static void mem_cgroup_remove_exceeded(struct mem_cgroup_per_zone *mz,
struct mem_cgroup_tree_per_zone *mctz)
{
- spin_lock(&mctz->lock);
+ unsigned long flags;
+
+ spin_lock_irqsave(&mctz->lock, flags);
__mem_cgroup_remove_exceeded(mz, mctz);
- spin_unlock(&mctz->lock);
+ spin_unlock_irqrestore(&mctz->lock, flags);
}
* mem is over its softlimit.
*/
if (excess || mz->on_tree) {
- spin_lock(&mctz->lock);
+ unsigned long flags;
+
+ spin_lock_irqsave(&mctz->lock, flags);
/* if on-tree, remove it */
if (mz->on_tree)
__mem_cgroup_remove_exceeded(mz, mctz);
* If excess is 0, no tree ops.
*/
__mem_cgroup_insert_exceeded(mz, mctz, excess);
- spin_unlock(&mctz->lock);
+ spin_unlock_irqrestore(&mctz->lock, flags);
}
}
}
{
struct mem_cgroup_per_zone *mz;
- spin_lock(&mctz->lock);
+ spin_lock_irq(&mctz->lock);
mz = __mem_cgroup_largest_soft_limit_node(mctz);
- spin_unlock(&mctz->lock);
+ spin_unlock_irq(&mctz->lock);
return mz;
}
return val;
}
-static void mem_cgroup_swap_statistics(struct mem_cgroup *memcg,
- bool charge)
-{
- int val = (charge) ? 1 : -1;
- this_cpu_add(memcg->stat->count[MEM_CGROUP_STAT_SWAP], val);
-}
-
static unsigned long mem_cgroup_read_events(struct mem_cgroup *memcg,
enum mem_cgroup_events_index idx)
{
static void mem_cgroup_charge_statistics(struct mem_cgroup *memcg,
struct page *page,
- bool anon, 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 (anon)
+ if (PageAnon(page))
__this_cpu_add(memcg->stat->count[MEM_CGROUP_STAT_RSS],
nr_pages);
else
*/
static void memcg_check_events(struct mem_cgroup *memcg, struct page *page)
{
- preempt_disable();
/* threshold event is triggered in finer grain than soft limit */
if (unlikely(mem_cgroup_event_ratelimit(memcg,
MEM_CGROUP_TARGET_THRESH))) {
do_numainfo = mem_cgroup_event_ratelimit(memcg,
MEM_CGROUP_TARGET_NUMAINFO);
#endif
- preempt_enable();
-
mem_cgroup_threshold(memcg);
if (unlikely(do_softlimit))
mem_cgroup_update_tree(memcg, page);
if (unlikely(do_numainfo))
atomic_inc(&memcg->numainfo_events);
#endif
- } else
- preempt_enable();
+ }
}
struct mem_cgroup *mem_cgroup_from_task(struct task_struct *p)
return lruvec;
}
-/*
- * Following LRU functions are allowed to be used without PCG_LOCK.
- * Operations are called by routine of global LRU independently from memcg.
- * What we have to take care of here is validness of pc->mem_cgroup.
- *
- * Changes to pc->mem_cgroup happens when
- * 1. charge
- * 2. moving account
- * In typical case, "charge" is done before add-to-lru. Exception is SwapCache.
- * It is added to LRU before charge.
- * If PCG_USED bit is not set, page_cgroup is not added to this private LRU.
- * When moving account, the page is not on LRU. It's isolated.
- */
-
/**
* mem_cgroup_page_lruvec - return lruvec for adding an lru page
* @page: the page
*
* Notes: Race condition
*
- * We usually use lock_page_cgroup() for accessing page_cgroup member but
- * it tends to be costly. But considering some conditions, we doesn't need
- * to do so _always_.
+ * Charging occurs during page instantiation, while the page is
+ * unmapped and locked in page migration, or while the page table is
+ * locked in THP migration. No race is possible.
*
- * Considering "charge", lock_page_cgroup() is not required because all
- * file-stat operations happen after a page is attached to radix-tree. There
- * are no race with "charge".
+ * Uncharge happens to pages with zero references, no race possible.
*
- * Considering "uncharge", we know that memcg doesn't clear pc->mem_cgroup
- * at "uncharge" intentionally. So, we always see valid pc->mem_cgroup even
- * if there are race with "uncharge". Statistics itself is properly handled
- * by flags.
- *
- * Considering "move", this is an only case we see a race. To make the race
- * small, we check memcg->moving_account and detect there are possibility
- * of race or not. If there is, we take a lock.
+ * Charge moving between groups is protected by checking mm->moving
+ * account and taking the move_lock in the slowpath.
*/
void __mem_cgroup_begin_update_page_stat(struct page *page,
return NOTIFY_OK;
}
-
-/* See mem_cgroup_try_charge() for details */
-enum {
- CHARGE_OK, /* success */
- CHARGE_RETRY, /* need to retry but retry is not bad */
- CHARGE_NOMEM, /* we can't do more. return -ENOMEM */
- CHARGE_WOULDBLOCK, /* GFP_WAIT wasn't set and no enough res. */
-};
-
-static int mem_cgroup_do_charge(struct mem_cgroup *memcg, gfp_t gfp_mask,
- unsigned int nr_pages, unsigned int min_pages,
- bool invoke_oom)
+static int try_charge(struct mem_cgroup *memcg, gfp_t gfp_mask,
+ unsigned int nr_pages)
{
- unsigned long csize = nr_pages * PAGE_SIZE;
+ unsigned int batch = max(CHARGE_BATCH, nr_pages);
+ int nr_retries = MEM_CGROUP_RECLAIM_RETRIES;
struct mem_cgroup *mem_over_limit;
struct res_counter *fail_res;
+ unsigned long nr_reclaimed;
unsigned long flags = 0;
- int ret;
+ unsigned long long size;
+ int ret = 0;
- ret = res_counter_charge(&memcg->res, csize, &fail_res);
+retry:
+ if (consume_stock(memcg, nr_pages))
+ goto done;
- if (likely(!ret)) {
+ size = batch * PAGE_SIZE;
+ if (!res_counter_charge(&memcg->res, size, &fail_res)) {
if (!do_swap_account)
- return CHARGE_OK;
- ret = res_counter_charge(&memcg->memsw, csize, &fail_res);
- if (likely(!ret))
- return CHARGE_OK;
-
- res_counter_uncharge(&memcg->res, csize);
+ goto done_restock;
+ if (!res_counter_charge(&memcg->memsw, size, &fail_res))
+ goto done_restock;
+ res_counter_uncharge(&memcg->res, size);
mem_over_limit = mem_cgroup_from_res_counter(fail_res, memsw);
flags |= MEM_CGROUP_RECLAIM_NOSWAP;
} else
mem_over_limit = mem_cgroup_from_res_counter(fail_res, res);
+
+ if (batch > nr_pages) {
+ batch = nr_pages;
+ goto retry;
+ }
+
/*
- * Never reclaim on behalf of optional batching, retry with a
- * single page instead.
+ * 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 (nr_pages > min_pages)
- return CHARGE_RETRY;
+ if (unlikely(test_thread_flag(TIF_MEMDIE) ||
+ fatal_signal_pending(current) ||
+ current->flags & PF_EXITING))
+ goto bypass;
+
+ if (unlikely(task_in_memcg_oom(current)))
+ goto nomem;
if (!(gfp_mask & __GFP_WAIT))
- return CHARGE_WOULDBLOCK;
+ goto nomem;
- if (gfp_mask & __GFP_NORETRY)
- return CHARGE_NOMEM;
+ nr_reclaimed = mem_cgroup_reclaim(mem_over_limit, gfp_mask, flags);
- ret = mem_cgroup_reclaim(mem_over_limit, gfp_mask, flags);
if (mem_cgroup_margin(mem_over_limit) >= nr_pages)
- return CHARGE_RETRY;
+ goto retry;
+
+ if (gfp_mask & __GFP_NORETRY)
+ goto nomem;
/*
* Even though the limit is exceeded at this point, reclaim
* may have been able to free some pages. Retry the charge
* unlikely to succeed so close to the limit, and we fall back
* to regular pages anyway in case of failure.
*/
- if (nr_pages <= (1 << PAGE_ALLOC_COSTLY_ORDER) && ret)
- return CHARGE_RETRY;
-
+ if (nr_reclaimed && nr_pages <= (1 << PAGE_ALLOC_COSTLY_ORDER))
+ goto retry;
/*
* At task move, charge accounts can be doubly counted. So, it's
* better to wait until the end of task_move if something is going on.
*/
if (mem_cgroup_wait_acct_move(mem_over_limit))
- return CHARGE_RETRY;
-
- if (invoke_oom)
- mem_cgroup_oom(mem_over_limit, gfp_mask, get_order(csize));
-
- return CHARGE_NOMEM;
-}
-
-/**
- * mem_cgroup_try_charge - try charging a memcg
- * @memcg: memcg to charge
- * @nr_pages: number of pages to charge
- * @oom: trigger OOM if reclaim fails
- *
- * Returns 0 if @memcg was charged successfully, -EINTR if the charge
- * was bypassed to root_mem_cgroup, and -ENOMEM if the charge failed.
- */
-static int mem_cgroup_try_charge(struct mem_cgroup *memcg,
- gfp_t gfp_mask,
- unsigned int nr_pages,
- bool oom)
-{
- unsigned int batch = max(CHARGE_BATCH, nr_pages);
- int nr_oom_retries = MEM_CGROUP_RECLAIM_RETRIES;
- int ret;
-
- if (mem_cgroup_is_root(memcg))
- goto done;
- /*
- * 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(test_thread_flag(TIF_MEMDIE) ||
- fatal_signal_pending(current) ||
- current->flags & PF_EXITING))
- goto bypass;
+ goto retry;
- if (unlikely(task_in_memcg_oom(current)))
- goto nomem;
+ if (nr_retries--)
+ goto retry;
if (gfp_mask & __GFP_NOFAIL)
- oom = false;
-again:
- if (consume_stock(memcg, nr_pages))
- goto done;
-
- do {
- bool invoke_oom = oom && !nr_oom_retries;
-
- /* If killed, bypass charge */
- if (fatal_signal_pending(current))
- goto bypass;
+ goto bypass;
- ret = mem_cgroup_do_charge(memcg, gfp_mask, batch,
- nr_pages, invoke_oom);
- switch (ret) {
- case CHARGE_OK:
- break;
- case CHARGE_RETRY: /* not in OOM situation but retry */
- batch = nr_pages;
- goto again;
- case CHARGE_WOULDBLOCK: /* !__GFP_WAIT */
- goto nomem;
- case CHARGE_NOMEM: /* OOM routine works */
- if (!oom || invoke_oom)
- goto nomem;
- nr_oom_retries--;
- break;
- }
- } while (ret != CHARGE_OK);
+ if (fatal_signal_pending(current))
+ goto bypass;
- if (batch > nr_pages)
- refill_stock(memcg, batch - nr_pages);
-done:
- return 0;
+ mem_cgroup_oom(mem_over_limit, gfp_mask, get_order(nr_pages));
nomem:
if (!(gfp_mask & __GFP_NOFAIL))
return -ENOMEM;
bypass:
- return -EINTR;
-}
-
-/**
- * mem_cgroup_try_charge_mm - try charging a mm
- * @mm: mm_struct to charge
- * @nr_pages: number of pages to charge
- * @oom: trigger OOM if reclaim fails
- *
- * Returns the charged mem_cgroup associated with the given mm_struct or
- * NULL the charge failed.
- */
-static struct mem_cgroup *mem_cgroup_try_charge_mm(struct mm_struct *mm,
- gfp_t gfp_mask,
- unsigned int nr_pages,
- bool oom)
-
-{
- struct mem_cgroup *memcg;
- int ret;
-
- memcg = get_mem_cgroup_from_mm(mm);
- ret = mem_cgroup_try_charge(memcg, gfp_mask, nr_pages, oom);
- css_put(&memcg->css);
- if (ret == -EINTR)
- memcg = root_mem_cgroup;
- else if (ret)
- memcg = NULL;
+ memcg = root_mem_cgroup;
+ ret = -EINTR;
+ goto retry;
- return memcg;
+done_restock:
+ if (batch > nr_pages)
+ refill_stock(memcg, batch - nr_pages);
+done:
+ return ret;
}
-/*
- * Somemtimes we have to undo a charge we got by try_charge().
- * This function is for that and do uncharge, put css's refcnt.
- * gotten by try_charge().
- */
-static void __mem_cgroup_cancel_charge(struct mem_cgroup *memcg,
- unsigned int nr_pages)
+static void cancel_charge(struct mem_cgroup *memcg, unsigned int nr_pages)
{
- if (!mem_cgroup_is_root(memcg)) {
- unsigned long bytes = nr_pages * PAGE_SIZE;
+ unsigned long bytes = nr_pages * PAGE_SIZE;
- res_counter_uncharge(&memcg->res, bytes);
- if (do_swap_account)
- res_counter_uncharge(&memcg->memsw, bytes);
- }
+ res_counter_uncharge(&memcg->res, bytes);
+ if (do_swap_account)
+ res_counter_uncharge(&memcg->memsw, bytes);
}
/*
{
unsigned long bytes = nr_pages * PAGE_SIZE;
- if (mem_cgroup_is_root(memcg))
- return;
-
res_counter_uncharge_until(&memcg->res, memcg->res.parent, bytes);
if (do_swap_account)
res_counter_uncharge_until(&memcg->memsw,
return mem_cgroup_from_id(id);
}
+/*
+ * try_get_mem_cgroup_from_page - look up page's memcg association
+ * @page: the page
+ *
+ * Look up, get a css reference, and return the memcg that owns @page.
+ *
+ * The page must be locked to prevent racing with swap-in and page
+ * cache charges. If coming from an unlocked page table, the caller
+ * must ensure the page is on the LRU or this can race with charging.
+ */
struct mem_cgroup *try_get_mem_cgroup_from_page(struct page *page)
{
struct mem_cgroup *memcg = NULL;
VM_BUG_ON_PAGE(!PageLocked(page), page);
pc = lookup_page_cgroup(page);
- lock_page_cgroup(pc);
if (PageCgroupUsed(pc)) {
memcg = pc->mem_cgroup;
if (memcg && !css_tryget_online(&memcg->css))
memcg = NULL;
rcu_read_unlock();
}
- unlock_page_cgroup(pc);
return memcg;
}
-static void __mem_cgroup_commit_charge(struct mem_cgroup *memcg,
- struct page *page,
- unsigned int nr_pages,
- enum charge_type ctype,
- bool lrucare)
+static void lock_page_lru(struct page *page, int *isolated)
+{
+ struct zone *zone = page_zone(page);
+
+ spin_lock_irq(&zone->lru_lock);
+ if (PageLRU(page)) {
+ struct lruvec *lruvec;
+
+ lruvec = mem_cgroup_page_lruvec(page, zone);
+ ClearPageLRU(page);
+ del_page_from_lru_list(page, lruvec, page_lru(page));
+ *isolated = 1;
+ } else
+ *isolated = 0;
+}
+
+static void unlock_page_lru(struct page *page, int isolated)
+{
+ struct zone *zone = page_zone(page);
+
+ if (isolated) {
+ struct lruvec *lruvec;
+
+ lruvec = mem_cgroup_page_lruvec(page, zone);
+ VM_BUG_ON_PAGE(PageLRU(page), page);
+ SetPageLRU(page);
+ add_page_to_lru_list(page, lruvec, page_lru(page));
+ }
+ spin_unlock_irq(&zone->lru_lock);
+}
+
+static void commit_charge(struct page *page, struct mem_cgroup *memcg,
+ bool lrucare)
{
struct page_cgroup *pc = lookup_page_cgroup(page);
- struct zone *uninitialized_var(zone);
- struct lruvec *lruvec;
- bool was_on_lru = false;
- bool anon;
+ int isolated;
- lock_page_cgroup(pc);
VM_BUG_ON_PAGE(PageCgroupUsed(pc), page);
/*
* we don't need page_cgroup_lock about tail pages, becase they are not
* 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.
*/
- if (lrucare) {
- zone = page_zone(page);
- spin_lock_irq(&zone->lru_lock);
- if (PageLRU(page)) {
- lruvec = mem_cgroup_zone_lruvec(zone, pc->mem_cgroup);
- ClearPageLRU(page);
- del_page_from_lru_list(page, lruvec, page_lru(page));
- was_on_lru = true;
- }
- }
+ if (lrucare)
+ lock_page_lru(page, &isolated);
- pc->mem_cgroup = memcg;
/*
- * We access a page_cgroup asynchronously without lock_page_cgroup().
- * Especially when a page_cgroup is taken from a page, pc->mem_cgroup
- * is accessed after testing USED bit. To make pc->mem_cgroup visible
- * before USED bit, we need memory barrier here.
- * See mem_cgroup_add_lru_list(), etc.
+ * Nobody should be changing or seriously looking at
+ * pc->mem_cgroup and pc->flags 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
*/
- smp_wmb();
- SetPageCgroupUsed(pc);
-
- if (lrucare) {
- if (was_on_lru) {
- lruvec = mem_cgroup_zone_lruvec(zone, pc->mem_cgroup);
- VM_BUG_ON_PAGE(PageLRU(page), page);
- SetPageLRU(page);
- add_page_to_lru_list(page, lruvec, page_lru(page));
- }
- spin_unlock_irq(&zone->lru_lock);
- }
-
- if (ctype == MEM_CGROUP_CHARGE_TYPE_ANON)
- anon = true;
- else
- anon = false;
-
- mem_cgroup_charge_statistics(memcg, page, anon, nr_pages);
- unlock_page_cgroup(pc);
+ pc->mem_cgroup = memcg;
+ pc->flags = PCG_USED | PCG_MEM | (do_swap_account ? PCG_MEMSW : 0);
- /*
- * "charge_statistics" updated event counter. Then, check it.
- * Insert ancestor (and ancestor's ancestors), to softlimit RB-tree.
- * if they exceeds softlimit.
- */
- memcg_check_events(memcg, page);
+ if (lrucare)
+ unlock_page_lru(page, isolated);
}
static DEFINE_MUTEX(set_limit_mutex);
if (ret)
return ret;
- ret = mem_cgroup_try_charge(memcg, gfp, size >> PAGE_SHIFT,
- oom_gfp_allowed(gfp));
+ ret = try_charge(memcg, gfp, size >> PAGE_SHIFT);
if (ret == -EINTR) {
/*
- * mem_cgroup_try_charge() chosed to bypass to root due to
- * OOM kill or fatal signal. Since our only options are to
- * either fail the allocation or charge it to this cgroup, do
- * it as a temporary condition. But we can't fail. From a
- * kmem/slab perspective, the cache has already been selected,
- * by mem_cgroup_kmem_get_cache(), so it is too late to change
+ * try_charge() chose to bypass to root due to OOM kill or
+ * fatal signal. Since our only options are to either fail
+ * the allocation or charge it to this cgroup, do it as a
+ * temporary condition. But we can't fail. From a kmem/slab
+ * perspective, the cache has already been selected, by
+ * mem_cgroup_kmem_get_cache(), so it is too late to change
* our minds.
*
* This condition will only trigger if the task entered
- * memcg_charge_kmem in a sane state, but was OOM-killed during
- * mem_cgroup_try_charge() above. Tasks that were already
- * dying when the allocation triggers should have been already
+ * memcg_charge_kmem in a sane state, but was OOM-killed
+ * during try_charge() above. Tasks that were already dying
+ * when the allocation triggers should have been already
* directed to the root cgroup in memcontrol.h
*/
res_counter_charge_nofail(&memcg->res, size, &fail_res);
memcg_uncharge_kmem(memcg, PAGE_SIZE << order);
return;
}
-
+ /*
+ * The page is freshly allocated and not visible to any
+ * outside callers yet. Set up pc non-atomically.
+ */
pc = lookup_page_cgroup(page);
- lock_page_cgroup(pc);
pc->mem_cgroup = memcg;
- SetPageCgroupUsed(pc);
- unlock_page_cgroup(pc);
+ pc->flags = PCG_USED;
}
void __memcg_kmem_uncharge_pages(struct page *page, int order)
pc = lookup_page_cgroup(page);
- /*
- * Fast unlocked return. Theoretically might have changed, have to
- * check again after locking.
- */
if (!PageCgroupUsed(pc))
return;
- lock_page_cgroup(pc);
- if (PageCgroupUsed(pc)) {
- memcg = pc->mem_cgroup;
- ClearPageCgroupUsed(pc);
- }
- unlock_page_cgroup(pc);
+ memcg = pc->mem_cgroup;
+ pc->flags = 0;
/*
* We trust that only if there is a memcg associated with the page, it
#ifdef CONFIG_TRANSPARENT_HUGEPAGE
-#define PCGF_NOCOPY_AT_SPLIT (1 << PCG_LOCK | 1 << PCG_MIGRATION)
/*
* Because tail pages are not marked as "used", set it. We're under
* zone->lru_lock, 'splitting on pmd' and compound_lock.
for (i = 1; i < HPAGE_PMD_NR; i++) {
pc = head_pc + i;
pc->mem_cgroup = memcg;
- smp_wmb();/* see __commit_charge() */
- pc->flags = head_pc->flags & ~PCGF_NOCOPY_AT_SPLIT;
+ pc->flags = head_pc->flags;
}
__this_cpu_sub(memcg->stat->count[MEM_CGROUP_STAT_RSS_HUGE],
HPAGE_PMD_NR);
{
unsigned long flags;
int ret;
- bool anon = PageAnon(page);
VM_BUG_ON(from == to);
VM_BUG_ON_PAGE(PageLRU(page), page);
if (nr_pages > 1 && !PageTransHuge(page))
goto out;
- lock_page_cgroup(pc);
+ /*
+ * Prevent mem_cgroup_migrate() from looking at pc->mem_cgroup
+ * of its source page while we change it: page migration takes
+ * both pages off the LRU, but page cache replacement doesn't.
+ */
+ if (!trylock_page(page))
+ goto out;
ret = -EINVAL;
if (!PageCgroupUsed(pc) || pc->mem_cgroup != from)
- goto unlock;
+ goto out_unlock;
move_lock_mem_cgroup(from, &flags);
- if (!anon && page_mapped(page)) {
+ if (!PageAnon(page) && page_mapped(page)) {
__this_cpu_sub(from->stat->count[MEM_CGROUP_STAT_FILE_MAPPED],
nr_pages);
__this_cpu_add(to->stat->count[MEM_CGROUP_STAT_FILE_MAPPED],
nr_pages);
}
- mem_cgroup_charge_statistics(from, page, anon, -nr_pages);
+ /*
+ * It is safe to change pc->mem_cgroup here because the page
+ * is referenced, charged, and isolated - we can't race with
+ * uncharging, charging, migration, or LRU putback.
+ */
/* caller should have done css_get */
pc->mem_cgroup = to;
- mem_cgroup_charge_statistics(to, page, anon, nr_pages);
move_unlock_mem_cgroup(from, &flags);
ret = 0;
-unlock:
- unlock_page_cgroup(pc);
- /*
- * check events
- */
+
+ local_irq_disable();
+ mem_cgroup_charge_statistics(to, page, nr_pages);
memcg_check_events(to, page);
+ mem_cgroup_charge_statistics(from, page, -nr_pages);
memcg_check_events(from, page);
+ local_irq_enable();
+out_unlock:
+ unlock_page(page);
out:
return ret;
}
return ret;
}
-int mem_cgroup_charge_anon(struct page *page,
- struct mm_struct *mm, gfp_t gfp_mask)
+#ifdef CONFIG_MEMCG_SWAP
+static void mem_cgroup_swap_statistics(struct mem_cgroup *memcg,
+ bool charge)
{
- unsigned int nr_pages = 1;
- struct mem_cgroup *memcg;
- bool oom = true;
+ int val = (charge) ? 1 : -1;
+ this_cpu_add(memcg->stat->count[MEM_CGROUP_STAT_SWAP], val);
+}
- if (mem_cgroup_disabled())
- return 0;
+/**
+ * mem_cgroup_move_swap_account - move swap charge and swap_cgroup's record.
+ * @entry: swap entry to be moved
+ * @from: mem_cgroup which the entry is moved from
+ * @to: mem_cgroup which the entry is moved to
+ *
+ * It succeeds only when the swap_cgroup's record for this entry is the same
+ * as the mem_cgroup's id of @from.
+ *
+ * Returns 0 on success, -EINVAL on failure.
+ *
+ * The caller must have charged to @to, IOW, called res_counter_charge() about
+ * both res and memsw, and called css_get().
+ */
+static int mem_cgroup_move_swap_account(swp_entry_t entry,
+ struct mem_cgroup *from, struct mem_cgroup *to)
+{
+ unsigned short old_id, new_id;
- VM_BUG_ON_PAGE(page_mapped(page), page);
- VM_BUG_ON_PAGE(page->mapping && !PageAnon(page), page);
- VM_BUG_ON(!mm);
+ old_id = mem_cgroup_id(from);
+ new_id = mem_cgroup_id(to);
- if (PageTransHuge(page)) {
- nr_pages <<= compound_order(page);
- VM_BUG_ON_PAGE(!PageTransHuge(page), page);
+ if (swap_cgroup_cmpxchg(entry, old_id, new_id) == old_id) {
+ mem_cgroup_swap_statistics(from, false);
+ mem_cgroup_swap_statistics(to, true);
/*
- * Never OOM-kill a process for a huge page. The
- * fault handler will fall back to regular pages.
+ * This function is only called from task migration context now.
+ * It postpones res_counter and refcount handling till the end
+ * of task migration(mem_cgroup_clear_mc()) for performance
+ * improvement. But we cannot postpone css_get(to) because if
+ * the process that has been moved to @to does swap-in, the
+ * refcount of @to might be decreased to 0.
+ *
+ * We are in attach() phase, so the cgroup is guaranteed to be
+ * alive, so we can just call css_get().
*/
- oom = false;
+ css_get(&to->css);
+ return 0;
}
-
- memcg = mem_cgroup_try_charge_mm(mm, gfp_mask, nr_pages, oom);
- if (!memcg)
- return -ENOMEM;
- __mem_cgroup_commit_charge(memcg, page, nr_pages,
- MEM_CGROUP_CHARGE_TYPE_ANON, false);
- return 0;
+ return -EINVAL;
+}
+#else
+static inline int mem_cgroup_move_swap_account(swp_entry_t entry,
+ struct mem_cgroup *from, struct mem_cgroup *to)
+{
+ return -EINVAL;
}
+#endif
-/*
- * While swap-in, try_charge -> commit or cancel, the page is locked.
- * And when try_charge() successfully returns, one refcnt to memcg without
- * struct page_cgroup is acquired. This refcnt will be consumed by
- * "commit()" or removed by "cancel()"
- */
-static int __mem_cgroup_try_charge_swapin(struct mm_struct *mm,
- struct page *page,
- gfp_t mask,
- struct mem_cgroup **memcgp)
+#ifdef CONFIG_DEBUG_VM
+static struct page_cgroup *lookup_page_cgroup_used(struct page *page)
{
- struct mem_cgroup *memcg = NULL;
struct page_cgroup *pc;
- int ret;
pc = lookup_page_cgroup(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.
- */
- if (PageCgroupUsed(pc))
- goto out;
- if (do_swap_account)
- memcg = try_get_mem_cgroup_from_page(page);
- if (!memcg)
- memcg = get_mem_cgroup_from_mm(mm);
- ret = mem_cgroup_try_charge(memcg, mask, 1, true);
- css_put(&memcg->css);
- if (ret == -EINTR)
- memcg = root_mem_cgroup;
- else if (ret)
- return ret;
-out:
- *memcgp = memcg;
- return 0;
-}
-
-int mem_cgroup_try_charge_swapin(struct mm_struct *mm, struct page *page,
- gfp_t gfp_mask, struct mem_cgroup **memcgp)
-{
- if (mem_cgroup_disabled()) {
- *memcgp = NULL;
- return 0;
- }
- /*
- * A racing thread's fault, or swapoff, may have already
- * updated the pte, and even removed page from swap cache: in
- * those cases unuse_pte()'s pte_same() test will fail; but
- * there's also a KSM case which does need to charge the page.
- */
- if (!PageSwapCache(page)) {
- struct mem_cgroup *memcg;
-
- memcg = mem_cgroup_try_charge_mm(mm, gfp_mask, 1, true);
- if (!memcg)
- return -ENOMEM;
- *memcgp = memcg;
- return 0;
- }
- return __mem_cgroup_try_charge_swapin(mm, page, gfp_mask, memcgp);
-}
-
-void mem_cgroup_cancel_charge_swapin(struct mem_cgroup *memcg)
-{
- if (mem_cgroup_disabled())
- return;
- if (!memcg)
- return;
- __mem_cgroup_cancel_charge(memcg, 1);
-}
-
-static void
-__mem_cgroup_commit_charge_swapin(struct page *page, struct mem_cgroup *memcg,
- enum charge_type ctype)
-{
- if (mem_cgroup_disabled())
- return;
- if (!memcg)
- return;
-
- __mem_cgroup_commit_charge(memcg, page, 1, ctype, true);
- /*
- * Now swap is on-memory. This means this page may be
- * counted both as mem and swap....double count.
- * Fix it by uncharging from memsw. Basically, this SwapCache is stable
- * under lock_page(). But in do_swap_page()::memory.c, reuse_swap_page()
- * may call delete_from_swap_cache() before reach here.
- */
- if (do_swap_account && PageSwapCache(page)) {
- swp_entry_t ent = {.val = page_private(page)};
- mem_cgroup_uncharge_swap(ent);
- }
-}
-
-void mem_cgroup_commit_charge_swapin(struct page *page,
- struct mem_cgroup *memcg)
-{
- __mem_cgroup_commit_charge_swapin(page, memcg,
- MEM_CGROUP_CHARGE_TYPE_ANON);
-}
-
-int mem_cgroup_charge_file(struct page *page, struct mm_struct *mm,
- gfp_t gfp_mask)
-{
- enum charge_type type = MEM_CGROUP_CHARGE_TYPE_CACHE;
- struct mem_cgroup *memcg;
- int ret;
-
- if (mem_cgroup_disabled())
- return 0;
- if (PageCompound(page))
- return 0;
-
- if (PageSwapCache(page)) { /* shmem */
- ret = __mem_cgroup_try_charge_swapin(mm, page,
- gfp_mask, &memcg);
- if (ret)
- return ret;
- __mem_cgroup_commit_charge_swapin(page, memcg, type);
- return 0;
- }
-
- memcg = mem_cgroup_try_charge_mm(mm, gfp_mask, 1, true);
- if (!memcg)
- return -ENOMEM;
- __mem_cgroup_commit_charge(memcg, page, 1, type, false);
- return 0;
-}
-
-static void mem_cgroup_do_uncharge(struct mem_cgroup *memcg,
- unsigned int nr_pages,
- const enum charge_type ctype)
-{
- struct memcg_batch_info *batch = NULL;
- bool uncharge_memsw = true;
-
- /* If swapout, usage of swap doesn't decrease */
- if (!do_swap_account || ctype == MEM_CGROUP_CHARGE_TYPE_SWAPOUT)
- uncharge_memsw = false;
-
- batch = ¤t->memcg_batch;
- /*
- * In usual, we do css_get() when we remember memcg pointer.
- * But in this case, we keep res->usage until end of a series of
- * uncharges. Then, it's ok to ignore memcg's refcnt.
- */
- if (!batch->memcg)
- batch->memcg = memcg;
- /*
- * do_batch > 0 when unmapping pages or inode invalidate/truncate.
- * In those cases, all pages freed continuously can be expected to be in
- * the same cgroup and we have chance to coalesce uncharges.
- * But we do uncharge one by one if this is killed by OOM(TIF_MEMDIE)
- * because we want to do uncharge as soon as possible.
- */
-
- if (!batch->do_batch || test_thread_flag(TIF_MEMDIE))
- goto direct_uncharge;
-
- if (nr_pages > 1)
- goto direct_uncharge;
-
- /*
- * In typical case, batch->memcg == mem. This means we can
- * merge a series of uncharges to an uncharge of res_counter.
- * If not, we uncharge res_counter ony by one.
- */
- if (batch->memcg != memcg)
- goto direct_uncharge;
- /* remember freed charge and uncharge it later */
- batch->nr_pages++;
- if (uncharge_memsw)
- batch->memsw_nr_pages++;
- return;
-direct_uncharge:
- res_counter_uncharge(&memcg->res, nr_pages * PAGE_SIZE);
- if (uncharge_memsw)
- res_counter_uncharge(&memcg->memsw, nr_pages * PAGE_SIZE);
- if (unlikely(batch->memcg != memcg))
- memcg_oom_recover(memcg);
-}
-
-/*
- * uncharge if !page_mapped(page)
- */
-static struct mem_cgroup *
-__mem_cgroup_uncharge_common(struct page *page, enum charge_type ctype,
- bool end_migration)
-{
- struct mem_cgroup *memcg = NULL;
- unsigned int nr_pages = 1;
- struct page_cgroup *pc;
- bool anon;
-
- if (mem_cgroup_disabled())
- return NULL;
-
- if (PageTransHuge(page)) {
- nr_pages <<= compound_order(page);
- VM_BUG_ON_PAGE(!PageTransHuge(page), page);
- }
- /*
- * Check if our page_cgroup is valid
- */
- pc = lookup_page_cgroup(page);
- if (unlikely(!PageCgroupUsed(pc)))
- return NULL;
-
- lock_page_cgroup(pc);
-
- memcg = pc->mem_cgroup;
-
- if (!PageCgroupUsed(pc))
- goto unlock_out;
-
- anon = PageAnon(page);
-
- switch (ctype) {
- case MEM_CGROUP_CHARGE_TYPE_ANON:
- /*
- * Generally PageAnon tells if it's the anon statistics to be
- * updated; but sometimes e.g. mem_cgroup_uncharge_page() is
- * used before page reached the stage of being marked PageAnon.
- */
- anon = true;
- /* fallthrough */
- case MEM_CGROUP_CHARGE_TYPE_DROP:
- /* See mem_cgroup_prepare_migration() */
- if (page_mapped(page))
- goto unlock_out;
- /*
- * Pages under migration may not be uncharged. But
- * end_migration() /must/ be the one uncharging the
- * unused post-migration page and so it has to call
- * here with the migration bit still set. See the
- * res_counter handling below.
- */
- if (!end_migration && PageCgroupMigration(pc))
- goto unlock_out;
- break;
- case MEM_CGROUP_CHARGE_TYPE_SWAPOUT:
- if (!PageAnon(page)) { /* Shared memory */
- if (page->mapping && !page_is_file_cache(page))
- goto unlock_out;
- } else if (page_mapped(page)) /* Anon */
- goto unlock_out;
- break;
- default:
- break;
- }
-
- mem_cgroup_charge_statistics(memcg, page, anon, -nr_pages);
-
- ClearPageCgroupUsed(pc);
- /*
- * pc->mem_cgroup is not cleared here. It will be accessed when it's
- * freed from LRU. This is safe because uncharged page is expected not
- * to be reused (freed soon). Exception is SwapCache, it's handled by
- * special functions.
- */
-
- unlock_page_cgroup(pc);
- /*
- * even after unlock, we have memcg->res.usage here and this memcg
- * will never be freed, so it's safe to call css_get().
- */
- memcg_check_events(memcg, page);
- if (do_swap_account && ctype == MEM_CGROUP_CHARGE_TYPE_SWAPOUT) {
- mem_cgroup_swap_statistics(memcg, true);
- css_get(&memcg->css);
- }
- /*
- * Migration does not charge the res_counter for the
- * replacement page, so leave it alone when phasing out the
- * page that is unused after the migration.
- */
- if (!end_migration && !mem_cgroup_is_root(memcg))
- mem_cgroup_do_uncharge(memcg, nr_pages, ctype);
-
- return memcg;
-
-unlock_out:
- unlock_page_cgroup(pc);
- return NULL;
-}
-
-void mem_cgroup_uncharge_page(struct page *page)
-{
- /* early check. */
- if (page_mapped(page))
- return;
- VM_BUG_ON_PAGE(page->mapping && !PageAnon(page), page);
- /*
- * If the page is in swap cache, uncharge should be deferred
- * to the swap path, which also properly accounts swap usage
- * and handles memcg lifetime.
- *
- * Note that this check is not stable and reclaim may add the
- * page to swap cache at any time after this. However, if the
- * page is not in swap cache by the time page->mapcount hits
- * 0, there won't be any page table references to the swap
- * slot, and reclaim will free it and not actually write the
- * page to disk.
- */
- if (PageSwapCache(page))
- return;
- __mem_cgroup_uncharge_common(page, MEM_CGROUP_CHARGE_TYPE_ANON, false);
-}
-
-void mem_cgroup_uncharge_cache_page(struct page *page)
-{
- VM_BUG_ON_PAGE(page_mapped(page), page);
- VM_BUG_ON_PAGE(page->mapping, page);
- __mem_cgroup_uncharge_common(page, MEM_CGROUP_CHARGE_TYPE_CACHE, false);
-}
-
-/*
- * Batch_start/batch_end is called in unmap_page_range/invlidate/trucate.
- * In that cases, pages are freed continuously and we can expect pages
- * are in the same memcg. All these calls itself limits the number of
- * pages freed at once, then uncharge_start/end() is called properly.
- * This may be called prural(2) times in a context,
- */
-
-void mem_cgroup_uncharge_start(void)
-{
- current->memcg_batch.do_batch++;
- /* We can do nest. */
- if (current->memcg_batch.do_batch == 1) {
- current->memcg_batch.memcg = NULL;
- current->memcg_batch.nr_pages = 0;
- current->memcg_batch.memsw_nr_pages = 0;
- }
-}
-
-void mem_cgroup_uncharge_end(void)
-{
- struct memcg_batch_info *batch = ¤t->memcg_batch;
-
- if (!batch->do_batch)
- return;
-
- batch->do_batch--;
- if (batch->do_batch) /* If stacked, do nothing. */
- return;
-
- if (!batch->memcg)
- return;
- /*
- * This "batch->memcg" is valid without any css_get/put etc...
- * bacause we hide charges behind us.
- */
- if (batch->nr_pages)
- res_counter_uncharge(&batch->memcg->res,
- batch->nr_pages * PAGE_SIZE);
- if (batch->memsw_nr_pages)
- res_counter_uncharge(&batch->memcg->memsw,
- batch->memsw_nr_pages * PAGE_SIZE);
- memcg_oom_recover(batch->memcg);
- /* forget this pointer (for sanity check) */
- batch->memcg = NULL;
-}
-
-#ifdef CONFIG_SWAP
-/*
- * called after __delete_from_swap_cache() and drop "page" account.
- * memcg information is recorded to swap_cgroup of "ent"
- */
-void
-mem_cgroup_uncharge_swapcache(struct page *page, swp_entry_t ent, bool swapout)
-{
- struct mem_cgroup *memcg;
- int ctype = MEM_CGROUP_CHARGE_TYPE_SWAPOUT;
-
- if (!swapout) /* this was a swap cache but the swap is unused ! */
- ctype = MEM_CGROUP_CHARGE_TYPE_DROP;
-
- memcg = __mem_cgroup_uncharge_common(page, ctype, false);
-
- /*
- * record memcg information, if swapout && memcg != NULL,
- * css_get() was called in uncharge().
- */
- if (do_swap_account && swapout && memcg)
- swap_cgroup_record(ent, mem_cgroup_id(memcg));
-}
-#endif
-
-#ifdef CONFIG_MEMCG_SWAP
-/*
- * called from swap_entry_free(). remove record in swap_cgroup and
- * uncharge "memsw" account.
- */
-void mem_cgroup_uncharge_swap(swp_entry_t ent)
-{
- struct mem_cgroup *memcg;
- unsigned short id;
-
- if (!do_swap_account)
- return;
-
- id = swap_cgroup_record(ent, 0);
- rcu_read_lock();
- memcg = mem_cgroup_lookup(id);
- if (memcg) {
- /*
- * We uncharge this because swap is freed. This memcg can
- * be obsolete one. We avoid calling css_tryget_online().
- */
- if (!mem_cgroup_is_root(memcg))
- res_counter_uncharge(&memcg->memsw, PAGE_SIZE);
- mem_cgroup_swap_statistics(memcg, false);
- css_put(&memcg->css);
- }
- rcu_read_unlock();
-}
-
-/**
- * mem_cgroup_move_swap_account - move swap charge and swap_cgroup's record.
- * @entry: swap entry to be moved
- * @from: mem_cgroup which the entry is moved from
- * @to: mem_cgroup which the entry is moved to
- *
- * It succeeds only when the swap_cgroup's record for this entry is the same
- * as the mem_cgroup's id of @from.
- *
- * Returns 0 on success, -EINVAL on failure.
- *
- * The caller must have charged to @to, IOW, called res_counter_charge() about
- * both res and memsw, and called css_get().
- */
-static int mem_cgroup_move_swap_account(swp_entry_t entry,
- struct mem_cgroup *from, struct mem_cgroup *to)
-{
- unsigned short old_id, new_id;
-
- old_id = mem_cgroup_id(from);
- new_id = mem_cgroup_id(to);
-
- if (swap_cgroup_cmpxchg(entry, old_id, new_id) == old_id) {
- mem_cgroup_swap_statistics(from, false);
- mem_cgroup_swap_statistics(to, true);
- /*
- * This function is only called from task migration context now.
- * It postpones res_counter and refcount handling till the end
- * of task migration(mem_cgroup_clear_mc()) for performance
- * improvement. But we cannot postpone css_get(to) because if
- * the process that has been moved to @to does swap-in, the
- * refcount of @to might be decreased to 0.
- *
- * We are in attach() phase, so the cgroup is guaranteed to be
- * alive, so we can just call css_get().
- */
- css_get(&to->css);
- return 0;
- }
- return -EINVAL;
-}
-#else
-static inline int mem_cgroup_move_swap_account(swp_entry_t entry,
- struct mem_cgroup *from, struct mem_cgroup *to)
-{
- return -EINVAL;
-}
-#endif
-
-/*
- * Before starting migration, account PAGE_SIZE to mem_cgroup that the old
- * page belongs to.
- */
-void mem_cgroup_prepare_migration(struct page *page, struct page *newpage,
- struct mem_cgroup **memcgp)
-{
- struct mem_cgroup *memcg = NULL;
- unsigned int nr_pages = 1;
- struct page_cgroup *pc;
- enum charge_type ctype;
-
- *memcgp = NULL;
-
- if (mem_cgroup_disabled())
- return;
-
- if (PageTransHuge(page))
- nr_pages <<= compound_order(page);
-
- pc = lookup_page_cgroup(page);
- lock_page_cgroup(pc);
- if (PageCgroupUsed(pc)) {
- memcg = pc->mem_cgroup;
- css_get(&memcg->css);
- /*
- * At migrating an anonymous page, its mapcount goes down
- * to 0 and uncharge() will be called. But, even if it's fully
- * unmapped, migration may fail and this page has to be
- * charged again. We set MIGRATION flag here and delay uncharge
- * until end_migration() is called
- *
- * Corner Case Thinking
- * A)
- * When the old page was mapped as Anon and it's unmap-and-freed
- * while migration was ongoing.
- * If unmap finds the old page, uncharge() of it will be delayed
- * until end_migration(). If unmap finds a new page, it's
- * uncharged when it make mapcount to be 1->0. If unmap code
- * finds swap_migration_entry, the new page will not be mapped
- * and end_migration() will find it(mapcount==0).
- *
- * B)
- * When the old page was mapped but migraion fails, the kernel
- * remaps it. A charge for it is kept by MIGRATION flag even
- * if mapcount goes down to 0. We can do remap successfully
- * without charging it again.
- *
- * C)
- * The "old" page is under lock_page() until the end of
- * migration, so, the old page itself will not be swapped-out.
- * If the new page is swapped out before end_migraton, our
- * hook to usual swap-out path will catch the event.
- */
- if (PageAnon(page))
- SetPageCgroupMigration(pc);
- }
- unlock_page_cgroup(pc);
- /*
- * If the page is not charged at this point,
- * we return here.
- */
- if (!memcg)
- return;
-
- *memcgp = memcg;
- /*
- * We charge new page before it's used/mapped. So, even if unlock_page()
- * is called before end_migration, we can catch all events on this new
- * page. In the case new page is migrated but not remapped, new page's
- * mapcount will be finally 0 and we call uncharge in end_migration().
- */
- if (PageAnon(page))
- ctype = MEM_CGROUP_CHARGE_TYPE_ANON;
- else
- ctype = MEM_CGROUP_CHARGE_TYPE_CACHE;
- /*
- * The page is committed to the memcg, but it's not actually
- * charged to the res_counter since we plan on replacing the
- * old one and only one page is going to be left afterwards.
- */
- __mem_cgroup_commit_charge(memcg, newpage, nr_pages, ctype, false);
-}
-
-/* remove redundant charge if migration failed*/
-void mem_cgroup_end_migration(struct mem_cgroup *memcg,
- struct page *oldpage, struct page *newpage, bool migration_ok)
-{
- struct page *used, *unused;
- struct page_cgroup *pc;
- bool anon;
-
- if (!memcg)
- return;
-
- if (!migration_ok) {
- used = oldpage;
- unused = newpage;
- } else {
- used = newpage;
- unused = oldpage;
- }
- anon = PageAnon(used);
- __mem_cgroup_uncharge_common(unused,
- anon ? MEM_CGROUP_CHARGE_TYPE_ANON
- : MEM_CGROUP_CHARGE_TYPE_CACHE,
- true);
- css_put(&memcg->css);
- /*
- * We disallowed uncharge of pages under migration because mapcount
- * of the page goes down to zero, temporarly.
- * Clear the flag and check the page should be charged.
- */
- pc = lookup_page_cgroup(oldpage);
- lock_page_cgroup(pc);
- ClearPageCgroupMigration(pc);
- unlock_page_cgroup(pc);
-
- /*
- * If a page is a file cache, radix-tree replacement is very atomic
- * and we can skip this check. When it was an Anon page, its mapcount
- * goes down to 0. But because we added MIGRATION flage, it's not
- * uncharged yet. There are several case but page->mapcount check
- * and USED bit check in mem_cgroup_uncharge_page() will do enough
- * check. (see prepare_charge() also)
- */
- if (anon)
- mem_cgroup_uncharge_page(used);
-}
-
-/*
- * At replace page cache, newpage is not under any memcg but it's on
- * LRU. So, this function doesn't touch res_counter but handles LRU
- * in correct way. Both pages are locked so we cannot race with uncharge.
- */
-void mem_cgroup_replace_page_cache(struct page *oldpage,
- struct page *newpage)
-{
- struct mem_cgroup *memcg = NULL;
- struct page_cgroup *pc;
- enum charge_type type = MEM_CGROUP_CHARGE_TYPE_CACHE;
-
- if (mem_cgroup_disabled())
- return;
-
- pc = lookup_page_cgroup(oldpage);
- /* fix accounting on old pages */
- lock_page_cgroup(pc);
- if (PageCgroupUsed(pc)) {
- memcg = pc->mem_cgroup;
- mem_cgroup_charge_statistics(memcg, oldpage, false, -1);
- ClearPageCgroupUsed(pc);
- }
- unlock_page_cgroup(pc);
-
- /*
- * When called from shmem_replace_page(), in some cases the
- * oldpage has already been charged, and in some cases not.
- */
- if (!memcg)
- return;
- /*
- * Even if newpage->mapping was NULL before starting replacement,
- * the newpage may be on LRU(or pagevec for LRU) already. We lock
- * LRU while we overwrite pc->mem_cgroup.
- */
- __mem_cgroup_commit_charge(memcg, newpage, 1, type, true);
-}
-
-#ifdef CONFIG_DEBUG_VM
-static struct page_cgroup *lookup_page_cgroup_used(struct page *page)
-{
- struct page_cgroup *pc;
-
- pc = lookup_page_cgroup(page);
- /*
- * Can be NULL while feeding pages into the page allocator for
- * the first time, i.e. during boot or memory hotplug;
- * or when mem_cgroup_disabled().
+ * Can be NULL while feeding pages into the page allocator for
+ * the first time, i.e. during boot or memory hotplug;
+ * or when mem_cgroup_disabled().
*/
if (likely(pc) && PageCgroupUsed(pc))
return pc;
gfp_mask, &nr_scanned);
nr_reclaimed += reclaimed;
*total_scanned += nr_scanned;
- spin_lock(&mctz->lock);
+ spin_lock_irq(&mctz->lock);
/*
* If we failed to reclaim anything from this memory cgroup
*/
/* If excess == 0, no tree ops */
__mem_cgroup_insert_exceeded(mz, mctz, excess);
- spin_unlock(&mctz->lock);
+ spin_unlock_irq(&mctz->lock);
css_put(&mz->memcg->css);
loop++;
/*
return retval;
}
-
-static unsigned long mem_cgroup_recursive_stat(struct mem_cgroup *memcg,
- enum mem_cgroup_stat_index idx)
-{
- struct mem_cgroup *iter;
- long val = 0;
-
- /* Per-cpu values can be negative, use a signed accumulator */
- for_each_mem_cgroup_tree(iter, memcg)
- val += mem_cgroup_read_stat(iter, idx);
-
- if (val < 0) /* race ? */
- val = 0;
- return val;
-}
-
-static inline u64 mem_cgroup_usage(struct mem_cgroup *memcg, bool swap)
-{
- u64 val;
-
- if (!mem_cgroup_is_root(memcg)) {
- if (!swap)
- return res_counter_read_u64(&memcg->res, RES_USAGE);
- else
- return res_counter_read_u64(&memcg->memsw, RES_USAGE);
- }
-
- /*
- * Transparent hugepages are still accounted for in MEM_CGROUP_STAT_RSS
- * as well as in MEM_CGROUP_STAT_RSS_HUGE.
- */
- val = mem_cgroup_recursive_stat(memcg, MEM_CGROUP_STAT_CACHE);
- val += mem_cgroup_recursive_stat(memcg, MEM_CGROUP_STAT_RSS);
-
- if (swap)
- val += mem_cgroup_recursive_stat(memcg, MEM_CGROUP_STAT_SWAP);
-
- return val << PAGE_SHIFT;
-}
-
static u64 mem_cgroup_read_u64(struct cgroup_subsys_state *css,
- struct cftype *cft)
+ struct cftype *cft)
{
struct mem_cgroup *memcg = mem_cgroup_from_css(css);
- u64 val;
- int name;
- enum res_type type;
-
- type = MEMFILE_TYPE(cft->private);
- name = MEMFILE_ATTR(cft->private);
+ enum res_type type = MEMFILE_TYPE(cft->private);
+ int name = MEMFILE_ATTR(cft->private);
switch (type) {
case _MEM:
- if (name == RES_USAGE)
- val = mem_cgroup_usage(memcg, false);
- else
- val = res_counter_read_u64(&memcg->res, name);
- break;
- case _MEMSWAP:
- if (name == RES_USAGE)
- val = mem_cgroup_usage(memcg, true);
- else
- val = res_counter_read_u64(&memcg->memsw, name);
- break;
+ return res_counter_read_u64(&memcg->res, name);
+ case _MEMSWAP:
+ return res_counter_read_u64(&memcg->memsw, name);
case _KMEM:
- val = res_counter_read_u64(&memcg->kmem, name);
+ return res_counter_read_u64(&memcg->kmem, name);
break;
default:
BUG();
}
-
- return val;
}
#ifdef CONFIG_MEMCG_KMEM
if (!t)
goto unlock;
- usage = mem_cgroup_usage(memcg, swap);
+ if (!swap)
+ usage = res_counter_read_u64(&memcg->res, RES_USAGE);
+ else
+ usage = res_counter_read_u64(&memcg->memsw, RES_USAGE);
/*
* current_threshold points to threshold just below or equal to usage.
mutex_lock(&memcg->thresholds_lock);
- if (type == _MEM)
+ if (type == _MEM) {
thresholds = &memcg->thresholds;
- else if (type == _MEMSWAP)
+ usage = res_counter_read_u64(&memcg->res, RES_USAGE);
+ } else if (type == _MEMSWAP) {
thresholds = &memcg->memsw_thresholds;
- else
+ usage = res_counter_read_u64(&memcg->memsw, RES_USAGE);
+ } else
BUG();
- usage = mem_cgroup_usage(memcg, type == _MEMSWAP);
-
/* Check if a threshold crossed before adding a new one */
if (thresholds->primary)
__mem_cgroup_threshold(memcg, type == _MEMSWAP);
int i, j, size;
mutex_lock(&memcg->thresholds_lock);
- if (type == _MEM)
+
+ if (type == _MEM) {
thresholds = &memcg->thresholds;
- else if (type == _MEMSWAP)
+ usage = res_counter_read_u64(&memcg->res, RES_USAGE);
+ } else if (type == _MEMSWAP) {
thresholds = &memcg->memsw_thresholds;
- else
+ usage = res_counter_read_u64(&memcg->memsw, RES_USAGE);
+ } else
BUG();
if (!thresholds->primary)
goto unlock;
- usage = mem_cgroup_usage(memcg, type == _MEMSWAP);
-
/* Check if a threshold crossed before removing */
__mem_cgroup_threshold(memcg, type == _MEMSWAP);
},
{
.name = "use_hierarchy",
- .flags = CFTYPE_INSANE,
.write_u64 = mem_cgroup_hierarchy_write,
.read_u64 = mem_cgroup_hierarchy_read,
},
* core guarantees its existence.
*/
} else {
- res_counter_init(&memcg->res, NULL);
- res_counter_init(&memcg->memsw, NULL);
- res_counter_init(&memcg->kmem, NULL);
+ res_counter_init(&memcg->res, &root_mem_cgroup->res);
+ res_counter_init(&memcg->memsw, &root_mem_cgroup->memsw);
+ res_counter_init(&memcg->kmem, &root_mem_cgroup->kmem);
/*
* Deeper hierachy with use_hierarchy == false doesn't make
* much sense so let cgroup subsystem know about this
__mem_cgroup_free(memcg);
}
+/**
+ * mem_cgroup_css_reset - reset the states of a mem_cgroup
+ * @css: the target css
+ *
+ * Reset the states of the mem_cgroup associated with @css. This is
+ * invoked when the userland requests disabling on the default hierarchy
+ * but the memcg is pinned through dependency. The memcg should stop
+ * applying policies and should revert to the vanilla state as it may be
+ * made visible again.
+ *
+ * The current implementation only resets the essential configurations.
+ * This needs to be expanded to cover all the visible parts.
+ */
+static void mem_cgroup_css_reset(struct cgroup_subsys_state *css)
+{
+ struct mem_cgroup *memcg = mem_cgroup_from_css(css);
+
+ mem_cgroup_resize_limit(memcg, ULLONG_MAX);
+ mem_cgroup_resize_memsw_limit(memcg, ULLONG_MAX);
+ memcg_update_kmem_limit(memcg, ULLONG_MAX);
+ res_counter_set_soft_limit(&memcg->res, ULLONG_MAX);
+}
+
#ifdef CONFIG_MMU
/* Handlers for move charge at task migration. */
-#define PRECHARGE_COUNT_AT_ONCE 256
static int mem_cgroup_do_precharge(unsigned long count)
{
- int ret = 0;
- int batch_count = PRECHARGE_COUNT_AT_ONCE;
- struct mem_cgroup *memcg = mc.to;
+ int ret;
- if (mem_cgroup_is_root(memcg)) {
+ /* Try a single bulk charge without reclaim first */
+ ret = try_charge(mc.to, GFP_KERNEL & ~__GFP_WAIT, count);
+ if (!ret) {
mc.precharge += count;
- /* we don't need css_get for root */
return ret;
}
- /* try to charge at once */
- if (count > 1) {
- struct res_counter *dummy;
- /*
- * "memcg" cannot be under rmdir() because we've already checked
- * by cgroup_lock_live_cgroup() that it is not removed and we
- * are still under the same cgroup_mutex. So we can postpone
- * css_get().
- */
- if (res_counter_charge(&memcg->res, PAGE_SIZE * count, &dummy))
- goto one_by_one;
- if (do_swap_account && res_counter_charge(&memcg->memsw,
- PAGE_SIZE * count, &dummy)) {
- res_counter_uncharge(&memcg->res, PAGE_SIZE * count);
- goto one_by_one;
- }
- mc.precharge += count;
+ if (ret == -EINTR) {
+ cancel_charge(root_mem_cgroup, count);
return ret;
}
-one_by_one:
- /* fall back to one by one charge */
+
+ /* Try charges one by one with reclaim */
while (count--) {
- if (signal_pending(current)) {
- ret = -EINTR;
- break;
- }
- if (!batch_count--) {
- batch_count = PRECHARGE_COUNT_AT_ONCE;
- cond_resched();
- }
- ret = mem_cgroup_try_charge(memcg, GFP_KERNEL, 1, false);
+ ret = try_charge(mc.to, GFP_KERNEL & ~__GFP_NORETRY, 1);
+ /*
+ * In case of failure, any residual charges against
+ * mc.to will be dropped by mem_cgroup_clear_mc()
+ * later on. However, cancel any charges that are
+ * bypassed to root right away or they'll be lost.
+ */
+ if (ret == -EINTR)
+ cancel_charge(root_mem_cgroup, 1);
if (ret)
- /* mem_cgroup_clear_mc() will do uncharge later */
return ret;
mc.precharge++;
+ cond_resched();
}
- return ret;
+ return 0;
}
/**
if (page) {
pc = lookup_page_cgroup(page);
/*
- * Do only loose check w/o page_cgroup lock.
- * mem_cgroup_move_account() checks the pc is valid or not under
- * the lock.
+ * Do only loose check w/o serialization.
+ * mem_cgroup_move_account() checks the pc is valid or
+ * not under LRU exclusion.
*/
if (PageCgroupUsed(pc) && pc->mem_cgroup == mc.from) {
ret = MC_TARGET_PAGE;
/* we must uncharge all the leftover precharges from mc.to */
if (mc.precharge) {
- __mem_cgroup_cancel_charge(mc.to, mc.precharge);
+ cancel_charge(mc.to, mc.precharge);
mc.precharge = 0;
}
/*
* we must uncharge here.
*/
if (mc.moved_charge) {
- __mem_cgroup_cancel_charge(mc.from, mc.moved_charge);
+ cancel_charge(mc.from, mc.moved_charge);
mc.moved_charge = 0;
}
/* we must fixup refcnts and charges */
if (mc.moved_swap) {
/* uncharge swap account from the old cgroup */
- if (!mem_cgroup_is_root(mc.from))
- res_counter_uncharge(&mc.from->memsw,
- PAGE_SIZE * mc.moved_swap);
+ res_counter_uncharge(&mc.from->memsw,
+ PAGE_SIZE * mc.moved_swap);
for (i = 0; i < mc.moved_swap; i++)
css_put(&mc.from->css);
- if (!mem_cgroup_is_root(mc.to)) {
- /*
- * we charged both to->res and to->memsw, so we should
- * uncharge to->res.
- */
- res_counter_uncharge(&mc.to->res,
- PAGE_SIZE * mc.moved_swap);
- }
+ /*
+ * we charged both to->res and to->memsw, so we should
+ * uncharge to->res.
+ */
+ res_counter_uncharge(&mc.to->res,
+ PAGE_SIZE * mc.moved_swap);
/* we've already done css_get(mc.to) */
mc.moved_swap = 0;
}
/*
* Cgroup retains root cgroups across [un]mount cycles making it necessary
- * to verify sane_behavior flag on each mount attempt.
+ * 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)
{
/*
- * use_hierarchy is forced with sane_behavior. cgroup core
+ * 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_sane_behavior(root_css->cgroup))
+ if (cgroup_on_dfl(root_css->cgroup))
mem_cgroup_from_css(root_css)->use_hierarchy = true;
}
.css_online = mem_cgroup_css_online,
.css_offline = mem_cgroup_css_offline,
.css_free = mem_cgroup_css_free,
+ .css_reset = mem_cgroup_css_reset,
.can_attach = mem_cgroup_can_attach,
.cancel_attach = mem_cgroup_cancel_attach,
.attach = mem_cgroup_move_task,
.bind = mem_cgroup_bind,
- .base_cftypes = mem_cgroup_files,
+ .legacy_cftypes = mem_cgroup_files,
.early_init = 0,
};
static void __init memsw_file_init(void)
{
- WARN_ON(cgroup_add_cftypes(&memory_cgrp_subsys, memsw_cgroup_files));
+ WARN_ON(cgroup_add_legacy_cftypes(&memory_cgrp_subsys,
+ memsw_cgroup_files));
}
static void __init enable_swap_cgroup(void)
}
#endif
+#ifdef CONFIG_MEMCG_SWAP
+/**
+ * mem_cgroup_swapout - transfer a memsw charge to swap
+ * @page: page whose memsw charge to transfer
+ * @entry: swap entry to move the charge to
+ *
+ * Transfer the memsw charge of @page to @entry.
+ */
+void mem_cgroup_swapout(struct page *page, swp_entry_t entry)
+{
+ struct page_cgroup *pc;
+ unsigned short oldid;
+
+ VM_BUG_ON_PAGE(PageLRU(page), page);
+ VM_BUG_ON_PAGE(page_count(page), page);
+
+ if (!do_swap_account)
+ return;
+
+ pc = lookup_page_cgroup(page);
+
+ /* Readahead page, never charged */
+ if (!PageCgroupUsed(pc))
+ return;
+
+ VM_BUG_ON_PAGE(!(pc->flags & PCG_MEMSW), page);
+
+ oldid = swap_cgroup_record(entry, mem_cgroup_id(pc->mem_cgroup));
+ VM_BUG_ON_PAGE(oldid, page);
+
+ pc->flags &= ~PCG_MEMSW;
+ css_get(&pc->mem_cgroup->css);
+ mem_cgroup_swap_statistics(pc->mem_cgroup, true);
+}
+
+/**
+ * mem_cgroup_uncharge_swap - uncharge a swap entry
+ * @entry: swap entry to uncharge
+ *
+ * Drop the memsw charge associated with @entry.
+ */
+void mem_cgroup_uncharge_swap(swp_entry_t entry)
+{
+ struct mem_cgroup *memcg;
+ unsigned short id;
+
+ if (!do_swap_account)
+ return;
+
+ id = swap_cgroup_record(entry, 0);
+ rcu_read_lock();
+ memcg = mem_cgroup_lookup(id);
+ if (memcg) {
+ res_counter_uncharge(&memcg->memsw, PAGE_SIZE);
+ mem_cgroup_swap_statistics(memcg, false);
+ css_put(&memcg->css);
+ }
+ rcu_read_unlock();
+}
+#endif
+
+/**
+ * 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
+ *
+ * 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)
+{
+ struct mem_cgroup *memcg = NULL;
+ unsigned int nr_pages = 1;
+ int ret = 0;
+
+ if (mem_cgroup_disabled())
+ goto out;
+
+ if (PageSwapCache(page)) {
+ struct page_cgroup *pc = lookup_page_cgroup(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.
+ */
+ if (PageCgroupUsed(pc))
+ goto out;
+ }
+
+ if (PageTransHuge(page)) {
+ nr_pages <<= compound_order(page);
+ VM_BUG_ON_PAGE(!PageTransHuge(page), page);
+ }
+
+ if (do_swap_account && PageSwapCache(page))
+ memcg = try_get_mem_cgroup_from_page(page);
+ if (!memcg)
+ memcg = get_mem_cgroup_from_mm(mm);
+
+ ret = try_charge(memcg, gfp_mask, nr_pages);
+
+ css_put(&memcg->css);
+
+ if (ret == -EINTR) {
+ memcg = root_mem_cgroup;
+ ret = 0;
+ }
+out:
+ *memcgp = memcg;
+ 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
+ *
+ * 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.
+ *
+ * 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.
+ *
+ * Use mem_cgroup_cancel_charge() to cancel the transaction instead.
+ */
+void mem_cgroup_commit_charge(struct page *page, struct mem_cgroup *memcg,
+ bool lrucare)
+{
+ unsigned int nr_pages = 1;
+
+ VM_BUG_ON_PAGE(!page->mapping, page);
+ VM_BUG_ON_PAGE(PageLRU(page) && !lrucare, page);
+
+ 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;
+
+ commit_charge(page, memcg, lrucare);
+
+ if (PageTransHuge(page)) {
+ nr_pages <<= compound_order(page);
+ VM_BUG_ON_PAGE(!PageTransHuge(page), page);
+ }
+
+ local_irq_disable();
+ mem_cgroup_charge_statistics(memcg, page, nr_pages);
+ memcg_check_events(memcg, page);
+ local_irq_enable();
+
+ if (do_swap_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);
+ }
+}
+
+/**
+ * mem_cgroup_cancel_charge - cancel a page charge
+ * @page: page to charge
+ * @memcg: memcg to charge the page to
+ *
+ * Cancel a charge transaction started by mem_cgroup_try_charge().
+ */
+void mem_cgroup_cancel_charge(struct page *page, struct mem_cgroup *memcg)
+{
+ unsigned int nr_pages = 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().
+ */
+ if (!memcg)
+ return;
+
+ if (PageTransHuge(page)) {
+ nr_pages <<= compound_order(page);
+ VM_BUG_ON_PAGE(!PageTransHuge(page), page);
+ }
+
+ cancel_charge(memcg, nr_pages);
+}
+
+static void uncharge_batch(struct mem_cgroup *memcg, unsigned long pgpgout,
+ unsigned long nr_mem, unsigned long nr_memsw,
+ unsigned long nr_anon, unsigned long nr_file,
+ unsigned long nr_huge, struct page *dummy_page)
+{
+ unsigned long flags;
+
+ if (nr_mem)
+ res_counter_uncharge(&memcg->res, nr_mem * PAGE_SIZE);
+ if (nr_memsw)
+ res_counter_uncharge(&memcg->memsw, nr_memsw * PAGE_SIZE);
+
+ memcg_oom_recover(memcg);
+
+ local_irq_save(flags);
+ __this_cpu_sub(memcg->stat->count[MEM_CGROUP_STAT_RSS], nr_anon);
+ __this_cpu_sub(memcg->stat->count[MEM_CGROUP_STAT_CACHE], nr_file);
+ __this_cpu_sub(memcg->stat->count[MEM_CGROUP_STAT_RSS_HUGE], nr_huge);
+ __this_cpu_add(memcg->stat->events[MEM_CGROUP_EVENTS_PGPGOUT], pgpgout);
+ __this_cpu_add(memcg->stat->nr_page_events, nr_anon + nr_file);
+ memcg_check_events(memcg, dummy_page);
+ local_irq_restore(flags);
+}
+
+static void uncharge_list(struct list_head *page_list)
+{
+ struct mem_cgroup *memcg = NULL;
+ unsigned long nr_memsw = 0;
+ unsigned long nr_anon = 0;
+ unsigned long nr_file = 0;
+ unsigned long nr_huge = 0;
+ unsigned long pgpgout = 0;
+ unsigned long nr_mem = 0;
+ struct list_head *next;
+ struct page *page;
+
+ next = page_list->next;
+ do {
+ unsigned int nr_pages = 1;
+ struct page_cgroup *pc;
+
+ page = list_entry(next, struct page, lru);
+ next = page->lru.next;
+
+ VM_BUG_ON_PAGE(PageLRU(page), page);
+ VM_BUG_ON_PAGE(page_count(page), page);
+
+ pc = lookup_page_cgroup(page);
+ if (!PageCgroupUsed(pc))
+ continue;
+
+ /*
+ * Nobody should be changing or seriously looking at
+ * pc->mem_cgroup and pc->flags at this point, we have
+ * fully exclusive access to the page.
+ */
+
+ if (memcg != pc->mem_cgroup) {
+ if (memcg) {
+ uncharge_batch(memcg, pgpgout, nr_mem, nr_memsw,
+ nr_anon, nr_file, nr_huge, page);
+ pgpgout = nr_mem = nr_memsw = 0;
+ nr_anon = nr_file = nr_huge = 0;
+ }
+ memcg = pc->mem_cgroup;
+ }
+
+ if (PageTransHuge(page)) {
+ nr_pages <<= compound_order(page);
+ VM_BUG_ON_PAGE(!PageTransHuge(page), page);
+ nr_huge += nr_pages;
+ }
+
+ if (PageAnon(page))
+ nr_anon += nr_pages;
+ else
+ nr_file += nr_pages;
+
+ if (pc->flags & PCG_MEM)
+ nr_mem += nr_pages;
+ if (pc->flags & PCG_MEMSW)
+ nr_memsw += nr_pages;
+ pc->flags = 0;
+
+ pgpgout++;
+ } while (next != page_list);
+
+ if (memcg)
+ uncharge_batch(memcg, pgpgout, nr_mem, nr_memsw,
+ nr_anon, nr_file, nr_huge, page);
+}
+
+/**
+ * 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)
+{
+ struct page_cgroup *pc;
+
+ if (mem_cgroup_disabled())
+ return;
+
+ /* Don't touch page->lru of any random page, pre-check: */
+ pc = lookup_page_cgroup(page);
+ if (!PageCgroupUsed(pc))
+ return;
+
+ INIT_LIST_HEAD(&page->lru);
+ uncharge_list(&page->lru);
+}
+
+/**
+ * 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().
+ */
+void mem_cgroup_uncharge_list(struct list_head *page_list)
+{
+ if (mem_cgroup_disabled())
+ return;
+
+ if (!list_empty(page_list))
+ uncharge_list(page_list);
+}
+
+/**
+ * mem_cgroup_migrate - migrate a charge to another page
+ * @oldpage: currently charged page
+ * @newpage: page to transfer the charge to
+ * @lrucare: both pages might be on the LRU already
+ *
+ * Migrate the charge from @oldpage to @newpage.
+ *
+ * Both pages must be locked, @newpage->mapping must be set up.
+ */
+void mem_cgroup_migrate(struct page *oldpage, struct page *newpage,
+ bool lrucare)
+{
+ struct page_cgroup *pc;
+ int isolated;
+
+ VM_BUG_ON_PAGE(!PageLocked(oldpage), oldpage);
+ VM_BUG_ON_PAGE(!PageLocked(newpage), newpage);
+ VM_BUG_ON_PAGE(!lrucare && PageLRU(oldpage), oldpage);
+ VM_BUG_ON_PAGE(!lrucare && PageLRU(newpage), newpage);
+ VM_BUG_ON_PAGE(PageAnon(oldpage) != PageAnon(newpage), newpage);
+ VM_BUG_ON_PAGE(PageTransHuge(oldpage) != PageTransHuge(newpage),
+ newpage);
+
+ if (mem_cgroup_disabled())
+ return;
+
+ /* Page cache replacement: new page already charged? */
+ pc = lookup_page_cgroup(newpage);
+ if (PageCgroupUsed(pc))
+ return;
+
+ /* Re-entrant migration: old page already uncharged? */
+ pc = lookup_page_cgroup(oldpage);
+ if (!PageCgroupUsed(pc))
+ return;
+
+ VM_BUG_ON_PAGE(!(pc->flags & PCG_MEM), oldpage);
+ VM_BUG_ON_PAGE(do_swap_account && !(pc->flags & PCG_MEMSW), oldpage);
+
+ if (lrucare)
+ lock_page_lru(oldpage, &isolated);
+
+ pc->flags = 0;
+
+ if (lrucare)
+ unlock_page_lru(oldpage, isolated);
+
+ commit_charge(newpage, pc->mem_cgroup, lrucare);
+}
+
/*
* subsys_initcall() for memory controller.
*
git.openpandora.org / pandora-kernel.git / blobdiff