/* 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;
/* Kernel memory accounting disabled? */
-static bool cgroup_memory_nokmem;
+bool cgroup_memory_nokmem;
/* Whether the swap controller is active */
#ifdef CONFIG_MEMCG_SWAP
static void obj_cgroup_release(struct percpu_ref *ref)
{
struct obj_cgroup *objcg = container_of(ref, struct obj_cgroup, refcnt);
- struct mem_cgroup *memcg;
unsigned int nr_bytes;
unsigned int nr_pages;
unsigned long flags;
WARN_ON_ONCE(nr_bytes & (PAGE_SIZE - 1));
nr_pages = nr_bytes >> PAGE_SHIFT;
- spin_lock_irqsave(&css_set_lock, flags);
- memcg = obj_cgroup_memcg(objcg);
if (nr_pages)
obj_cgroup_uncharge_pages(objcg, nr_pages);
+
+ spin_lock_irqsave(&css_set_lock, flags);
list_del(&objcg->list);
- mem_cgroup_put(memcg);
spin_unlock_irqrestore(&css_set_lock, flags);
percpu_ref_exit(ref);
spin_lock_irq(&css_set_lock);
- /* Move active objcg to the parent's list */
- xchg(&objcg->memcg, parent);
- css_get(&parent->css);
- list_add(&objcg->list, &parent->objcg_list);
-
- /* Move already reparented objcgs to the parent's list */
- list_for_each_entry(iter, &memcg->objcg_list, list) {
- css_get(&parent->css);
- xchg(&iter->memcg, parent);
- css_put(&memcg->css);
- }
+ /* 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);
spin_unlock_irq(&css_set_lock);
rcu_read_unlock();
}
+/*
+ * 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();
+}
+
/**
* __count_memcg_events - account VM events in a cgroup
* @memcg: the memory cgroup
}
EXPORT_SYMBOL(mem_cgroup_from_task);
+static __always_inline struct mem_cgroup *active_memcg(void)
+{
+ if (in_interrupt())
+ 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)
{
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 without 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);
-static __always_inline struct mem_cgroup *active_memcg(void)
-{
- if (in_interrupt())
- return this_cpu_read(int_active_memcg);
- else
- return current->active_memcg;
-}
-
static __always_inline bool memcg_kmem_bypass(void)
{
/* Allow remote memcg charging from any context. */
struct lruvec *lock_page_lruvec(struct page *page)
{
struct lruvec *lruvec;
- struct pglist_data *pgdat = page_pgdat(page);
- lruvec = mem_cgroup_page_lruvec(page, pgdat);
+ lruvec = mem_cgroup_page_lruvec(page);
spin_lock(&lruvec->lru_lock);
lruvec_memcg_debug(lruvec, page);
struct lruvec *lock_page_lruvec_irq(struct page *page)
{
struct lruvec *lruvec;
- struct pglist_data *pgdat = page_pgdat(page);
- lruvec = mem_cgroup_page_lruvec(page, pgdat);
+ lruvec = mem_cgroup_page_lruvec(page);
spin_lock_irq(&lruvec->lru_lock);
lruvec_memcg_debug(lruvec, page);
struct lruvec *lock_page_lruvec_irqsave(struct page *page, unsigned long *flags)
{
struct lruvec *lruvec;
- struct pglist_data *pgdat = page_pgdat(page);
- lruvec = mem_cgroup_page_lruvec(page, pgdat);
+ lruvec = mem_cgroup_page_lruvec(page);
spin_lock_irqsave(&lruvec->lru_lock, *flags);
lruvec_memcg_debug(lruvec, page);
}
EXPORT_SYMBOL(unlock_page_memcg);
-struct memcg_stock_pcp {
- struct mem_cgroup *cached; /* this never be root cgroup */
- unsigned int nr_pages;
-
+struct obj_stock {
#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;
static DEFINE_MUTEX(percpu_charge_mutex);
#ifdef CONFIG_MEMCG_KMEM
-static void drain_obj_stock(struct memcg_stock_pcp *stock);
+static void drain_obj_stock(struct obj_stock *stock);
static bool obj_stock_flush_required(struct memcg_stock_pcp *stock,
struct mem_cgroup *root_memcg);
#else
-static inline void drain_obj_stock(struct memcg_stock_pcp *stock)
+static inline void drain_obj_stock(struct obj_stock *stock)
{
}
static bool obj_stock_flush_required(struct memcg_stock_pcp *stock,
}
#endif
+/*
+ * 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);
+}
+
/**
* consume_stock: Try to consume stocked charge on this cpu.
* @memcg: memcg to consume from.
local_irq_save(flags);
stock = this_cpu_ptr(&memcg_stock);
- drain_obj_stock(stock);
+ drain_obj_stock(&stock->irq_obj);
+ if (in_task())
+ drain_obj_stock(&stock->task_obj);
drain_stock(stock);
clear_bit(FLUSHING_CACHED_CHARGE, &stock->flags);
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 = MAX_RECLAIM_RETRIES;
bool drained = false;
unsigned long pflags;
- if (mem_cgroup_is_root(memcg))
- return 0;
retry:
if (consume_stock(memcg, nr_pages))
return 0;
return 0;
}
+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);
+}
+
#if defined(CONFIG_MEMCG_KMEM) || defined(CONFIG_MMU)
static void cancel_charge(struct mem_cgroup *memcg, unsigned int nr_pages)
{
}
#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)
+
int memcg_alloc_page_obj_cgroups(struct page *page, struct kmem_cache *s,
gfp_t gfp, bool new_page)
{
unsigned long memcg_data;
void *vec;
+ gfp &= ~OBJCGS_CLEAR_MASK;
vec = kcalloc_node(objects, sizeof(struct obj_cgroup *), gfp,
page_to_nid(page));
if (!vec)
memcg = get_mem_cgroup_from_objcg(objcg);
- ret = try_charge(memcg, gfp, nr_pages);
+ ret = try_charge_memcg(memcg, gfp, nr_pages);
if (ret)
goto out;
obj_cgroup_put(objcg);
}
+void mod_objcg_state(struct obj_cgroup *objcg, struct pglist_data *pgdat,
+ enum node_stat_item idx, int nr)
+{
+ unsigned long flags;
+ struct obj_stock *stock = get_obj_stock(&flags);
+ int *bytes;
+
+ /*
+ * 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);
+ 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 */
+ if (stock->nr_slab_reclaimable_b) {
+ mod_objcg_mlstate(objcg, pgdat, 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, pgdat, 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;
+ /*
+ * Even for large object >= PAGE_SIZE, the vmstat data will still be
+ * cached locally at least once before pushing it out.
+ */
+ 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);
+
+ put_obj_stock(flags);
+}
+
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_irq_save(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_irq_restore(flags);
+ put_obj_stock(flags);
return ret;
}
-static void drain_obj_stock(struct memcg_stock_pcp *stock)
+static void drain_obj_stock(struct obj_stock *stock)
{
struct obj_cgroup *old = stock->cached_objcg;
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;
+ }
+ 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;
+ }
+
obj_cgroup_put(old);
stock->cached_objcg = NULL;
}
{
struct mem_cgroup *memcg;
- if (stock->cached_objcg) {
- memcg = obj_cgroup_memcg(stock->cached_objcg);
+ 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 (memcg && mem_cgroup_is_descendant(memcg, root_memcg))
return true;
}
return false;
}
-static void refill_obj_stock(struct obj_cgroup *objcg, unsigned int nr_bytes)
+static void refill_obj_stock(struct obj_cgroup *objcg, unsigned int nr_bytes,
+ bool allow_uncharge)
{
- struct memcg_stock_pcp *stock;
unsigned long flags;
+ struct obj_stock *stock = get_obj_stock(&flags);
+ unsigned int nr_pages = 0;
- local_irq_save(flags);
-
- stock = this_cpu_ptr(&memcg_stock);
if (stock->cached_objcg != objcg) { /* reset if necessary */
drain_obj_stock(stock);
obj_cgroup_get(objcg);
stock->cached_objcg = objcg;
- stock->nr_bytes = atomic_xchg(&objcg->nr_charged_bytes, 0);
+ 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 (stock->nr_bytes > PAGE_SIZE)
- drain_obj_stock(stock);
+ if (allow_uncharge && (stock->nr_bytes > PAGE_SIZE)) {
+ nr_pages = stock->nr_bytes >> PAGE_SHIFT;
+ stock->nr_bytes &= (PAGE_SIZE - 1);
+ }
- local_irq_restore(flags);
+ put_obj_stock(flags);
+
+ if (nr_pages)
+ obj_cgroup_uncharge_pages(objcg, nr_pages);
}
int obj_cgroup_charge(struct obj_cgroup *objcg, gfp_t gfp, size_t size)
return 0;
/*
- * In theory, memcg->nr_charged_bytes can have enough
+ * In theory, objcg->nr_charged_bytes can have enough
* pre-charged bytes to satisfy the allocation. However,
- * flushing memcg->nr_charged_bytes requires two atomic
- * operations, and memcg->nr_charged_bytes can't be big,
- * so it's better to ignore it and try grab some new pages.
- * memcg->nr_charged_bytes will be flushed in
- * refill_obj_stock(), called from this function or
- * independently later.
+ * 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);
ret = obj_cgroup_charge_pages(objcg, gfp, nr_pages);
if (!ret && nr_bytes)
- refill_obj_stock(objcg, PAGE_SIZE - nr_bytes);
+ refill_obj_stock(objcg, PAGE_SIZE - nr_bytes, false);
return ret;
}
void obj_cgroup_uncharge(struct obj_cgroup *objcg, size_t size)
{
- refill_obj_stock(objcg, size);
+ refill_obj_stock(objcg, size, true);
}
#endif /* CONFIG_MEMCG_KMEM */
* @gfp_mask: reclaim mode
*
* Try to charge @page to the memcg that @mm belongs to, reclaiming
- * pages according to @gfp_mask if necessary.
+ * pages according to @gfp_mask if necessary. if @mm is NULL, try to
+ * charge to the active memcg.
*
* Do not use this for pages allocated for swapin.
*
unsigned long nr_pages;
struct mem_cgroup *memcg;
struct obj_cgroup *objcg;
+ bool use_objcg = PageMemcgKmem(page);
VM_BUG_ON_PAGE(PageLRU(page), page);
* page memcg or objcg at this point, we have fully
* exclusive access to the page.
*/
- if (PageMemcgKmem(page)) {
+ if (use_objcg) {
objcg = __page_objcg(page);
/*
* This get matches the put at the end of the function and
nr_pages = compound_nr(page);
- if (PageMemcgKmem(page)) {
+ if (use_objcg) {
ug->nr_memory += nr_pages;
ug->nr_kmem += nr_pages;
/* Force-charge the new page. The old one will be freed soon */
nr_pages = thp_nr_pages(newpage);
- page_counter_charge(&memcg->memory, nr_pages);
- if (do_memsw_account())
- page_counter_charge(&memcg->memsw, 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);
+ }
css_get(&memcg->css);
commit_charge(newpage, memcg);
projects / linux-2.6-microblaze.git / blobdiff