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-rw-r--r--mm/memcontrol.c1232
1 files changed, 591 insertions, 641 deletions
diff --git a/mm/memcontrol.c b/mm/memcontrol.c
index 94da8ee9e2c..58a08fc7414 100644
--- a/mm/memcontrol.c
+++ b/mm/memcontrol.c
@@ -123,16 +123,22 @@ struct mem_cgroup_stat_cpu {
unsigned long targets[MEM_CGROUP_NTARGETS];
};
+struct mem_cgroup_reclaim_iter {
+ /* css_id of the last scanned hierarchy member */
+ int position;
+ /* scan generation, increased every round-trip */
+ unsigned int generation;
+};
+
/*
* per-zone information in memory controller.
*/
struct mem_cgroup_per_zone {
- /*
- * spin_lock to protect the per cgroup LRU
- */
- struct list_head lists[NR_LRU_LISTS];
+ struct lruvec lruvec;
unsigned long count[NR_LRU_LISTS];
+ struct mem_cgroup_reclaim_iter reclaim_iter[DEF_PRIORITY + 1];
+
struct zone_reclaim_stat reclaim_stat;
struct rb_node tree_node; /* RB tree node */
unsigned long long usage_in_excess;/* Set to the value by which */
@@ -224,20 +230,35 @@ struct mem_cgroup {
* the counter to account for memory usage
*/
struct res_counter res;
- /*
- * the counter to account for mem+swap usage.
- */
- struct res_counter memsw;
+
+ union {
+ /*
+ * the counter to account for mem+swap usage.
+ */
+ struct res_counter memsw;
+
+ /*
+ * rcu_freeing is used only when freeing struct mem_cgroup,
+ * so put it into a union to avoid wasting more memory.
+ * It must be disjoint from the css field. It could be
+ * in a union with the res field, but res plays a much
+ * larger part in mem_cgroup life than memsw, and might
+ * be of interest, even at time of free, when debugging.
+ * So share rcu_head with the less interesting memsw.
+ */
+ struct rcu_head rcu_freeing;
+ /*
+ * But when using vfree(), that cannot be done at
+ * interrupt time, so we must then queue the work.
+ */
+ struct work_struct work_freeing;
+ };
+
/*
* Per cgroup active and inactive list, similar to the
* per zone LRU lists.
*/
struct mem_cgroup_lru_info info;
- /*
- * While reclaiming in a hierarchy, we cache the last child we
- * reclaimed from.
- */
- int last_scanned_child;
int last_scanned_node;
#if MAX_NUMNODES > 1
nodemask_t scan_nodes;
@@ -366,31 +387,37 @@ enum charge_type {
#define MEM_CGROUP_RECLAIM_NOSWAP (1 << MEM_CGROUP_RECLAIM_NOSWAP_BIT)
#define MEM_CGROUP_RECLAIM_SHRINK_BIT 0x1
#define MEM_CGROUP_RECLAIM_SHRINK (1 << MEM_CGROUP_RECLAIM_SHRINK_BIT)
-#define MEM_CGROUP_RECLAIM_SOFT_BIT 0x2
-#define MEM_CGROUP_RECLAIM_SOFT (1 << MEM_CGROUP_RECLAIM_SOFT_BIT)
static void mem_cgroup_get(struct mem_cgroup *memcg);
static void mem_cgroup_put(struct mem_cgroup *memcg);
/* Writing them here to avoid exposing memcg's inner layout */
#ifdef CONFIG_CGROUP_MEM_RES_CTLR_KMEM
-#ifdef CONFIG_INET
#include <net/sock.h>
#include <net/ip.h>
static bool mem_cgroup_is_root(struct mem_cgroup *memcg);
void sock_update_memcg(struct sock *sk)
{
- /* A socket spends its whole life in the same cgroup */
- if (sk->sk_cgrp) {
- WARN_ON(1);
- return;
- }
- if (static_branch(&memcg_socket_limit_enabled)) {
+ if (mem_cgroup_sockets_enabled) {
struct mem_cgroup *memcg;
BUG_ON(!sk->sk_prot->proto_cgroup);
+ /* Socket cloning can throw us here with sk_cgrp already
+ * filled. It won't however, necessarily happen from
+ * process context. So the test for root memcg given
+ * the current task's memcg won't help us in this case.
+ *
+ * Respecting the original socket's memcg is a better
+ * decision in this case.
+ */
+ if (sk->sk_cgrp) {
+ BUG_ON(mem_cgroup_is_root(sk->sk_cgrp->memcg));
+ mem_cgroup_get(sk->sk_cgrp->memcg);
+ return;
+ }
+
rcu_read_lock();
memcg = mem_cgroup_from_task(current);
if (!mem_cgroup_is_root(memcg)) {
@@ -404,7 +431,7 @@ EXPORT_SYMBOL(sock_update_memcg);
void sock_release_memcg(struct sock *sk)
{
- if (static_branch(&memcg_socket_limit_enabled) && sk->sk_cgrp) {
+ if (mem_cgroup_sockets_enabled && sk->sk_cgrp) {
struct mem_cgroup *memcg;
WARN_ON(!sk->sk_cgrp->memcg);
memcg = sk->sk_cgrp->memcg;
@@ -412,6 +439,7 @@ void sock_release_memcg(struct sock *sk)
}
}
+#ifdef CONFIG_INET
struct cg_proto *tcp_proto_cgroup(struct mem_cgroup *memcg)
{
if (!memcg || mem_cgroup_is_root(memcg))
@@ -557,7 +585,7 @@ static void mem_cgroup_remove_from_trees(struct mem_cgroup *memcg)
struct mem_cgroup_per_zone *mz;
struct mem_cgroup_tree_per_zone *mctz;
- for_each_node_state(node, N_POSSIBLE) {
+ for_each_node(node) {
for (zone = 0; zone < MAX_NR_ZONES; zone++) {
mz = mem_cgroup_zoneinfo(memcg, node, zone);
mctz = soft_limit_tree_node_zone(node, zone);
@@ -647,16 +675,6 @@ static void mem_cgroup_swap_statistics(struct mem_cgroup *memcg,
this_cpu_add(memcg->stat->count[MEM_CGROUP_STAT_SWAPOUT], val);
}
-void mem_cgroup_pgfault(struct mem_cgroup *memcg, int val)
-{
- this_cpu_add(memcg->stat->events[MEM_CGROUP_EVENTS_PGFAULT], val);
-}
-
-void mem_cgroup_pgmajfault(struct mem_cgroup *memcg, int val)
-{
- this_cpu_add(memcg->stat->events[MEM_CGROUP_EVENTS_PGMAJFAULT], val);
-}
-
static unsigned long mem_cgroup_read_events(struct mem_cgroup *memcg,
enum mem_cgroup_events_index idx)
{
@@ -740,37 +758,32 @@ static unsigned long mem_cgroup_nr_lru_pages(struct mem_cgroup *memcg,
return total;
}
-static bool __memcg_event_check(struct mem_cgroup *memcg, int target)
+static bool mem_cgroup_event_ratelimit(struct mem_cgroup *memcg,
+ enum mem_cgroup_events_target target)
{
unsigned long val, next;
val = __this_cpu_read(memcg->stat->events[MEM_CGROUP_EVENTS_COUNT]);
next = __this_cpu_read(memcg->stat->targets[target]);
/* from time_after() in jiffies.h */
- return ((long)next - (long)val < 0);
-}
-
-static void __mem_cgroup_target_update(struct mem_cgroup *memcg, int target)
-{
- unsigned long val, next;
-
- val = __this_cpu_read(memcg->stat->events[MEM_CGROUP_EVENTS_COUNT]);
-
- switch (target) {
- case MEM_CGROUP_TARGET_THRESH:
- next = val + THRESHOLDS_EVENTS_TARGET;
- break;
- case MEM_CGROUP_TARGET_SOFTLIMIT:
- next = val + SOFTLIMIT_EVENTS_TARGET;
- break;
- case MEM_CGROUP_TARGET_NUMAINFO:
- next = val + NUMAINFO_EVENTS_TARGET;
- break;
- default:
- return;
+ if ((long)next - (long)val < 0) {
+ switch (target) {
+ case MEM_CGROUP_TARGET_THRESH:
+ next = val + THRESHOLDS_EVENTS_TARGET;
+ break;
+ case MEM_CGROUP_TARGET_SOFTLIMIT:
+ next = val + SOFTLIMIT_EVENTS_TARGET;
+ break;
+ case MEM_CGROUP_TARGET_NUMAINFO:
+ next = val + NUMAINFO_EVENTS_TARGET;
+ break;
+ default:
+ break;
+ }
+ __this_cpu_write(memcg->stat->targets[target], next);
+ return true;
}
-
- __this_cpu_write(memcg->stat->targets[target], next);
+ return false;
}
/*
@@ -781,25 +794,28 @@ 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(__memcg_event_check(memcg, MEM_CGROUP_TARGET_THRESH))) {
+ if (unlikely(mem_cgroup_event_ratelimit(memcg,
+ MEM_CGROUP_TARGET_THRESH))) {
+ bool do_softlimit;
+ bool do_numainfo __maybe_unused;
+
+ do_softlimit = mem_cgroup_event_ratelimit(memcg,
+ MEM_CGROUP_TARGET_SOFTLIMIT);
+#if MAX_NUMNODES > 1
+ do_numainfo = mem_cgroup_event_ratelimit(memcg,
+ MEM_CGROUP_TARGET_NUMAINFO);
+#endif
+ preempt_enable();
+
mem_cgroup_threshold(memcg);
- __mem_cgroup_target_update(memcg, MEM_CGROUP_TARGET_THRESH);
- if (unlikely(__memcg_event_check(memcg,
- MEM_CGROUP_TARGET_SOFTLIMIT))) {
+ if (unlikely(do_softlimit))
mem_cgroup_update_tree(memcg, page);
- __mem_cgroup_target_update(memcg,
- MEM_CGROUP_TARGET_SOFTLIMIT);
- }
#if MAX_NUMNODES > 1
- if (unlikely(__memcg_event_check(memcg,
- MEM_CGROUP_TARGET_NUMAINFO))) {
+ if (unlikely(do_numainfo))
atomic_inc(&memcg->numainfo_events);
- __mem_cgroup_target_update(memcg,
- MEM_CGROUP_TARGET_NUMAINFO);
- }
#endif
- }
- preempt_enable();
+ } else
+ preempt_enable();
}
struct mem_cgroup *mem_cgroup_from_cont(struct cgroup *cont)
@@ -844,83 +860,116 @@ struct mem_cgroup *try_get_mem_cgroup_from_mm(struct mm_struct *mm)
return memcg;
}
-/* The caller has to guarantee "mem" exists before calling this */
-static struct mem_cgroup *mem_cgroup_start_loop(struct mem_cgroup *memcg)
+/**
+ * mem_cgroup_iter - iterate over memory cgroup hierarchy
+ * @root: hierarchy root
+ * @prev: previously returned memcg, NULL on first invocation
+ * @reclaim: cookie for shared reclaim walks, NULL for full walks
+ *
+ * Returns references to children of the hierarchy below @root, or
+ * @root itself, or %NULL after a full round-trip.
+ *
+ * Caller must pass the return value in @prev on subsequent
+ * invocations for reference counting, or use mem_cgroup_iter_break()
+ * to cancel a hierarchy walk before the round-trip is complete.
+ *
+ * Reclaimers can specify a zone and a priority level in @reclaim to
+ * divide up the memcgs in the hierarchy among all concurrent
+ * reclaimers operating on the same zone and priority.
+ */
+struct mem_cgroup *mem_cgroup_iter(struct mem_cgroup *root,
+ struct mem_cgroup *prev,
+ struct mem_cgroup_reclaim_cookie *reclaim)
{
- struct cgroup_subsys_state *css;
- int found;
+ struct mem_cgroup *memcg = NULL;
+ int id = 0;
- if (!memcg) /* ROOT cgroup has the smallest ID */
- return root_mem_cgroup; /*css_put/get against root is ignored*/
- if (!memcg->use_hierarchy) {
- if (css_tryget(&memcg->css))
- return memcg;
+ if (mem_cgroup_disabled())
return NULL;
- }
- rcu_read_lock();
- /*
- * searching a memory cgroup which has the smallest ID under given
- * ROOT cgroup. (ID >= 1)
- */
- css = css_get_next(&mem_cgroup_subsys, 1, &memcg->css, &found);
- if (css && css_tryget(css))
- memcg = container_of(css, struct mem_cgroup, css);
- else
- memcg = NULL;
- rcu_read_unlock();
- return memcg;
-}
-static struct mem_cgroup *mem_cgroup_get_next(struct mem_cgroup *iter,
- struct mem_cgroup *root,
- bool cond)
-{
- int nextid = css_id(&iter->css) + 1;
- int found;
- int hierarchy_used;
- struct cgroup_subsys_state *css;
+ if (!root)
+ root = root_mem_cgroup;
- hierarchy_used = iter->use_hierarchy;
+ if (prev && !reclaim)
+ id = css_id(&prev->css);
- css_put(&iter->css);
- /* If no ROOT, walk all, ignore hierarchy */
- if (!cond || (root && !hierarchy_used))
- return NULL;
+ if (prev && prev != root)
+ css_put(&prev->css);
- if (!root)
- root = root_mem_cgroup;
+ if (!root->use_hierarchy && root != root_mem_cgroup) {
+ if (prev)
+ return NULL;
+ return root;
+ }
- do {
- iter = NULL;
- rcu_read_lock();
+ while (!memcg) {
+ struct mem_cgroup_reclaim_iter *uninitialized_var(iter);
+ struct cgroup_subsys_state *css;
+
+ if (reclaim) {
+ int nid = zone_to_nid(reclaim->zone);
+ int zid = zone_idx(reclaim->zone);
+ struct mem_cgroup_per_zone *mz;
+
+ mz = mem_cgroup_zoneinfo(root, nid, zid);
+ iter = &mz->reclaim_iter[reclaim->priority];
+ if (prev && reclaim->generation != iter->generation)
+ return NULL;
+ id = iter->position;
+ }
- css = css_get_next(&mem_cgroup_subsys, nextid,
- &root->css, &found);
- if (css && css_tryget(css))
- iter = container_of(css, struct mem_cgroup, css);
+ rcu_read_lock();
+ css = css_get_next(&mem_cgroup_subsys, id + 1, &root->css, &id);
+ if (css) {
+ if (css == &root->css || css_tryget(css))
+ memcg = container_of(css,
+ struct mem_cgroup, css);
+ } else
+ id = 0;
rcu_read_unlock();
- /* If css is NULL, no more cgroups will be found */
- nextid = found + 1;
- } while (css && !iter);
- return iter;
+ if (reclaim) {
+ iter->position = id;
+ if (!css)
+ iter->generation++;
+ else if (!prev && memcg)
+ reclaim->generation = iter->generation;
+ }
+
+ if (prev && !css)
+ return NULL;
+ }
+ return memcg;
}
-/*
- * for_eacn_mem_cgroup_tree() for visiting all cgroup under tree. Please
- * be careful that "break" loop is not allowed. We have reference count.
- * Instead of that modify "cond" to be false and "continue" to exit the loop.
- */
-#define for_each_mem_cgroup_tree_cond(iter, root, cond) \
- for (iter = mem_cgroup_start_loop(root);\
- iter != NULL;\
- iter = mem_cgroup_get_next(iter, root, cond))
-#define for_each_mem_cgroup_tree(iter, root) \
- for_each_mem_cgroup_tree_cond(iter, root, true)
+/**
+ * mem_cgroup_iter_break - abort a hierarchy walk prematurely
+ * @root: hierarchy root
+ * @prev: last visited hierarchy member as returned by mem_cgroup_iter()
+ */
+void mem_cgroup_iter_break(struct mem_cgroup *root,
+ struct mem_cgroup *prev)
+{
+ if (!root)
+ root = root_mem_cgroup;
+ if (prev && prev != root)
+ css_put(&prev->css);
+}
-#define for_each_mem_cgroup_all(iter) \
- for_each_mem_cgroup_tree_cond(iter, NULL, true)
+/*
+ * Iteration constructs for visiting all cgroups (under a tree). If
+ * loops are exited prematurely (break), mem_cgroup_iter_break() must
+ * be used for reference counting.
+ */
+#define for_each_mem_cgroup_tree(iter, root) \
+ for (iter = mem_cgroup_iter(root, NULL, NULL); \
+ iter != NULL; \
+ iter = mem_cgroup_iter(root, iter, NULL))
+#define for_each_mem_cgroup(iter) \
+ for (iter = mem_cgroup_iter(NULL, NULL, NULL); \
+ iter != NULL; \
+ iter = mem_cgroup_iter(NULL, iter, NULL))
static inline bool mem_cgroup_is_root(struct mem_cgroup *memcg)
{
@@ -940,11 +989,11 @@ void mem_cgroup_count_vm_event(struct mm_struct *mm, enum vm_event_item idx)
goto out;
switch (idx) {
- case PGMAJFAULT:
- mem_cgroup_pgmajfault(memcg, 1);
- break;
case PGFAULT:
- mem_cgroup_pgfault(memcg, 1);
+ this_cpu_inc(memcg->stat->events[MEM_CGROUP_EVENTS_PGFAULT]);
+ break;
+ case PGMAJFAULT:
+ this_cpu_inc(memcg->stat->events[MEM_CGROUP_EVENTS_PGMAJFAULT]);
break;
default:
BUG();
@@ -954,6 +1003,27 @@ out:
}
EXPORT_SYMBOL(mem_cgroup_count_vm_event);
+/**
+ * mem_cgroup_zone_lruvec - get the lru list vector for a zone and memcg
+ * @zone: zone of the wanted lruvec
+ * @mem: memcg of the wanted lruvec
+ *
+ * Returns the lru list vector holding pages for the given @zone and
+ * @mem. This can be the global zone lruvec, if the memory controller
+ * is disabled.
+ */
+struct lruvec *mem_cgroup_zone_lruvec(struct zone *zone,
+ struct mem_cgroup *memcg)
+{
+ struct mem_cgroup_per_zone *mz;
+
+ if (mem_cgroup_disabled())
+ return &zone->lruvec;
+
+ mz = mem_cgroup_zoneinfo(memcg, zone_to_nid(zone), zone_idx(zone));
+ return &mz->lruvec;
+}
+
/*
* Following LRU functions are allowed to be used without PCG_LOCK.
* Operations are called by routine of global LRU independently from memcg.
@@ -968,180 +1038,104 @@ EXPORT_SYMBOL(mem_cgroup_count_vm_event);
* When moving account, the page is not on LRU. It's isolated.
*/
-void mem_cgroup_del_lru_list(struct page *page, enum lru_list lru)
-{
- struct page_cgroup *pc;
- struct mem_cgroup_per_zone *mz;
-
- if (mem_cgroup_disabled())
- return;
- pc = lookup_page_cgroup(page);
- /* can happen while we handle swapcache. */
- if (!TestClearPageCgroupAcctLRU(pc))
- return;
- VM_BUG_ON(!pc->mem_cgroup);
- /*
- * We don't check PCG_USED bit. It's cleared when the "page" is finally
- * removed from global LRU.
- */
- mz = page_cgroup_zoneinfo(pc->mem_cgroup, page);
- /* huge page split is done under lru_lock. so, we have no races. */
- MEM_CGROUP_ZSTAT(mz, lru) -= 1 << compound_order(page);
- if (mem_cgroup_is_root(pc->mem_cgroup))
- return;
- VM_BUG_ON(list_empty(&pc->lru));
- list_del_init(&pc->lru);
-}
-
-void mem_cgroup_del_lru(struct page *page)
-{
- mem_cgroup_del_lru_list(page, page_lru(page));
-}
-
-/*
- * Writeback is about to end against a page which has been marked for immediate
- * reclaim. If it still appears to be reclaimable, move it to the tail of the
- * inactive list.
+/**
+ * mem_cgroup_lru_add_list - account for adding an lru page and return lruvec
+ * @zone: zone of the page
+ * @page: the page
+ * @lru: current lru
+ *
+ * This function accounts for @page being added to @lru, and returns
+ * the lruvec for the given @zone and the memcg @page is charged to.
+ *
+ * The callsite is then responsible for physically linking the page to
+ * the returned lruvec->lists[@lru].
*/
-void mem_cgroup_rotate_reclaimable_page(struct page *page)
-{
- struct mem_cgroup_per_zone *mz;
- struct page_cgroup *pc;
- enum lru_list lru = page_lru(page);
-
- if (mem_cgroup_disabled())
- return;
-
- pc = lookup_page_cgroup(page);
- /* unused or root page is not rotated. */
- if (!PageCgroupUsed(pc))
- return;
- /* Ensure pc->mem_cgroup is visible after reading PCG_USED. */
- smp_rmb();
- if (mem_cgroup_is_root(pc->mem_cgroup))
- return;
- mz = page_cgroup_zoneinfo(pc->mem_cgroup, page);
- list_move_tail(&pc->lru, &mz->lists[lru]);
-}
-
-void mem_cgroup_rotate_lru_list(struct page *page, enum lru_list lru)
+struct lruvec *mem_cgroup_lru_add_list(struct zone *zone, struct page *page,
+ enum lru_list lru)
{
struct mem_cgroup_per_zone *mz;
+ struct mem_cgroup *memcg;
struct page_cgroup *pc;
if (mem_cgroup_disabled())
- return;
+ return &zone->lruvec;
pc = lookup_page_cgroup(page);
- /* unused or root page is not rotated. */
- if (!PageCgroupUsed(pc))
- return;
- /* Ensure pc->mem_cgroup is visible after reading PCG_USED. */
- smp_rmb();
- if (mem_cgroup_is_root(pc->mem_cgroup))
- return;
- mz = page_cgroup_zoneinfo(pc->mem_cgroup, page);
- list_move(&pc->lru, &mz->lists[lru]);
-}
-
-void mem_cgroup_add_lru_list(struct page *page, enum lru_list lru)
-{
- struct page_cgroup *pc;
- struct mem_cgroup_per_zone *mz;
+ memcg = pc->mem_cgroup;
- if (mem_cgroup_disabled())
- return;
- pc = lookup_page_cgroup(page);
- VM_BUG_ON(PageCgroupAcctLRU(pc));
/*
- * putback: charge:
- * SetPageLRU SetPageCgroupUsed
- * smp_mb smp_mb
- * PageCgroupUsed && add to memcg LRU PageLRU && add to memcg LRU
+ * Surreptitiously switch any uncharged page to root:
+ * an uncharged page off lru does nothing to secure
+ * its former mem_cgroup from sudden removal.
*
- * Ensure that one of the two sides adds the page to the memcg
- * LRU during a race.
+ * Our caller holds lru_lock, and PageCgroupUsed is updated
+ * under page_cgroup lock: between them, they make all uses
+ * of pc->mem_cgroup safe.
*/
- smp_mb();
- if (!PageCgroupUsed(pc))
- return;
- /* Ensure pc->mem_cgroup is visible after reading PCG_USED. */
- smp_rmb();
- mz = page_cgroup_zoneinfo(pc->mem_cgroup, page);
- /* huge page split is done under lru_lock. so, we have no races. */
+ if (!PageCgroupUsed(pc) && memcg != root_mem_cgroup)
+ pc->mem_cgroup = memcg = root_mem_cgroup;
+
+ mz = page_cgroup_zoneinfo(memcg, page);
+ /* compound_order() is stabilized through lru_lock */
MEM_CGROUP_ZSTAT(mz, lru) += 1 << compound_order(page);
- SetPageCgroupAcctLRU(pc);
- if (mem_cgroup_is_root(pc->mem_cgroup))
- return;
- list_add(&pc->lru, &mz->lists[lru]);
+ return &mz->lruvec;
}
-/*
- * At handling SwapCache and other FUSE stuff, pc->mem_cgroup may be changed
- * while it's linked to lru because the page may be reused after it's fully
- * uncharged. To handle that, unlink page_cgroup from LRU when charge it again.
- * It's done under lock_page and expected that zone->lru_lock isnever held.
+/**
+ * mem_cgroup_lru_del_list - account for removing an lru page
+ * @page: the page
+ * @lru: target lru
+ *
+ * This function accounts for @page being removed from @lru.
+ *
+ * The callsite is then responsible for physically unlinking
+ * @page->lru.
*/
-static void mem_cgroup_lru_del_before_commit(struct page *page)
+void mem_cgroup_lru_del_list(struct page *page, enum lru_list lru)
{
- unsigned long flags;
- struct zone *zone = page_zone(page);
- struct page_cgroup *pc = lookup_page_cgroup(page);
+ struct mem_cgroup_per_zone *mz;
+ struct mem_cgroup *memcg;
+ struct page_cgroup *pc;
- /*
- * Doing this check without taking ->lru_lock seems wrong but this
- * is safe. Because if page_cgroup's USED bit is unset, the page
- * will not be added to any memcg's LRU. If page_cgroup's USED bit is
- * set, the commit after this will fail, anyway.
- * This all charge/uncharge is done under some mutual execustion.
- * So, we don't need to taking care of changes in USED bit.
- */
- if (likely(!PageLRU(page)))
+ if (mem_cgroup_disabled())
return;
- spin_lock_irqsave(&zone->lru_lock, flags);
- /*
- * Forget old LRU when this page_cgroup is *not* used. This Used bit
- * is guarded by lock_page() because the page is SwapCache.
- */
- if (!PageCgroupUsed(pc))
- mem_cgroup_del_lru_list(page, page_lru(page));
- spin_unlock_irqrestore(&zone->lru_lock, flags);
+ pc = lookup_page_cgroup(page);
+ memcg = pc->mem_cgroup;
+ VM_BUG_ON(!memcg);
+ mz = page_cgroup_zoneinfo(memcg, page);
+ /* huge page split is done under lru_lock. so, we have no races. */
+ VM_BUG_ON(MEM_CGROUP_ZSTAT(mz, lru) < (1 << compound_order(page)));
+ MEM_CGROUP_ZSTAT(mz, lru) -= 1 << compound_order(page);
}
-static void mem_cgroup_lru_add_after_commit(struct page *page)
+void mem_cgroup_lru_del(struct page *page)
{
- unsigned long flags;
- struct zone *zone = page_zone(page);
- struct page_cgroup *pc = lookup_page_cgroup(page);
- /*
- * putback: charge:
- * SetPageLRU SetPageCgroupUsed
- * smp_mb smp_mb
- * PageCgroupUsed && add to memcg LRU PageLRU && add to memcg LRU
- *
- * Ensure that one of the two sides adds the page to the memcg
- * LRU during a race.
- */
- smp_mb();
- /* taking care of that the page is added to LRU while we commit it */
- if (likely(!PageLRU(page)))
- return;
- spin_lock_irqsave(&zone->lru_lock, flags);
- /* link when the page is linked to LRU but page_cgroup isn't */
- if (PageLRU(page) && !PageCgroupAcctLRU(pc))
- mem_cgroup_add_lru_list(page, page_lru(page));
- spin_unlock_irqrestore(&zone->lru_lock, flags);
+ mem_cgroup_lru_del_list(page, page_lru(page));
}
-
-void mem_cgroup_move_lists(struct page *page,
- enum lru_list from, enum lru_list to)
+/**
+ * mem_cgroup_lru_move_lists - account for moving a page between lrus
+ * @zone: zone of the page
+ * @page: the page
+ * @from: current lru
+ * @to: target lru
+ *
+ * This function accounts for @page being moved between the lrus @from
+ * and @to, and returns the lruvec for the given @zone and the memcg
+ * @page is charged to.
+ *
+ * The callsite is then responsible for physically relinking
+ * @page->lru to the returned lruvec->lists[@to].
+ */
+struct lruvec *mem_cgroup_lru_move_lists(struct zone *zone,
+ struct page *page,
+ enum lru_list from,
+ enum lru_list to)
{
- if (mem_cgroup_disabled())
- return;
- mem_cgroup_del_lru_list(page, from);
- mem_cgroup_add_lru_list(page, to);
+ /* XXX: Optimize this, especially for @from == @to */
+ mem_cgroup_lru_del_list(page, from);
+ return mem_cgroup_lru_add_list(zone, page, to);
}
/*
@@ -1166,10 +1160,21 @@ int task_in_mem_cgroup(struct task_struct *task, const struct mem_cgroup *memcg)
struct task_struct *p;
p = find_lock_task_mm(task);
- if (!p)
- return 0;
- curr = try_get_mem_cgroup_from_mm(p->mm);
- task_unlock(p);
+ if (p) {
+ curr = try_get_mem_cgroup_from_mm(p->mm);
+ task_unlock(p);
+ } else {
+ /*
+ * All threads may have already detached their mm's, but the oom
+ * killer still needs to detect if they have already been oom
+ * killed to prevent needlessly killing additional tasks.
+ */
+ task_lock(task);
+ curr = mem_cgroup_from_task(task);
+ if (curr)
+ css_get(&curr->css);
+ task_unlock(task);
+ }
if (!curr)
return 0;
/*
@@ -1249,68 +1254,6 @@ mem_cgroup_get_reclaim_stat_from_page(struct page *page)
return &mz->reclaim_stat;
}
-unsigned long mem_cgroup_isolate_pages(unsigned long nr_to_scan,
- struct list_head *dst,
- unsigned long *scanned, int order,
- isolate_mode_t mode,
- struct zone *z,
- struct mem_cgroup *mem_cont,
- int active, int file)
-{
- unsigned long nr_taken = 0;
- struct page *page;
- unsigned long scan;
- LIST_HEAD(pc_list);
- struct list_head *src;
- struct page_cgroup *pc, *tmp;
- int nid = zone_to_nid(z);
- int zid = zone_idx(z);
- struct mem_cgroup_per_zone *mz;
- int lru = LRU_FILE * file + active;
- int ret;
-
- BUG_ON(!mem_cont);
- mz = mem_cgroup_zoneinfo(mem_cont, nid, zid);
- src = &mz->lists[lru];
-
- scan = 0;
- list_for_each_entry_safe_reverse(pc, tmp, src, lru) {
- if (scan >= nr_to_scan)
- break;
-
- if (unlikely(!PageCgroupUsed(pc)))
- continue;
-
- page = lookup_cgroup_page(pc);
-
- if (unlikely(!PageLRU(page)))
- continue;
-
- scan++;
- ret = __isolate_lru_page(page, mode, file);
- switch (ret) {
- case 0:
- list_move(&page->lru, dst);
- mem_cgroup_del_lru(page);
- nr_taken += hpage_nr_pages(page);
- break;
- case -EBUSY:
- /* we don't affect global LRU but rotate in our LRU */
- mem_cgroup_rotate_lru_list(page, page_lru(page));
- break;
- default:
- break;
- }
- }
-
- *scanned = scan;
-
- trace_mm_vmscan_memcg_isolate(0, nr_to_scan, scan, nr_taken,
- 0, 0, 0, mode);
-
- return nr_taken;
-}
-
#define mem_cgroup_from_res_counter(counter, member) \
container_of(counter, struct mem_cgroup, member)
@@ -1527,41 +1470,40 @@ u64 mem_cgroup_get_limit(struct mem_cgroup *memcg)
return min(limit, memsw);
}
-/*
- * Visit the first child (need not be the first child as per the ordering
- * of the cgroup list, since we track last_scanned_child) of @mem and use
- * that to reclaim free pages from.
- */
-static struct mem_cgroup *
-mem_cgroup_select_victim(struct mem_cgroup *root_memcg)
+static unsigned long mem_cgroup_reclaim(struct mem_cgroup *memcg,
+ gfp_t gfp_mask,
+ unsigned long flags)
{
- struct mem_cgroup *ret = NULL;
- struct cgroup_subsys_state *css;
- int nextid, found;
-
- if (!root_memcg->use_hierarchy) {
- css_get(&root_memcg->css);
- ret = root_memcg;
- }
+ unsigned long total = 0;
+ bool noswap = false;
+ int loop;
- while (!ret) {
- rcu_read_lock();
- nextid = root_memcg->last_scanned_child + 1;
- css = css_get_next(&mem_cgroup_subsys, nextid, &root_memcg->css,
- &found);
- if (css && css_tryget(css))
- ret = container_of(css, struct mem_cgroup, css);
+ if (flags & MEM_CGROUP_RECLAIM_NOSWAP)
+ noswap = true;
+ if (!(flags & MEM_CGROUP_RECLAIM_SHRINK) && memcg->memsw_is_minimum)
+ noswap = true;
- rcu_read_unlock();
- /* Updates scanning parameter */
- if (!css) {
- /* this means start scan from ID:1 */
- root_memcg->last_scanned_child = 0;
- } else
- root_memcg->last_scanned_child = found;
+ for (loop = 0; loop < MEM_CGROUP_MAX_RECLAIM_LOOPS; loop++) {
+ if (loop)
+ drain_all_stock_async(memcg);
+ total += try_to_free_mem_cgroup_pages(memcg, gfp_mask, noswap);
+ /*
+ * Allow limit shrinkers, which are triggered directly
+ * by userspace, to catch signals and stop reclaim
+ * after minimal progress, regardless of the margin.
+ */
+ if (total && (flags & MEM_CGROUP_RECLAIM_SHRINK))
+ break;
+ if (mem_cgroup_margin(memcg))
+ break;
+ /*
+ * If nothing was reclaimed after two attempts, there
+ * may be no reclaimable pages in this hierarchy.
+ */
+ if (loop && !total)
+ break;
}
-
- return ret;
+ return total;
}
/**
@@ -1701,61 +1643,35 @@ bool mem_cgroup_reclaimable(struct mem_cgroup *memcg, bool noswap)
}
#endif
-/*
- * Scan the hierarchy if needed to reclaim memory. We remember the last child
- * we reclaimed from, so that we don't end up penalizing one child extensively
- * based on its position in the children list.
- *
- * root_memcg is the original ancestor that we've been reclaim from.
- *
- * We give up and return to the caller when we visit root_memcg twice.
- * (other groups can be removed while we're walking....)
- *
- * If shrink==true, for avoiding to free too much, this returns immedieately.
- */
-static int mem_cgroup_hierarchical_reclaim(struct mem_cgroup *root_memcg,
- struct zone *zone,
- gfp_t gfp_mask,
- unsigned long reclaim_options,
- unsigned long *total_scanned)
-{
- struct mem_cgroup *victim;
- int ret, total = 0;
+static int mem_cgroup_soft_reclaim(struct mem_cgroup *root_memcg,
+ struct zone *zone,
+ gfp_t gfp_mask,
+ unsigned long *total_scanned)
+{
+ struct mem_cgroup *victim = NULL;
+ int total = 0;
int loop = 0;
- bool noswap = reclaim_options & MEM_CGROUP_RECLAIM_NOSWAP;
- bool shrink = reclaim_options & MEM_CGROUP_RECLAIM_SHRINK;
- bool check_soft = reclaim_options & MEM_CGROUP_RECLAIM_SOFT;
unsigned long excess;
unsigned long nr_scanned;
+ struct mem_cgroup_reclaim_cookie reclaim = {
+ .zone = zone,
+ .priority = 0,
+ };
excess = res_counter_soft_limit_excess(&root_memcg->res) >> PAGE_SHIFT;
- /* If memsw_is_minimum==1, swap-out is of-no-use. */
- if (!check_soft && !shrink && root_memcg->memsw_is_minimum)
- noswap = true;
-
while (1) {
- victim = mem_cgroup_select_victim(root_memcg);
- if (victim == root_memcg) {
+ victim = mem_cgroup_iter(root_memcg, victim, &reclaim);
+ if (!victim) {
loop++;
- /*
- * We are not draining per cpu cached charges during
- * soft limit reclaim because global reclaim doesn't
- * care about charges. It tries to free some memory and
- * charges will not give any.
- */
- if (!check_soft && loop >= 1)
- drain_all_stock_async(root_memcg);
if (loop >= 2) {
/*
* If we have not been able to reclaim
* anything, it might because there are
* no reclaimable pages under this hierarchy
*/
- if (!check_soft || !total) {
- css_put(&victim->css);
+ if (!total)
break;
- }
/*
* We want to do more targeted reclaim.
* excess >> 2 is not to excessive so as to
@@ -1763,40 +1679,20 @@ static int mem_cgroup_hierarchical_reclaim(struct mem_cgroup *root_memcg,
* coming back to reclaim from this cgroup
*/
if (total >= (excess >> 2) ||
- (loop > MEM_CGROUP_MAX_RECLAIM_LOOPS)) {
- css_put(&victim->css);
+ (loop > MEM_CGROUP_MAX_RECLAIM_LOOPS))
break;
- }
}
- }
- if (!mem_cgroup_reclaimable(victim, noswap)) {
- /* this cgroup's local usage == 0 */
- css_put(&victim->css);
continue;
}
- /* we use swappiness of local cgroup */
- if (check_soft) {
- ret = mem_cgroup_shrink_node_zone(victim, gfp_mask,
- noswap, zone, &nr_scanned);
- *total_scanned += nr_scanned;
- } else
- ret = try_to_free_mem_cgroup_pages(victim, gfp_mask,
- noswap);
- css_put(&victim->css);
- /*
- * At shrinking usage, we can't check we should stop here or
- * reclaim more. It's depends on callers. last_scanned_child
- * will work enough for keeping fairness under tree.
- */
- if (shrink)
- return ret;
- total += ret;
- if (check_soft) {
- if (!res_counter_soft_limit_excess(&root_memcg->res))
- return total;
- } else if (mem_cgroup_margin(root_memcg))
- return total;
+ if (!mem_cgroup_reclaimable(victim, false))
+ continue;
+ total += mem_cgroup_shrink_node_zone(victim, gfp_mask, false,
+ zone, &nr_scanned);
+ *total_scanned += nr_scanned;
+ if (!res_counter_soft_limit_excess(&root_memcg->res))
+ break;
}
+ mem_cgroup_iter_break(root_memcg, victim);
return total;
}
@@ -1808,16 +1704,16 @@ static int mem_cgroup_hierarchical_reclaim(struct mem_cgroup *root_memcg,
static bool mem_cgroup_oom_lock(struct mem_cgroup *memcg)
{
struct mem_cgroup *iter, *failed = NULL;
- bool cond = true;
- for_each_mem_cgroup_tree_cond(iter, memcg, cond) {
+ for_each_mem_cgroup_tree(iter, memcg) {
if (iter->oom_lock) {
/*
* this subtree of our hierarchy is already locked
* so we cannot give a lock.
*/
failed = iter;
- cond = false;
+ mem_cgroup_iter_break(memcg, iter);
+ break;
} else
iter->oom_lock = true;
}
@@ -1829,11 +1725,10 @@ static bool mem_cgroup_oom_lock(struct mem_cgroup *memcg)
* OK, we failed to lock the whole subtree so we have to clean up
* what we set up to the failing subtree
*/
- cond = true;
- for_each_mem_cgroup_tree_cond(iter, memcg, cond) {
+ for_each_mem_cgroup_tree(iter, memcg) {
if (iter == failed) {
- cond = false;
- continue;
+ mem_cgroup_iter_break(memcg, iter);
+ break;
}
iter->oom_lock = false;
}
@@ -1998,7 +1893,7 @@ void mem_cgroup_update_page_stat(struct page *page,
bool need_unlock = false;
unsigned long uninitialized_var(flags);
- if (unlikely(!pc))
+ if (mem_cgroup_disabled())
return;
rcu_read_lock();
@@ -2229,7 +2124,7 @@ static int __cpuinit memcg_cpu_hotplug_callback(struct notifier_block *nb,
struct mem_cgroup *iter;
if ((action == CPU_ONLINE)) {
- for_each_mem_cgroup_all(iter)
+ for_each_mem_cgroup(iter)
synchronize_mem_cgroup_on_move(iter, cpu);
return NOTIFY_OK;
}
@@ -2237,7 +2132,7 @@ static int __cpuinit memcg_cpu_hotplug_callback(struct notifier_block *nb,
if ((action != CPU_DEAD) || action != CPU_DEAD_FROZEN)
return NOTIFY_OK;
- for_each_mem_cgroup_all(iter)
+ for_each_mem_cgroup(iter)
mem_cgroup_drain_pcp_counter(iter, cpu);
stock = &per_cpu(memcg_stock, cpu);
@@ -2291,8 +2186,7 @@ static int mem_cgroup_do_charge(struct mem_cgroup *memcg, gfp_t gfp_mask,
if (!(gfp_mask & __GFP_WAIT))
return CHARGE_WOULDBLOCK;
- ret = mem_cgroup_hierarchical_reclaim(mem_over_limit, NULL,
- gfp_mask, flags, NULL);
+ ret = mem_cgroup_reclaim(mem_over_limit, gfp_mask, flags);
if (mem_cgroup_margin(mem_over_limit) >= nr_pages)
return CHARGE_RETRY;
/*
@@ -2325,8 +2219,25 @@ static int mem_cgroup_do_charge(struct mem_cgroup *memcg, gfp_t gfp_mask,
}
/*
- * Unlike exported interface, "oom" parameter is added. if oom==true,
- * oom-killer can be invoked.
+ * __mem_cgroup_try_charge() does
+ * 1. detect memcg to be charged against from passed *mm and *ptr,
+ * 2. update res_counter
+ * 3. call memory reclaim if necessary.
+ *
+ * In some special case, if the task is fatal, fatal_signal_pending() or
+ * has TIF_MEMDIE, this function returns -EINTR while writing root_mem_cgroup
+ * to *ptr. There are two reasons for this. 1: fatal threads should quit as soon
+ * as possible without any hazards. 2: all pages should have a valid
+ * pc->mem_cgroup. If mm is NULL and the caller doesn't pass a valid memcg
+ * pointer, that is treated as a charge to root_mem_cgroup.
+ *
+ * So __mem_cgroup_try_charge() will return
+ * 0 ... on success, filling *ptr with a valid memcg pointer.
+ * -ENOMEM ... charge failure because of resource limits.
+ * -EINTR ... if thread is fatal. *ptr is filled with root_mem_cgroup.
+ *
+ * Unlike the exported interface, an "oom" parameter is added. if oom==true,
+ * the oom-killer can be invoked.
*/
static int __mem_cgroup_try_charge(struct mm_struct *mm,
gfp_t gfp_mask,
@@ -2355,7 +2266,7 @@ static int __mem_cgroup_try_charge(struct mm_struct *mm,
* set, if so charge the init_mm (happens for pagecache usage).
*/
if (!*ptr && !mm)
- goto bypass;
+ *ptr = root_mem_cgroup;
again:
if (*ptr) { /* css should be a valid one */
memcg = *ptr;
@@ -2381,7 +2292,9 @@ again:
* task-struct. So, mm->owner can be NULL.
*/
memcg = mem_cgroup_from_task(p);
- if (!memcg || mem_cgroup_is_root(memcg)) {
+ if (!memcg)
+ memcg = root_mem_cgroup;
+ if (mem_cgroup_is_root(memcg)) {
rcu_read_unlock();
goto done;
}
@@ -2456,8 +2369,8 @@ nomem:
*ptr = NULL;
return -ENOMEM;
bypass:
- *ptr = NULL;
- return 0;
+ *ptr = root_mem_cgroup;
+ return -EINTR;
}
/*
@@ -2513,7 +2426,7 @@ struct mem_cgroup *try_get_mem_cgroup_from_page(struct page *page)
memcg = NULL;
} else if (PageSwapCache(page)) {
ent.val = page_private(page);
- id = lookup_swap_cgroup(ent);
+ id = lookup_swap_cgroup_id(ent);
rcu_read_lock();
memcg = mem_cgroup_lookup(id);
if (memcg && !css_tryget(&memcg->css))
@@ -2528,8 +2441,12 @@ static void __mem_cgroup_commit_charge(struct mem_cgroup *memcg,
struct page *page,
unsigned int nr_pages,
struct page_cgroup *pc,
- enum charge_type ctype)
+ enum charge_type ctype,
+ bool lrucare)
{
+ struct zone *uninitialized_var(zone);
+ bool was_on_lru = false;
+
lock_page_cgroup(pc);
if (unlikely(PageCgroupUsed(pc))) {
unlock_page_cgroup(pc);
@@ -2540,6 +2457,21 @@ static void __mem_cgroup_commit_charge(struct mem_cgroup *memcg,
* we don't need page_cgroup_lock about tail pages, becase they are not
* accessed by any other context at this point.
*/
+
+ /*
+ * 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)) {
+ ClearPageLRU(page);
+ del_page_from_lru_list(zone, page, page_lru(page));
+ was_on_lru = true;
+ }
+ }
+
pc->mem_cgroup = memcg;
/*
* We access a page_cgroup asynchronously without lock_page_cgroup().
@@ -2563,8 +2495,18 @@ static void __mem_cgroup_commit_charge(struct mem_cgroup *memcg,
break;
}
+ if (lrucare) {
+ if (was_on_lru) {
+ VM_BUG_ON(PageLRU(page));
+ SetPageLRU(page);
+ add_page_to_lru_list(zone, page, page_lru(page));
+ }
+ spin_unlock_irq(&zone->lru_lock);
+ }
+
mem_cgroup_charge_statistics(memcg, PageCgroupCache(pc), nr_pages);
unlock_page_cgroup(pc);
+
/*
* "charge_statistics" updated event counter. Then, check it.
* Insert ancestor (and ancestor's ancestors), to softlimit RB-tree.
@@ -2576,44 +2518,29 @@ static void __mem_cgroup_commit_charge(struct mem_cgroup *memcg,
#ifdef CONFIG_TRANSPARENT_HUGEPAGE
#define PCGF_NOCOPY_AT_SPLIT ((1 << PCG_LOCK) | (1 << PCG_MOVE_LOCK) |\
- (1 << PCG_ACCT_LRU) | (1 << PCG_MIGRATION))
+ (1 << PCG_MIGRATION))
/*
* Because tail pages are not marked as "used", set it. We're under
- * zone->lru_lock, 'splitting on pmd' and compund_lock.
+ * zone->lru_lock, 'splitting on pmd' and compound_lock.
+ * charge/uncharge will be never happen and move_account() is done under
+ * compound_lock(), so we don't have to take care of races.
*/
-void mem_cgroup_split_huge_fixup(struct page *head, struct page *tail)
+void mem_cgroup_split_huge_fixup(struct page *head)
{
struct page_cgroup *head_pc = lookup_page_cgroup(head);
- struct page_cgroup *tail_pc = lookup_page_cgroup(tail);
- unsigned long flags;
+ struct page_cgroup *pc;
+ int i;
if (mem_cgroup_disabled())
return;
- /*
- * We have no races with charge/uncharge but will have races with
- * page state accounting.
- */
- move_lock_page_cgroup(head_pc, &flags);
-
- tail_pc->mem_cgroup = head_pc->mem_cgroup;
- smp_wmb(); /* see __commit_charge() */
- if (PageCgroupAcctLRU(head_pc)) {
- enum lru_list lru;
- struct mem_cgroup_per_zone *mz;
-
- /*
- * LRU flags cannot be copied because we need to add tail
- *.page to LRU by generic call and our hook will be called.
- * We hold lru_lock, then, reduce counter directly.
- */
- lru = page_lru(head);
- mz = page_cgroup_zoneinfo(head_pc->mem_cgroup, head);
- MEM_CGROUP_ZSTAT(mz, lru) -= 1;
+ for (i = 1; i < HPAGE_PMD_NR; i++) {
+ pc = head_pc + i;
+ pc->mem_cgroup = head_pc->mem_cgroup;
+ smp_wmb();/* see __commit_charge() */
+ pc->flags = head_pc->flags & ~PCGF_NOCOPY_AT_SPLIT;
}
- tail_pc->flags = head_pc->flags & ~PCGF_NOCOPY_AT_SPLIT;
- move_unlock_page_cgroup(head_pc, &flags);
}
-#endif
+#endif /* CONFIG_TRANSPARENT_HUGEPAGE */
/**
* mem_cgroup_move_account - move account of the page
@@ -2728,7 +2655,7 @@ static int mem_cgroup_move_parent(struct page *page,
parent = mem_cgroup_from_cont(pcg);
ret = __mem_cgroup_try_charge(NULL, gfp_mask, nr_pages, &parent, false);
- if (ret || !parent)
+ if (ret)
goto put_back;
if (nr_pages > 1)
@@ -2774,13 +2701,10 @@ static int mem_cgroup_charge_common(struct page *page, struct mm_struct *mm,
}
pc = lookup_page_cgroup(page);
- BUG_ON(!pc); /* XXX: remove this and move pc lookup into commit */
-
ret = __mem_cgroup_try_charge(mm, gfp_mask, nr_pages, &memcg, oom);
- if (ret || !memcg)
+ if (ret == -ENOMEM)
return ret;
-
- __mem_cgroup_commit_charge(memcg, page, nr_pages, pc, ctype);
+ __mem_cgroup_commit_charge(memcg, page, nr_pages, pc, ctype, false);
return 0;
}
@@ -2789,45 +2713,22 @@ int mem_cgroup_newpage_charge(struct page *page,
{
if (mem_cgroup_disabled())
return 0;
- /*
- * If already mapped, we don't have to account.
- * If page cache, page->mapping has address_space.
- * But page->mapping may have out-of-use anon_vma pointer,
- * detecit it by PageAnon() check. newly-mapped-anon's page->mapping
- * is NULL.
- */
- if (page_mapped(page) || (page->mapping && !PageAnon(page)))
- return 0;
- if (unlikely(!mm))
- mm = &init_mm;
+ VM_BUG_ON(page_mapped(page));
+ VM_BUG_ON(page->mapping && !PageAnon(page));
+ VM_BUG_ON(!mm);
return mem_cgroup_charge_common(page, mm, gfp_mask,
- MEM_CGROUP_CHARGE_TYPE_MAPPED);
+ MEM_CGROUP_CHARGE_TYPE_MAPPED);
}
static void
__mem_cgroup_commit_charge_swapin(struct page *page, struct mem_cgroup *ptr,
enum charge_type ctype);
-static void
-__mem_cgroup_commit_charge_lrucare(struct page *page, struct mem_cgroup *memcg,
- enum charge_type ctype)
-{
- struct page_cgroup *pc = lookup_page_cgroup(page);
- /*
- * In some case, SwapCache, FUSE(splice_buf->radixtree), the page
- * is already on LRU. It means the page may on some other page_cgroup's
- * LRU. Take care of it.
- */
- mem_cgroup_lru_del_before_commit(page);
- __mem_cgroup_commit_charge(memcg, page, 1, pc, ctype);
- mem_cgroup_lru_add_after_commit(page);
- return;
-}
-
int mem_cgroup_cache_charge(struct page *page, struct mm_struct *mm,
gfp_t gfp_mask)
{
struct mem_cgroup *memcg = NULL;
+ enum charge_type type = MEM_CGROUP_CHARGE_TYPE_CACHE;
int ret;
if (mem_cgroup_disabled())
@@ -2837,31 +2738,16 @@ int mem_cgroup_cache_charge(struct page *page, struct mm_struct *mm,
if (unlikely(!mm))
mm = &init_mm;
+ if (!page_is_file_cache(page))
+ type = MEM_CGROUP_CHARGE_TYPE_SHMEM;
- if (page_is_file_cache(page)) {
- ret = __mem_cgroup_try_charge(mm, gfp_mask, 1, &memcg, true);
- if (ret || !memcg)
- return ret;
-
- /*
- * FUSE reuses pages without going through the final
- * put that would remove them from the LRU list, make
- * sure that they get relinked properly.
- */
- __mem_cgroup_commit_charge_lrucare(page, memcg,
- MEM_CGROUP_CHARGE_TYPE_CACHE);
- return ret;
- }
- /* shmem */
- if (PageSwapCache(page)) {
+ if (!PageSwapCache(page))
+ ret = mem_cgroup_charge_common(page, mm, gfp_mask, type);
+ else { /* page is swapcache/shmem */
ret = mem_cgroup_try_charge_swapin(mm, page, gfp_mask, &memcg);
if (!ret)
- __mem_cgroup_commit_charge_swapin(page, memcg,
- MEM_CGROUP_CHARGE_TYPE_SHMEM);
- } else
- ret = mem_cgroup_charge_common(page, mm, gfp_mask,
- MEM_CGROUP_CHARGE_TYPE_SHMEM);
-
+ __mem_cgroup_commit_charge_swapin(page, memcg, type);
+ }
return ret;
}
@@ -2873,12 +2759,12 @@ int mem_cgroup_cache_charge(struct page *page, struct mm_struct *mm,
*/
int mem_cgroup_try_charge_swapin(struct mm_struct *mm,
struct page *page,
- gfp_t mask, struct mem_cgroup **ptr)
+ gfp_t mask, struct mem_cgroup **memcgp)
{
struct mem_cgroup *memcg;
int ret;
- *ptr = NULL;
+ *memcgp = NULL;
if (mem_cgroup_disabled())
return 0;
@@ -2896,27 +2782,35 @@ int mem_cgroup_try_charge_swapin(struct mm_struct *mm,
memcg = try_get_mem_cgroup_from_page(page);
if (!memcg)
goto charge_cur_mm;
- *ptr = memcg;
- ret = __mem_cgroup_try_charge(NULL, mask, 1, ptr, true);
+ *memcgp = memcg;
+ ret = __mem_cgroup_try_charge(NULL, mask, 1, memcgp, true);
css_put(&memcg->css);
+ if (ret == -EINTR)
+ ret = 0;
return ret;
charge_cur_mm:
if (unlikely(!mm))
mm = &init_mm;
- return __mem_cgroup_try_charge(mm, mask, 1, ptr, true);
+ ret = __mem_cgroup_try_charge(mm, mask, 1, memcgp, true);
+ if (ret == -EINTR)
+ ret = 0;
+ return ret;
}
static void
-__mem_cgroup_commit_charge_swapin(struct page *page, struct mem_cgroup *ptr,
+__mem_cgroup_commit_charge_swapin(struct page *page, struct mem_cgroup *memcg,
enum charge_type ctype)
{
+ struct page_cgroup *pc;
+
if (mem_cgroup_disabled())
return;
- if (!ptr)
+ if (!memcg)
return;
- cgroup_exclude_rmdir(&ptr->css);
+ cgroup_exclude_rmdir(&memcg->css);
- __mem_cgroup_commit_charge_lrucare(page, ptr, ctype);
+ pc = lookup_page_cgroup(page);
+ __mem_cgroup_commit_charge(memcg, page, 1, pc, ctype, true);
/*
* Now swap is on-memory. This means this page may be
* counted both as mem and swap....double count.
@@ -2926,21 +2820,22 @@ __mem_cgroup_commit_charge_swapin(struct page *page, struct mem_cgroup *ptr,
*/
if (do_swap_account && PageSwapCache(page)) {
swp_entry_t ent = {.val = page_private(page)};
+ struct mem_cgroup *swap_memcg;
unsigned short id;
- struct mem_cgroup *memcg;
id = swap_cgroup_record(ent, 0);
rcu_read_lock();
- memcg = mem_cgroup_lookup(id);
- if (memcg) {
+ swap_memcg = mem_cgroup_lookup(id);
+ if (swap_memcg) {
/*
* This recorded memcg can be obsolete one. So, avoid
* calling css_tryget
*/
- if (!mem_cgroup_is_root(memcg))
- res_counter_uncharge(&memcg->memsw, PAGE_SIZE);
- mem_cgroup_swap_statistics(memcg, false);
- mem_cgroup_put(memcg);
+ if (!mem_cgroup_is_root(swap_memcg))
+ res_counter_uncharge(&swap_memcg->memsw,
+ PAGE_SIZE);
+ mem_cgroup_swap_statistics(swap_memcg, false);
+ mem_cgroup_put(swap_memcg);
}
rcu_read_unlock();
}
@@ -2949,13 +2844,14 @@ __mem_cgroup_commit_charge_swapin(struct page *page, struct mem_cgroup *ptr,
* So, rmdir()->pre_destroy() can be called while we do this charge.
* In that case, we need to call pre_destroy() again. check it here.
*/
- cgroup_release_and_wakeup_rmdir(&ptr->css);
+ cgroup_release_and_wakeup_rmdir(&memcg->css);
}
-void mem_cgroup_commit_charge_swapin(struct page *page, struct mem_cgroup *ptr)
+void mem_cgroup_commit_charge_swapin(struct page *page,
+ struct mem_cgroup *memcg)
{
- __mem_cgroup_commit_charge_swapin(page, ptr,
- MEM_CGROUP_CHARGE_TYPE_MAPPED);
+ __mem_cgroup_commit_charge_swapin(page, memcg,
+ MEM_CGROUP_CHARGE_TYPE_MAPPED);
}
void mem_cgroup_cancel_charge_swapin(struct mem_cgroup *memcg)
@@ -3045,7 +2941,7 @@ __mem_cgroup_uncharge_common(struct page *page, enum charge_type ctype)
* Check if our page_cgroup is valid
*/
pc = lookup_page_cgroup(page);
- if (unlikely(!pc || !PageCgroupUsed(pc)))
+ if (unlikely(!PageCgroupUsed(pc)))
return NULL;
lock_page_cgroup(pc);
@@ -3108,8 +3004,7 @@ void mem_cgroup_uncharge_page(struct page *page)
/* early check. */
if (page_mapped(page))
return;
- if (page->mapping && !PageAnon(page))
- return;
+ VM_BUG_ON(page->mapping && !PageAnon(page));
__mem_cgroup_uncharge_common(page, MEM_CGROUP_CHARGE_TYPE_MAPPED);
}
@@ -3284,14 +3179,14 @@ static inline int mem_cgroup_move_swap_account(swp_entry_t entry,
* page belongs to.
*/
int mem_cgroup_prepare_migration(struct page *page,
- struct page *newpage, struct mem_cgroup **ptr, gfp_t gfp_mask)
+ struct page *newpage, struct mem_cgroup **memcgp, gfp_t gfp_mask)
{
struct mem_cgroup *memcg = NULL;
struct page_cgroup *pc;
enum charge_type ctype;
int ret = 0;
- *ptr = NULL;
+ *memcgp = NULL;
VM_BUG_ON(PageTransHuge(page));
if (mem_cgroup_disabled())
@@ -3342,10 +3237,10 @@ int mem_cgroup_prepare_migration(struct page *page,
if (!memcg)
return 0;
- *ptr = memcg;
- ret = __mem_cgroup_try_charge(NULL, gfp_mask, 1, ptr, false);
+ *memcgp = memcg;
+ ret = __mem_cgroup_try_charge(NULL, gfp_mask, 1, memcgp, false);
css_put(&memcg->css);/* drop extra refcnt */
- if (ret || *ptr == NULL) {
+ if (ret) {
if (PageAnon(page)) {
lock_page_cgroup(pc);
ClearPageCgroupMigration(pc);
@@ -3355,6 +3250,7 @@ int mem_cgroup_prepare_migration(struct page *page,
*/
mem_cgroup_uncharge_page(page);
}
+ /* we'll need to revisit this error code (we have -EINTR) */
return -ENOMEM;
}
/*
@@ -3370,7 +3266,7 @@ int mem_cgroup_prepare_migration(struct page *page,
ctype = MEM_CGROUP_CHARGE_TYPE_CACHE;
else
ctype = MEM_CGROUP_CHARGE_TYPE_SHMEM;
- __mem_cgroup_commit_charge(memcg, page, 1, pc, ctype);
+ __mem_cgroup_commit_charge(memcg, newpage, 1, pc, ctype, false);
return ret;
}
@@ -3423,12 +3319,51 @@ void mem_cgroup_end_migration(struct mem_cgroup *memcg,
cgroup_release_and_wakeup_rmdir(&memcg->css);
}
+/*
+ * 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;
+ 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);
+ memcg = pc->mem_cgroup;
+ mem_cgroup_charge_statistics(memcg, PageCgroupCache(pc), -1);
+ ClearPageCgroupUsed(pc);
+ unlock_page_cgroup(pc);
+
+ if (PageSwapBacked(oldpage))
+ type = MEM_CGROUP_CHARGE_TYPE_SHMEM;
+
+ /*
+ * 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, pc, 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().
+ */
if (likely(pc) && PageCgroupUsed(pc))
return pc;
return NULL;
@@ -3448,23 +3383,8 @@ void mem_cgroup_print_bad_page(struct page *page)
pc = lookup_page_cgroup_used(page);
if (pc) {
- int ret = -1;
- char *path;
-
- printk(KERN_ALERT "pc:%p pc->flags:%lx pc->mem_cgroup:%p",
+ printk(KERN_ALERT "pc:%p pc->flags:%lx pc->mem_cgroup:%p\n",
pc, pc->flags, pc->mem_cgroup);
-
- path = kmalloc(PATH_MAX, GFP_KERNEL);
- if (path) {
- rcu_read_lock();
- ret = cgroup_path(pc->mem_cgroup->css.cgroup,
- path, PATH_MAX);
- rcu_read_unlock();
- }
-
- printk(KERN_CONT "(%s)\n",
- (ret < 0) ? "cannot get the path" : path);
- kfree(path);
}
}
#endif
@@ -3525,9 +3445,8 @@ static int mem_cgroup_resize_limit(struct mem_cgroup *memcg,
if (!ret)
break;
- mem_cgroup_hierarchical_reclaim(memcg, NULL, GFP_KERNEL,
- MEM_CGROUP_RECLAIM_SHRINK,
- NULL);
+ mem_cgroup_reclaim(memcg, GFP_KERNEL,
+ MEM_CGROUP_RECLAIM_SHRINK);
curusage = res_counter_read_u64(&memcg->res, RES_USAGE);
/* Usage is reduced ? */
if (curusage >= oldusage)
@@ -3585,10 +3504,9 @@ static int mem_cgroup_resize_memsw_limit(struct mem_cgroup *memcg,
if (!ret)
break;
- mem_cgroup_hierarchical_reclaim(memcg, NULL, GFP_KERNEL,
- MEM_CGROUP_RECLAIM_NOSWAP |
- MEM_CGROUP_RECLAIM_SHRINK,
- NULL);
+ mem_cgroup_reclaim(memcg, GFP_KERNEL,
+ MEM_CGROUP_RECLAIM_NOSWAP |
+ MEM_CGROUP_RECLAIM_SHRINK);
curusage = res_counter_read_u64(&memcg->memsw, RES_USAGE);
/* Usage is reduced ? */
if (curusage >= oldusage)
@@ -3631,10 +3549,8 @@ unsigned long mem_cgroup_soft_limit_reclaim(struct zone *zone, int order,
break;
nr_scanned = 0;
- reclaimed = mem_cgroup_hierarchical_reclaim(mz->mem, zone,
- gfp_mask,
- MEM_CGROUP_RECLAIM_SOFT,
- &nr_scanned);
+ reclaimed = mem_cgroup_soft_reclaim(mz->mem, zone,
+ gfp_mask, &nr_scanned);
nr_reclaimed += reclaimed;
*total_scanned += nr_scanned;
spin_lock(&mctz->lock);
@@ -3702,22 +3618,23 @@ unsigned long mem_cgroup_soft_limit_reclaim(struct zone *zone, int order,
static int mem_cgroup_force_empty_list(struct mem_cgroup *memcg,
int node, int zid, enum lru_list lru)
{
- struct zone *zone;
struct mem_cgroup_per_zone *mz;
- struct page_cgroup *pc, *busy;
unsigned long flags, loop;
struct list_head *list;
+ struct page *busy;
+ struct zone *zone;
int ret = 0;
zone = &NODE_DATA(node)->node_zones[zid];
mz = mem_cgroup_zoneinfo(memcg, node, zid);
- list = &mz->lists[lru];
+ list = &mz->lruvec.lists[lru];
loop = MEM_CGROUP_ZSTAT(mz, lru);
/* give some margin against EBUSY etc...*/
loop += 256;
busy = NULL;
while (loop--) {
+ struct page_cgroup *pc;
struct page *page;
ret = 0;
@@ -3726,24 +3643,24 @@ static int mem_cgroup_force_empty_list(struct mem_cgroup *memcg,
spin_unlock_irqrestore(&zone->lru_lock, flags);
break;
}
- pc = list_entry(list->prev, struct page_cgroup, lru);
- if (busy == pc) {
- list_move(&pc->lru, list);
+ page = list_entry(list->prev, struct page, lru);
+ if (busy == page) {
+ list_move(&page->lru, list);
busy = NULL;
spin_unlock_irqrestore(&zone->lru_lock, flags);
continue;
}
spin_unlock_irqrestore(&zone->lru_lock, flags);
- page = lookup_cgroup_page(pc);
+ pc = lookup_page_cgroup(page);
ret = mem_cgroup_move_parent(page, pc, memcg, GFP_KERNEL);
- if (ret == -ENOMEM)
+ if (ret == -ENOMEM || ret == -EINTR)
break;
if (ret == -EBUSY || ret == -EINVAL) {
/* found lock contention or "pc" is obsolete. */
- busy = pc;
+ busy = page;
cond_resched();
} else
busy = NULL;
@@ -4515,6 +4432,9 @@ static void mem_cgroup_usage_unregister_event(struct cgroup *cgrp,
*/
BUG_ON(!thresholds);
+ if (!thresholds->primary)
+ goto unlock;
+
usage = mem_cgroup_usage(memcg, type == _MEMSWAP);
/* Check if a threshold crossed before removing */
@@ -4563,7 +4483,7 @@ swap_buffers:
/* To be sure that nobody uses thresholds */
synchronize_rcu();
-
+unlock:
mutex_unlock(&memcg->thresholds_lock);
}
@@ -4837,7 +4757,7 @@ static int alloc_mem_cgroup_per_zone_info(struct mem_cgroup *memcg, int node)
for (zone = 0; zone < MAX_NR_ZONES; zone++) {
mz = &pn->zoneinfo[zone];
for_each_lru(l)
- INIT_LIST_HEAD(&mz->lists[l]);
+ INIT_LIST_HEAD(&mz->lruvec.lists[l]);
mz->usage_in_excess = 0;
mz->on_tree = false;
mz->mem = memcg;
@@ -4880,6 +4800,27 @@ out_free:
}
/*
+ * Helpers for freeing a vzalloc()ed mem_cgroup by RCU,
+ * but in process context. The work_freeing structure is overlaid
+ * on the rcu_freeing structure, which itself is overlaid on memsw.
+ */
+static void vfree_work(struct work_struct *work)
+{
+ struct mem_cgroup *memcg;
+
+ memcg = container_of(work, struct mem_cgroup, work_freeing);
+ vfree(memcg);
+}
+static void vfree_rcu(struct rcu_head *rcu_head)
+{
+ struct mem_cgroup *memcg;
+
+ memcg = container_of(rcu_head, struct mem_cgroup, rcu_freeing);
+ INIT_WORK(&memcg->work_freeing, vfree_work);
+ schedule_work(&memcg->work_freeing);
+}
+
+/*
* At destroying mem_cgroup, references from swap_cgroup can remain.
* (scanning all at force_empty is too costly...)
*
@@ -4897,14 +4838,14 @@ static void __mem_cgroup_free(struct mem_cgroup *memcg)
mem_cgroup_remove_from_trees(memcg);
free_css_id(&mem_cgroup_subsys, &memcg->css);
- for_each_node_state(node, N_POSSIBLE)
+ for_each_node(node)
free_mem_cgroup_per_zone_info(memcg, node);
free_percpu(memcg->stat);
if (sizeof(struct mem_cgroup) < PAGE_SIZE)
- kfree(memcg);
+ kfree_rcu(memcg, rcu_freeing);
else
- vfree(memcg);
+ call_rcu(&memcg->rcu_freeing, vfree_rcu);
}
static void mem_cgroup_get(struct mem_cgroup *memcg)
@@ -4956,13 +4897,13 @@ static int mem_cgroup_soft_limit_tree_init(void)
struct mem_cgroup_tree_per_zone *rtpz;
int tmp, node, zone;
- for_each_node_state(node, N_POSSIBLE) {
+ for_each_node(node) {
tmp = node;
if (!node_state(node, N_NORMAL_MEMORY))
tmp = -1;
rtpn = kzalloc_node(sizeof(*rtpn), GFP_KERNEL, tmp);
if (!rtpn)
- return 1;
+ goto err_cleanup;
soft_limit_tree.rb_tree_per_node[node] = rtpn;
@@ -4973,6 +4914,16 @@ static int mem_cgroup_soft_limit_tree_init(void)
}
}
return 0;
+
+err_cleanup:
+ for_each_node(node) {
+ if (!soft_limit_tree.rb_tree_per_node[node])
+ break;
+ kfree(soft_limit_tree.rb_tree_per_node[node]);
+ soft_limit_tree.rb_tree_per_node[node] = NULL;
+ }
+ return 1;
+
}
static struct cgroup_subsys_state * __ref
@@ -4986,7 +4937,7 @@ mem_cgroup_create(struct cgroup_subsys *ss, struct cgroup *cont)
if (!memcg)
return ERR_PTR(error);
- for_each_node_state(node, N_POSSIBLE)
+ for_each_node(node)
if (alloc_mem_cgroup_per_zone_info(memcg, node))
goto free_out;
@@ -5024,7 +4975,6 @@ mem_cgroup_create(struct cgroup_subsys *ss, struct cgroup *cont)
res_counter_init(&memcg->res, NULL);
res_counter_init(&memcg->memsw, NULL);
}
- memcg->last_scanned_child = 0;
memcg->last_scanned_node = MAX_NUMNODES;
INIT_LIST_HEAD(&memcg->oom_notify);
@@ -5120,9 +5070,9 @@ one_by_one:
}
ret = __mem_cgroup_try_charge(NULL,
GFP_KERNEL, 1, &memcg, false);
- if (ret || !memcg)
+ if (ret)
/* mem_cgroup_clear_mc() will do uncharge later */
- return -ENOMEM;
+ return ret;
mc.precharge++;
}
return ret;
@@ -5267,7 +5217,7 @@ static int is_target_pte_for_mc(struct vm_area_struct *vma,
}
/* There is a swap entry and a page doesn't exist or isn't charged */
if (ent.val && !ret &&
- css_id(&mc.from->css) == lookup_swap_cgroup(ent)) {
+ css_id(&mc.from->css) == lookup_swap_cgroup_id(ent)) {
ret = MC_TARGET_SWAP;
if (target)
target->ent = ent;
@@ -5391,8 +5341,9 @@ static void mem_cgroup_clear_mc(void)
static int mem_cgroup_can_attach(struct cgroup_subsys *ss,
struct cgroup *cgroup,
- struct task_struct *p)
+ struct cgroup_taskset *tset)
{
+ struct task_struct *p = cgroup_taskset_first(tset);
int ret = 0;
struct mem_cgroup *memcg = mem_cgroup_from_cont(cgroup);
@@ -5430,7 +5381,7 @@ static int mem_cgroup_can_attach(struct cgroup_subsys *ss,
static void mem_cgroup_cancel_attach(struct cgroup_subsys *ss,
struct cgroup *cgroup,
- struct task_struct *p)
+ struct cgroup_taskset *tset)
{
mem_cgroup_clear_mc();
}
@@ -5547,9 +5498,9 @@ retry:
static void mem_cgroup_move_task(struct cgroup_subsys *ss,
struct cgroup *cont,
- struct cgroup *old_cont,
- struct task_struct *p)
+ struct cgroup_taskset *tset)
{
+ struct task_struct *p = cgroup_taskset_first(tset);
struct mm_struct *mm = get_task_mm(p);
if (mm) {
@@ -5564,19 +5515,18 @@ static void mem_cgroup_move_task(struct cgroup_subsys *ss,
#else /* !CONFIG_MMU */
static int mem_cgroup_can_attach(struct cgroup_subsys *ss,
struct cgroup *cgroup,
- struct task_struct *p)
+ struct cgroup_taskset *tset)
{
return 0;
}
static void mem_cgroup_cancel_attach(struct cgroup_subsys *ss,
struct cgroup *cgroup,
- struct task_struct *p)
+ struct cgroup_taskset *tset)
{
}
static void mem_cgroup_move_task(struct cgroup_subsys *ss,
struct cgroup *cont,
- struct cgroup *old_cont,
- struct task_struct *p)
+ struct cgroup_taskset *tset)
{
}
#endif