsw, nr_pages); - - css_put_many(&memcg->css, nr_pages); } -static void lock_page_lru(struct page *page, int *isolated) +static void commit_charge(struct folio *folio, struct mem_cgroup *memcg) { - pg_data_t *pgdat = page_pgdat(page); + VM_BUG_ON_FOLIO(folio_memcg(folio), folio); + /* + * Any of the following ensures page's memcg stability: + * + * - the page lock + * - LRU isolation + * - lock_page_memcg() + * - exclusive reference + * - mem_cgroup_trylock_pages() + */ + folio->memcg_data = (unsigned long)memcg; +} - spin_lock_irq(&pgdat->lru_lock); - if (PageLRU(page)) { - struct lruvec *lruvec; +#ifdef CONFIG_MEMCG_KMEM +/* + * The allocated objcg pointers array is not accounted directly. + * Moreover, it should not come from DMA buffer and is not readily + * reclaimable. So those GFP bits should be masked off. + */ +#define OBJCGS_CLEAR_MASK (__GFP_DMA | __GFP_RECLAIMABLE | __GFP_ACCOUNT) - lruvec = mem_cgroup_page_lruvec(page, pgdat); - ClearPageLRU(page); - del_page_from_lru_list(page, lruvec, page_lru(page)); - *isolated = 1; - } else - *isolated = 0; +/* + * mod_objcg_mlstate() may be called with irq enabled, so + * mod_memcg_lruvec_state() should be used. + */ +static inline void mod_objcg_mlstate(struct obj_cgroup *objcg, + struct pglist_data *pgdat, + enum node_stat_item idx, int nr) +{ + struct mem_cgroup *memcg; + struct lruvec *lruvec; + + rcu_read_lock(); + memcg = obj_cgroup_memcg(objcg); + lruvec = mem_cgroup_lruvec(memcg, pgdat); + mod_memcg_lruvec_state(lruvec, idx, nr); + rcu_read_unlock(); } -static void unlock_page_lru(struct page *page, int isolated) +int memcg_alloc_slab_cgroups(struct slab *slab, struct kmem_cache *s, + gfp_t gfp, bool new_slab) { - pg_data_t *pgdat = page_pgdat(page); + unsigned int objects = objs_per_slab(s, slab); + unsigned long memcg_data; + void *vec; - if (isolated) { - struct lruvec *lruvec; + gfp &= ~OBJCGS_CLEAR_MASK; + vec = kcalloc_node(objects, sizeof(struct obj_cgroup *), gfp, + slab_nid(slab)); + if (!vec) + return -ENOMEM; - lruvec = mem_cgroup_page_lruvec(page, pgdat); - VM_BUG_ON_PAGE(PageLRU(page), page); - SetPageLRU(page); - add_page_to_lru_list(page, lruvec, page_lru(page)); + memcg_data = (unsigned long) vec | MEMCG_DATA_OBJCGS; + if (new_slab) { + /* + * If the slab is brand new and nobody can yet access its + * memcg_data, no synchronization is required and memcg_data can + * be simply assigned. + */ + slab->memcg_data = memcg_data; + } else if (cmpxchg(&slab->memcg_data, 0, memcg_data)) { + /* + * If the slab is already in use, somebody can allocate and + * assign obj_cgroups in parallel. In this case the existing + * objcg vector should be reused. + */ + kfree(vec); + return 0; } - spin_unlock_irq(&pgdat->lru_lock); + + kmemleak_not_leak(vec); + return 0; } -static void commit_charge(struct page *page, struct mem_cgroup *memcg, - bool lrucare) +static __always_inline +struct mem_cgroup *mem_cgroup_from_obj_folio(struct folio *folio, void *p) { - int isolated; - - VM_BUG_ON_PAGE(page->mem_cgroup, page); - /* - * In some cases, SwapCache and FUSE(splice_buf->radixtree), the page - * may already be on some other mem_cgroup's LRU. Take care of it. + * Slab objects are accounted individually, not per-page. + * Memcg membership data for each individual object is saved in + * slab->memcg_data. */ - if (lrucare) - lock_page_lru(page, &isolated); + if (folio_test_slab(folio)) { + struct obj_cgroup **objcgs; + struct slab *slab; + unsigned int off; + + slab = folio_slab(folio); + objcgs = slab_objcgs(slab); + if (!objcgs) + return NULL; + + off = obj_to_index(slab->slab_cache, slab, p); + if (objcgs[off]) + return obj_cgroup_memcg(objcgs[off]); + + return NULL; + } /* - * Nobody should be changing or seriously looking at - * page->mem_cgroup at this point: - * - * - the page is uncharged - * - * - the page is off-LRU - * - * - an anonymous fault has exclusive page access, except for - * a locked page table - * - * - a page cache insertion, a swapin fault, or a migration - * have the page locked + * page_memcg_check() is used here, because in theory we can encounter + * a folio where the slab flag has been cleared already, but + * slab->memcg_data has not been freed yet + * page_memcg_check(page) will guarantee that a proper memory + * cgroup pointer or NULL will be returned. */ - page->mem_cgroup = memcg; + return page_memcg_check(folio_page(folio, 0)); +} + +/* + * Returns a pointer to the memory cgroup to which the kernel object is charged. + * + * A passed kernel object can be a slab object, vmalloc object or a generic + * kernel page, so different mechanisms for getting the memory cgroup pointer + * should be used. + * + * In certain cases (e.g. kernel stacks or large kmallocs with SLUB) the caller + * can not know for sure how the kernel object is implemented. + * mem_cgroup_from_obj() can be safely used in such cases. + * + * The caller must ensure the memcg lifetime, e.g. by taking rcu_read_lock(), + * cgroup_mutex, etc. + */ +struct mem_cgroup *mem_cgroup_from_obj(void *p) +{ + struct folio *folio; - if (lrucare) - unlock_page_lru(page, isolated); + if (mem_cgroup_disabled()) + return NULL; + + if (unlikely(is_vmalloc_addr(p))) + folio = page_folio(vmalloc_to_page(p)); + else + folio = virt_to_folio(p); + + return mem_cgroup_from_obj_folio(folio, p); } -#ifdef CONFIG_MEMCG_KMEM -static int memcg_alloc_cache_id(void) +/* + * Returns a pointer to the memory cgroup to which the kernel object is charged. + * Similar to mem_cgroup_from_obj(), but faster and not suitable for objects, + * allocated using vmalloc(). + * + * A passed kernel object must be a slab object or a generic kernel page. + * + * The caller must ensure the memcg lifetime, e.g. by taking rcu_read_lock(), + * cgroup_mutex, etc. + */ +struct mem_cgroup *mem_cgroup_from_slab_obj(void *p) { - int id, size; - int err; + if (mem_cgroup_disabled()) + return NULL; - id = ida_simple_get(&memcg_cache_ida, - 0, MEMCG_CACHES_MAX_SIZE, GFP_KERNEL); - if (id < 0) - return id; + return mem_cgroup_from_obj_folio(virt_to_folio(p), p); +} - if (id < memcg_nr_cache_ids) - return id; +static struct obj_cgroup *__get_obj_cgroup_from_memcg(struct mem_cgroup *memcg) +{ + struct obj_cgroup *objcg = NULL; - /* - * There's no space for the new id in memcg_caches arrays, - * so we have to grow them. - */ - down_write(&memcg_cache_ids_sem); + for (; memcg != root_mem_cgroup; memcg = parent_mem_cgroup(memcg)) { + objcg = rcu_dereference(memcg->objcg); + if (objcg && obj_cgroup_tryget(objcg)) + break; + objcg = NULL; + } + return objcg; +} + +__always_inline struct obj_cgroup *get_obj_cgroup_from_current(void) +{ + struct obj_cgroup *objcg = NULL; + struct mem_cgroup *memcg; + + if (memcg_kmem_bypass()) + return NULL; - size = 2 * (id + 1); - if (size < MEMCG_CACHES_MIN_SIZE) - size = MEMCG_CACHES_MIN_SIZE; - else if (size > MEMCG_CACHES_MAX_SIZE) - size = MEMCG_CACHES_MAX_SIZE; + rcu_read_lock(); + if (unlikely(active_memcg())) + memcg = active_memcg(); + else + memcg = mem_cgroup_from_task(current); + objcg = __get_obj_cgroup_from_memcg(memcg); + rcu_read_unlock(); + return objcg; +} - err = memcg_update_all_caches(size); - if (!err) - err = memcg_update_all_list_lrus(size); - if (!err) - memcg_nr_cache_ids = size; +struct obj_cgroup *get_obj_cgroup_from_page(struct page *page) +{ + struct obj_cgroup *objcg; - up_write(&memcg_cache_ids_sem); + if (!memcg_kmem_enabled() || memcg_kmem_bypass()) + return NULL; - if (err) { - ida_simple_remove(&memcg_cache_ida, id); - return err; + if (PageMemcgKmem(page)) { + objcg = __folio_objcg(page_folio(page)); + obj_cgroup_get(objcg); + } else { + struct mem_cgroup *memcg; + + rcu_read_lock(); + memcg = __folio_memcg(page_folio(page)); + if (memcg) + objcg = __get_obj_cgroup_from_memcg(memcg); + else + objcg = NULL; + rcu_read_unlock(); } - return id; + return objcg; } -static void memcg_free_cache_id(int id) +static void memcg_account_kmem(struct mem_cgroup *memcg, int nr_pages) { - ida_simple_remove(&memcg_cache_ida, id); + mod_memcg_state(memcg, MEMCG_KMEM, nr_pages); + if (!cgroup_subsys_on_dfl(memory_cgrp_subsys)) { + if (nr_pages > 0) + page_counter_charge(&memcg->kmem, nr_pages); + else + page_counter_uncharge(&memcg->kmem, -nr_pages); + } } -struct memcg_kmem_cache_create_work { - struct mem_cgroup *memcg; - struct kmem_cache *cachep; - struct work_struct work; -}; -static void memcg_kmem_cache_create_func(struct work_struct *w) +/* + * obj_cgroup_uncharge_pages: uncharge a number of kernel pages from a objcg + * @objcg: object cgroup to uncharge + * @nr_pages: number of pages to uncharge + */ +static void obj_cgroup_uncharge_pages(struct obj_cgroup *objcg, + unsigned int nr_pages) { - struct memcg_kmem_cache_create_work *cw = - container_of(w, struct memcg_kmem_cache_create_work, work); - struct mem_cgroup *memcg = cw->memcg; - struct kmem_cache *cachep = cw->cachep; + struct mem_cgroup *memcg; - memcg_create_kmem_cache(memcg, cachep); + memcg = get_mem_cgroup_from_objcg(objcg); + + memcg_account_kmem(memcg, -nr_pages); + refill_stock(memcg, nr_pages); css_put(&memcg->css); - kfree(cw); } /* - * Enqueue the creation of a per-memcg kmem_cache. + * obj_cgroup_charge_pages: charge a number of kernel pages to a objcg + * @objcg: object cgroup to charge + * @gfp: reclaim mode + * @nr_pages: number of pages to charge + * + * Returns 0 on success, an error code on failure. */ -static void memcg_schedule_kmem_cache_create(struct mem_cgroup *memcg, - struct kmem_cache *cachep) +static int obj_cgroup_charge_pages(struct obj_cgroup *objcg, gfp_t gfp, + unsigned int nr_pages) { - struct memcg_kmem_cache_create_work *cw; - - if (!css_tryget_online(&memcg->css)) - return; + struct mem_cgroup *memcg; + int ret; - cw = kmalloc(sizeof(*cw), GFP_NOWAIT | __GFP_NOWARN); - if (!cw) - return; + memcg = get_mem_cgroup_from_objcg(objcg); - cw->memcg = memcg; - cw->cachep = cachep; - INIT_WORK(&cw->work, memcg_kmem_cache_create_func); + ret = try_charge_memcg(memcg, gfp, nr_pages); + if (ret) + goto out; - queue_work(memcg_kmem_cache_wq, &cw->work); -} + memcg_account_kmem(memcg, nr_pages); +out: + css_put(&memcg->css); -static inline bool memcg_kmem_bypass(void) -{ - if (in_interrupt() || !current->mm || (current->flags & PF_KTHREAD)) - return true; - return false; + return ret; } /** - * memcg_kmem_get_cache: select the correct per-memcg cache for allocation - * @cachep: the original global kmem cache - * - * Return the kmem_cache we're supposed to use for a slab allocation. - * We try to use the current memcg's version of the cache. - * - * If the cache does not exist yet, if we are the first user of it, we - * create it asynchronously in a workqueue and let the current allocation - * go through with the original cache. + * __memcg_kmem_charge_page: charge a kmem page to the current memory cgroup + * @page: page to charge + * @gfp: reclaim mode + * @order: allocation order * - * This function takes a reference to the cache it returns to assure it - * won't get destroyed while we are working with it. Once the caller is - * done with it, memcg_kmem_put_cache() must be called to release the - * reference. + * Returns 0 on success, an error code on failure. */ -struct kmem_cache *memcg_kmem_get_cache(struct kmem_cache *cachep) +int __memcg_kmem_charge_page(struct page *page, gfp_t gfp, int order) { - struct mem_cgroup *memcg; - struct kmem_cache *memcg_cachep; - struct memcg_cache_array *arr; - int kmemcg_id; - - VM_BUG_ON(!is_root_cache(cachep)); + struct obj_cgroup *objcg; + int ret = 0; - if (memcg_kmem_bypass()) - return cachep; + objcg = get_obj_cgroup_from_current(); + if (objcg) { + ret = obj_cgroup_charge_pages(objcg, gfp, 1 << order); + if (!ret) { + page->memcg_data = (unsigned long)objcg | + MEMCG_DATA_KMEM; + return 0; + } + obj_cgroup_put(objcg); + } + return ret; +} - rcu_read_lock(); +/** + * __memcg_kmem_uncharge_page: uncharge a kmem page + * @page: page to uncharge + * @order: allocation order + */ +void __memcg_kmem_uncharge_page(struct page *page, int order) +{ + struct folio *folio = page_folio(page); + struct obj_cgroup *objcg; + unsigned int nr_pages = 1 << order; - if (unlikely(current->active_memcg)) - memcg = current->active_memcg; - else - memcg = mem_cgroup_from_task(current); + if (!folio_memcg_kmem(folio)) + return; - if (!memcg || memcg == root_mem_cgroup) - goto out_unlock; + objcg = __folio_objcg(folio); + obj_cgroup_uncharge_pages(objcg, nr_pages); + folio->memcg_data = 0; + obj_cgroup_put(objcg); +} - kmemcg_id = READ_ONCE(memcg->kmemcg_id); - if (kmemcg_id < 0) - goto out_unlock; +void mod_objcg_state(struct obj_cgroup *objcg, struct pglist_data *pgdat, + enum node_stat_item idx, int nr) +{ + struct memcg_stock_pcp *stock; + struct obj_cgroup *old = NULL; + unsigned long flags; + int *bytes; - arr = rcu_dereference(cachep->memcg_params.memcg_caches); + local_lock_irqsave(&memcg_stock.stock_lock, flags); + stock = this_cpu_ptr(&memcg_stock); /* - * Make sure we will access the up-to-date value. The code updating - * memcg_caches issues a write barrier to match the data dependency - * barrier inside READ_ONCE() (see memcg_create_kmem_cache()). + * Save vmstat data in stock and skip vmstat array update unless + * accumulating over a page of vmstat data or when pgdat or idx + * changes. */ - memcg_cachep = READ_ONCE(arr->entries[kmemcg_id]); + if (stock->cached_objcg != objcg) { + old = drain_obj_stock(stock); + obj_cgroup_get(objcg); + stock->nr_bytes = atomic_read(&objcg->nr_charged_bytes) + ? atomic_xchg(&objcg->nr_charged_bytes, 0) : 0; + stock->cached_objcg = objcg; + stock->cached_pgdat = pgdat; + } else if (stock->cached_pgdat != pgdat) { + /* Flush the existing cached vmstat data */ + struct pglist_data *oldpg = stock->cached_pgdat; + + if (stock->nr_slab_reclaimable_b) { + mod_objcg_mlstate(objcg, oldpg, NR_SLAB_RECLAIMABLE_B, + stock->nr_slab_reclaimable_b); + stock->nr_slab_reclaimable_b = 0; + } + if (stock->nr_slab_unreclaimable_b) { + mod_objcg_mlstate(objcg, oldpg, NR_SLAB_UNRECLAIMABLE_B, + stock->nr_slab_unreclaimable_b); + stock->nr_slab_unreclaimable_b = 0; + } + stock->cached_pgdat = pgdat; + } + bytes = (idx == NR_SLAB_RECLAIMABLE_B) ? &stock->nr_slab_reclaimable_b + : &stock->nr_slab_unreclaimable_b; /* - * If we are in a safe context (can wait, and not in interrupt - * context), we could be be predictable and return right away. - * This would guarantee that the allocation being performed - * already belongs in the new cache. - * - * However, there are some clashes that can arrive from locking. - * For instance, because we acquire the slab_mutex while doing - * memcg_create_kmem_cache, this means no further allocation - * could happen with the slab_mutex held. So it's better to - * defer everything. - * - * If the memcg is dying or memcg_cache is about to be released, - * don't bother creating new kmem_caches. Because memcg_cachep - * is ZEROed as the fist step of kmem offlining, we don't need - * percpu_ref_tryget_live() here. css_tryget_online() check in - * memcg_schedule_kmem_cache_create() will prevent us from - * creation of a new kmem_cache. + * Even for large object >= PAGE_SIZE, the vmstat data will still be + * cached locally at least once before pushing it out. */ - if (unlikely(!memcg_cachep)) - memcg_schedule_kmem_cache_create(memcg, cachep); - else if (percpu_ref_tryget(&memcg_cachep->memcg_params.refcnt)) - cachep = memcg_cachep; -out_unlock: - rcu_read_unlock(); - return cachep; + if (!*bytes) { + *bytes = nr; + nr = 0; + } else { + *bytes += nr; + if (abs(*bytes) > PAGE_SIZE) { + nr = *bytes; + *bytes = 0; + } else { + nr = 0; + } + } + if (nr) + mod_objcg_mlstate(objcg, pgdat, idx, nr); + + local_unlock_irqrestore(&memcg_stock.stock_lock, flags); + if (old) + obj_cgroup_put(old); } -/** - * memcg_kmem_put_cache: drop reference taken by memcg_kmem_get_cache - * @cachep: the cache returned by memcg_kmem_get_cache - */ -void memcg_kmem_put_cache(struct kmem_cache *cachep) +static bool consume_obj_stock(struct obj_cgroup *objcg, unsigned int nr_bytes) { - if (!is_root_cache(cachep)) - percpu_ref_put(&cachep->memcg_params.refcnt); + struct memcg_stock_pcp *stock; + unsigned long flags; + bool ret = false; + + local_lock_irqsave(&memcg_stock.stock_lock, flags); + + stock = this_cpu_ptr(&memcg_stock); + if (objcg == stock->cached_objcg && stock->nr_bytes >= nr_bytes) { + stock->nr_bytes -= nr_bytes; + ret = true; + } + + local_unlock_irqrestore(&memcg_stock.stock_lock, flags); + + return ret; } -/** - * __memcg_kmem_charge_memcg: charge a kmem page - * @page: page to charge - * @gfp: reclaim mode - * @order: allocation order - * @memcg: memory cgroup to charge - * - * Returns 0 on success, an error code on failure. - */ -int __memcg_kmem_charge_memcg(struct page *page, gfp_t gfp, int order, - struct mem_cgroup *memcg) +static struct obj_cgroup *drain_obj_stock(struct memcg_stock_pcp *stock) { - unsigned int nr_pages = 1 << order; - struct page_counter *counter; - int ret; + struct obj_cgroup *old = stock->cached_objcg; - ret = try_charge(memcg, gfp, nr_pages); - if (ret) - return ret; + if (!old) + return NULL; + + if (stock->nr_bytes) { + unsigned int nr_pages = stock->nr_bytes >> PAGE_SHIFT; + unsigned int nr_bytes = stock->nr_bytes & (PAGE_SIZE - 1); + + if (nr_pages) { + struct mem_cgroup *memcg; + + memcg = get_mem_cgroup_from_objcg(old); + + memcg_account_kmem(memcg, -nr_pages); + __refill_stock(memcg, nr_pages); - if (!cgroup_subsys_on_dfl(memory_cgrp_subsys) && - !page_counter_try_charge(&memcg->kmem, nr_pages, &counter)) { + css_put(&memcg->css); + } /* - * Enforce __GFP_NOFAIL allocation because callers are not - * prepared to see failures and likely do not have any failure - * handling code. + * The leftover is flushed to the centralized per-memcg value. + * On the next attempt to refill obj stock it will be moved + * to a per-cpu stock (probably, on an other CPU), see + * refill_obj_stock(). + * + * How often it's flushed is a trade-off between the memory + * limit enforcement accuracy and potential CPU contention, + * so it might be changed in the future. */ - if (gfp & __GFP_NOFAIL) { - page_counter_charge(&memcg->kmem, nr_pages); - return 0; + atomic_add(nr_bytes, &old->nr_charged_bytes); + stock->nr_bytes = 0; + } + + /* + * Flush the vmstat data in current stock + */ + if (stock->nr_slab_reclaimable_b || stock->nr_slab_unreclaimable_b) { + if (stock->nr_slab_reclaimable_b) { + mod_objcg_mlstate(old, stock->cached_pgdat, + NR_SLAB_RECLAIMABLE_B, + stock->nr_slab_reclaimable_b); + stock->nr_slab_reclaimable_b = 0; } - cancel_charge(memcg, nr_pages); - return -ENOMEM; + if (stock->nr_slab_unreclaimable_b) { + mod_objcg_mlstate(old, stock->cached_pgdat, + NR_SLAB_UNRECLAIMABLE_B, + stock->nr_slab_unreclaimable_b); + stock->nr_slab_unreclaimable_b = 0; + } + stock->cached_pgdat = NULL; } - return 0; + + stock->cached_objcg = NULL; + /* + * The `old' objects needs to be released by the caller via + * obj_cgroup_put() outside of memcg_stock_pcp::stock_lock. + */ + return old; } -/** - * __memcg_kmem_charge: charge a kmem page to the current memory cgroup - * @page: page to charge - * @gfp: reclaim mode - * @order: allocation order - * - * Returns 0 on success, an error code on failure. - */ -int __memcg_kmem_charge(struct page *page, gfp_t gfp, int order) +static bool obj_stock_flush_required(struct memcg_stock_pcp *stock, + struct mem_cgroup *root_memcg) { struct mem_cgroup *memcg; - int ret = 0; - - if (memcg_kmem_bypass()) - return 0; - memcg = get_mem_cgroup_from_current(); - if (!mem_cgroup_is_root(memcg)) { - ret = __memcg_kmem_charge_memcg(page, gfp, order, memcg); - if (!ret) { - page->mem_cgroup = memcg; - __SetPageKmemcg(page); - } + if (stock->cached_objcg) { + memcg = obj_cgroup_memcg(stock->cached_objcg); + if (memcg && mem_cgroup_is_descendant(memcg, root_memcg)) + return true; } - css_put(&memcg->css); - return ret; + + return false; } -/** - * __memcg_kmem_uncharge_memcg: uncharge a kmem page - * @memcg: memcg to uncharge - * @nr_pages: number of pages to uncharge - */ -void __memcg_kmem_uncharge_memcg(struct mem_cgroup *memcg, - unsigned int nr_pages) +static void refill_obj_stock(struct obj_cgroup *objcg, unsigned int nr_bytes, + bool allow_uncharge) { - if (!cgroup_subsys_on_dfl(memory_cgrp_subsys)) - page_counter_uncharge(&memcg->kmem, nr_pages); + struct memcg_stock_pcp *stock; + struct obj_cgroup *old = NULL; + unsigned long flags; + unsigned int nr_pages = 0; - page_counter_uncharge(&memcg->memory, nr_pages); - if (do_memsw_account()) - page_counter_uncharge(&memcg->memsw, nr_pages); + local_lock_irqsave(&memcg_stock.stock_lock, flags); + + stock = this_cpu_ptr(&memcg_stock); + if (stock->cached_objcg != objcg) { /* reset if necessary */ + old = drain_obj_stock(stock); + obj_cgroup_get(objcg); + stock->cached_objcg = objcg; + stock->nr_bytes = atomic_read(&objcg->nr_charged_bytes) + ? atomic_xchg(&objcg->nr_charged_bytes, 0) : 0; + allow_uncharge = true; /* Allow uncharge when objcg changes */ + } + stock->nr_bytes += nr_bytes; + + if (allow_uncharge && (stock->nr_bytes > PAGE_SIZE)) { + nr_pages = stock->nr_bytes >> PAGE_SHIFT; + stock->nr_bytes &= (PAGE_SIZE - 1); + } + + local_unlock_irqrestore(&memcg_stock.stock_lock, flags); + if (old) + obj_cgroup_put(old); + + if (nr_pages) + obj_cgroup_uncharge_pages(objcg, nr_pages); } -/** - * __memcg_kmem_uncharge: uncharge a kmem page - * @page: page to uncharge - * @order: allocation order - */ -void __memcg_kmem_uncharge(struct page *page, int order) + +int obj_cgroup_charge(struct obj_cgroup *objcg, gfp_t gfp, size_t size) { - struct mem_cgroup *memcg = page->mem_cgroup; - unsigned int nr_pages = 1 << order; + unsigned int nr_pages, nr_bytes; + int ret; - if (!memcg) - return; + if (consume_obj_stock(objcg, size)) + return 0; + + /* + * In theory, objcg->nr_charged_bytes can have enough + * pre-charged bytes to satisfy the allocation. However, + * flushing objcg->nr_charged_bytes requires two atomic + * operations, and objcg->nr_charged_bytes can't be big. + * The shared objcg->nr_charged_bytes can also become a + * performance bottleneck if all tasks of the same memcg are + * trying to update it. So it's better to ignore it and try + * grab some new pages. The stock's nr_bytes will be flushed to + * objcg->nr_charged_bytes later on when objcg changes. + * + * The stock's nr_bytes may contain enough pre-charged bytes + * to allow one less page from being charged, but we can't rely + * on the pre-charged bytes not being changed outside of + * consume_obj_stock() or refill_obj_stock(). So ignore those + * pre-charged bytes as well when charging pages. To avoid a + * page uncharge right after a page charge, we set the + * allow_uncharge flag to false when calling refill_obj_stock() + * to temporarily allow the pre-charged bytes to exceed the page + * size limit. The maximum reachable value of the pre-charged + * bytes is (sizeof(object) + PAGE_SIZE - 2) if there is no data + * race. + */ + nr_pages = size >> PAGE_SHIFT; + nr_bytes = size & (PAGE_SIZE - 1); + + if (nr_bytes) + nr_pages += 1; - VM_BUG_ON_PAGE(mem_cgroup_is_root(memcg), page); - __memcg_kmem_uncharge_memcg(memcg, nr_pages); - page->mem_cgroup = NULL; + ret = obj_cgroup_charge_pages(objcg, gfp, nr_pages); + if (!ret && nr_bytes) + refill_obj_stock(objcg, PAGE_SIZE - nr_bytes, false); - /* slab pages do not have PageKmemcg flag set */ - if (PageKmemcg(page)) - __ClearPageKmemcg(page); + return ret; +} - css_put_many(&memcg->css, nr_pages); +void obj_cgroup_uncharge(struct obj_cgroup *objcg, size_t size) +{ + refill_obj_stock(objcg, size, true); } -#endif /* CONFIG_MEMCG_KMEM */ -#ifdef CONFIG_TRANSPARENT_HUGEPAGE +#endif /* CONFIG_MEMCG_KMEM */ /* - * Because tail pages are not marked as "used", set it. We're under - * pgdat->lru_lock and migration entries setup in all page mappings. + * Because page_memcg(head) is not set on tails, set it now. */ -void mem_cgroup_split_huge_fixup(struct page *head) +void split_page_memcg(struct page *head, unsigned int nr) { + struct folio *folio = page_folio(head); + struct mem_cgroup *memcg = folio_memcg(folio); int i; - if (mem_cgroup_disabled()) + if (mem_cgroup_disabled() || !memcg) return; - for (i = 1; i < HPAGE_PMD_NR; i++) - head[i].mem_cgroup = head->mem_cgroup; + for (i = 1; i < nr; i++) + folio_page(folio, i)->memcg_data = folio->memcg_data; - __mod_memcg_state(head->mem_cgroup, MEMCG_RSS_HUGE, -HPAGE_PMD_NR); + if (folio_memcg_kmem(folio)) + obj_cgroup_get_many(__folio_objcg(folio), nr - 1); + else + css_get_many(&memcg->css, nr - 1); } -#endif /* CONFIG_TRANSPARENT_HUGEPAGE */ -#ifdef CONFIG_MEMCG_SWAP +#ifdef CONFIG_SWAP /** * mem_cgroup_move_swap_account - move swap charge and swap_cgroup's record. * @entry: swap entry to be moved @@ -3029,7 +3477,7 @@ static int mem_cgroup_resize_max(struct mem_cgroup *memcg, * Make sure that the new limit (memsw or memory limit) doesn't * break our basic invariant rule memory.max <= memsw.max. */ - limits_invariant = memsw ? max >= memcg->memory.max : + limits_invariant = memsw ? max >= READ_ONCE(memcg->memory.max) : max <= memcg->memsw.max; if (!limits_invariant) { mutex_unlock(&memcg_max_mutex); @@ -3050,8 +3498,8 @@ static int mem_cgroup_resize_max(struct mem_cgroup *memcg, continue; } - if (!try_to_free_mem_cgroup_pages(memcg, 1, - GFP_KERNEL, !memsw)) { + if (!try_to_free_mem_cgroup_pages(memcg, 1, GFP_KERNEL, + memsw ? 0 : MEMCG_RECLAIM_MAY_SWAP)) { ret = -EBUSY; break; } @@ -3073,12 +3521,11 @@ unsigned long mem_cgroup_soft_limit_reclaim(pg_data_t *pgdat, int order, int loop = 0; struct mem_cgroup_tree_per_node *mctz; unsigned long excess; - unsigned long nr_scanned; if (order > 0) return 0; - mctz = soft_limit_tree_node(pgdat->node_id); + mctz = soft_limit_tree.rb_tree_per_node[pgdat->node_id]; /* * Do not even bother to check the largest node if the root @@ -3101,13 +3548,10 @@ unsigned long mem_cgroup_soft_limit_reclaim(pg_data_t *pgdat, int order, if (!mz) break; - nr_scanned = 0; reclaimed = mem_cgroup_soft_reclaim(mz->memcg, pgdat, - gfp_mask, &nr_scanned); + gfp_mask, total_scanned); nr_reclaimed += reclaimed; - *total_scanned += nr_scanned; spin_lock_irq(&mctz->lock); - __mem_cgroup_remove_exceeded(mz, mctz); /* * If we failed to reclaim anything from this memory cgroup @@ -3147,29 +3591,13 @@ unsigned long mem_cgroup_soft_limit_reclaim(pg_data_t *pgdat, int order, } /* - * Test whether @memcg has children, dead or alive. Note that this - * function doesn't care whether @memcg has use_hierarchy enabled and - * returns %true if there are child csses according to the cgroup - * hierarchy. Testing use_hierarchy is the caller's responsiblity. - */ -static inline bool memcg_has_children(struct mem_cgroup *memcg) -{ - bool ret; - - rcu_read_lock(); - ret = css_next_child(NULL, &memcg->css); - rcu_read_unlock(); - return ret; -} - -/* * Reclaims as many pages from the given memcg as possible. * * Caller is responsible for holding css reference for memcg. */ static int mem_cgroup_force_empty(struct mem_cgroup *memcg) { - int nr_retries = MEM_CGROUP_RECLAIM_RETRIES; + int nr_retries = MAX_RECLAIM_RETRIES; /* we call try-to-free pages for make this cgroup empty */ lru_add_drain_all(); @@ -3178,19 +3606,12 @@ static int mem_cgroup_force_empty(struct mem_cgroup *memcg) /* try to free all pages in this cgroup */ while (nr_retries && page_counter_read(&memcg->memory)) { - int progress; - if (signal_pending(current)) return -EINTR; - progress = try_to_free_mem_cgroup_pages(memcg, 1, - GFP_KERNEL, true); - if (!progress) { + if (!try_to_free_mem_cgroup_pages(memcg, 1, GFP_KERNEL, + MEMCG_RECLAIM_MAY_SWAP)) nr_retries--; - /* maybe some writeback is necessary */ - congestion_wait(BLK_RW_ASYNC, HZ/10); - } - } return 0; @@ -3210,37 +3631,20 @@ static ssize_t mem_cgroup_force_empty_write(struct kernfs_open_file *of, static u64 mem_cgroup_hierarchy_read(struct cgroup_subsys_state *css, struct cftype *cft) { - return mem_cgroup_from_css(css)->use_hierarchy; + return 1; } static int mem_cgroup_hierarchy_write(struct cgroup_subsys_state *css, struct cftype *cft, u64 val) { - int retval = 0; - struct mem_cgroup *memcg = mem_cgroup_from_css(css); - struct mem_cgroup *parent_memcg = mem_cgroup_from_css(memcg->css.parent); - - if (memcg->use_hierarchy == val) + if (val == 1) return 0; - /* - * If parent's use_hierarchy is set, we can't make any modifications - * in the child subtrees. If it is unset, then the change can - * occur, provided the current cgroup has no children. - * - * For the root cgroup, parent_mem is NULL, we allow value to be - * set if there are no children. - */ - if ((!parent_memcg || !parent_memcg->use_hierarchy) && - (val == 1 || val == 0)) { - if (!memcg_has_children(memcg)) - memcg->use_hierarchy = val; - else - retval = -EBUSY; - } else - retval = -EINVAL; + pr_warn_once("Non-hierarchical mode is deprecated. " + "Please report your usecase to linux-mm@kvack.org if you " + "depend on this functionality.\n"); - return retval; + return -EINVAL; } static unsigned long mem_cgroup_usage(struct mem_cgroup *memcg, bool swap) @@ -3248,8 +3652,9 @@ static unsigned long mem_cgroup_usage(struct mem_cgroup *memcg, bool swap) unsigned long val; if (mem_cgroup_is_root(memcg)) { - val = memcg_page_state(memcg, MEMCG_CACHE) + - memcg_page_state(memcg, MEMCG_RSS); + mem_cgroup_flush_stats(); + val = memcg_page_state(memcg, NR_FILE_PAGES) + + memcg_page_state(memcg, NR_ANON_MAPPED); if (swap) val += memcg_page_state(memcg, MEMCG_SWAP); } else { @@ -3312,147 +3717,54 @@ static u64 mem_cgroup_read_u64(struct cgroup_subsys_state *css, } } -static void memcg_flush_percpu_vmstats(struct mem_cgroup *memcg) -{ - unsigned long stat[MEMCG_NR_STAT] = {0}; - struct mem_cgroup *mi; - int node, cpu, i; - - for_each_online_cpu(cpu) - for (i = 0; i < MEMCG_NR_STAT; i++) - stat[i] += per_cpu(memcg->vmstats_percpu->stat[i], cpu); - - for (mi = memcg; mi; mi = parent_mem_cgroup(mi)) - for (i = 0; i < MEMCG_NR_STAT; i++) - atomic_long_add(stat[i], &mi->vmstats[i]); - - for_each_node(node) { - struct mem_cgroup_per_node *pn = memcg->nodeinfo[node]; - struct mem_cgroup_per_node *pi; - - for (i = 0; i < NR_VM_NODE_STAT_ITEMS; i++) - stat[i] = 0; - - for_each_online_cpu(cpu) - for (i = 0; i < NR_VM_NODE_STAT_ITEMS; i++) - stat[i] += per_cpu( - pn->lruvec_stat_cpu->count[i], cpu); - - for (pi = pn; pi; pi = parent_nodeinfo(pi, node)) - for (i = 0; i < NR_VM_NODE_STAT_ITEMS; i++) - atomic_long_add(stat[i], &pi->lruvec_stat[i]); - } -} - -static void memcg_flush_percpu_vmevents(struct mem_cgroup *memcg) -{ - unsigned long events[NR_VM_EVENT_ITEMS]; - struct mem_cgroup *mi; - int cpu, i; - - for (i = 0; i < NR_VM_EVENT_ITEMS; i++) - events[i] = 0; - - for_each_online_cpu(cpu) - for (i = 0; i < NR_VM_EVENT_ITEMS; i++) - events[i] += per_cpu(memcg->vmstats_percpu->events[i], - cpu); - - for (mi = memcg; mi; mi = parent_mem_cgroup(mi)) - for (i = 0; i < NR_VM_EVENT_ITEMS; i++) - atomic_long_add(events[i], &mi->vmevents[i]); -} - #ifdef CONFIG_MEMCG_KMEM static int memcg_online_kmem(struct mem_cgroup *memcg) { - int memcg_id; + struct obj_cgroup *objcg; + + if (mem_cgroup_kmem_disabled()) + return 0; - if (cgroup_memory_nokmem) + if (unlikely(mem_cgroup_is_root(memcg))) return 0; - BUG_ON(memcg->kmemcg_id >= 0); - BUG_ON(memcg->kmem_state); + objcg = obj_cgroup_alloc(); + if (!objcg) + return -ENOMEM; - memcg_id = memcg_alloc_cache_id(); - if (memcg_id < 0) - return memcg_id; + objcg->memcg = memcg; + rcu_assign_pointer(memcg->objcg, objcg); - static_branch_inc(&memcg_kmem_enabled_key); - /* - * A memory cgroup is considered kmem-online as soon as it gets - * kmemcg_id. Setting the id after enabling static branching will - * guarantee no one starts accounting before all call sites are - * patched. - */ - memcg->kmemcg_id = memcg_id; - memcg->kmem_state = KMEM_ONLINE; - INIT_LIST_HEAD(&memcg->kmem_caches); + static_branch_enable(&memcg_kmem_enabled_key); + + memcg->kmemcg_id = memcg->id.id; return 0; } static void memcg_offline_kmem(struct mem_cgroup *memcg) { - struct cgroup_subsys_state *css; - struct mem_cgroup *parent, *child; - int kmemcg_id; + struct mem_cgroup *parent; - if (memcg->kmem_state != KMEM_ONLINE) + if (mem_cgroup_kmem_disabled()) + return; + + if (unlikely(mem_cgroup_is_root(memcg))) return; - /* - * Clear the online state before clearing memcg_caches array - * entries. The slab_mutex in memcg_deactivate_kmem_caches() - * guarantees that no cache will be created for this cgroup - * after we are done (see memcg_create_kmem_cache()). - */ - memcg->kmem_state = KMEM_ALLOCATED; parent = parent_mem_cgroup(memcg); if (!parent) parent = root_mem_cgroup; - /* - * Deactivate and reparent kmem_caches. - */ - memcg_deactivate_kmem_caches(memcg, parent); - - kmemcg_id = memcg->kmemcg_id; - BUG_ON(kmemcg_id < 0); + memcg_reparent_objcgs(memcg, parent); /* - * Change kmemcg_id of this cgroup and all its descendants to the - * parent's id, and then move all entries from this cgroup's list_lrus - * to ones of the parent. After we have finished, all list_lrus - * corresponding to this cgroup are guaranteed to remain empty. The - * ordering is imposed by list_lru_node->lock taken by - * memcg_drain_all_list_lrus(). + * After we have finished memcg_reparent_objcgs(), all list_lrus + * corresponding to this cgroup are guaranteed to remain empty. + * The ordering is imposed by list_lru_node->lock taken by + * memcg_reparent_list_lrus(). */ - rcu_read_lock(); /* can be called from css_free w/o cgroup_mutex */ - css_for_each_descendant_pre(css, &memcg->css) { - child = mem_cgroup_from_css(css); - BUG_ON(child->kmemcg_id != kmemcg_id); - child->kmemcg_id = parent->kmemcg_id; - if (!memcg->use_hierarchy) - break; - } - rcu_read_unlock(); - - memcg_drain_all_list_lrus(kmemcg_id, parent); - - memcg_free_cache_id(kmemcg_id); -} - -static void memcg_free_kmem(struct mem_cgroup *memcg) -{ - /* css_alloc() failed, offlining didn't happen */ - if (unlikely(memcg->kmem_state == KMEM_ONLINE)) - memcg_offline_kmem(memcg); - - if (memcg->kmem_state == KMEM_ALLOCATED) { - WARN_ON(!list_empty(&memcg->kmem_caches)); - static_branch_dec(&memcg_kmem_enabled_key); - } + memcg_reparent_list_lrus(memcg, parent); } #else static int memcg_online_kmem(struct mem_cgroup *memcg) @@ -3462,22 +3774,8 @@ static int memcg_online_kmem(struct mem_cgroup *memcg) static void memcg_offline_kmem(struct mem_cgroup *memcg) { } -static void memcg_free_kmem(struct mem_cgroup *memcg) -{ -} #endif /* CONFIG_MEMCG_KMEM */ -static int memcg_update_kmem_max(struct mem_cgroup *memcg, - unsigned long max) -{ - int ret; - - mutex_lock(&memcg_max_mutex); - ret = page_counter_set_max(&memcg->kmem, max); - mutex_unlock(&memcg_max_mutex); - return ret; -} - static int memcg_update_tcp_max(struct mem_cgroup *memcg, unsigned long max) { int ret; @@ -3543,10 +3841,8 @@ static ssize_t mem_cgroup_write(struct kernfs_open_file *of, ret = mem_cgroup_resize_max(memcg, nr_pages, true); break; case _KMEM: - pr_warn_once("kmem.limit_in_bytes is deprecated and will be removed. " - "Please report your usecase to linux-mm@kvack.org if you " - "depend on this functionality.\n"); - ret = memcg_update_kmem_max(memcg, nr_pages); + /* kmem.limit_in_bytes is deprecated. */ + ret = -EOPNOTSUPP; break; case _TCP: ret = memcg_update_tcp_max(memcg, nr_pages); @@ -3554,8 +3850,12 @@ static ssize_t mem_cgroup_write(struct kernfs_open_file *of, } break; case RES_SOFT_LIMIT: - memcg->soft_limit = nr_pages; - ret = 0; + if (IS_ENABLED(CONFIG_PREEMPT_RT)) { + ret = -EOPNOTSUPP; + } else { + memcg->soft_limit = nr_pages; + ret = 0; + } break; } return ret ?: nbytes; @@ -3637,7 +3937,7 @@ static int mem_cgroup_move_charge_write(struct cgroup_subsys_state *css, #define LRU_ALL ((1 << NR_LRU_LISTS) - 1) static unsigned long mem_cgroup_node_nr_lru_pages(struct mem_cgroup *memcg, - int nid, unsigned int lru_mask) + int nid, unsigned int lru_mask, bool tree) { struct lruvec *lruvec = mem_cgroup_lruvec(memcg, NODE_DATA(nid)); unsigned long nr = 0; @@ -3648,13 +3948,17 @@ static unsigned long mem_cgroup_node_nr_lru_pages(struct mem_cgroup *memcg, for_each_lru(lru) { if (!(BIT(lru) & lru_mask)) continue; - nr += lruvec_page_state_local(lruvec, NR_LRU_BASE + lru); + if (tree) + nr += lruvec_page_state(lruvec, NR_LRU_BASE + lru); + else + nr += lruvec_page_state_local(lruvec, NR_LRU_BASE + lru); } return nr; } static unsigned long mem_cgroup_nr_lru_pages(struct mem_cgroup *memcg, - unsigned int lru_mask) + unsigned int lru_mask, + bool tree) { unsigned long nr = 0; enum lru_list lru; @@ -3662,7 +3966,10 @@ static unsigned long mem_cgroup_nr_lru_pages(struct mem_cgroup *memcg, for_each_lru(lru) { if (!(BIT(lru) & lru_mask)) continue; - nr += memcg_page_state_local(memcg, NR_LRU_BASE + lru); + if (tree) + nr += memcg_page_state(memcg, NR_LRU_BASE + lru); + else + nr += memcg_page_state_local(memcg, NR_LRU_BASE + lru); } return nr; } @@ -3682,34 +3989,30 @@ static int memcg_numa_stat_show(struct seq_file *m, void *v) }; const struct numa_stat *stat; int nid; - unsigned long nr; struct mem_cgroup *memcg = mem_cgroup_from_seq(m); + mem_cgroup_flush_stats(); + for (stat = stats; stat < stats + ARRAY_SIZE(stats); stat++) { - nr = mem_cgroup_nr_lru_pages(memcg, stat->lru_mask); - seq_printf(m, "%s=%lu", stat->name, nr); - for_each_node_state(nid, N_MEMORY) { - nr = mem_cgroup_node_nr_lru_pages(memcg, nid, - stat->lru_mask); - seq_printf(m, " N%d=%lu", nid, nr); - } + seq_printf(m, "%s=%lu", stat->name, + mem_cgroup_nr_lru_pages(memcg, stat->lru_mask, + false)); + for_each_node_state(nid, N_MEMORY) + seq_printf(m, " N%d=%lu", nid, + mem_cgroup_node_nr_lru_pages(memcg, nid, + stat->lru_mask, false)); seq_putc(m, '\n'); } for (stat = stats; stat < stats + ARRAY_SIZE(stats); stat++) { - struct mem_cgroup *iter; - nr = 0; - for_each_mem_cgroup_tree(iter, memcg) - nr += mem_cgroup_nr_lru_pages(iter, stat->lru_mask); - seq_printf(m, "hierarchical_%s=%lu", stat->name, nr); - for_each_node_state(nid, N_MEMORY) { - nr = 0; - for_each_mem_cgroup_tree(iter, memcg) - nr += mem_cgroup_node_nr_lru_pages( - iter, nid, stat->lru_mask); - seq_printf(m, " N%d=%lu", nid, nr); - } + seq_printf(m, "hierarchical_%s=%lu", stat->name, + mem_cgroup_nr_lru_pages(memcg, stat->lru_mask, + true)); + for_each_node_state(nid, N_MEMORY) + seq_printf(m, " N%d=%lu", nid, + mem_cgroup_node_nr_lru_pages(memcg, nid, + stat->lru_mask, true)); seq_putc(m, '\n'); } @@ -3718,24 +4021,32 @@ static int memcg_numa_stat_show(struct seq_file *m, void *v) #endif /* CONFIG_NUMA */ static const unsigned int memcg1_stats[] = { - MEMCG_CACHE, - MEMCG_RSS, - MEMCG_RSS_HUGE, + NR_FILE_PAGES, + NR_ANON_MAPPED, +#ifdef CONFIG_TRANSPARENT_HUGEPAGE + NR_ANON_THPS, +#endif NR_SHMEM, NR_FILE_MAPPED, NR_FILE_DIRTY, NR_WRITEBACK, + WORKINGSET_REFAULT_ANON, + WORKINGSET_REFAULT_FILE, MEMCG_SWAP, }; static const char *const memcg1_stat_names[] = { "cache", "rss", +#ifdef CONFIG_TRANSPARENT_HUGEPAGE "rss_huge", +#endif "shmem", "mapped_file", "dirty", "writeback", + "workingset_refault_anon", + "workingset_refault_file", "swap", }; @@ -3756,12 +4067,16 @@ static int memcg_stat_show(struct seq_file *m, void *v) BUILD_BUG_ON(ARRAY_SIZE(memcg1_stat_names) != ARRAY_SIZE(memcg1_stats)); + mem_cgroup_flush_stats(); + for (i = 0; i < ARRAY_SIZE(memcg1_stats); i++) { + unsigned long nr; + if (memcg1_stats[i] == MEMCG_SWAP && !do_memsw_account()) continue; + nr = memcg_page_state_local(memcg, memcg1_stats[i]); seq_printf(m, "%s %lu\n", memcg1_stat_names[i], - memcg_page_state_local(memcg, memcg1_stats[i]) * - PAGE_SIZE); + nr * memcg_page_state_unit(memcg1_stats[i])); } for (i = 0; i < ARRAY_SIZE(memcg1_events); i++) @@ -3776,8 +4091,8 @@ static int memcg_stat_show(struct seq_file *m, void *v) /* Hierarchical information */ memory = memsw = PAGE_COUNTER_MAX; for (mi = memcg; mi; mi = parent_mem_cgroup(mi)) { - memory = min(memory, mi->memory.max); - memsw = min(memsw, mi->memsw.max); + memory = min(memory, READ_ONCE(mi->memory.max)); + memsw = min(memsw, READ_ONCE(mi->memsw.max)); } seq_printf(m, "hierarchical_memory_limit %llu\n", (u64)memory * PAGE_SIZE); @@ -3786,11 +4101,13 @@ static int memcg_stat_show(struct seq_file *m, void *v) (u64)memsw * PAGE_SIZE); for (i = 0; i < ARRAY_SIZE(memcg1_stats); i++) { + unsigned long nr; + if (memcg1_stats[i] == MEMCG_SWAP && !do_memsw_account()) continue; + nr = memcg_page_state(memcg, memcg1_stats[i]); seq_printf(m, "total_%s %llu\n", memcg1_stat_names[i], - (u64)memcg_page_state(memcg, memcg1_stats[i]) * - PAGE_SIZE); + (u64)nr * memcg_page_state_unit(memcg1_stats[i])); } for (i = 0; i < ARRAY_SIZE(memcg1_events); i++) @@ -3807,23 +4124,17 @@ static int memcg_stat_show(struct seq_file *m, void *v) { pg_data_t *pgdat; struct mem_cgroup_per_node *mz; - struct zone_reclaim_stat *rstat; - unsigned long recent_rotated[2] = {0, 0}; - unsigned long recent_scanned[2] = {0, 0}; + unsigned long anon_cost = 0; + unsigned long file_cost = 0; for_each_online_pgdat(pgdat) { - mz = mem_cgroup_nodeinfo(memcg, pgdat->node_id); - rstat = &mz->lruvec.reclaim_stat; + mz = memcg->nodeinfo[pgdat->node_id]; - recent_rotated[0] += rstat->recent_rotated[0]; - recent_rotated[1] += rstat->recent_rotated[1]; - recent_scanned[0] += rstat->recent_scanned[0]; - recent_scanned[1] += rstat->recent_scanned[1]; + anon_cost += mz->lruvec.anon_cost; + file_cost += mz->lruvec.file_cost; } - seq_printf(m, "recent_rotated_anon %lu\n", recent_rotated[0]); - seq_printf(m, "recent_rotated_file %lu\n", recent_rotated[1]); - seq_printf(m, "recent_scanned_anon %lu\n", recent_scanned[0]); - seq_printf(m, "recent_scanned_file %lu\n", recent_scanned[1]); + seq_printf(m, "anon_cost %lu\n", anon_cost); + seq_printf(m, "file_cost %lu\n", file_cost); } #endif @@ -3843,10 +4154,10 @@ static int mem_cgroup_swappiness_write(struct cgroup_subsys_state *css, { struct mem_cgroup *memcg = mem_cgroup_from_css(css); - if (val > 100) + if (val > 200) return -EINVAL; - if (css->parent) + if (!mem_cgroup_is_root(memcg)) memcg->swappiness = val; else vm_swappiness = val; @@ -3990,17 +4301,16 @@ static int __mem_cgroup_usage_register_event(struct mem_cgroup *memcg, new->size = size; /* Copy thresholds (if any) to new array */ - if (thresholds->primary) { - memcpy(new->entries, thresholds->primary->entries, (size - 1) * - sizeof(struct mem_cgroup_threshold)); - } + if (thresholds->primary) + memcpy(new->entries, thresholds->primary->entries, + flex_array_size(new, entries, size - 1)); /* Add new threshold */ new->entries[size - 1].eventfd = eventfd; new->entries[size - 1].threshold = threshold; /* Sort thresholds. Registering of new threshold isn't time-critical */ - sort(new->entries, size, sizeof(struct mem_cgroup_threshold), + sort(new->entries, size, sizeof(*new->entries), compare_thresholds, NULL); /* Find current threshold */ @@ -4197,7 +4507,7 @@ static int mem_cgroup_oom_control_write(struct cgroup_subsys_state *css, struct mem_cgroup *memcg = mem_cgroup_from_css(css); /* cannot set to root cgroup and only 0 and 1 are allowed */ - if (!css->parent || !((val == 0) || (val == 1))) + if (mem_cgroup_is_root(memcg) || !((val == 0) || (val == 1))) return -EINVAL; memcg->oom_kill_disable = val; @@ -4236,22 +4546,6 @@ struct wb_domain *mem_cgroup_wb_domain(struct bdi_writeback *wb) return &memcg->cgwb_domain; } -/* - * idx can be of type enum memcg_stat_item or node_stat_item. - * Keep in sync with memcg_exact_page(). - */ -static unsigned long memcg_exact_page_state(struct mem_cgroup *memcg, int idx) -{ - long x = atomic_long_read(&memcg->vmstats[idx]); - int cpu; - - for_each_online_cpu(cpu) - x += per_cpu_ptr(memcg->vmstats_percpu, cpu)->stat[idx]; - if (x < 0) - x = 0; - return x; -} - /** * mem_cgroup_wb_stats - retrieve writeback related stats from its memcg * @wb: bdi_writeback in question @@ -4277,16 +4571,17 @@ void mem_cgroup_wb_stats(struct bdi_writeback *wb, unsigned long *pfilepages, struct mem_cgroup *memcg = mem_cgroup_from_css(wb->memcg_css); struct mem_cgroup *parent; - *pdirty = memcg_exact_page_state(memcg, NR_FILE_DIRTY); + mem_cgroup_flush_stats(); - /* this should eventually include NR_UNSTABLE_NFS */ - *pwriteback = memcg_exact_page_state(memcg, NR_WRITEBACK); - *pfilepages = memcg_exact_page_state(memcg, NR_INACTIVE_FILE) + - memcg_exact_page_state(memcg, NR_ACTIVE_FILE); - *pheadroom = PAGE_COUNTER_MAX; + *pdirty = memcg_page_state(memcg, NR_FILE_DIRTY); + *pwriteback = memcg_page_state(memcg, NR_WRITEBACK); + *pfilepages = memcg_page_state(memcg, NR_INACTIVE_FILE) + + memcg_page_state(memcg, NR_ACTIVE_FILE); + *pheadroom = PAGE_COUNTER_MAX; while ((parent = parent_mem_cgroup(memcg))) { - unsigned long ceiling = min(memcg->memory.max, memcg->high); + unsigned long ceiling = min(READ_ONCE(memcg->memory.max), + READ_ONCE(memcg->memory.high)); unsigned long used = page_counter_read(&memcg->memory); *pheadroom = min(*pheadroom, ceiling - min(ceiling, used)); @@ -4298,7 +4593,7 @@ void mem_cgroup_wb_stats(struct bdi_writeback *wb, unsigned long *pfilepages, * Foreign dirty flushing * * There's an inherent mismatch between memcg and writeback. The former - * trackes ownership per-page while the latter per-inode. This was a + * tracks ownership per-page while the latter per-inode. This was a * deliberate design decision because honoring per-page ownership in the * writeback path is complicated, may lead to higher CPU and IO overheads * and deemed unnecessary given that write-sharing an inode across @@ -4313,9 +4608,9 @@ void mem_cgroup_wb_stats(struct bdi_writeback *wb, unsigned long *pfilepages, * triggering background writeback. A will be slowed down without a way to * make writeback of the dirty pages happen. * - * Conditions like the above can lead to a cgroup getting repatedly and + * Conditions like the above can lead to a cgroup getting repeatedly and * severely throttled after making some progress after each - * dirty_expire_interval while the underyling IO device is almost + * dirty_expire_interval while the underlying IO device is almost * completely idle. * * Solving this problem completely requires matching the ownership tracking @@ -4338,17 +4633,17 @@ void mem_cgroup_wb_stats(struct bdi_writeback *wb, unsigned long *pfilepages, * As being wrong occasionally doesn't matter, updates and accesses to the * records are lockless and racy. */ -void mem_cgroup_track_foreign_dirty_slowpath(struct page *page, +void mem_cgroup_track_foreign_dirty_slowpath(struct folio *folio, struct bdi_writeback *wb) { - struct mem_cgroup *memcg = page->mem_cgroup; + struct mem_cgroup *memcg = folio_memcg(folio); struct memcg_cgwb_frn *frn; u64 now = get_jiffies_64(); u64 oldest_at = now; int oldest = -1; int i; - trace_track_foreign_dirty(page, wb); + trace_track_foreign_dirty(folio, wb); /* * Pick the slot to use. If there is already a slot for @wb, keep @@ -4411,7 +4706,7 @@ void mem_cgroup_flush_foreign(struct bdi_writeback *wb) atomic_read(&frn->done.cnt) == 1) { frn->at = 0; trace_flush_foreign(wb, frn->bdi_id, frn->memcg_id); - cgroup_writeback_by_id(frn->bdi_id, frn->memcg_id, 0, + cgroup_writeback_by_id(frn->bdi_id, frn->memcg_id, WB_REASON_FOREIGN_FLUSH, &frn->done); } @@ -4541,6 +4836,9 @@ static ssize_t memcg_write_event_control(struct kernfs_open_file *of, char *endp; int ret; + if (IS_ENABLED(CONFIG_PREEMPT_RT)) + return -EOPNOTSUPP; + buf = strstrip(buf); efd = simple_strtoul(buf, &endp, 10); @@ -4583,7 +4881,7 @@ static ssize_t memcg_write_event_control(struct kernfs_open_file *of, /* the process need read permission on control file */ /* AV: shouldn't we check that it's been opened for read instead? */ - ret = inode_permission(file_inode(cfile.file), MAY_READ); + ret = file_permission(cfile.file, MAY_READ); if (ret < 0) goto out_put_cfile; @@ -4635,9 +4933,9 @@ static ssize_t memcg_write_event_control(struct kernfs_open_file *of, vfs_poll(efile.file, &event->pt); - spin_lock(&memcg->event_list_lock); + spin_lock_irq(&memcg->event_list_lock); list_add(&event->list, &memcg->event_list); - spin_unlock(&memcg->event_list_lock); + spin_unlock_irq(&memcg->event_list_lock); fdput(cfile); fdput(efile); @@ -4658,6 +4956,17 @@ out_kfree: return ret; } +#if defined(CONFIG_MEMCG_KMEM) && (defined(CONFIG_SLAB) || defined(CONFIG_SLUB_DEBUG)) +static int mem_cgroup_slab_show(struct seq_file *m, void *p) +{ + /* + * Deprecated. + * Please, take a look at tools/cgroup/memcg_slabinfo.py . + */ + return 0; +} +#endif + static struct cftype mem_cgroup_legacy_files[] = { { .name = "usage_in_bytes", @@ -4720,7 +5029,6 @@ static struct cftype mem_cgroup_legacy_files[] = { .name = "oom_control", .seq_show = mem_cgroup_oom_control_read, .write_u64 = mem_cgroup_oom_control_write, - .private = MEMFILE_PRIVATE(_OOM_TYPE, OOM_CONTROL), }, { .name = "pressure_level", @@ -4754,13 +5062,11 @@ static struct cftype mem_cgroup_legacy_files[] = { .write = mem_cgroup_reset, .read_u64 = mem_cgroup_read_u64, }, -#if defined(CONFIG_SLAB) || defined(CONFIG_SLUB_DEBUG) +#if defined(CONFIG_MEMCG_KMEM) && \ + (defined(CONFIG_SLAB) || defined(CONFIG_SLUB_DEBUG)) { .name = "kmem.slabinfo", - .seq_start = memcg_slab_start, - .seq_next = memcg_slab_next, - .seq_stop = memcg_slab_stop, - .seq_show = memcg_slab_show, + .seq_show = mem_cgroup_slab_show, }, #endif { @@ -4797,7 +5103,7 @@ static struct cftype mem_cgroup_legacy_files[] = { * limited to 16 bit (MEM_CGROUP_ID_MAX), limiting the total number of * memory-controlled cgroups to 64k. * - * However, there usually are many references to the oflline CSS after + * However, there usually are many references to the offline CSS after * the cgroup has been destroyed, such as page cache or reclaimable * slab objects, that don't need to hang on to the ID. We want to keep * those dead CSS from occupying IDs, or we might quickly exhaust the @@ -4823,7 +5129,8 @@ static void mem_cgroup_id_remove(struct mem_cgroup *memcg) } } -static void mem_cgroup_id_get_many(struct mem_cgroup *memcg, unsigned int n) +static void __maybe_unused mem_cgroup_id_get_many(struct mem_cgroup *memcg, + unsigned int n) { refcount_add(n, &memcg->id.ref); } @@ -4855,40 +5162,45 @@ struct mem_cgroup *mem_cgroup_from_id(unsigned short id) return idr_find(&mem_cgroup_idr, id); } +#ifdef CONFIG_SHRINKER_DEBUG +struct mem_cgroup *mem_cgroup_get_from_ino(unsigned long ino) +{ + struct cgroup *cgrp; + struct cgroup_subsys_state *css; + struct mem_cgroup *memcg; + + cgrp = cgroup_get_from_id(ino); + if (IS_ERR(cgrp)) + return ERR_CAST(cgrp); + + css = cgroup_get_e_css(cgrp, &memory_cgrp_subsys); + if (css) + memcg = container_of(css, struct mem_cgroup, css); + else + memcg = ERR_PTR(-ENOENT); + + cgroup_put(cgrp); + + return memcg; +} +#endif + static int alloc_mem_cgroup_per_node_info(struct mem_cgroup *memcg, int node) { struct mem_cgroup_per_node *pn; - int 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 = kzalloc_node(sizeof(*pn), GFP_KERNEL, tmp); - if (!pn) - return 1; - pn->lruvec_stat_local = alloc_percpu(struct lruvec_stat); - if (!pn->lruvec_stat_local) { - kfree(pn); + pn = kzalloc_node(sizeof(*pn), GFP_KERNEL, node); + if (!pn) return 1; - } - pn->lruvec_stat_cpu = alloc_percpu(struct lruvec_stat); - if (!pn->lruvec_stat_cpu) { - free_percpu(pn->lruvec_stat_local); + pn->lruvec_stats_percpu = alloc_percpu_gfp(struct lruvec_stats_percpu, + GFP_KERNEL_ACCOUNT); + if (!pn->lruvec_stats_percpu) { kfree(pn); return 1; } lruvec_init(&pn->lruvec); - pn->usage_in_excess = 0; - pn->on_tree = false; pn->memcg = memcg; memcg->nodeinfo[node] = pn; @@ -4902,8 +5214,7 @@ static void free_mem_cgroup_per_node_info(struct mem_cgroup *memcg, int node) if (!pn) return; - free_percpu(pn->lruvec_stat_cpu); - free_percpu(pn->lruvec_stat_local); + free_percpu(pn->lruvec_stats_percpu); kfree(pn); } @@ -4913,48 +5224,42 @@ static void __mem_cgroup_free(struct mem_cgroup *memcg) for_each_node(node) free_mem_cgroup_per_node_info(memcg, node); + kfree(memcg->vmstats); free_percpu(memcg->vmstats_percpu); - free_percpu(memcg->vmstats_local); kfree(memcg); } static void mem_cgroup_free(struct mem_cgroup *memcg) { + lru_gen_exit_memcg(memcg); memcg_wb_domain_exit(memcg); - /* - * Flush percpu vmstats and vmevents to guarantee the value correctness - * on parent's and all ancestor levels. - */ - memcg_flush_percpu_vmstats(memcg); - memcg_flush_percpu_vmevents(memcg); __mem_cgroup_free(memcg); } static struct mem_cgroup *mem_cgroup_alloc(void) { struct mem_cgroup *memcg; - unsigned int size; int node; int __maybe_unused i; + long error = -ENOMEM; - size = sizeof(struct mem_cgroup); - size += nr_node_ids * sizeof(struct mem_cgroup_per_node *); - - memcg = kzalloc(size, GFP_KERNEL); + memcg = kzalloc(struct_size(memcg, nodeinfo, nr_node_ids), GFP_KERNEL); if (!memcg) - return NULL; + return ERR_PTR(error); memcg->id.id = idr_alloc(&mem_cgroup_idr, NULL, - 1, MEM_CGROUP_ID_MAX, - GFP_KERNEL); - if (memcg->id.id < 0) + 1, MEM_CGROUP_ID_MAX + 1, GFP_KERNEL); + if (memcg->id.id < 0) { + error = memcg->id.id; goto fail; + } - memcg->vmstats_local = alloc_percpu(struct memcg_vmstats_percpu); - if (!memcg->vmstats_local) + memcg->vmstats = kzalloc(sizeof(struct memcg_vmstats), GFP_KERNEL); + if (!memcg->vmstats) goto fail; - memcg->vmstats_percpu = alloc_percpu(struct memcg_vmstats_percpu); + memcg->vmstats_percpu = alloc_percpu_gfp(struct memcg_vmstats_percpu, + GFP_KERNEL_ACCOUNT); if (!memcg->vmstats_percpu) goto fail; @@ -4975,6 +5280,7 @@ static struct mem_cgroup *mem_cgroup_alloc(void) memcg->socket_pressure = jiffies; #ifdef CONFIG_MEMCG_KMEM memcg->kmemcg_id = -1; + INIT_LIST_HEAD(&memcg->objcg_list); #endif #ifdef CONFIG_CGROUP_WRITEBACK INIT_LIST_HEAD(&memcg->cgwb_list); @@ -4988,93 +5294,85 @@ static struct mem_cgroup *mem_cgroup_alloc(void) memcg->deferred_split_queue.split_queue_len = 0; #endif idr_replace(&mem_cgroup_idr, memcg, memcg->id.id); + lru_gen_init_memcg(memcg); return memcg; fail: mem_cgroup_id_remove(memcg); __mem_cgroup_free(memcg); - return NULL; + return ERR_PTR(error); } static struct cgroup_subsys_state * __ref mem_cgroup_css_alloc(struct cgroup_subsys_state *parent_css) { struct mem_cgroup *parent = mem_cgroup_from_css(parent_css); - struct mem_cgroup *memcg; - long error = -ENOMEM; + struct mem_cgroup *memcg, *old_memcg; + old_memcg = set_active_memcg(parent); memcg = mem_cgroup_alloc(); - if (!memcg) - return ERR_PTR(error); + set_active_memcg(old_memcg); + if (IS_ERR(memcg)) + return ERR_CAST(memcg); - memcg->high = PAGE_COUNTER_MAX; + page_counter_set_high(&memcg->memory, PAGE_COUNTER_MAX); memcg->soft_limit = PAGE_COUNTER_MAX; +#if defined(CONFIG_MEMCG_KMEM) && defined(CONFIG_ZSWAP) + memcg->zswap_max = PAGE_COUNTER_MAX; +#endif + page_counter_set_high(&memcg->swap, PAGE_COUNTER_MAX); if (parent) { memcg->swappiness = mem_cgroup_swappiness(parent); memcg->oom_kill_disable = parent->oom_kill_disable; - } - if (parent && parent->use_hierarchy) { - memcg->use_hierarchy = true; + page_counter_init(&memcg->memory, &parent->memory); page_counter_init(&memcg->swap, &parent->swap); - page_counter_init(&memcg->memsw, &parent->memsw); page_counter_init(&memcg->kmem, &parent->kmem); page_counter_init(&memcg->tcpmem, &parent->tcpmem); } else { + init_memcg_events(); page_counter_init(&memcg->memory, NULL); page_counter_init(&memcg->swap, NULL); - page_counter_init(&memcg->memsw, NULL); page_counter_init(&memcg->kmem, NULL); page_counter_init(&memcg->tcpmem, NULL); - /* - * Deeper hierachy with use_hierarchy == false doesn't make - * much sense so let cgroup subsystem know about this - * unfortunate state in our controller. - */ - if (parent != root_mem_cgroup) - memory_cgrp_subsys.broken_hierarchy = true; - } - /* The following stuff does not apply to the root */ - if (!parent) { -#ifdef CONFIG_MEMCG_KMEM - INIT_LIST_HEAD(&memcg->kmem_caches); -#endif root_mem_cgroup = memcg; return &memcg->css; } - error = memcg_online_kmem(memcg); - if (error) - goto fail; - if (cgroup_subsys_on_dfl(memory_cgrp_subsys) && !cgroup_memory_nosocket) static_branch_inc(&memcg_sockets_enabled_key); return &memcg->css; -fail: - mem_cgroup_id_remove(memcg); - mem_cgroup_free(memcg); - return ERR_PTR(-ENOMEM); } static int mem_cgroup_css_online(struct cgroup_subsys_state *css) { struct mem_cgroup *memcg = mem_cgroup_from_css(css); + if (memcg_online_kmem(memcg)) + goto remove_id; + /* - * A memcg must be visible for memcg_expand_shrinker_maps() + * A memcg must be visible for expand_shrinker_info() * by the time the maps are allocated. So, we allocate maps * here, when for_each_mem_cgroup() can't skip it. */ - if (memcg_alloc_shrinker_maps(memcg)) { - mem_cgroup_id_remove(memcg); - return -ENOMEM; - } + if (alloc_shrinker_info(memcg)) + goto offline_kmem; /* Online state pins memcg ID, memcg ID pins CSS */ refcount_set(&memcg->id.ref, 1); css_get(css); + + if (unlikely(mem_cgroup_is_root(memcg))) + queue_delayed_work(system_unbound_wq, &stats_flush_dwork, + 2UL*HZ); return 0; +offline_kmem: + memcg_offline_kmem(memcg); +remove_id: + mem_cgroup_id_remove(memcg); + return -ENOMEM; } static void mem_cgroup_css_offline(struct cgroup_subsys_state *css) @@ -5087,17 +5385,18 @@ static void mem_cgroup_css_offline(struct cgroup_subsys_state *css) * Notify userspace about cgroup removing only after rmdir of cgroup * directory to avoid race between userspace and kernelspace. */ - spin_lock(&memcg->event_list_lock); + spin_lock_irq(&memcg->event_list_lock); list_for_each_entry_safe(event, tmp, &memcg->event_list, list) { list_del_init(&event->list); schedule_work(&event->remove); } - spin_unlock(&memcg->event_list_lock); + spin_unlock_irq(&memcg->event_list_lock); page_counter_set_min(&memcg->memory, 0); page_counter_set_low(&memcg->memory, 0); memcg_offline_kmem(memcg); + reparent_shrinker_deferred(memcg); wb_memcg_offline(memcg); drain_all_stock(memcg); @@ -5130,8 +5429,7 @@ static void mem_cgroup_css_free(struct cgroup_subsys_state *css) vmpressure_cleanup(&memcg->vmpressure); cancel_work_sync(&memcg->high_work); mem_cgroup_remove_from_trees(memcg); - memcg_free_shrinker_maps(memcg); - memcg_free_kmem(memcg); + free_shrinker_info(memcg); mem_cgroup_free(memcg); } @@ -5154,16 +5452,102 @@ static void mem_cgroup_css_reset(struct cgroup_subsys_state *css) page_counter_set_max(&memcg->memory, PAGE_COUNTER_MAX); page_counter_set_max(&memcg->swap, PAGE_COUNTER_MAX); - page_counter_set_max(&memcg->memsw, PAGE_COUNTER_MAX); page_counter_set_max(&memcg->kmem, PAGE_COUNTER_MAX); page_counter_set_max(&memcg->tcpmem, PAGE_COUNTER_MAX); page_counter_set_min(&memcg->memory, 0); page_counter_set_low(&memcg->memory, 0); - memcg->high = PAGE_COUNTER_MAX; + page_counter_set_high(&memcg->memory, PAGE_COUNTER_MAX); memcg->soft_limit = PAGE_COUNTER_MAX; + page_counter_set_high(&memcg->swap, PAGE_COUNTER_MAX); memcg_wb_domain_size_changed(memcg); } +static void mem_cgroup_css_rstat_flush(struct cgroup_subsys_state *css, int cpu) +{ + struct mem_cgroup *memcg = mem_cgroup_from_css(css); + struct mem_cgroup *parent = parent_mem_cgroup(memcg); + struct memcg_vmstats_percpu *statc; + long delta, v; + int i, nid; + + statc = per_cpu_ptr(memcg->vmstats_percpu, cpu); + + for (i = 0; i < MEMCG_NR_STAT; i++) { + /* + * Collect the aggregated propagation counts of groups + * below us. We're in a per-cpu loop here and this is + * a global counter, so the first cycle will get them. + */ + delta = memcg->vmstats->state_pending[i]; + if (delta) + memcg->vmstats->state_pending[i] = 0; + + /* Add CPU changes on this level since the last flush */ + v = READ_ONCE(statc->state[i]); + if (v != statc->state_prev[i]) { + delta += v - statc->state_prev[i]; + statc->state_prev[i] = v; + } + + if (!delta) + continue; + + /* Aggregate counts on this level and propagate upwards */ + memcg->vmstats->state[i] += delta; + if (parent) + parent->vmstats->state_pending[i] += delta; + } + + for (i = 0; i < NR_MEMCG_EVENTS; i++) { + delta = memcg->vmstats->events_pending[i]; + if (delta) + memcg->vmstats->events_pending[i] = 0; + + v = READ_ONCE(statc->events[i]); + if (v != statc->events_prev[i]) { + delta += v - statc->events_prev[i]; + statc->events_prev[i] = v; + } + + if (!delta) + continue; + + memcg->vmstats->events[i] += delta; + if (parent) + parent->vmstats->events_pending[i] += delta; + } + + for_each_node_state(nid, N_MEMORY) { + struct mem_cgroup_per_node *pn = memcg->nodeinfo[nid]; + struct mem_cgroup_per_node *ppn = NULL; + struct lruvec_stats_percpu *lstatc; + + if (parent) + ppn = parent->nodeinfo[nid]; + + lstatc = per_cpu_ptr(pn->lruvec_stats_percpu, cpu); + + for (i = 0; i < NR_VM_NODE_STAT_ITEMS; i++) { + delta = pn->lruvec_stats.state_pending[i]; + if (delta) + pn->lruvec_stats.state_pending[i] = 0; + + v = READ_ONCE(lstatc->state[i]); + if (v != lstatc->state_prev[i]) { + delta += v - lstatc->state_prev[i]; + lstatc->state_prev[i] = v; + } + + if (!delta) + continue; + + pn->lruvec_stats.state[i] += delta; + if (ppn) + ppn->lruvec_stats.state_pending[i] += delta; + } + } +} + #ifdef CONFIG_MMU /* Handlers for move charge at task migration. */ static int mem_cgroup_do_precharge(unsigned long count) @@ -5227,32 +5611,29 @@ static struct page *mc_handle_swap_pte(struct vm_area_struct *vma, struct page *page = NULL; swp_entry_t ent = pte_to_swp_entry(ptent); - if (!(mc.flags & MOVE_ANON) || non_swap_entry(ent)) + if (!(mc.flags & MOVE_ANON)) return NULL; /* - * Handle MEMORY_DEVICE_PRIVATE which are ZONE_DEVICE page belonging to - * a device and because they are not accessible by CPU they are store - * as special swap entry in the CPU page table. + * Handle device private pages that are not accessible by the CPU, but + * stored as special swap entries in the page table. */ if (is_device_private_entry(ent)) { - page = device_private_entry_to_page(ent); - /* - * MEMORY_DEVICE_PRIVATE means ZONE_DEVICE page and which have - * a refcount of 1 when free (unlike normal page) - */ - if (!page_ref_add_unless(page, 1, 1)) + page = pfn_swap_entry_to_page(ent); + if (!get_page_unless_zero(page)) return NULL; return page; } + if (non_swap_entry(ent)) + return NULL; + /* - * Because lookup_swap_cache() updates some statistics counter, + * Because swap_cache_get_folio() updates some statistics counter, * we call find_get_page() with swapper_space directly. */ page = find_get_page(swap_address_space(ent), swp_offset(ent)); - if (do_memsw_account()) - entry->val = ent.val; + entry->val = ent.val; return page; } @@ -5265,38 +5646,17 @@ static struct page *mc_handle_swap_pte(struct vm_area_struct *vma, #endif static struct page *mc_handle_file_pte(struct vm_area_struct *vma, - unsigned long addr, pte_t ptent, swp_entry_t *entry) + unsigned long addr, pte_t ptent) { - struct page *page = NULL; - struct address_space *mapping; - pgoff_t pgoff; - if (!vma->vm_file) /* anonymous vma */ return NULL; if (!(mc.flags & MOVE_FILE)) return NULL; - mapping = vma->vm_file->f_mapping; - pgoff = linear_page_index(vma, addr); - /* page is moved even if it's not RSS of this task(page-faulted). */ -#ifdef CONFIG_SWAP /* shmem/tmpfs may report page out on swap: account for that too. */ - if (shmem_mapping(mapping)) { - page = find_get_entry(mapping, pgoff); - if (xa_is_value(page)) { - swp_entry_t swp = radix_to_swp_entry(page); - if (do_memsw_account()) - *entry = swp; - page = find_get_page(swap_address_space(swp), - swp_offset(swp)); - } - } else - page = find_get_page(mapping, pgoff); -#else - page = find_get_page(mapping, pgoff); -#endif - return page; + return find_get_incore_page(vma->vm_file->f_mapping, + linear_page_index(vma, addr)); } /** @@ -5316,82 +5676,109 @@ static int mem_cgroup_move_account(struct page *page, struct mem_cgroup *from, struct mem_cgroup *to) { + struct folio *folio = page_folio(page); struct lruvec *from_vec, *to_vec; struct pglist_data *pgdat; - unsigned long flags; - unsigned int nr_pages = compound ? hpage_nr_pages(page) : 1; - int ret; - bool anon; + unsigned int nr_pages = compound ? folio_nr_pages(folio) : 1; + int nid, ret; VM_BUG_ON(from == to); - VM_BUG_ON_PAGE(PageLRU(page), page); - VM_BUG_ON(compound && !PageTransHuge(page)); + VM_BUG_ON_FOLIO(folio_test_lru(folio), folio); + VM_BUG_ON(compound && !folio_test_large(folio)); /* * Prevent mem_cgroup_migrate() from looking at - * page->mem_cgroup of its source page while we change it. + * page's memory cgroup of its source page while we change it. */ ret = -EBUSY; - if (!trylock_page(page)) + if (!folio_trylock(folio)) goto out; ret = -EINVAL; - if (page->mem_cgroup != from) + if (folio_memcg(folio) != from) goto out_unlock; - anon = PageAnon(page); - - pgdat = page_pgdat(page); + pgdat = folio_pgdat(folio); from_vec = mem_cgroup_lruvec(from, pgdat); to_vec = mem_cgroup_lruvec(to, pgdat); - spin_lock_irqsave(&from->move_lock, flags); + folio_memcg_lock(folio); + + if (folio_test_anon(folio)) { + if (folio_mapped(folio)) { + __mod_lruvec_state(from_vec, NR_ANON_MAPPED, -nr_pages); + __mod_lruvec_state(to_vec, NR_ANON_MAPPED, nr_pages); + if (folio_test_transhuge(folio)) { + __mod_lruvec_state(from_vec, NR_ANON_THPS, + -nr_pages); + __mod_lruvec_state(to_vec, NR_ANON_THPS, + nr_pages); + } + } + } else { + __mod_lruvec_state(from_vec, NR_FILE_PAGES, -nr_pages); + __mod_lruvec_state(to_vec, NR_FILE_PAGES, nr_pages); - if (!anon && page_mapped(page)) { - __mod_lruvec_state(from_vec, NR_FILE_MAPPED, -nr_pages); - __mod_lruvec_state(to_vec, NR_FILE_MAPPED, nr_pages); - } + if (folio_test_swapbacked(folio)) { + __mod_lruvec_state(from_vec, NR_SHMEM, -nr_pages); + __mod_lruvec_state(to_vec, NR_SHMEM, nr_pages); + } - /* - * move_lock grabbed above and caller set from->moving_account, so - * mod_memcg_page_state will serialize updates to PageDirty. - * So mapping should be stable for dirty pages. - */ - if (!anon && PageDirty(page)) { - struct address_space *mapping = page_mapping(page); + if (folio_mapped(folio)) { + __mod_lruvec_state(from_vec, NR_FILE_MAPPED, -nr_pages); + __mod_lruvec_state(to_vec, NR_FILE_MAPPED, nr_pages); + } + + if (folio_test_dirty(folio)) { + struct address_space *mapping = folio_mapping(folio); - if (mapping_cap_account_dirty(mapping)) { - __mod_lruvec_state(from_vec, NR_FILE_DIRTY, -nr_pages); - __mod_lruvec_state(to_vec, NR_FILE_DIRTY, nr_pages); + if (mapping_can_writeback(mapping)) { + __mod_lruvec_state(from_vec, NR_FILE_DIRTY, + -nr_pages); + __mod_lruvec_state(to_vec, NR_FILE_DIRTY, + nr_pages); + } } } - if (PageWriteback(page)) { + if (folio_test_writeback(folio)) { __mod_lruvec_state(from_vec, NR_WRITEBACK, -nr_pages); __mod_lruvec_state(to_vec, NR_WRITEBACK, nr_pages); } /* - * It is safe to change page->mem_cgroup here because the page - * is referenced, charged, and isolated - we can't race with - * uncharging, charging, migration, or LRU putback. + * All state has been migrated, let's switch to the new memcg. + * + * It is safe to change page's memcg here because the page + * is referenced, charged, isolated, and locked: we can't race + * with (un)charging, migration, LRU putback, or anything else + * that would rely on a stable page's memory cgroup. + * + * Note that lock_page_memcg is a memcg lock, not a page lock, + * to save space. As soon as we switch page's memory cgroup to a + * new memcg that isn't locked, the above state can change + * concurrently again. Make sure we're truly done with it. */ + smp_mb(); - /* caller should have done css_get */ - page->mem_cgroup = to; + css_get(&to->css); + css_put(&from->css); - spin_unlock_irqrestore(&from->move_lock, flags); + folio->memcg_data = (unsigned long)to; + + __folio_memcg_unlock(from); ret = 0; + nid = folio_nid(folio); local_irq_disable(); - mem_cgroup_charge_statistics(to, page, compound, nr_pages); - memcg_check_events(to, page); - mem_cgroup_charge_statistics(from, page, compound, -nr_pages); - memcg_check_events(from, page); + mem_cgroup_charge_statistics(to, nr_pages); + memcg_check_events(to, nid); + mem_cgroup_charge_statistics(from, -nr_pages); + memcg_check_events(from, nid); local_irq_enable(); out_unlock: - unlock_page(page); + folio_unlock(folio); out: return ret; } @@ -5411,8 +5798,8 @@ out: * 2(MC_TARGET_SWAP): if the swap entry corresponding to this pte is a * target for charge migration. if @target is not NULL, the entry is stored * in target->ent. - * 3(MC_TARGET_DEVICE): like MC_TARGET_PAGE but page is MEMORY_DEVICE_PRIVATE - * (so ZONE_DEVICE page and thus not on the lru). + * 3(MC_TARGET_DEVICE): like MC_TARGET_PAGE but page is device memory and + * thus not on the lru. * For now we such page is charge like a regular page would be as for all * intent and purposes it is just special memory taking the place of a * regular page. @@ -5431,10 +5818,14 @@ static enum mc_target_type get_mctgt_type(struct vm_area_struct *vma, if (pte_present(ptent)) page = mc_handle_present_pte(vma, addr, ptent); + else if (pte_none_mostly(ptent)) + /* + * PTE markers should be treated as a none pte here, separated + * from other swap handling below. + */ + page = mc_handle_file_pte(vma, addr, ptent); else if (is_swap_pte(ptent)) page = mc_handle_swap_pte(vma, ptent, &ent); - else if (pte_none(ptent)) - page = mc_handle_file_pte(vma, addr, ptent, &ent); if (!page && !ent.val) return ret; @@ -5444,9 +5835,10 @@ static enum mc_target_type get_mctgt_type(struct vm_area_struct *vma, * mem_cgroup_move_account() checks the page is valid or * not under LRU exclusion. */ - if (page->mem_cgroup == mc.from) { + if (page_memcg(page) == mc.from) { ret = MC_TARGET_PAGE; - if (is_device_private_page(page)) + if (is_device_private_page(page) || + is_device_coherent_page(page)) ret = MC_TARGET_DEVICE; if (target) target->page = page; @@ -5488,7 +5880,7 @@ static enum mc_target_type get_mctgt_type_thp(struct vm_area_struct *vma, VM_BUG_ON_PAGE(!page || !PageHead(page), page); if (!(mc.flags & MOVE_ANON)) return ret; - if (page->mem_cgroup == mc.from) { + if (page_memcg(page) == mc.from) { ret = MC_TARGET_PAGE; if (target) { get_page(page); @@ -5546,9 +5938,9 @@ static unsigned long mem_cgroup_count_precharge(struct mm_struct *mm) { unsigned long precharge; - down_read(&mm->mmap_sem); - walk_page_range(mm, 0, mm->highest_vm_end, &precharge_walk_ops, NULL); - up_read(&mm->mmap_sem); + mmap_read_lock(mm); + walk_page_range(mm, 0, ULONG_MAX, &precharge_walk_ops, NULL); + mmap_read_unlock(mm); precharge = mc.precharge; mc.precharge = 0; @@ -5599,9 +5991,6 @@ static void __mem_cgroup_clear_mc(void) if (!mem_cgroup_is_root(mc.to)) page_counter_uncharge(&mc.to->memory, mc.moved_swap); - mem_cgroup_id_get_many(mc.to, mc.moved_swap); - css_put_many(&mc.to->css, mc.moved_swap); - mc.moved_swap = 0; } memcg_oom_recover(from); @@ -5658,7 +6047,7 @@ static int mem_cgroup_can_attach(struct cgroup_taskset *tset) return 0; /* - * We are now commited to this value whatever it is. Changes in this + * We are now committed to this value whatever it is. Changes in this * tunable will only affect upcoming migrations, not the current one. * So we need to save it, and keep it going. */ @@ -5762,7 +6151,7 @@ retry: switch (get_mctgt_type(vma, addr, ptent, &target)) { case MC_TARGET_DEVICE: device = true; - /* fall through */ + fallthrough; case MC_TARGET_PAGE: page = target.page; /* @@ -5790,7 +6179,8 @@ put: /* get_mctgt_type() gets the page */ ent = target.ent; if (!mem_cgroup_move_swap_account(ent, mc.from, mc.to)) { mc.precharge--; - /* we fixup refcnts and charges later. */ + mem_cgroup_id_get_many(mc.to, 1); + /* we fixup other refcnts and charges later. */ mc.moved_swap++; } break; @@ -5831,9 +6221,9 @@ static void mem_cgroup_move_charge(void) atomic_inc(&mc.from->moving_account); synchronize_rcu(); retry: - if (unlikely(!down_read_trylock(&mc.mm->mmap_sem))) { + if (unlikely(!mmap_read_trylock(mc.mm))) { /* - * Someone who are holding the mmap_sem might be waiting in + * Someone who are holding the mmap_lock might be waiting in * waitq. So we cancel all extra charges, wake up all waiters, * and retry. Because we cancel precharges, we might not be able * to move enough charges, but moving charge is a best-effort @@ -5847,10 +6237,8 @@ retry: * When we have consumed all precharges and failed in doing * additional charge, the page walk just aborts. */ - walk_page_range(mc.mm, 0, mc.mm->highest_vm_end, &charge_walk_ops, - NULL); - - up_read(&mc.mm->mmap_sem); + walk_page_range(mc.mm, 0, ULONG_MAX, &charge_walk_ops, NULL); + mmap_read_unlock(mc.mm); atomic_dec(&mc.from->moving_account); } @@ -5874,23 +6262,29 @@ static void mem_cgroup_move_task(void) } #endif -/* - * Cgroup retains root cgroups across [un]mount cycles making it necessary - * to verify whether we're attached to the default hierarchy on each mount - * attempt. - */ -static void mem_cgroup_bind(struct cgroup_subsys_state *root_css) +#ifdef CONFIG_LRU_GEN +static void mem_cgroup_attach(struct cgroup_taskset *tset) { - /* - * use_hierarchy is forced on the default hierarchy. cgroup core - * guarantees that @root doesn't have any children, so turning it - * on for the root memcg is enough. - */ - if (cgroup_subsys_on_dfl(memory_cgrp_subsys)) - root_mem_cgroup->use_hierarchy = true; - else - root_mem_cgroup->use_hierarchy = false; + struct task_struct *task; + struct cgroup_subsys_state *css; + + /* find the first leader if there is any */ + cgroup_taskset_for_each_leader(task, css, tset) + break; + + if (!task) + return; + + task_lock(task); + if (task->mm && READ_ONCE(task->mm->owner) == task) + lru_gen_migrate_mm(task->mm); + task_unlock(task); } +#else +static void mem_cgroup_attach(struct cgroup_taskset *tset) +{ +} +#endif /* CONFIG_LRU_GEN */ static int seq_puts_memcg_tunable(struct seq_file *m, unsigned long value) { @@ -5910,6 +6304,14 @@ static u64 memory_current_read(struct cgroup_subsys_state *css, return (u64)page_counter_read(&memcg->memory) * PAGE_SIZE; } +static u64 memory_peak_read(struct cgroup_subsys_state *css, + struct cftype *cft) +{ + struct mem_cgroup *memcg = mem_cgroup_from_css(css); + + return (u64)memcg->memory.watermark * PAGE_SIZE; +} + static int memory_min_show(struct seq_file *m, void *v) { return seq_puts_memcg_tunable(m, @@ -5958,14 +6360,15 @@ static ssize_t memory_low_write(struct kernfs_open_file *of, static int memory_high_show(struct seq_file *m, void *v) { - return seq_puts_memcg_tunable(m, READ_ONCE(mem_cgroup_from_seq(m)->high)); + return seq_puts_memcg_tunable(m, + READ_ONCE(mem_cgroup_from_seq(m)->memory.high)); } static ssize_t memory_high_write(struct kernfs_open_file *of, char *buf, size_t nbytes, loff_t off) { struct mem_cgroup *memcg = mem_cgroup_from_css(of_css(of)); - unsigned int nr_retries = MEM_CGROUP_RECLAIM_RETRIES; + unsigned int nr_retries = MAX_RECLAIM_RETRIES; bool drained = false; unsigned long high; int err; @@ -5975,7 +6378,7 @@ static ssize_t memory_high_write(struct kernfs_open_file *of, if (err) return err; - memcg->high = high; + page_counter_set_high(&memcg->memory, high); for (;;) { unsigned long nr_pages = page_counter_read(&memcg->memory); @@ -5994,12 +6397,13 @@ static ssize_t memory_high_write(struct kernfs_open_file *of, } reclaimed = try_to_free_mem_cgroup_pages(memcg, nr_pages - high, - GFP_KERNEL, true); + GFP_KERNEL, MEMCG_RECLAIM_MAY_SWAP); if (!reclaimed && !nr_retries--) break; } + memcg_wb_domain_size_changed(memcg); return nbytes; } @@ -6013,7 +6417,7 @@ static ssize_t memory_max_write(struct kernfs_open_file *of, char *buf, size_t nbytes, loff_t off) { struct mem_cgroup *memcg = mem_cgroup_from_css(of_css(of)); - unsigned int nr_reclaims = MEM_CGROUP_RECLAIM_RETRIES; + unsigned int nr_reclaims = MAX_RECLAIM_RETRIES; bool drained = false; unsigned long max; int err; @@ -6042,7 +6446,7 @@ static ssize_t memory_max_write(struct kernfs_open_file *of, if (nr_reclaims) { if (!try_to_free_mem_cgroup_pages(memcg, nr_pages - max, - GFP_KERNEL, true)) + GFP_KERNEL, MEMCG_RECLAIM_MAY_SWAP)) nr_reclaims--; continue; } @@ -6064,6 +6468,8 @@ static void __memory_events_show(struct seq_file *m, atomic_long_t *events) seq_printf(m, "oom %lu\n", atomic_long_read(&events[MEMCG_OOM])); seq_printf(m, "oom_kill %lu\n", atomic_long_read(&events[MEMCG_OOM_KILL])); + seq_printf(m, "oom_group_kill %lu\n", + atomic_long_read(&events[MEMCG_OOM_GROUP_KILL])); } static int memory_events_show(struct seq_file *m, void *v) @@ -6085,16 +6491,53 @@ static int memory_events_local_show(struct seq_file *m, void *v) static int memory_stat_show(struct seq_file *m, void *v) { struct mem_cgroup *memcg = mem_cgroup_from_seq(m); - char *buf; + char *buf = kmalloc(PAGE_SIZE, GFP_KERNEL); - buf = memory_stat_format(memcg); if (!buf) return -ENOMEM; + memory_stat_format(memcg, buf, PAGE_SIZE); seq_puts(m, buf); kfree(buf); return 0; } +#ifdef CONFIG_NUMA +static inline unsigned long lruvec_page_state_output(struct lruvec *lruvec, + int item) +{ + return lruvec_page_state(lruvec, item) * memcg_page_state_unit(item); +} + +static int memory_numa_stat_show(struct seq_file *m, void *v) +{ + int i; + struct mem_cgroup *memcg = mem_cgroup_from_seq(m); + + mem_cgroup_flush_stats(); + + for (i = 0; i < ARRAY_SIZE(memory_stats); i++) { + int nid; + + if (memory_stats[i].idx >= NR_VM_NODE_STAT_ITEMS) + continue; + + seq_printf(m, "%s", memory_stats[i].name); + for_each_node_state(nid, N_MEMORY) { + u64 size; + struct lruvec *lruvec; + + lruvec = mem_cgroup_lruvec(memcg, NODE_DATA(nid)); + size = lruvec_page_state_output(lruvec, + memory_stats[i].idx); + seq_printf(m, " N%d=%llu", nid, size); + } + seq_putc(m, '\n'); + } + + return 0; +} +#endif + static int memory_oom_group_show(struct seq_file *m, void *v) { struct mem_cgroup *memcg = mem_cgroup_from_seq(m); @@ -6126,6 +6569,48 @@ static ssize_t memory_oom_group_write(struct kernfs_open_file *of, return nbytes; } +static ssize_t memory_reclaim(struct kernfs_open_file *of, char *buf, + size_t nbytes, loff_t off) +{ + struct mem_cgroup *memcg = mem_cgroup_from_css(of_css(of)); + unsigned int nr_retries = MAX_RECLAIM_RETRIES; + unsigned long nr_to_reclaim, nr_reclaimed = 0; + unsigned int reclaim_options; + int err; + + buf = strstrip(buf); + err = page_counter_memparse(buf, "", &nr_to_reclaim); + if (err) + return err; + + reclaim_options = MEMCG_RECLAIM_MAY_SWAP | MEMCG_RECLAIM_PROACTIVE; + while (nr_reclaimed < nr_to_reclaim) { + unsigned long reclaimed; + + if (signal_pending(current)) + return -EINTR; + + /* + * This is the final attempt, drain percpu lru caches in the + * hope of introducing more evictable pages for + * try_to_free_mem_cgroup_pages(). + */ + if (!nr_retries) + lru_add_drain_all(); + + reclaimed = try_to_free_mem_cgroup_pages(memcg, + nr_to_reclaim - nr_reclaimed, + GFP_KERNEL, reclaim_options); + + if (!reclaimed && !nr_retries--) + return -EAGAIN; + + nr_reclaimed += reclaimed; + } + + return nbytes; +} + static struct cftype memory_files[] = { { .name = "current", @@ -6133,6 +6618,11 @@ static struct cftype memory_files[] = { .read_u64 = memory_current_read, }, { + .name = "peak", + .flags = CFTYPE_NOT_ON_ROOT, + .read_u64 = memory_peak_read, + }, + { .name = "min", .flags = CFTYPE_NOT_ON_ROOT, .seq_show = memory_min_show, @@ -6170,15 +6660,25 @@ static struct cftype memory_files[] = { }, { .name = "stat", - .flags = CFTYPE_NOT_ON_ROOT, .seq_show = memory_stat_show, }, +#ifdef CONFIG_NUMA + { + .name = "numa_stat", + .seq_show = memory_numa_stat_show, + }, +#endif { .name = "oom.group", .flags = CFTYPE_NOT_ON_ROOT | CFTYPE_NS_DELEGATABLE, .seq_show = memory_oom_group_show, .write = memory_oom_group_write, }, + { + .name = "reclaim", + .flags = CFTYPE_NS_DELEGATABLE, + .write = memory_reclaim, + }, { } /* terminate */ }; @@ -6189,321 +6689,294 @@ struct cgroup_subsys memory_cgrp_subsys = { .css_released = mem_cgroup_css_released, .css_free = mem_cgroup_css_free, .css_reset = mem_cgroup_css_reset, + .css_rstat_flush = mem_cgroup_css_rstat_flush, .can_attach = mem_cgroup_can_attach, + .attach = mem_cgroup_attach, .cancel_attach = mem_cgroup_cancel_attach, .post_attach = mem_cgroup_move_task, - .bind = mem_cgroup_bind, .dfl_cftypes = memory_files, .legacy_cftypes = mem_cgroup_legacy_files, .early_init = 0, }; -/** - * mem_cgroup_protected - check if memory consumption is in the normal range - * @root: the top ancestor of the sub-tree being checked - * @memcg: the memory cgroup to check - * - * WARNING: This function is not stateless! It can only be used as part - * of a top-down tree iteration, not for isolated queries. - * - * Returns one of the following: - * MEMCG_PROT_NONE: cgroup memory is not protected - * MEMCG_PROT_LOW: cgroup memory is protected as long there is - * an unprotected supply of reclaimable memory from other cgroups. - * MEMCG_PROT_MIN: cgroup memory is protected - * - * @root is exclusive; it is never protected when looked at directly - * - * To provide a proper hierarchical behavior, effective memory.min/low values - * are used. Below is the description of how effective memory.low is calculated. - * Effective memory.min values is calculated in the same way. - * - * Effective memory.low is always equal or less than the original memory.low. - * If there is no memory.low overcommittment (which is always true for - * top-level memory cgroups), these two values are equal. - * Otherwise, it's a part of parent's effective memory.low, - * calculated as a cgroup's memory.low usage divided by sum of sibling's - * memory.low usages, where memory.low usage is the size of actually - * protected memory. - * - * low_usage - * elow = min( memory.low, parent->elow * ------------------ ), - * siblings_low_usage +/* + * This function calculates an individual cgroup's effective + * protection which is derived from its own memory.min/low, its + * parent's and siblings' settings, as well as the actual memory + * distribution in the tree. * - * | memory.current, if memory.current < memory.low - * low_usage = | - * | 0, otherwise. + * The following rules apply to the effective protection values: * + * 1. At the first level of reclaim, effective protection is equal to + * the declared protection in memory.min and memory.low. * - * Such definition of the effective memory.low provides the expected - * hierarchical behavior: parent's memory.low value is limiting - * children, unprotected memory is reclaimed first and cgroups, - * which are not using their guarantee do not affect actual memory - * distribution. + * 2. To enable safe delegation of the protection configuration, at + * subsequent levels the effective protection is capped to the + * parent's effective protection. * - * For example, if there are memcgs A, A/B, A/C, A/D and A/E: + * 3. To make complex and dynamic subtrees easier to configure, the + * user is allowed to overcommit the declared protection at a given + * level. If that is the case, the parent's effective protection is + * distributed to the children in proportion to how much protection + * they have declared and how much of it they are utilizing. * - * A A/memory.low = 2G, A/memory.current = 6G - * //\\ - * BC DE B/memory.low = 3G B/memory.current = 2G - * C/memory.low = 1G C/memory.current = 2G - * D/memory.low = 0 D/memory.current = 2G - * E/memory.low = 10G E/memory.current = 0 + * This makes distribution proportional, but also work-conserving: + * if one cgroup claims much more protection than it uses memory, + * the unused remainder is available to its siblings. * - * and the memory pressure is applied, the following memory distribution - * is expected (approximately): + * 4. Conversely, when the declared protection is undercommitted at a + * given level, the distribution of the larger parental protection + * budget is NOT proportional. A cgroup's protection from a sibling + * is capped to its own memory.min/low setting. * - * A/memory.current = 2G + * 5. However, to allow protecting recursive subtrees from each other + * without having to declare each individual cgroup's fixed share + * of the ancestor's claim to protection, any unutilized - + * "floating" - protection from up the tree is distributed in + * proportion to each cgroup's *usage*. This makes the protection + * neutral wrt sibling cgroups and lets them compete freely over + * the shared parental protection budget, but it protects the + * subtree as a whole from neighboring subtrees. * - * B/memory.current = 1.3G - * C/memory.current = 0.6G - * D/memory.current = 0 - * E/memory.current = 0 + * Note that 4. and 5. are not in conflict: 4. is about protecting + * against immediate siblings whereas 5. is about protecting against + * neighboring subtrees. + */ +static unsigned long effective_protection(unsigned long usage, + unsigned long parent_usage, + unsigned long setting, + unsigned long parent_effective, + unsigned long siblings_protected) +{ + unsigned long protected; + unsigned long ep; + + protected = min(usage, setting); + /* + * If all cgroups at this level combined claim and use more + * protection then what the parent affords them, distribute + * shares in proportion to utilization. + * + * We are using actual utilization rather than the statically + * claimed protection in order to be work-conserving: claimed + * but unused protection is available to siblings that would + * otherwise get a smaller chunk than what they claimed. + */ + if (siblings_protected > parent_effective) + return protected * parent_effective / siblings_protected; + + /* + * Ok, utilized protection of all children is within what the + * parent affords them, so we know whatever this child claims + * and utilizes is effectively protected. + * + * If there is unprotected usage beyond this value, reclaim + * will apply pressure in proportion to that amount. + * + * If there is unutilized protection, the cgroup will be fully + * shielded from reclaim, but we do return a smaller value for + * protection than what the group could enjoy in theory. This + * is okay. With the overcommit distribution above, effective + * protection is always dependent on how memory is actually + * consumed among the siblings anyway. + */ + ep = protected; + + /* + * If the children aren't claiming (all of) the protection + * afforded to them by the parent, distribute the remainder in + * proportion to the (unprotected) memory of each cgroup. That + * way, cgroups that aren't explicitly prioritized wrt each + * other compete freely over the allowance, but they are + * collectively protected from neighboring trees. + * + * We're using unprotected memory for the weight so that if + * some cgroups DO claim explicit protection, we don't protect + * the same bytes twice. + * + * Check both usage and parent_usage against the respective + * protected values. One should imply the other, but they + * aren't read atomically - make sure the division is sane. + */ + if (!(cgrp_dfl_root.flags & CGRP_ROOT_MEMORY_RECURSIVE_PROT)) + return ep; + if (parent_effective > siblings_protected && + parent_usage > siblings_protected && + usage > protected) { + unsigned long unclaimed; + + unclaimed = parent_effective - siblings_protected; + unclaimed *= usage - protected; + unclaimed /= parent_usage - siblings_protected; + + ep += unclaimed; + } + + return ep; +} + +/** + * mem_cgroup_calculate_protection - check if memory consumption is in the normal range + * @root: the top ancestor of the sub-tree being checked + * @memcg: the memory cgroup to check * - * These calculations require constant tracking of the actual low usages - * (see propagate_protected_usage()), as well as recursive calculation of - * effective memory.low values. But as we do call mem_cgroup_protected() - * path for each memory cgroup top-down from the reclaim, - * it's possible to optimize this part, and save calculated elow - * for next usage. This part is intentionally racy, but it's ok, - * as memory.low is a best-effort mechanism. + * WARNING: This function is not stateless! It can only be used as part + * of a top-down tree iteration, not for isolated queries. */ -enum mem_cgroup_protection mem_cgroup_protected(struct mem_cgroup *root, - struct mem_cgroup *memcg) +void mem_cgroup_calculate_protection(struct mem_cgroup *root, + struct mem_cgroup *memcg) { + unsigned long usage, parent_usage; struct mem_cgroup *parent; - unsigned long emin, parent_emin; - unsigned long elow, parent_elow; - unsigned long usage; if (mem_cgroup_disabled()) - return MEMCG_PROT_NONE; + return; if (!root) root = root_mem_cgroup; + + /* + * Effective values of the reclaim targets are ignored so they + * can be stale. Have a look at mem_cgroup_protection for more + * details. + * TODO: calculation should be more robust so that we do not need + * that special casing. + */ if (memcg == root) - return MEMCG_PROT_NONE; + return; usage = page_counter_read(&memcg->memory); if (!usage) - return MEMCG_PROT_NONE; - - emin = memcg->memory.min; - elow = memcg->memory.low; + return; parent = parent_mem_cgroup(memcg); - /* No parent means a non-hierarchical mode on v1 memcg */ - if (!parent) - return MEMCG_PROT_NONE; - - if (parent == root) - goto exit; - - parent_emin = READ_ONCE(parent->memory.emin); - emin = min(emin, parent_emin); - if (emin && parent_emin) { - unsigned long min_usage, siblings_min_usage; - - min_usage = min(usage, memcg->memory.min); - siblings_min_usage = atomic_long_read( - &parent->memory.children_min_usage); - if (min_usage && siblings_min_usage) - emin = min(emin, parent_emin * min_usage / - siblings_min_usage); + if (parent == root) { + memcg->memory.emin = READ_ONCE(memcg->memory.min); + memcg->memory.elow = READ_ONCE(memcg->memory.low); + return; } - parent_elow = READ_ONCE(parent->memory.elow); - elow = min(elow, parent_elow); - if (elow && parent_elow) { - unsigned long low_usage, siblings_low_usage; - - low_usage = min(usage, memcg->memory.low); - siblings_low_usage = atomic_long_read( - &parent->memory.children_low_usage); - - if (low_usage && siblings_low_usage) - elow = min(elow, parent_elow * low_usage / - siblings_low_usage); - } + parent_usage = page_counter_read(&parent->memory); -exit: - memcg->memory.emin = emin; - memcg->memory.elow = elow; + WRITE_ONCE(memcg->memory.emin, effective_protection(usage, parent_usage, + READ_ONCE(memcg->memory.min), + READ_ONCE(parent->memory.emin), + atomic_long_read(&parent->memory.children_min_usage))); - if (usage <= emin) - return MEMCG_PROT_MIN; - else if (usage <= elow) - return MEMCG_PROT_LOW; - else - return MEMCG_PROT_NONE; + WRITE_ONCE(memcg->memory.elow, effective_protection(usage, parent_usage, + READ_ONCE(memcg->memory.low), + READ_ONCE(parent->memory.elow), + atomic_long_read(&parent->memory.children_low_usage))); } -/** - * mem_cgroup_try_charge - try charging a page - * @page: page to charge - * @mm: mm context of the victim - * @gfp_mask: reclaim mode - * @memcgp: charged memcg return - * @compound: charge the page as compound or small page - * - * Try to charge @page to the memcg that @mm belongs to, reclaiming - * pages according to @gfp_mask if necessary. - * - * Returns 0 on success, with *@memcgp pointing to the charged memcg. - * Otherwise, an error code is returned. - * - * After page->mapping has been set up, the caller must finalize the - * charge with mem_cgroup_commit_charge(). Or abort the transaction - * with mem_cgroup_cancel_charge() in case page instantiation fails. - */ -int mem_cgroup_try_charge(struct page *page, struct mm_struct *mm, - gfp_t gfp_mask, struct mem_cgroup **memcgp, - bool compound) +static int charge_memcg(struct folio *folio, struct mem_cgroup *memcg, + gfp_t gfp) { - struct mem_cgroup *memcg = NULL; - unsigned int nr_pages = compound ? hpage_nr_pages(page) : 1; - int ret = 0; + long nr_pages = folio_nr_pages(folio); + int ret; - if (mem_cgroup_disabled()) + ret = try_charge(memcg, gfp, nr_pages); + if (ret) goto out; - if (PageSwapCache(page)) { - /* - * Every swap fault against a single page tries to charge the - * page, bail as early as possible. shmem_unuse() encounters - * already charged pages, too. The USED bit is protected by - * the page lock, which serializes swap cache removal, which - * in turn serializes uncharging. - */ - VM_BUG_ON_PAGE(!PageLocked(page), page); - if (compound_head(page)->mem_cgroup) - goto out; - - if (do_swap_account) { - swp_entry_t ent = { .val = page_private(page), }; - unsigned short id = lookup_swap_cgroup_id(ent); - - rcu_read_lock(); - memcg = mem_cgroup_from_id(id); - if (memcg && !css_tryget_online(&memcg->css)) - memcg = NULL; - rcu_read_unlock(); - } - } + css_get(&memcg->css); + commit_charge(folio, memcg); - if (!memcg) - memcg = get_mem_cgroup_from_mm(mm); - - ret = try_charge(memcg, gfp_mask, nr_pages); - - css_put(&memcg->css); + local_irq_disable(); + mem_cgroup_charge_statistics(memcg, nr_pages); + memcg_check_events(memcg, folio_nid(folio)); + local_irq_enable(); out: - *memcgp = memcg; return ret; } -int mem_cgroup_try_charge_delay(struct page *page, struct mm_struct *mm, - gfp_t gfp_mask, struct mem_cgroup **memcgp, - bool compound) +int __mem_cgroup_charge(struct folio *folio, struct mm_struct *mm, gfp_t gfp) { struct mem_cgroup *memcg; int ret; - ret = mem_cgroup_try_charge(page, mm, gfp_mask, memcgp, compound); - memcg = *memcgp; - mem_cgroup_throttle_swaprate(memcg, page_to_nid(page), gfp_mask); + memcg = get_mem_cgroup_from_mm(mm); + ret = charge_memcg(folio, memcg, gfp); + css_put(&memcg->css); + return ret; } /** - * mem_cgroup_commit_charge - commit a page charge - * @page: page to charge - * @memcg: memcg to charge the page to - * @lrucare: page might be on LRU already - * @compound: charge the page as compound or small page - * - * Finalize a charge transaction started by mem_cgroup_try_charge(), - * after page->mapping has been set up. This must happen atomically - * as part of the page instantiation, i.e. under the page table lock - * for anonymous pages, under the page lock for page and swap cache. + * mem_cgroup_swapin_charge_folio - Charge a newly allocated folio for swapin. + * @folio: folio to charge. + * @mm: mm context of the victim + * @gfp: reclaim mode + * @entry: swap entry for which the folio is allocated * - * In addition, the page must not be on the LRU during the commit, to - * prevent racing with task migration. If it might be, use @lrucare. + * This function charges a folio allocated for swapin. Please call this before + * adding the folio to the swapcache. * - * Use mem_cgroup_cancel_charge() to cancel the transaction instead. + * Returns 0 on success. Otherwise, an error code is returned. */ -void mem_cgroup_commit_charge(struct page *page, struct mem_cgroup *memcg, - bool lrucare, bool compound) +int mem_cgroup_swapin_charge_folio(struct folio *folio, struct mm_struct *mm, + gfp_t gfp, swp_entry_t entry) { - unsigned int nr_pages = compound ? hpage_nr_pages(page) : 1; - - VM_BUG_ON_PAGE(!page->mapping, page); - VM_BUG_ON_PAGE(PageLRU(page) && !lrucare, page); + struct mem_cgroup *memcg; + unsigned short id; + int ret; if (mem_cgroup_disabled()) - return; - /* - * Swap faults will attempt to charge the same page multiple - * times. But reuse_swap_page() might have removed the page - * from swapcache already, so we can't check PageSwapCache(). - */ - if (!memcg) - return; + return 0; - commit_charge(page, memcg, lrucare); + id = lookup_swap_cgroup_id(entry); + rcu_read_lock(); + memcg = mem_cgroup_from_id(id); + if (!memcg || !css_tryget_online(&memcg->css)) + memcg = get_mem_cgroup_from_mm(mm); + rcu_read_unlock(); - local_irq_disable(); - mem_cgroup_charge_statistics(memcg, page, compound, nr_pages); - memcg_check_events(memcg, page); - local_irq_enable(); + ret = charge_memcg(folio, memcg, gfp); - if (do_memsw_account() && PageSwapCache(page)) { - swp_entry_t entry = { .val = page_private(page) }; - /* - * The swap entry might not get freed for a long time, - * let's not wait for it. The page already received a - * memory+swap charge, drop the swap entry duplicate. - */ - mem_cgroup_uncharge_swap(entry, nr_pages); - } + css_put(&memcg->css); + return ret; } -/** - * mem_cgroup_cancel_charge - cancel a page charge - * @page: page to charge - * @memcg: memcg to charge the page to - * @compound: charge the page as compound or small page +/* + * mem_cgroup_swapin_uncharge_swap - uncharge swap slot + * @entry: swap entry for which the page is charged + * + * Call this function after successfully adding the charged page to swapcache. * - * Cancel a charge transaction started by mem_cgroup_try_charge(). + * Note: This function assumes the page for which swap slot is being uncharged + * is order 0 page. */ -void mem_cgroup_cancel_charge(struct page *page, struct mem_cgroup *memcg, - bool compound) +void mem_cgroup_swapin_uncharge_swap(swp_entry_t entry) { - unsigned int nr_pages = compound ? hpage_nr_pages(page) : 1; - - if (mem_cgroup_disabled()) - return; /* - * Swap faults will attempt to charge the same page multiple - * times. But reuse_swap_page() might have removed the page - * from swapcache already, so we can't check PageSwapCache(). + * Cgroup1's unified memory+swap counter has been charged with the + * new swapcache page, finish the transfer by uncharging the swap + * slot. The swap slot would also get uncharged when it dies, but + * it can stick around indefinitely and we'd count the page twice + * the entire time. + * + * Cgroup2 has separate resource counters for memory and swap, + * so this is a non-issue here. Memory and swap charge lifetimes + * correspond 1:1 to page and swap slot lifetimes: we charge the + * page to memory here, and uncharge swap when the slot is freed. */ - if (!memcg) - return; - - cancel_charge(memcg, nr_pages); + if (!mem_cgroup_disabled() && do_memsw_account()) { + /* + * The swap entry might not get freed for a long time, + * let's not wait for it. The page already received a + * memory+swap charge, drop the swap entry duplicate. + */ + mem_cgroup_uncharge_swap(entry, 1); + } } struct uncharge_gather { struct mem_cgroup *memcg; + unsigned long nr_memory; unsigned long pgpgout; - unsigned long nr_anon; - unsigned long nr_file; unsigned long nr_kmem; - unsigned long nr_huge; - unsigned long nr_shmem; - struct page *dummy_page; + int nid; }; static inline void uncharge_gather_clear(struct uncharge_gather *ug) @@ -6513,191 +6986,164 @@ static inline void uncharge_gather_clear(struct uncharge_gather *ug) static void uncharge_batch(const struct uncharge_gather *ug) { - unsigned long nr_pages = ug->nr_anon + ug->nr_file + ug->nr_kmem; unsigned long flags; - if (!mem_cgroup_is_root(ug->memcg)) { - page_counter_uncharge(&ug->memcg->memory, nr_pages); + if (ug->nr_memory) { + page_counter_uncharge(&ug->memcg->memory, ug->nr_memory); if (do_memsw_account()) - page_counter_uncharge(&ug->memcg->memsw, nr_pages); - if (!cgroup_subsys_on_dfl(memory_cgrp_subsys) && ug->nr_kmem) - page_counter_uncharge(&ug->memcg->kmem, ug->nr_kmem); + page_counter_uncharge(&ug->memcg->memsw, ug->nr_memory); + if (ug->nr_kmem) + memcg_account_kmem(ug->memcg, -ug->nr_kmem); memcg_oom_recover(ug->memcg); } local_irq_save(flags); - __mod_memcg_state(ug->memcg, MEMCG_RSS, -ug->nr_anon); - __mod_memcg_state(ug->memcg, MEMCG_CACHE, -ug->nr_file); - __mod_memcg_state(ug->memcg, MEMCG_RSS_HUGE, -ug->nr_huge); - __mod_memcg_state(ug->memcg, NR_SHMEM, -ug->nr_shmem); __count_memcg_events(ug->memcg, PGPGOUT, ug->pgpgout); - __this_cpu_add(ug->memcg->vmstats_percpu->nr_page_events, nr_pages); - memcg_check_events(ug->memcg, ug->dummy_page); + __this_cpu_add(ug->memcg->vmstats_percpu->nr_page_events, ug->nr_memory); + memcg_check_events(ug->memcg, ug->nid); local_irq_restore(flags); - if (!mem_cgroup_is_root(ug->memcg)) - css_put_many(&ug->memcg->css, nr_pages); + /* drop reference from uncharge_folio */ + css_put(&ug->memcg->css); } -static void uncharge_page(struct page *page, struct uncharge_gather *ug) +static void uncharge_folio(struct folio *folio, struct uncharge_gather *ug) { - VM_BUG_ON_PAGE(PageLRU(page), page); - VM_BUG_ON_PAGE(page_count(page) && !is_zone_device_page(page) && - !PageHWPoison(page) , page); + long nr_pages; + struct mem_cgroup *memcg; + struct obj_cgroup *objcg; - if (!page->mem_cgroup) - return; + VM_BUG_ON_FOLIO(folio_test_lru(folio), folio); /* * Nobody should be changing or seriously looking at - * page->mem_cgroup at this point, we have fully - * exclusive access to the page. + * folio memcg or objcg at this point, we have fully + * exclusive access to the folio. */ + if (folio_memcg_kmem(folio)) { + objcg = __folio_objcg(folio); + /* + * This get matches the put at the end of the function and + * kmem pages do not hold memcg references anymore. + */ + memcg = get_mem_cgroup_from_objcg(objcg); + } else { + memcg = __folio_memcg(folio); + } - if (ug->memcg != page->mem_cgroup) { + if (!memcg) + return; + + if (ug->memcg != memcg) { if (ug->memcg) { uncharge_batch(ug); uncharge_gather_clear(ug); } - ug->memcg = page->mem_cgroup; - } - - if (!PageKmemcg(page)) { - unsigned int nr_pages = 1; + ug->memcg = memcg; + ug->nid = folio_nid(folio); - if (PageTransHuge(page)) { - nr_pages = compound_nr(page); - ug->nr_huge += nr_pages; - } - if (PageAnon(page)) - ug->nr_anon += nr_pages; - else { - ug->nr_file += nr_pages; - if (PageSwapBacked(page)) - ug->nr_shmem += nr_pages; - } - ug->pgpgout++; - } else { - ug->nr_kmem += compound_nr(page); - __ClearPageKmemcg(page); + /* pairs with css_put in uncharge_batch */ + css_get(&memcg->css); } - ug->dummy_page = page; - page->mem_cgroup = NULL; -} - -static void uncharge_list(struct list_head *page_list) -{ - struct uncharge_gather ug; - struct list_head *next; + nr_pages = folio_nr_pages(folio); - uncharge_gather_clear(&ug); + if (folio_memcg_kmem(folio)) { + ug->nr_memory += nr_pages; + ug->nr_kmem += nr_pages; - /* - * Note that the list can be a single page->lru; hence the - * do-while loop instead of a simple list_for_each_entry(). - */ - next = page_list->next; - do { - struct page *page; - - page = list_entry(next, struct page, lru); - next = page->lru.next; + folio->memcg_data = 0; + obj_cgroup_put(objcg); + } else { + /* LRU pages aren't accounted at the root level */ + if (!mem_cgroup_is_root(memcg)) + ug->nr_memory += nr_pages; + ug->pgpgout++; - uncharge_page(page, &ug); - } while (next != page_list); + folio->memcg_data = 0; + } - if (ug.memcg) - uncharge_batch(&ug); + css_put(&memcg->css); } -/** - * mem_cgroup_uncharge - uncharge a page - * @page: page to uncharge - * - * Uncharge a page previously charged with mem_cgroup_try_charge() and - * mem_cgroup_commit_charge(). - */ -void mem_cgroup_uncharge(struct page *page) +void __mem_cgroup_uncharge(struct folio *folio) { struct uncharge_gather ug; - if (mem_cgroup_disabled()) - return; - - /* Don't touch page->lru of any random page, pre-check: */ - if (!page->mem_cgroup) + /* Don't touch folio->lru of any random page, pre-check: */ + if (!folio_memcg(folio)) return; uncharge_gather_clear(&ug); - uncharge_page(page, &ug); + uncharge_folio(folio, &ug); uncharge_batch(&ug); } /** - * mem_cgroup_uncharge_list - uncharge a list of page + * __mem_cgroup_uncharge_list - uncharge a list of page * @page_list: list of pages to uncharge * * Uncharge a list of pages previously charged with - * mem_cgroup_try_charge() and mem_cgroup_commit_charge(). + * __mem_cgroup_charge(). */ -void mem_cgroup_uncharge_list(struct list_head *page_list) +void __mem_cgroup_uncharge_list(struct list_head *page_list) { - if (mem_cgroup_disabled()) - return; + struct uncharge_gather ug; + struct folio *folio; - if (!list_empty(page_list)) - uncharge_list(page_list); + uncharge_gather_clear(&ug); + list_for_each_entry(folio, page_list, lru) + uncharge_folio(folio, &ug); + if (ug.memcg) + uncharge_batch(&ug); } /** - * mem_cgroup_migrate - charge a page's replacement - * @oldpage: currently circulating page - * @newpage: replacement page + * mem_cgroup_migrate - Charge a folio's replacement. + * @old: Currently circulating folio. + * @new: Replacement folio. * - * Charge @newpage as a replacement page for @oldpage. @oldpage will + * Charge @new as a replacement folio for @old. @old will * be uncharged upon free. * - * Both pages must be locked, @newpage->mapping must be set up. + * Both folios must be locked, @new->mapping must be set up. */ -void mem_cgroup_migrate(struct page *oldpage, struct page *newpage) +void mem_cgroup_migrate(struct folio *old, struct folio *new) { struct mem_cgroup *memcg; - unsigned int nr_pages; + long nr_pages = folio_nr_pages(new); unsigned long flags; - VM_BUG_ON_PAGE(!PageLocked(oldpage), oldpage); - VM_BUG_ON_PAGE(!PageLocked(newpage), newpage); - VM_BUG_ON_PAGE(PageAnon(oldpage) != PageAnon(newpage), newpage); - VM_BUG_ON_PAGE(PageTransHuge(oldpage) != PageTransHuge(newpage), - newpage); + VM_BUG_ON_FOLIO(!folio_test_locked(old), old); + VM_BUG_ON_FOLIO(!folio_test_locked(new), new); + VM_BUG_ON_FOLIO(folio_test_anon(old) != folio_test_anon(new), new); + VM_BUG_ON_FOLIO(folio_nr_pages(old) != nr_pages, new); if (mem_cgroup_disabled()) return; - /* Page cache replacement: new page already charged? */ - if (newpage->mem_cgroup) + /* Page cache replacement: new folio already charged? */ + if (folio_memcg(new)) return; - /* Swapcache readahead pages can get replaced before being charged */ - memcg = oldpage->mem_cgroup; + memcg = folio_memcg(old); + VM_WARN_ON_ONCE_FOLIO(!memcg, old); if (!memcg) return; /* Force-charge the new page. The old one will be freed soon */ - nr_pages = hpage_nr_pages(newpage); - - page_counter_charge(&memcg->memory, nr_pages); - if (do_memsw_account()) - page_counter_charge(&memcg->memsw, nr_pages); - css_get_many(&memcg->css, nr_pages); + if (!mem_cgroup_is_root(memcg)) { + page_counter_charge(&memcg->memory, nr_pages); + if (do_memsw_account()) + page_counter_charge(&memcg->memsw, nr_pages); + } - commit_charge(newpage, memcg, false); + css_get(&memcg->css); + commit_charge(new, memcg); local_irq_save(flags); - mem_cgroup_charge_statistics(memcg, newpage, PageTransHuge(newpage), - nr_pages); - memcg_check_events(memcg, newpage); + mem_cgroup_charge_statistics(memcg, nr_pages); + memcg_check_events(memcg, folio_nid(new)); local_irq_restore(flags); } @@ -6712,7 +7158,7 @@ void mem_cgroup_sk_alloc(struct sock *sk) return; /* Do not associate the sock with unrelated interrupted task's memcg. */ - if (in_interrupt()) + if (!in_task()) return; rcu_read_lock(); @@ -6721,7 +7167,7 @@ void mem_cgroup_sk_alloc(struct sock *sk) goto out; if (!cgroup_subsys_on_dfl(memory_cgrp_subsys) && !memcg->tcpmem_active) goto out; - if (css_tryget_online(&memcg->css)) + if (css_tryget(&memcg->css)) sk->sk_memcg = memcg; out: rcu_read_unlock(); @@ -6737,14 +7183,14 @@ void mem_cgroup_sk_free(struct sock *sk) * mem_cgroup_charge_skmem - charge socket memory * @memcg: memcg to charge * @nr_pages: number of pages to charge + * @gfp_mask: reclaim mode * * Charges @nr_pages to @memcg. Returns %true if the charge fit within - * @memcg's configured limit, %false if the charge had to be forced. + * @memcg's configured limit, %false if it doesn't. */ -bool mem_cgroup_charge_skmem(struct mem_cgroup *memcg, unsigned int nr_pages) +bool mem_cgroup_charge_skmem(struct mem_cgroup *memcg, unsigned int nr_pages, + gfp_t gfp_mask) { - gfp_t gfp_mask = GFP_KERNEL; - if (!cgroup_subsys_on_dfl(memory_cgrp_subsys)) { struct page_counter *fail; @@ -6752,21 +7198,19 @@ bool mem_cgroup_charge_skmem(struct mem_cgroup *memcg, unsigned int nr_pages) memcg->tcpmem_pressure = 0; return true; } - page_counter_charge(&memcg->tcpmem, nr_pages); memcg->tcpmem_pressure = 1; + if (gfp_mask & __GFP_NOFAIL) { + page_counter_charge(&memcg->tcpmem, nr_pages); + return true; + } return false; } - /* Don't block in the packet receive path */ - if (in_softirq()) - gfp_mask = GFP_NOWAIT; - - mod_memcg_state(memcg, MEMCG_SOCK, nr_pages); - - if (try_charge(memcg, gfp_mask, nr_pages) == 0) + if (try_charge(memcg, gfp_mask, nr_pages) == 0) { + mod_memcg_state(memcg, MEMCG_SOCK, nr_pages); return true; + } - try_charge(memcg, gfp_mask|__GFP_NOFAIL, nr_pages); return false; } @@ -6799,7 +7243,7 @@ static int __init cgroup_memory(char *s) if (!strcmp(token, "nokmem")) cgroup_memory_nokmem = true; } - return 0; + return 1; } __setup("cgroup.memory=", cgroup_memory); @@ -6815,16 +7259,13 @@ static int __init mem_cgroup_init(void) { int cpu, node; -#ifdef CONFIG_MEMCG_KMEM /* - * Kmem cache creation is mostly done with the slab_mutex held, - * so use a workqueue with limited concurrency to avoid stalling - * all worker threads in case lots of cgroups are created and - * destroyed simultaneously. + * Currently s32 type (can refer to struct batched_lruvec_stat) is + * used for per-memcg-per-cpu caching of per-node statistics. In order + * to work fine, we should make sure that the overfill threshold can't + * exceed S32_MAX / PAGE_SIZE. */ - memcg_kmem_cache_wq = alloc_workqueue("memcg_kmem_cache", 0, 1); - BUG_ON(!memcg_kmem_cache_wq); -#endif + BUILD_BUG_ON(MEMCG_CHARGE_BATCH > S32_MAX / PAGE_SIZE); cpuhp_setup_state_nocalls(CPUHP_MM_MEMCQ_DEAD, "mm/memctrl:dead", NULL, memcg_hotplug_cpu_dead); @@ -6849,7 +7290,7 @@ static int __init mem_cgroup_init(void) } subsys_initcall(mem_cgroup_init); -#ifdef CONFIG_MEMCG_SWAP +#ifdef CONFIG_SWAP static struct mem_cgroup *mem_cgroup_id_get_online(struct mem_cgroup *memcg) { while (!refcount_inc_not_zero(&memcg->id.ref)) { @@ -6870,26 +7311,29 @@ static struct mem_cgroup *mem_cgroup_id_get_online(struct mem_cgroup *memcg) /** * mem_cgroup_swapout - transfer a memsw charge to swap - * @page: page whose memsw charge to transfer + * @folio: folio whose memsw charge to transfer * @entry: swap entry to move the charge to * - * Transfer the memsw charge of @page to @entry. + * Transfer the memsw charge of @folio to @entry. */ -void mem_cgroup_swapout(struct page *page, swp_entry_t entry) +void mem_cgroup_swapout(struct folio *folio, swp_entry_t entry) { struct mem_cgroup *memcg, *swap_memcg; unsigned int nr_entries; unsigned short oldid; - VM_BUG_ON_PAGE(PageLRU(page), page); - VM_BUG_ON_PAGE(page_count(page), page); + VM_BUG_ON_FOLIO(folio_test_lru(folio), folio); + VM_BUG_ON_FOLIO(folio_ref_count(folio), folio); + + if (mem_cgroup_disabled()) + return; if (!do_memsw_account()) return; - memcg = page->mem_cgroup; + memcg = folio_memcg(folio); - /* Readahead page, never charged */ + VM_WARN_ON_ONCE_FOLIO(!memcg, folio); if (!memcg) return; @@ -6899,16 +7343,16 @@ void mem_cgroup_swapout(struct page *page, swp_entry_t entry) * ancestor for the swap instead and transfer the memory+swap charge. */ swap_memcg = mem_cgroup_id_get_online(memcg); - nr_entries = hpage_nr_pages(page); + nr_entries = folio_nr_pages(folio); /* Get references for the tail pages, too */ if (nr_entries > 1) mem_cgroup_id_get_many(swap_memcg, nr_entries - 1); oldid = swap_cgroup_record(entry, mem_cgroup_id(swap_memcg), nr_entries); - VM_BUG_ON_PAGE(oldid, page); + VM_BUG_ON_FOLIO(oldid, folio); mod_memcg_state(swap_memcg, MEMCG_SWAP, nr_entries); - page->mem_cgroup = NULL; + folio->memcg_data = 0; if (!mem_cgroup_is_root(memcg)) page_counter_uncharge(&memcg->memory, nr_entries); @@ -6925,37 +7369,36 @@ void mem_cgroup_swapout(struct page *page, swp_entry_t entry) * important here to have the interrupts disabled because it is the * only synchronisation we have for updating the per-CPU variables. */ - VM_BUG_ON(!irqs_disabled()); - mem_cgroup_charge_statistics(memcg, page, PageTransHuge(page), - -nr_entries); - memcg_check_events(memcg, page); + memcg_stats_lock(); + mem_cgroup_charge_statistics(memcg, -nr_entries); + memcg_stats_unlock(); + memcg_check_events(memcg, folio_nid(folio)); - if (!mem_cgroup_is_root(memcg)) - css_put_many(&memcg->css, nr_entries); + css_put(&memcg->css); } /** - * mem_cgroup_try_charge_swap - try charging swap space for a page - * @page: page being added to swap + * __mem_cgroup_try_charge_swap - try charging swap space for a folio + * @folio: folio being added to swap * @entry: swap entry to charge * - * Try to charge @page's memcg for the swap space at @entry. + * Try to charge @folio's memcg for the swap space at @entry. * * Returns 0 on success, -ENOMEM on failure. */ -int mem_cgroup_try_charge_swap(struct page *page, swp_entry_t entry) +int __mem_cgroup_try_charge_swap(struct folio *folio, swp_entry_t entry) { - unsigned int nr_pages = hpage_nr_pages(page); + unsigned int nr_pages = folio_nr_pages(folio); struct page_counter *counter; struct mem_cgroup *memcg; unsigned short oldid; - if (!cgroup_subsys_on_dfl(memory_cgrp_subsys) || !do_swap_account) + if (do_memsw_account()) return 0; - memcg = page->mem_cgroup; + memcg = folio_memcg(folio); - /* Readahead page, never charged */ + VM_WARN_ON_ONCE_FOLIO(!memcg, folio); if (!memcg) return 0; @@ -6978,23 +7421,23 @@ int mem_cgroup_try_charge_swap(struct page *page, swp_entry_t entry) if (nr_pages > 1) mem_cgroup_id_get_many(memcg, nr_pages - 1); oldid = swap_cgroup_record(entry, mem_cgroup_id(memcg), nr_pages); - VM_BUG_ON_PAGE(oldid, page); + VM_BUG_ON_FOLIO(oldid, folio); mod_memcg_state(memcg, MEMCG_SWAP, nr_pages); return 0; } /** - * mem_cgroup_uncharge_swap - uncharge swap space + * __mem_cgroup_uncharge_swap - uncharge swap space * @entry: swap entry to uncharge * @nr_pages: the amount of swap space to uncharge */ -void mem_cgroup_uncharge_swap(swp_entry_t entry, unsigned int nr_pages) +void __mem_cgroup_uncharge_swap(swp_entry_t entry, unsigned int nr_pages) { struct mem_cgroup *memcg; unsigned short id; - if (!do_swap_account) + if (mem_cgroup_disabled()) return; id = swap_cgroup_record(entry, 0, nr_pages); @@ -7002,10 +7445,10 @@ void mem_cgroup_uncharge_swap(swp_entry_t entry, unsigned int nr_pages) memcg = mem_cgroup_from_id(id); if (memcg) { if (!mem_cgroup_is_root(memcg)) { - if (cgroup_subsys_on_dfl(memory_cgrp_subsys)) - page_counter_uncharge(&memcg->swap, nr_pages); - else + if (do_memsw_account()) page_counter_uncharge(&memcg->memsw, nr_pages); + else + page_counter_uncharge(&memcg->swap, nr_pages); } mod_memcg_state(memcg, MEMCG_SWAP, -nr_pages); mem_cgroup_id_put_many(memcg, nr_pages); @@ -7017,7 +7460,7 @@ long mem_cgroup_get_nr_swap_pages(struct mem_cgroup *memcg) { long nr_swap_pages = get_nr_swap_pages(); - if (!do_swap_account || !cgroup_subsys_on_dfl(memory_cgrp_subsys)) + if (mem_cgroup_disabled() || do_memsw_account()) return nr_swap_pages; for (; memcg != root_mem_cgroup; memcg = parent_mem_cgroup(memcg)) nr_swap_pages = min_t(long, nr_swap_pages, @@ -7026,44 +7469,40 @@ long mem_cgroup_get_nr_swap_pages(struct mem_cgroup *memcg) return nr_swap_pages; } -bool mem_cgroup_swap_full(struct page *page) +bool mem_cgroup_swap_full(struct folio *folio) { struct mem_cgroup *memcg; - VM_BUG_ON_PAGE(!PageLocked(page), page); + VM_BUG_ON_FOLIO(!folio_test_locked(folio), folio); if (vm_swap_full()) return true; - if (!do_swap_account || !cgroup_subsys_on_dfl(memory_cgrp_subsys)) + if (do_memsw_account()) return false; - memcg = page->mem_cgroup; + memcg = folio_memcg(folio); if (!memcg) return false; - for (; memcg != root_mem_cgroup; memcg = parent_mem_cgroup(memcg)) - if (page_counter_read(&memcg->swap) * 2 >= memcg->swap.max) + for (; memcg != root_mem_cgroup; memcg = parent_mem_cgroup(memcg)) { + unsigned long usage = page_counter_read(&memcg->swap); + + if (usage * 2 >= READ_ONCE(memcg->swap.high) || + usage * 2 >= READ_ONCE(memcg->swap.max)) return true; + } return false; } -/* for remember boot option*/ -#ifdef CONFIG_MEMCG_SWAP_ENABLED -static int really_do_swap_account __initdata = 1; -#else -static int really_do_swap_account __initdata; -#endif - -static int __init enable_swap_account(char *s) +static int __init setup_swap_account(char *s) { - if (!strcmp(s, "1")) - really_do_swap_account = 1; - else if (!strcmp(s, "0")) - really_do_swap_account = 0; + pr_warn_once("The swapaccount= commandline option is deprecated. " + "Please report your usecase to linux-mm@kvack.org if you " + "depend on this functionality.\n"); return 1; } -__setup("swapaccount=", enable_swap_account); +__setup("swapaccount=", setup_swap_account); static u64 swap_current_read(struct cgroup_subsys_state *css, struct cftype *cft) @@ -7073,6 +7512,29 @@ static u64 swap_current_read(struct cgroup_subsys_state *css, return (u64)page_counter_read(&memcg->swap) * PAGE_SIZE; } +static int swap_high_show(struct seq_file *m, void *v) +{ + return seq_puts_memcg_tunable(m, + READ_ONCE(mem_cgroup_from_seq(m)->swap.high)); +} + +static ssize_t swap_high_write(struct kernfs_open_file *of, + char *buf, size_t nbytes, loff_t off) +{ + struct mem_cgroup *memcg = mem_cgroup_from_css(of_css(of)); + unsigned long high; + int err; + + buf = strstrip(buf); + err = page_counter_memparse(buf, "max", &high); + if (err) + return err; + + page_counter_set_high(&memcg->swap, high); + + return nbytes; +} + static int swap_max_show(struct seq_file *m, void *v) { return seq_puts_memcg_tunable(m, @@ -7100,6 +7562,8 @@ static int swap_events_show(struct seq_file *m, void *v) { struct mem_cgroup *memcg = mem_cgroup_from_seq(m); + seq_printf(m, "high %lu\n", + atomic_long_read(&memcg->memory_events[MEMCG_SWAP_HIGH])); seq_printf(m, "max %lu\n", atomic_long_read(&memcg->memory_events[MEMCG_SWAP_MAX])); seq_printf(m, "fail %lu\n", @@ -7115,6 +7579,12 @@ static struct cftype swap_files[] = { .read_u64 = swap_current_read, }, { + .name = "swap.high", + .flags = CFTYPE_NOT_ON_ROOT, + .seq_show = swap_high_show, + .write = swap_high_write, + }, + { .name = "swap.max", .flags = CFTYPE_NOT_ON_ROOT, .seq_show = swap_max_show, @@ -7129,7 +7599,7 @@ static struct cftype swap_files[] = { { } /* terminate */ }; -static struct cftype memsw_cgroup_files[] = { +static struct cftype memsw_files[] = { { .name = "memsw.usage_in_bytes", .private = MEMFILE_PRIVATE(_MEMSWAP, RES_USAGE), @@ -7156,17 +7626,160 @@ static struct cftype memsw_cgroup_files[] = { { }, /* terminate */ }; -static int __init mem_cgroup_swap_init(void) +#if defined(CONFIG_MEMCG_KMEM) && defined(CONFIG_ZSWAP) +/** + * obj_cgroup_may_zswap - check if this cgroup can zswap + * @objcg: the object cgroup + * + * Check if the hierarchical zswap limit has been reached. + * + * This doesn't check for specific headroom, and it is not atomic + * either. But with zswap, the size of the allocation is only known + * once compression has occured, and this optimistic pre-check avoids + * spending cycles on compression when there is already no room left + * or zswap is disabled altogether somewhere in the hierarchy. + */ +bool obj_cgroup_may_zswap(struct obj_cgroup *objcg) { - if (!mem_cgroup_disabled() && really_do_swap_account) { - do_swap_account = 1; - WARN_ON(cgroup_add_dfl_cftypes(&memory_cgrp_subsys, - swap_files)); - WARN_ON(cgroup_add_legacy_cftypes(&memory_cgrp_subsys, - memsw_cgroup_files)); + struct mem_cgroup *memcg, *original_memcg; + bool ret = true; + + if (!cgroup_subsys_on_dfl(memory_cgrp_subsys)) + return true; + + original_memcg = get_mem_cgroup_from_objcg(objcg); + for (memcg = original_memcg; memcg != root_mem_cgroup; + memcg = parent_mem_cgroup(memcg)) { + unsigned long max = READ_ONCE(memcg->zswap_max); + unsigned long pages; + + if (max == PAGE_COUNTER_MAX) + continue; + if (max == 0) { + ret = false; + break; + } + + cgroup_rstat_flush(memcg->css.cgroup); + pages = memcg_page_state(memcg, MEMCG_ZSWAP_B) / PAGE_SIZE; + if (pages < max) + continue; + ret = false; + break; } + mem_cgroup_put(original_memcg); + return ret; +} + +/** + * obj_cgroup_charge_zswap - charge compression backend memory + * @objcg: the object cgroup + * @size: size of compressed object + * + * This forces the charge after obj_cgroup_may_swap() allowed + * compression and storage in zwap for this cgroup to go ahead. + */ +void obj_cgroup_charge_zswap(struct obj_cgroup *objcg, size_t size) +{ + struct mem_cgroup *memcg; + + if (!cgroup_subsys_on_dfl(memory_cgrp_subsys)) + return; + + VM_WARN_ON_ONCE(!(current->flags & PF_MEMALLOC)); + + /* PF_MEMALLOC context, charging must succeed */ + if (obj_cgroup_charge(objcg, GFP_KERNEL, size)) + VM_WARN_ON_ONCE(1); + + rcu_read_lock(); + memcg = obj_cgroup_memcg(objcg); + mod_memcg_state(memcg, MEMCG_ZSWAP_B, size); + mod_memcg_state(memcg, MEMCG_ZSWAPPED, 1); + rcu_read_unlock(); +} + +/** + * obj_cgroup_uncharge_zswap - uncharge compression backend memory + * @objcg: the object cgroup + * @size: size of compressed object + * + * Uncharges zswap memory on page in. + */ +void obj_cgroup_uncharge_zswap(struct obj_cgroup *objcg, size_t size) +{ + struct mem_cgroup *memcg; + + if (!cgroup_subsys_on_dfl(memory_cgrp_subsys)) + return; + + obj_cgroup_uncharge(objcg, size); + + rcu_read_lock(); + memcg = obj_cgroup_memcg(objcg); + mod_memcg_state(memcg, MEMCG_ZSWAP_B, -size); + mod_memcg_state(memcg, MEMCG_ZSWAPPED, -1); + rcu_read_unlock(); +} + +static u64 zswap_current_read(struct cgroup_subsys_state *css, + struct cftype *cft) +{ + cgroup_rstat_flush(css->cgroup); + return memcg_page_state(mem_cgroup_from_css(css), MEMCG_ZSWAP_B); +} + +static int zswap_max_show(struct seq_file *m, void *v) +{ + return seq_puts_memcg_tunable(m, + READ_ONCE(mem_cgroup_from_seq(m)->zswap_max)); +} + +static ssize_t zswap_max_write(struct kernfs_open_file *of, + char *buf, size_t nbytes, loff_t off) +{ + struct mem_cgroup *memcg = mem_cgroup_from_css(of_css(of)); + unsigned long max; + int err; + + buf = strstrip(buf); + err = page_counter_memparse(buf, "max", &max); + if (err) + return err; + + xchg(&memcg->zswap_max, max); + + return nbytes; +} + +static struct cftype zswap_files[] = { + { + .name = "zswap.current", + .flags = CFTYPE_NOT_ON_ROOT, + .read_u64 = zswap_current_read, + }, + { + .name = "zswap.max", + .flags = CFTYPE_NOT_ON_ROOT, + .seq_show = zswap_max_show, + .write = zswap_max_write, + }, + { } /* terminate */ +}; +#endif /* CONFIG_MEMCG_KMEM && CONFIG_ZSWAP */ + +static int __init mem_cgroup_swap_init(void) +{ + if (mem_cgroup_disabled()) + return 0; + + WARN_ON(cgroup_add_dfl_cftypes(&memory_cgrp_subsys, swap_files)); + WARN_ON(cgroup_add_legacy_cftypes(&memory_cgrp_subsys, memsw_files)); +#if defined(CONFIG_MEMCG_KMEM) && defined(CONFIG_ZSWAP) + WARN_ON(cgroup_add_dfl_cftypes(&memory_cgrp_subsys, zswap_files)); +#endif return 0; } subsys_initcall(mem_cgroup_swap_init); -#endif /* CONFIG_MEMCG_SWAP */ +#endif /* CONFIG_SWAP */ |