diff options
Diffstat (limited to 'mm/memcontrol.c')
| -rw-r--r-- | mm/memcontrol.c | 534 |
1 files changed, 231 insertions, 303 deletions
diff --git a/mm/memcontrol.c b/mm/memcontrol.c index 36e9f38c919d..725f76723220 100644 --- a/mm/memcontrol.c +++ b/mm/memcontrol.c @@ -53,13 +53,14 @@ #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" @@ -348,48 +349,6 @@ static void memcg_reparent_objcgs(struct mem_cgroup *memcg, } /* - * This will be used as a shrinker list's index. - * 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); -} - -void memcg_put_cache_ids(void) -{ - up_read(&memcg_cache_ids_sem); -} - -/* - * 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_slab_pre_alloc_hook() are * conditional to this static branch, we'll have to allow modules that does @@ -629,6 +588,35 @@ static DEFINE_SPINLOCK(stats_flush_lock); static DEFINE_PER_CPU(unsigned int, stats_updates); static atomic_t stats_flush_threshold = ATOMIC_INIT(0); +/* + * 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) +{ +#ifdef CONFIG_PREEMPT_RT + preempt_disable(); +#else + VM_BUG_ON(!irqs_disabled()); +#endif +} + +static void __memcg_stats_lock(void) +{ +#ifdef CONFIG_PREEMPT_RT + preempt_disable(); +#endif +} + +static void memcg_stats_unlock(void) +{ +#ifdef CONFIG_PREEMPT_RT + preempt_enable(); +#endif +} + static inline void memcg_rstat_updated(struct mem_cgroup *memcg, int val) { unsigned int x; @@ -705,6 +693,27 @@ void __mod_memcg_lruvec_state(struct lruvec *lruvec, enum node_stat_item idx, 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) && !IS_ENABLED(CONFIG_PREEMPT_RT)) { + 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: + WARN_ON_ONCE(!irqs_disabled()); + } + } + /* Update memcg */ __this_cpu_add(memcg->vmstats_percpu->state[idx], val); @@ -712,6 +721,7 @@ void __mod_memcg_lruvec_state(struct lruvec *lruvec, enum node_stat_item idx, __this_cpu_add(pn->lruvec_stats_percpu->state[idx], val); memcg_rstat_updated(memcg, val); + memcg_stats_unlock(); } /** @@ -794,8 +804,10 @@ void __count_memcg_events(struct mem_cgroup *memcg, enum vm_event_item idx, if (mem_cgroup_disabled()) return; + memcg_stats_lock(); __this_cpu_add(memcg->vmstats_percpu->events[idx], count); memcg_rstat_updated(memcg, count); + memcg_stats_unlock(); } static unsigned long memcg_events(struct mem_cgroup *memcg, int event) @@ -858,6 +870,9 @@ static bool mem_cgroup_event_ratelimit(struct mem_cgroup *memcg, */ 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))) { @@ -1257,8 +1272,7 @@ struct lruvec *folio_lruvec_lock_irqsave(struct folio *folio, * @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) @@ -1371,6 +1385,7 @@ struct memory_stat { 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 }, { "percpu", MEMCG_PERCPU_B }, @@ -1795,20 +1810,16 @@ 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); @@ -1831,14 +1842,13 @@ 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); @@ -1849,10 +1859,7 @@ 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); @@ -2085,45 +2092,47 @@ void unlock_page_memcg(struct page *page) folio_memcg_unlock(page_folio(page)); } -struct obj_stock { +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; -#else - int dummy[0]; #endif -}; - -struct memcg_stock_pcp { - struct mem_cgroup *cached; /* this never be root cgroup */ - unsigned int nr_pages; - struct obj_stock task_obj; - struct obj_stock irq_obj; 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 void drain_obj_stock(struct obj_stock *stock); +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 void drain_obj_stock(struct obj_stock *stock) +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 /** @@ -2146,7 +2155,7 @@ 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) { @@ -2154,7 +2163,7 @@ 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; } @@ -2183,6 +2192,7 @@ static void drain_stock(struct memcg_stock_pcp *stock) static void drain_local_stock(struct work_struct *dummy) { struct memcg_stock_pcp *stock; + struct obj_cgroup *old = NULL; unsigned long flags; /* @@ -2190,28 +2200,25 @@ static void drain_local_stock(struct work_struct *dummy) * 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); - drain_obj_stock(&stock->irq_obj); - if (in_task()) - drain_obj_stock(&stock->task_obj); + 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 */ @@ -2223,8 +2230,15 @@ static void refill_stock(struct mem_cgroup *memcg, unsigned int 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); } /* @@ -2244,7 +2258,8 @@ 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; @@ -2267,7 +2282,7 @@ 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); } @@ -2541,7 +2556,6 @@ static int try_charge_memcg(struct mem_cgroup *memcg, gfp_t gfp_mask, int nr_retries = MAX_RECLAIM_RETRIES; struct mem_cgroup *mem_over_limit; struct page_counter *counter; - enum oom_status oom_status; unsigned long nr_reclaimed; bool passed_oom = false; bool may_swap = true; @@ -2570,15 +2584,6 @@ 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; - - /* * 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 @@ -2644,15 +2649,20 @@ retry: * 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)); - if (oom_status == OOM_SUCCESS) { + 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; } 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: /* @@ -2688,7 +2698,7 @@ done_restock: READ_ONCE(memcg->swap.high); /* Don't bother a random interrupted task */ - if (in_interrupt()) { + if (!in_task()) { if (mem_high) { schedule_work(&memcg->high_work); break; @@ -2712,6 +2722,11 @@ done_restock: } } 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; } @@ -2748,20 +2763,6 @@ static void commit_charge(struct folio *folio, struct mem_cgroup *memcg) folio->memcg_data = (unsigned long)memcg; } -static struct mem_cgroup *get_mem_cgroup_from_objcg(struct obj_cgroup *objcg) -{ - struct mem_cgroup *memcg; - - rcu_read_lock(); -retry: - memcg = obj_cgroup_memcg(objcg); - if (unlikely(!css_tryget(&memcg->css))) - goto retry; - rcu_read_unlock(); - - return memcg; -} - #ifdef CONFIG_MEMCG_KMEM /* * The allocated objcg pointers array is not accounted directly. @@ -2771,41 +2772,6 @@ retry: #define OBJCGS_CLEAR_MASK (__GFP_DMA | __GFP_RECLAIMABLE | __GFP_ACCOUNT) /* - * Most kmem_cache_alloc() calls are from user context. The irq disable/enable - * sequence used in this case to access content from object stock is slow. - * To optimize for user context access, there are now two object stocks for - * task context and interrupt context access respectively. - * - * The task context object stock can be accessed by disabling preemption only - * which is cheap in non-preempt kernel. The interrupt context object stock - * can only be accessed after disabling interrupt. User context code can - * access interrupt object stock, but not vice versa. - */ -static inline struct obj_stock *get_obj_stock(unsigned long *pflags) -{ - struct memcg_stock_pcp *stock; - - if (likely(in_task())) { - *pflags = 0UL; - preempt_disable(); - stock = this_cpu_ptr(&memcg_stock); - return &stock->task_obj; - } - - local_irq_save(*pflags); - stock = this_cpu_ptr(&memcg_stock); - return &stock->irq_obj; -} - -static inline void put_obj_stock(unsigned long flags) -{ - if (likely(in_task())) - preempt_enable(); - else - local_irq_restore(flags); -} - -/* * mod_objcg_mlstate() may be called with irq enabled, so * mod_memcg_lruvec_state() should be used. */ @@ -2936,48 +2902,17 @@ __always_inline struct obj_cgroup *get_obj_cgroup_from_current(void) return objcg; } -static int memcg_alloc_cache_id(void) +static void memcg_account_kmem(struct mem_cgroup *memcg, int nr_pages) { - int id, size; - int err; - - id = ida_simple_get(&memcg_cache_ida, - 0, MEMCG_CACHES_MAX_SIZE, GFP_KERNEL); - if (id < 0) - return id; - - if (id < memcg_nr_cache_ids) - return id; - - /* - * There's no space for the new id in memcg_caches arrays, - * so we have to grow them. - */ - down_write(&memcg_cache_ids_sem); - - 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; - - err = memcg_update_all_list_lrus(size); - if (!err) - memcg_nr_cache_ids = size; - - up_write(&memcg_cache_ids_sem); - - if (err) { - ida_simple_remove(&memcg_cache_ida, id); - return err; + 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); } - return id; } -static void memcg_free_cache_id(int id) -{ - ida_simple_remove(&memcg_cache_ida, id); -} /* * obj_cgroup_uncharge_pages: uncharge a number of kernel pages from a objcg @@ -2991,8 +2926,7 @@ static void obj_cgroup_uncharge_pages(struct obj_cgroup *objcg, memcg = get_mem_cgroup_from_objcg(objcg); - if (!cgroup_subsys_on_dfl(memory_cgrp_subsys)) - page_counter_uncharge(&memcg->kmem, nr_pages); + memcg_account_kmem(memcg, -nr_pages); refill_stock(memcg, nr_pages); css_put(&memcg->css); @@ -3018,8 +2952,7 @@ static int obj_cgroup_charge_pages(struct obj_cgroup *objcg, gfp_t gfp, if (ret) goto out; - if (!cgroup_subsys_on_dfl(memory_cgrp_subsys)) - page_counter_charge(&memcg->kmem, nr_pages); + memcg_account_kmem(memcg, nr_pages); out: css_put(&memcg->css); @@ -3075,17 +3008,21 @@ void __memcg_kmem_uncharge_page(struct page *page, int order) 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; - struct obj_stock *stock = get_obj_stock(&flags); int *bytes; + local_lock_irqsave(&memcg_stock.stock_lock, flags); + stock = this_cpu_ptr(&memcg_stock); + /* * Save vmstat data in stock and skip vmstat array update unless * accumulating over a page of vmstat data or when pgdat or idx * changes. */ if (stock->cached_objcg != objcg) { - drain_obj_stock(stock); + 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; @@ -3129,38 +3066,51 @@ void mod_objcg_state(struct obj_cgroup *objcg, struct pglist_data *pgdat, if (nr) mod_objcg_mlstate(objcg, pgdat, idx, nr); - put_obj_stock(flags); + local_unlock_irqrestore(&memcg_stock.stock_lock, flags); + if (old) + obj_cgroup_put(old); } static bool consume_obj_stock(struct obj_cgroup *objcg, unsigned int nr_bytes) { + struct memcg_stock_pcp *stock; unsigned long flags; - struct obj_stock *stock = get_obj_stock(&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; } - put_obj_stock(flags); + local_unlock_irqrestore(&memcg_stock.stock_lock, flags); return ret; } -static void drain_obj_stock(struct obj_stock *stock) +static struct obj_cgroup *drain_obj_stock(struct memcg_stock_pcp *stock) { struct obj_cgroup *old = stock->cached_objcg; if (!old) - return; + 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) - obj_cgroup_uncharge_pages(old, nr_pages); + 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); + + css_put(&memcg->css); + } /* * The leftover is flushed to the centralized per-memcg value. @@ -3195,8 +3145,12 @@ static void drain_obj_stock(struct obj_stock *stock) stock->cached_pgdat = NULL; } - obj_cgroup_put(old); 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; } static bool obj_stock_flush_required(struct memcg_stock_pcp *stock, @@ -3204,13 +3158,8 @@ static bool obj_stock_flush_required(struct memcg_stock_pcp *stock, { struct mem_cgroup *memcg; - if (in_task() && stock->task_obj.cached_objcg) { - memcg = obj_cgroup_memcg(stock->task_obj.cached_objcg); - if (memcg && mem_cgroup_is_descendant(memcg, root_memcg)) - return true; - } - if (stock->irq_obj.cached_objcg) { - memcg = obj_cgroup_memcg(stock->irq_obj.cached_objcg); + if (stock->cached_objcg) { + memcg = obj_cgroup_memcg(stock->cached_objcg); if (memcg && mem_cgroup_is_descendant(memcg, root_memcg)) return true; } @@ -3221,12 +3170,16 @@ static bool obj_stock_flush_required(struct memcg_stock_pcp *stock, static void refill_obj_stock(struct obj_cgroup *objcg, unsigned int nr_bytes, bool allow_uncharge) { + struct memcg_stock_pcp *stock; + struct obj_cgroup *old = NULL; unsigned long flags; - struct obj_stock *stock = get_obj_stock(&flags); unsigned int nr_pages = 0; + local_lock_irqsave(&memcg_stock.stock_lock, flags); + + stock = this_cpu_ptr(&memcg_stock); if (stock->cached_objcg != objcg) { /* reset if necessary */ - drain_obj_stock(stock); + old = drain_obj_stock(stock); obj_cgroup_get(objcg); stock->cached_objcg = objcg; stock->nr_bytes = atomic_read(&objcg->nr_charged_bytes) @@ -3240,7 +3193,9 @@ static void refill_obj_stock(struct obj_cgroup *objcg, unsigned int nr_bytes, stock->nr_bytes &= (PAGE_SIZE - 1); } - put_obj_stock(flags); + local_unlock_irqrestore(&memcg_stock.stock_lock, flags); + if (old) + obj_cgroup_put(old); if (nr_pages) obj_cgroup_uncharge_pages(objcg, nr_pages); @@ -3625,28 +3580,23 @@ static u64 mem_cgroup_read_u64(struct cgroup_subsys_state *css, static int memcg_online_kmem(struct mem_cgroup *memcg) { struct obj_cgroup *objcg; - int memcg_id; if (cgroup_memory_nokmem) return 0; - BUG_ON(memcg->kmemcg_id >= 0); - - memcg_id = memcg_alloc_cache_id(); - if (memcg_id < 0) - return memcg_id; + if (unlikely(mem_cgroup_is_root(memcg))) + return 0; objcg = obj_cgroup_alloc(); - if (!objcg) { - memcg_free_cache_id(memcg_id); + if (!objcg) return -ENOMEM; - } + objcg->memcg = memcg; rcu_assign_pointer(memcg->objcg, objcg); static_branch_enable(&memcg_kmem_enabled_key); - memcg->kmemcg_id = memcg_id; + memcg->kmemcg_id = memcg->id.id; return 0; } @@ -3654,9 +3604,11 @@ static int memcg_online_kmem(struct mem_cgroup *memcg) static void memcg_offline_kmem(struct mem_cgroup *memcg) { struct mem_cgroup *parent; - int kmemcg_id; - if (memcg->kmemcg_id == -1) + if (cgroup_memory_nokmem) + return; + + if (unlikely(mem_cgroup_is_root(memcg))) return; parent = parent_mem_cgroup(memcg); @@ -3665,19 +3617,13 @@ static void memcg_offline_kmem(struct mem_cgroup *memcg) memcg_reparent_objcgs(memcg, parent); - kmemcg_id = memcg->kmemcg_id; - BUG_ON(kmemcg_id < 0); - /* * 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_drain_all_list_lrus(). + * memcg_reparent_list_lrus(). */ - memcg_drain_all_list_lrus(kmemcg_id, parent); - - memcg_free_cache_id(kmemcg_id); - memcg->kmemcg_id = -1; + memcg_reparent_list_lrus(memcg, parent); } #else static int memcg_online_kmem(struct mem_cgroup *memcg) @@ -3763,8 +3709,12 @@ 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; @@ -4740,6 +4690,9 @@ 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); @@ -5067,18 +5020,8 @@ struct mem_cgroup *mem_cgroup_from_id(unsigned short id) 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); + + pn = kzalloc_node(sizeof(*pn), GFP_KERNEL, node); if (!pn) return 1; @@ -5090,8 +5033,6 @@ static int alloc_mem_cgroup_per_node_info(struct mem_cgroup *memcg, int node) } lruvec_init(&pn->lruvec); - pn->usage_in_excess = 0; - pn->on_tree = false; pn->memcg = memcg; memcg->nodeinfo[node] = pn; @@ -5137,8 +5078,7 @@ static struct mem_cgroup *mem_cgroup_alloc(void) return ERR_PTR(error); memcg->id.id = idr_alloc(&mem_cgroup_idr, NULL, - 1, MEM_CGROUP_ID_MAX, - GFP_KERNEL); + 1, MEM_CGROUP_ID_MAX + 1, GFP_KERNEL); if (memcg->id.id < 0) { error = memcg->id.id; goto fail; @@ -5192,7 +5132,6 @@ mem_cgroup_css_alloc(struct cgroup_subsys_state *parent_css) { struct mem_cgroup *parent = mem_cgroup_from_css(parent_css); struct mem_cgroup *memcg, *old_memcg; - long error = -ENOMEM; old_memcg = set_active_memcg(parent); memcg = mem_cgroup_alloc(); @@ -5221,34 +5160,26 @@ mem_cgroup_css_alloc(struct cgroup_subsys_state *parent_css) return &memcg->css; } - /* The following stuff does not apply to the root */ - 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(error); } 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 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 (alloc_shrinker_info(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); @@ -5258,6 +5189,11 @@ static int mem_cgroup_css_online(struct cgroup_subsys_state *css) 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) @@ -5315,9 +5251,6 @@ static void mem_cgroup_css_free(struct cgroup_subsys_state *css) cancel_work_sync(&memcg->high_work); mem_cgroup_remove_from_trees(memcg); free_shrinker_info(memcg); - - /* Need to offline kmem if online_css() fails */ - memcg_offline_kmem(memcg); mem_cgroup_free(memcg); } @@ -5503,17 +5436,12 @@ static struct page *mc_handle_swap_pte(struct vm_area_struct *vma, 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 = pfn_swap_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)) + if (!get_page_unless_zero(page)) return NULL; return page; } @@ -6801,8 +6729,8 @@ static void uncharge_batch(const struct uncharge_gather *ug) page_counter_uncharge(&ug->memcg->memory, ug->nr_memory); if (do_memsw_account()) page_counter_uncharge(&ug->memcg->memsw, ug->nr_memory); - if (!cgroup_subsys_on_dfl(memory_cgrp_subsys) && ug->nr_kmem) - page_counter_uncharge(&ug->memcg->kmem, ug->nr_kmem); + if (ug->nr_kmem) + memcg_account_kmem(ug->memcg, -ug->nr_kmem); memcg_oom_recover(ug->memcg); } @@ -6821,7 +6749,6 @@ static void uncharge_folio(struct folio *folio, struct uncharge_gather *ug) long nr_pages; struct mem_cgroup *memcg; struct obj_cgroup *objcg; - bool use_objcg = folio_memcg_kmem(folio); VM_BUG_ON_FOLIO(folio_test_lru(folio), folio); @@ -6830,7 +6757,7 @@ static void uncharge_folio(struct folio *folio, struct uncharge_gather *ug) * folio memcg or objcg at this point, we have fully * exclusive access to the folio. */ - if (use_objcg) { + if (folio_memcg_kmem(folio)) { objcg = __folio_objcg(folio); /* * This get matches the put at the end of the function and @@ -6858,7 +6785,7 @@ static void uncharge_folio(struct folio *folio, struct uncharge_gather *ug) nr_pages = folio_nr_pages(folio); - if (use_objcg) { + if (folio_memcg_kmem(folio)) { ug->nr_memory += nr_pages; ug->nr_kmem += nr_pages; @@ -6968,7 +6895,7 @@ 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(); @@ -7053,7 +6980,7 @@ static int __init cgroup_memory(char *s) if (!strcmp(token, "nokmem")) cgroup_memory_nokmem = true; } - return 0; + return 1; } __setup("cgroup.memory=", cgroup_memory); @@ -7121,19 +7048,19 @@ 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; @@ -7141,9 +7068,9 @@ void mem_cgroup_swapout(struct page *page, swp_entry_t entry) if (cgroup_subsys_on_dfl(memory_cgrp_subsys)) return; - memcg = page_memcg(page); + memcg = folio_memcg(folio); - VM_WARN_ON_ONCE_PAGE(!memcg, page); + VM_WARN_ON_ONCE_FOLIO(!memcg, folio); if (!memcg) return; @@ -7153,16 +7080,16 @@ 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 = thp_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->memcg_data = 0; + folio->memcg_data = 0; if (!mem_cgroup_is_root(memcg)) page_counter_uncharge(&memcg->memory, nr_entries); @@ -7179,9 +7106,10 @@ 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()); + memcg_stats_lock(); mem_cgroup_charge_statistics(memcg, -nr_entries); - memcg_check_events(memcg, page_to_nid(page)); + memcg_stats_unlock(); + memcg_check_events(memcg, folio_nid(folio)); css_put(&memcg->css); } |