#include <linux/oom.h>
#include <linux/lockdep.h>
#include <linux/file.h>
+#include <linux/tracehook.h>
#include "internal.h"
#include <net/sock.h>
#include <net/ip.h>
#define MEM_CGROUP_RECLAIM_RETRIES 5
static struct mem_cgroup *root_mem_cgroup __read_mostly;
+struct cgroup_subsys_state *mem_cgroup_root_css __read_mostly;
/* Whether the swap controller is active */
#ifdef CONFIG_MEMCG_SWAP
"rss",
"rss_huge",
"mapped_file",
+ "dirty",
"writeback",
"swap",
};
"unevictable",
};
-/*
- * Per memcg event counter is incremented at every pagein/pageout. With THP,
- * it will be incremated by the number of pages. This counter is used for
- * for trigger some periodic events. This is straightforward and better
- * than using jiffies etc. to handle periodic memcg event.
- */
-enum mem_cgroup_events_target {
- MEM_CGROUP_TARGET_THRESH,
- MEM_CGROUP_TARGET_SOFTLIMIT,
- MEM_CGROUP_TARGET_NUMAINFO,
- MEM_CGROUP_NTARGETS,
-};
#define THRESHOLDS_EVENTS_TARGET 128
#define SOFTLIMIT_EVENTS_TARGET 1024
#define NUMAINFO_EVENTS_TARGET 1024
-struct mem_cgroup_stat_cpu {
- long count[MEM_CGROUP_STAT_NSTATS];
- unsigned long events[MEMCG_NR_EVENTS];
- unsigned long nr_page_events;
- unsigned long targets[MEM_CGROUP_NTARGETS];
-};
-
-struct reclaim_iter {
- struct mem_cgroup *position;
- /* scan generation, increased every round-trip */
- unsigned int generation;
-};
-
-/*
- * per-zone information in memory controller.
- */
-struct mem_cgroup_per_zone {
- struct lruvec lruvec;
- unsigned long lru_size[NR_LRU_LISTS];
-
- struct reclaim_iter iter[DEF_PRIORITY + 1];
-
- struct rb_node tree_node; /* RB tree node */
- unsigned long usage_in_excess;/* Set to the value by which */
- /* the soft limit is exceeded*/
- bool on_tree;
- struct mem_cgroup *memcg; /* Back pointer, we cannot */
- /* use container_of */
-};
-
-struct mem_cgroup_per_node {
- struct mem_cgroup_per_zone zoneinfo[MAX_NR_ZONES];
-};
-
/*
* Cgroups above their limits are maintained in a RB-Tree, independent of
* their hierarchy representation
static struct mem_cgroup_tree soft_limit_tree __read_mostly;
-struct mem_cgroup_threshold {
- struct eventfd_ctx *eventfd;
- unsigned long threshold;
-};
-
-/* For threshold */
-struct mem_cgroup_threshold_ary {
- /* An array index points to threshold just below or equal to usage. */
- int current_threshold;
- /* Size of entries[] */
- unsigned int size;
- /* Array of thresholds */
- struct mem_cgroup_threshold entries[0];
-};
-
-struct mem_cgroup_thresholds {
- /* Primary thresholds array */
- struct mem_cgroup_threshold_ary *primary;
- /*
- * Spare threshold array.
- * This is needed to make mem_cgroup_unregister_event() "never fail".
- * It must be able to store at least primary->size - 1 entries.
- */
- struct mem_cgroup_threshold_ary *spare;
-};
-
/* for OOM */
struct mem_cgroup_eventfd_list {
struct list_head list;
static void mem_cgroup_threshold(struct mem_cgroup *memcg);
static void mem_cgroup_oom_notify(struct mem_cgroup *memcg);
-/*
- * The memory controller data structure. The memory controller controls both
- * page cache and RSS per cgroup. We would eventually like to provide
- * statistics based on the statistics developed by Rik Van Riel for clock-pro,
- * to help the administrator determine what knobs to tune.
- */
-struct mem_cgroup {
- struct cgroup_subsys_state css;
-
- /* Accounted resources */
- struct page_counter memory;
- struct page_counter memsw;
- struct page_counter kmem;
-
- /* Normal memory consumption range */
- unsigned long low;
- unsigned long high;
-
- unsigned long soft_limit;
-
- /* vmpressure notifications */
- struct vmpressure vmpressure;
-
- /* css_online() has been completed */
- int initialized;
-
- /*
- * Should the accounting and control be hierarchical, per subtree?
- */
- bool use_hierarchy;
-
- bool oom_lock;
- atomic_t under_oom;
- atomic_t oom_wakeups;
-
- int swappiness;
- /* OOM-Killer disable */
- int oom_kill_disable;
-
- /* protect arrays of thresholds */
- struct mutex thresholds_lock;
-
- /* thresholds for memory usage. RCU-protected */
- struct mem_cgroup_thresholds thresholds;
-
- /* thresholds for mem+swap usage. RCU-protected */
- struct mem_cgroup_thresholds memsw_thresholds;
-
- /* For oom notifier event fd */
- struct list_head oom_notify;
-
- /*
- * Should we move charges of a task when a task is moved into this
- * mem_cgroup ? And what type of charges should we move ?
- */
- unsigned long move_charge_at_immigrate;
- /*
- * set > 0 if pages under this cgroup are moving to other cgroup.
- */
- atomic_t moving_account;
- /* taken only while moving_account > 0 */
- spinlock_t move_lock;
- struct task_struct *move_lock_task;
- unsigned long move_lock_flags;
- /*
- * percpu counter.
- */
- struct mem_cgroup_stat_cpu __percpu *stat;
- /*
- * used when a cpu is offlined or other synchronizations
- * See mem_cgroup_read_stat().
- */
- struct mem_cgroup_stat_cpu nocpu_base;
- spinlock_t pcp_counter_lock;
-
-#if defined(CONFIG_MEMCG_KMEM) && defined(CONFIG_INET)
- struct cg_proto tcp_mem;
-#endif
-#if defined(CONFIG_MEMCG_KMEM)
- /* Index in the kmem_cache->memcg_params.memcg_caches array */
- int kmemcg_id;
- bool kmem_acct_activated;
- bool kmem_acct_active;
-#endif
-
- int last_scanned_node;
-#if MAX_NUMNODES > 1
- nodemask_t scan_nodes;
- atomic_t numainfo_events;
- atomic_t numainfo_updating;
-#endif
-
- /* List of events which userspace want to receive */
- struct list_head event_list;
- spinlock_t event_list_lock;
-
- struct mem_cgroup_per_node *nodeinfo[0];
- /* WARNING: nodeinfo must be the last member here */
-};
-
-#ifdef CONFIG_MEMCG_KMEM
-bool memcg_kmem_is_active(struct mem_cgroup *memcg)
-{
- return memcg->kmem_acct_active;
-}
-#endif
-
/* Stuffs for move charges at task migration. */
/*
* Types of charges to be moved.
*/
static DEFINE_MUTEX(memcg_create_mutex);
-struct mem_cgroup *mem_cgroup_from_css(struct cgroup_subsys_state *s)
-{
- return s ? container_of(s, struct mem_cgroup, css) : NULL;
-}
-
/* Some nice accessors for the vmpressure. */
struct vmpressure *memcg_to_vmpressure(struct mem_cgroup *memcg)
{
rcu_read_lock();
memcg = mem_cgroup_from_task(current);
cg_proto = sk->sk_prot->proto_cgroup(memcg);
- if (!mem_cgroup_is_root(memcg) &&
- memcg_proto_active(cg_proto) &&
+ if (cg_proto && test_bit(MEMCG_SOCK_ACTIVE, &cg_proto->flags) &&
css_tryget_online(&memcg->css)) {
sk->sk_cgrp = cg_proto;
}
return &memcg->nodeinfo[nid]->zoneinfo[zid];
}
-struct cgroup_subsys_state *mem_cgroup_css(struct mem_cgroup *memcg)
+/**
+ * mem_cgroup_css_from_page - css of the memcg associated with a page
+ * @page: page of interest
+ *
+ * If memcg is bound to the default hierarchy, css of the memcg associated
+ * with @page is returned. The returned css remains associated with @page
+ * until it is released.
+ *
+ * If memcg is bound to a traditional hierarchy, the css of root_mem_cgroup
+ * is returned.
+ *
+ * XXX: The above description of behavior on the default hierarchy isn't
+ * strictly true yet as replace_page_cache_page() can modify the
+ * association before @page is released even on the default hierarchy;
+ * however, the current and planned usages don't mix the the two functions
+ * and replace_page_cache_page() will soon be updated to make the invariant
+ * actually true.
+ */
+struct cgroup_subsys_state *mem_cgroup_css_from_page(struct page *page)
{
+ struct mem_cgroup *memcg;
+
+ rcu_read_lock();
+
+ memcg = page->mem_cgroup;
+
+ if (!memcg || !cgroup_subsys_on_dfl(memory_cgrp_subsys))
+ memcg = root_mem_cgroup;
+
+ rcu_read_unlock();
return &memcg->css;
}
+/**
+ * page_cgroup_ino - return inode number of the memcg a page is charged to
+ * @page: the page
+ *
+ * Look up the closest online ancestor of the memory cgroup @page is charged to
+ * and return its inode number or 0 if @page is not charged to any cgroup. It
+ * is safe to call this function without holding a reference to @page.
+ *
+ * Note, this function is inherently racy, because there is nothing to prevent
+ * the cgroup inode from getting torn down and potentially reallocated a moment
+ * after page_cgroup_ino() returns, so it only should be used by callers that
+ * do not care (such as procfs interfaces).
+ */
+ino_t page_cgroup_ino(struct page *page)
+{
+ struct mem_cgroup *memcg;
+ unsigned long ino = 0;
+
+ rcu_read_lock();
+ memcg = READ_ONCE(page->mem_cgroup);
+ while (memcg && !(memcg->css.flags & CSS_ONLINE))
+ memcg = parent_mem_cgroup(memcg);
+ if (memcg)
+ ino = cgroup_ino(memcg->css.cgroup);
+ rcu_read_unlock();
+ return ino;
+}
+
static struct mem_cgroup_per_zone *
mem_cgroup_page_zoneinfo(struct mem_cgroup *memcg, struct page *page)
{
}
/*
+ * Return page count for single (non recursive) @memcg.
+ *
* Implementation Note: reading percpu statistics for memcg.
*
* Both of vmstat[] and percpu_counter has threshold and do periodic
* synchronization to implement "quick" read. There are trade-off between
* reading cost and precision of value. Then, we may have a chance to implement
- * a periodic synchronizion of counter in memcg's counter.
+ * a periodic synchronization of counter in memcg's counter.
*
* But this _read() function is used for user interface now. The user accounts
* memory usage by memory cgroup and he _always_ requires exact value because
*
* If there are kernel internal actions which can make use of some not-exact
* value, and reading all cpu value can be performance bottleneck in some
- * common workload, threashold and synchonization as vmstat[] should be
+ * common workload, threshold and synchronization as vmstat[] should be
* implemented.
*/
-static long mem_cgroup_read_stat(struct mem_cgroup *memcg,
- enum mem_cgroup_stat_index idx)
+static unsigned long
+mem_cgroup_read_stat(struct mem_cgroup *memcg, enum mem_cgroup_stat_index idx)
{
long val = 0;
int cpu;
- get_online_cpus();
- for_each_online_cpu(cpu)
+ /* Per-cpu values can be negative, use a signed accumulator */
+ for_each_possible_cpu(cpu)
val += per_cpu(memcg->stat->count[idx], cpu);
-#ifdef CONFIG_HOTPLUG_CPU
- spin_lock(&memcg->pcp_counter_lock);
- val += memcg->nocpu_base.count[idx];
- spin_unlock(&memcg->pcp_counter_lock);
-#endif
- put_online_cpus();
+ /*
+ * Summing races with updates, so val may be negative. Avoid exposing
+ * transient negative values.
+ */
+ if (val < 0)
+ val = 0;
return val;
}
unsigned long val = 0;
int cpu;
- get_online_cpus();
- for_each_online_cpu(cpu)
+ for_each_possible_cpu(cpu)
val += per_cpu(memcg->stat->events[idx], cpu);
-#ifdef CONFIG_HOTPLUG_CPU
- spin_lock(&memcg->pcp_counter_lock);
- val += memcg->nocpu_base.events[idx];
- spin_unlock(&memcg->pcp_counter_lock);
-#endif
- put_online_cpus();
return val;
}
__this_cpu_add(memcg->stat->nr_page_events, nr_pages);
}
-unsigned long mem_cgroup_get_lru_size(struct lruvec *lruvec, enum lru_list lru)
-{
- struct mem_cgroup_per_zone *mz;
-
- mz = container_of(lruvec, struct mem_cgroup_per_zone, lruvec);
- return mz->lru_size[lru];
-}
-
static unsigned long mem_cgroup_node_nr_lru_pages(struct mem_cgroup *memcg,
int nid,
unsigned int lru_mask)
return mem_cgroup_from_css(task_css(p, memory_cgrp_id));
}
+EXPORT_SYMBOL(mem_cgroup_from_task);
static struct mem_cgroup *get_mem_cgroup_from_mm(struct mm_struct *mm)
{
struct mem_cgroup *prev,
struct mem_cgroup_reclaim_cookie *reclaim)
{
- struct reclaim_iter *uninitialized_var(iter);
+ struct mem_cgroup_reclaim_iter *uninitialized_var(iter);
struct cgroup_subsys_state *css = NULL;
struct mem_cgroup *memcg = NULL;
struct mem_cgroup *pos = NULL;
if (prev && reclaim->generation != iter->generation)
goto out_unlock;
- do {
+ while (1) {
pos = READ_ONCE(iter->position);
+ if (!pos || css_tryget(&pos->css))
+ break;
/*
- * A racing update may change the position and
- * put the last reference, hence css_tryget(),
- * or retry to see the updated position.
+ * css reference reached zero, so iter->position will
+ * be cleared by ->css_released. However, we should not
+ * rely on this happening soon, because ->css_released
+ * is called from a work queue, and by busy-waiting we
+ * might block it. So we clear iter->position right
+ * away.
*/
- } while (pos && !css_tryget(&pos->css));
+ (void)cmpxchg(&iter->position, pos, NULL);
+ }
}
if (pos)
}
if (reclaim) {
- if (cmpxchg(&iter->position, pos, memcg) == pos) {
- if (memcg)
- css_get(&memcg->css);
- if (pos)
- css_put(&pos->css);
- }
-
/*
- * pairs with css_tryget when dereferencing iter->position
- * above.
+ * The position could have already been updated by a competing
+ * thread, so check that the value hasn't changed since we read
+ * it to avoid reclaiming from the same cgroup twice.
*/
+ (void)cmpxchg(&iter->position, pos, memcg);
+
if (pos)
css_put(&pos->css);
css_put(&prev->css);
}
+static void invalidate_reclaim_iterators(struct mem_cgroup *dead_memcg)
+{
+ struct mem_cgroup *memcg = dead_memcg;
+ struct mem_cgroup_reclaim_iter *iter;
+ struct mem_cgroup_per_zone *mz;
+ int nid, zid;
+ int i;
+
+ while ((memcg = parent_mem_cgroup(memcg))) {
+ for_each_node(nid) {
+ for (zid = 0; zid < MAX_NR_ZONES; zid++) {
+ mz = &memcg->nodeinfo[nid]->zoneinfo[zid];
+ for (i = 0; i <= DEF_PRIORITY; i++) {
+ iter = &mz->iter[i];
+ cmpxchg(&iter->position,
+ dead_memcg, NULL);
+ }
+ }
+ }
+ }
+}
+
/*
* Iteration constructs for visiting all cgroups (under a tree). If
* loops are exited prematurely (break), mem_cgroup_iter_break() must
iter != NULL; \
iter = mem_cgroup_iter(NULL, iter, NULL))
-void __mem_cgroup_count_vm_event(struct mm_struct *mm, enum vm_event_item idx)
-{
- struct mem_cgroup *memcg;
-
- rcu_read_lock();
- memcg = mem_cgroup_from_task(rcu_dereference(mm->owner));
- if (unlikely(!memcg))
- goto out;
-
- switch (idx) {
- case PGFAULT:
- 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();
- }
-out:
- rcu_read_unlock();
-}
-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
VM_BUG_ON((long)(*lru_size) < 0);
}
-bool mem_cgroup_is_descendant(struct mem_cgroup *memcg, struct mem_cgroup *root)
-{
- if (root == memcg)
- return true;
- if (!root->use_hierarchy)
- return false;
- return cgroup_is_descendant(memcg->css.cgroup, root->css.cgroup);
-}
-
bool task_in_mem_cgroup(struct task_struct *task, struct mem_cgroup *memcg)
{
struct mem_cgroup *task_memcg;
return ret;
}
-int mem_cgroup_inactive_anon_is_low(struct lruvec *lruvec)
-{
- unsigned long inactive_ratio;
- unsigned long inactive;
- unsigned long active;
- unsigned long gb;
-
- inactive = mem_cgroup_get_lru_size(lruvec, LRU_INACTIVE_ANON);
- active = mem_cgroup_get_lru_size(lruvec, LRU_ACTIVE_ANON);
-
- gb = (inactive + active) >> (30 - PAGE_SHIFT);
- if (gb)
- inactive_ratio = int_sqrt(10 * gb);
- else
- inactive_ratio = 1;
-
- return inactive * inactive_ratio < active;
-}
-
-bool mem_cgroup_lruvec_online(struct lruvec *lruvec)
-{
- struct mem_cgroup_per_zone *mz;
- struct mem_cgroup *memcg;
-
- if (mem_cgroup_disabled())
- return true;
-
- mz = container_of(lruvec, struct mem_cgroup_per_zone, lruvec);
- memcg = mz->memcg;
-
- return !!(memcg->css.flags & CSS_ONLINE);
-}
-
#define mem_cgroup_from_counter(counter, member) \
container_of(counter, struct mem_cgroup, member)
return margin;
}
-int mem_cgroup_swappiness(struct mem_cgroup *memcg)
-{
- /* root ? */
- if (mem_cgroup_disabled() || !memcg->css.parent)
- return vm_swappiness;
-
- return memcg->swappiness;
-}
-
/*
* A routine for checking "mem" is under move_account() or not.
*
for (i = 0; i < MEM_CGROUP_STAT_NSTATS; i++) {
if (i == MEM_CGROUP_STAT_SWAP && !do_swap_account)
continue;
- pr_cont(" %s:%ldKB", mem_cgroup_stat_names[i],
+ pr_cont(" %s:%luKB", mem_cgroup_stat_names[i],
K(mem_cgroup_read_stat(iter, i)));
}
static void mem_cgroup_out_of_memory(struct mem_cgroup *memcg, gfp_t gfp_mask,
int order)
{
+ struct oom_control oc = {
+ .zonelist = NULL,
+ .nodemask = NULL,
+ .gfp_mask = gfp_mask,
+ .order = order,
+ };
struct mem_cgroup *iter;
unsigned long chosen_points = 0;
unsigned long totalpages;
unsigned int points = 0;
struct task_struct *chosen = NULL;
+ mutex_lock(&oom_lock);
+
/*
* If current has a pending SIGKILL or is exiting, then automatically
* select it. The goal is to allow it to allocate so that it may
* quickly exit and free its memory.
*/
if (fatal_signal_pending(current) || task_will_free_mem(current)) {
- mark_tsk_oom_victim(current);
- return;
+ mark_oom_victim(current);
+ goto unlock;
}
- check_panic_on_oom(CONSTRAINT_MEMCG, gfp_mask, order, NULL, memcg);
+ check_panic_on_oom(&oc, CONSTRAINT_MEMCG, memcg);
totalpages = mem_cgroup_get_limit(memcg) ? : 1;
for_each_mem_cgroup_tree(iter, memcg) {
struct css_task_iter it;
css_task_iter_start(&iter->css, &it);
while ((task = css_task_iter_next(&it))) {
- switch (oom_scan_process_thread(task, totalpages, NULL,
- false)) {
+ switch (oom_scan_process_thread(&oc, task, totalpages)) {
case OOM_SCAN_SELECT:
if (chosen)
put_task_struct(chosen);
mem_cgroup_iter_break(memcg, iter);
if (chosen)
put_task_struct(chosen);
- return;
+ goto unlock;
case OOM_SCAN_OK:
break;
};
css_task_iter_end(&it);
}
- if (!chosen)
- return;
- points = chosen_points * 1000 / totalpages;
- oom_kill_process(chosen, gfp_mask, order, points, totalpages, memcg,
- NULL, "Memory cgroup out of memory");
+ if (chosen) {
+ points = chosen_points * 1000 / totalpages;
+ oom_kill_process(&oc, chosen, points, totalpages, memcg,
+ "Memory cgroup out of memory");
+ }
+unlock:
+ mutex_unlock(&oom_lock);
}
#if MAX_NUMNODES > 1
{
struct mem_cgroup *iter;
+ spin_lock(&memcg_oom_lock);
for_each_mem_cgroup_tree(iter, memcg)
- atomic_inc(&iter->under_oom);
+ iter->under_oom++;
+ spin_unlock(&memcg_oom_lock);
}
static void mem_cgroup_unmark_under_oom(struct mem_cgroup *memcg)
/*
* When a new child is created while the hierarchy is under oom,
- * mem_cgroup_oom_lock() may not be called. We have to use
- * atomic_add_unless() here.
+ * mem_cgroup_oom_lock() may not be called. Watch for underflow.
*/
+ spin_lock(&memcg_oom_lock);
for_each_mem_cgroup_tree(iter, memcg)
- atomic_add_unless(&iter->under_oom, -1, 0);
+ if (iter->under_oom > 0)
+ iter->under_oom--;
+ spin_unlock(&memcg_oom_lock);
}
static DECLARE_WAIT_QUEUE_HEAD(memcg_oom_waitq);
return autoremove_wake_function(wait, mode, sync, arg);
}
-static void memcg_wakeup_oom(struct mem_cgroup *memcg)
-{
- atomic_inc(&memcg->oom_wakeups);
- /* for filtering, pass "memcg" as argument. */
- __wake_up(&memcg_oom_waitq, TASK_NORMAL, 0, memcg);
-}
-
static void memcg_oom_recover(struct mem_cgroup *memcg)
{
- if (memcg && atomic_read(&memcg->under_oom))
- memcg_wakeup_oom(memcg);
+ /*
+ * For the following lockless ->under_oom test, the only required
+ * guarantee is that it must see the state asserted by an OOM when
+ * this function is called as a result of userland actions
+ * triggered by the notification of the OOM. This is trivially
+ * achieved by invoking mem_cgroup_mark_under_oom() before
+ * triggering notification.
+ */
+ if (memcg && memcg->under_oom)
+ __wake_up(&memcg_oom_waitq, TASK_NORMAL, 0, memcg);
}
static void mem_cgroup_oom(struct mem_cgroup *memcg, gfp_t mask, int order)
{
- if (!current->memcg_oom.may_oom)
+ if (!current->memcg_may_oom)
return;
/*
* We are in the middle of the charge context here, so we
* and when we know whether the fault was overall successful.
*/
css_get(&memcg->css);
- current->memcg_oom.memcg = memcg;
- current->memcg_oom.gfp_mask = mask;
- current->memcg_oom.order = order;
+ current->memcg_in_oom = memcg;
+ current->memcg_oom_gfp_mask = mask;
+ current->memcg_oom_order = order;
}
/**
*/
bool mem_cgroup_oom_synchronize(bool handle)
{
- struct mem_cgroup *memcg = current->memcg_oom.memcg;
+ struct mem_cgroup *memcg = current->memcg_in_oom;
struct oom_wait_info owait;
bool locked;
if (locked && !memcg->oom_kill_disable) {
mem_cgroup_unmark_under_oom(memcg);
finish_wait(&memcg_oom_waitq, &owait.wait);
- mem_cgroup_out_of_memory(memcg, current->memcg_oom.gfp_mask,
- current->memcg_oom.order);
+ mem_cgroup_out_of_memory(memcg, current->memcg_oom_gfp_mask,
+ current->memcg_oom_order);
} else {
schedule();
mem_cgroup_unmark_under_oom(memcg);
memcg_oom_recover(memcg);
}
cleanup:
- current->memcg_oom.memcg = NULL;
+ current->memcg_in_oom = NULL;
css_put(&memcg->css);
return true;
}
return memcg;
}
+EXPORT_SYMBOL(mem_cgroup_begin_page_stat);
/**
* mem_cgroup_end_page_stat - finish a page state statistics transaction
rcu_read_unlock();
}
-
-/**
- * mem_cgroup_update_page_stat - update page state statistics
- * @memcg: memcg to account against
- * @idx: page state item to account
- * @val: number of pages (positive or negative)
- *
- * See mem_cgroup_begin_page_stat() for locking requirements.
- */
-void mem_cgroup_update_page_stat(struct mem_cgroup *memcg,
- enum mem_cgroup_stat_index idx, int val)
-{
- VM_BUG_ON(!rcu_read_lock_held());
-
- if (memcg)
- this_cpu_add(memcg->stat->count[idx], val);
-}
+EXPORT_SYMBOL(mem_cgroup_end_page_stat);
/*
* size of first charge trial. "32" comes from vmscan.c's magic value.
mutex_unlock(&percpu_charge_mutex);
}
-/*
- * This function drains percpu counter value from DEAD cpu and
- * move it to local cpu. Note that this function can be preempted.
- */
-static void mem_cgroup_drain_pcp_counter(struct mem_cgroup *memcg, int cpu)
-{
- int i;
-
- spin_lock(&memcg->pcp_counter_lock);
- for (i = 0; i < MEM_CGROUP_STAT_NSTATS; i++) {
- long x = per_cpu(memcg->stat->count[i], cpu);
-
- per_cpu(memcg->stat->count[i], cpu) = 0;
- memcg->nocpu_base.count[i] += x;
- }
- for (i = 0; i < MEM_CGROUP_EVENTS_NSTATS; i++) {
- unsigned long x = per_cpu(memcg->stat->events[i], cpu);
-
- per_cpu(memcg->stat->events[i], cpu) = 0;
- memcg->nocpu_base.events[i] += x;
- }
- spin_unlock(&memcg->pcp_counter_lock);
-}
-
static int memcg_cpu_hotplug_callback(struct notifier_block *nb,
unsigned long action,
void *hcpu)
{
int cpu = (unsigned long)hcpu;
struct memcg_stock_pcp *stock;
- struct mem_cgroup *iter;
if (action == CPU_ONLINE)
return NOTIFY_OK;
if (action != CPU_DEAD && action != CPU_DEAD_FROZEN)
return NOTIFY_OK;
- for_each_mem_cgroup(iter)
- mem_cgroup_drain_pcp_counter(iter, cpu);
-
stock = &per_cpu(memcg_stock, cpu);
drain_stock(stock);
return NOTIFY_OK;
}
+/*
+ * Scheduled by try_charge() to be executed from the userland return path
+ * and reclaims memory over the high limit.
+ */
+void mem_cgroup_handle_over_high(void)
+{
+ unsigned int nr_pages = current->memcg_nr_pages_over_high;
+ struct mem_cgroup *memcg, *pos;
+
+ if (likely(!nr_pages))
+ return;
+
+ pos = memcg = get_mem_cgroup_from_mm(current->mm);
+
+ do {
+ if (page_counter_read(&pos->memory) <= pos->high)
+ continue;
+ mem_cgroup_events(pos, MEMCG_HIGH, 1);
+ try_to_free_mem_cgroup_pages(pos, nr_pages, GFP_KERNEL, true);
+ } while ((pos = parent_mem_cgroup(pos)));
+
+ css_put(&memcg->css);
+ current->memcg_nr_pages_over_high = 0;
+}
+
static int try_charge(struct mem_cgroup *memcg, gfp_t gfp_mask,
unsigned int nr_pages)
{
unsigned long nr_reclaimed;
bool may_swap = true;
bool drained = false;
- int ret = 0;
if (mem_cgroup_is_root(memcg))
- goto done;
+ return 0;
retry:
if (consume_stock(memcg, nr_pages))
- goto done;
+ return 0;
if (!do_swap_account ||
- !page_counter_try_charge(&memcg->memsw, batch, &counter)) {
- if (!page_counter_try_charge(&memcg->memory, batch, &counter))
+ page_counter_try_charge(&memcg->memsw, batch, &counter)) {
+ if (page_counter_try_charge(&memcg->memory, batch, &counter))
goto done_restock;
if (do_swap_account)
page_counter_uncharge(&memcg->memsw, batch);
if (unlikely(test_thread_flag(TIF_MEMDIE) ||
fatal_signal_pending(current) ||
current->flags & PF_EXITING))
- goto bypass;
+ goto force;
if (unlikely(task_in_memcg_oom(current)))
goto nomem;
- if (!(gfp_mask & __GFP_WAIT))
+ if (!gfpflags_allow_blocking(gfp_mask))
goto nomem;
mem_cgroup_events(mem_over_limit, MEMCG_MAX, 1);
goto retry;
if (gfp_mask & __GFP_NOFAIL)
- goto bypass;
+ goto force;
if (fatal_signal_pending(current))
- goto bypass;
+ goto force;
mem_cgroup_events(mem_over_limit, MEMCG_OOM, 1);
- mem_cgroup_oom(mem_over_limit, gfp_mask, get_order(nr_pages));
+ mem_cgroup_oom(mem_over_limit, gfp_mask,
+ get_order(nr_pages * PAGE_SIZE));
nomem:
if (!(gfp_mask & __GFP_NOFAIL))
return -ENOMEM;
-bypass:
- return -EINTR;
+force:
+ /*
+ * The allocation either can't fail or will lead to more memory
+ * being freed very soon. Allow memory usage go over the limit
+ * temporarily by force charging it.
+ */
+ page_counter_charge(&memcg->memory, nr_pages);
+ if (do_swap_account)
+ page_counter_charge(&memcg->memsw, nr_pages);
+ css_get_many(&memcg->css, nr_pages);
+
+ return 0;
done_restock:
css_get_many(&memcg->css, batch);
if (batch > nr_pages)
refill_stock(memcg, batch - nr_pages);
- if (!(gfp_mask & __GFP_WAIT))
- goto done;
+
/*
- * If the hierarchy is above the normal consumption range,
- * make the charging task trim their excess contribution.
+ * If the hierarchy is above the normal consumption range, schedule
+ * reclaim on returning to userland. We can perform reclaim here
+ * if __GFP_RECLAIM but let's always punt for simplicity and so that
+ * GFP_KERNEL can consistently be used during reclaim. @memcg is
+ * not recorded as it most likely matches current's and won't
+ * change in the meantime. As high limit is checked again before
+ * reclaim, the cost of mismatch is negligible.
*/
do {
- if (page_counter_read(&memcg->memory) <= memcg->high)
- continue;
- mem_cgroup_events(memcg, MEMCG_HIGH, 1);
- try_to_free_mem_cgroup_pages(memcg, nr_pages, gfp_mask, true);
+ if (page_counter_read(&memcg->memory) > memcg->high) {
+ current->memcg_nr_pages_over_high += batch;
+ set_notify_resume(current);
+ break;
+ }
} while ((memcg = parent_mem_cgroup(memcg)));
-done:
- return ret;
+
+ return 0;
}
static void cancel_charge(struct mem_cgroup *memcg, unsigned int nr_pages)
css_put_many(&memcg->css, nr_pages);
}
-/*
- * 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;
- unsigned short id;
- swp_entry_t ent;
-
- VM_BUG_ON_PAGE(!PageLocked(page), page);
-
- memcg = page->mem_cgroup;
- if (memcg) {
- if (!css_tryget_online(&memcg->css))
- memcg = NULL;
- } else if (PageSwapCache(page)) {
- ent.val = page_private(page);
- id = lookup_swap_cgroup_id(ent);
- rcu_read_lock();
- memcg = mem_cgroup_from_id(id);
- if (memcg && !css_tryget_online(&memcg->css))
- memcg = NULL;
- rcu_read_unlock();
- }
- return memcg;
-}
-
static void lock_page_lru(struct page *page, int *isolated)
{
struct zone *zone = page_zone(page);
}
#ifdef CONFIG_MEMCG_KMEM
-int memcg_charge_kmem(struct mem_cgroup *memcg, gfp_t gfp,
- unsigned long nr_pages)
-{
- struct page_counter *counter;
- int ret = 0;
-
- ret = page_counter_try_charge(&memcg->kmem, nr_pages, &counter);
- if (ret < 0)
- return ret;
-
- ret = try_charge(memcg, gfp, nr_pages);
- if (ret == -EINTR) {
- /*
- * 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 try_charge() above. Tasks that were already dying
- * when the allocation triggers should have been already
- * directed to the root cgroup in memcontrol.h
- */
- page_counter_charge(&memcg->memory, nr_pages);
- if (do_swap_account)
- page_counter_charge(&memcg->memsw, nr_pages);
- css_get_many(&memcg->css, nr_pages);
- ret = 0;
- } else if (ret)
- page_counter_uncharge(&memcg->kmem, nr_pages);
-
- return ret;
-}
-
-void memcg_uncharge_kmem(struct mem_cgroup *memcg, unsigned long nr_pages)
-{
- page_counter_uncharge(&memcg->memory, nr_pages);
- if (do_swap_account)
- page_counter_uncharge(&memcg->memsw, nr_pages);
-
- page_counter_uncharge(&memcg->kmem, nr_pages);
-
- css_put_many(&memcg->css, nr_pages);
-}
-
-/*
- * helper for acessing a memcg's index. It will be used as an index in the
- * child cache array in kmem_cache, and also to derive its name. This function
- * will return -1 when this is not a kmem-limited memcg.
- */
-int memcg_cache_id(struct mem_cgroup *memcg)
-{
- return memcg ? memcg->kmemcg_id : -1;
-}
-
static int memcg_alloc_cache_id(void)
{
int id, size;
css_put(&cachep->memcg_params.memcg->css);
}
-/*
- * We need to verify if the allocation against current->mm->owner's memcg is
- * possible for the given order. But the page is not allocated yet, so we'll
- * need a further commit step to do the final arrangements.
- *
- * It is possible for the task to switch cgroups in this mean time, so at
- * commit time, we can't rely on task conversion any longer. We'll then use
- * the handle argument to return to the caller which cgroup we should commit
- * against. We could also return the memcg directly and avoid the pointer
- * passing, but a boolean return value gives better semantics considering
- * the compiled-out case as well.
- *
- * Returning true means the allocation is possible.
- */
-bool
-__memcg_kmem_newpage_charge(gfp_t gfp, struct mem_cgroup **_memcg, int order)
+int __memcg_kmem_charge_memcg(struct page *page, gfp_t gfp, int order,
+ struct mem_cgroup *memcg)
{
- struct mem_cgroup *memcg;
+ unsigned int nr_pages = 1 << order;
+ struct page_counter *counter;
int ret;
- *_memcg = NULL;
+ if (!memcg_kmem_is_active(memcg))
+ return 0;
- memcg = get_mem_cgroup_from_mm(current->mm);
+ if (!page_counter_try_charge(&memcg->kmem, nr_pages, &counter))
+ return -ENOMEM;
- if (!memcg_kmem_is_active(memcg)) {
- css_put(&memcg->css);
- return true;
+ ret = try_charge(memcg, gfp, nr_pages);
+ if (ret) {
+ page_counter_uncharge(&memcg->kmem, nr_pages);
+ return ret;
}
- ret = memcg_charge_kmem(memcg, gfp, 1 << order);
- if (!ret)
- *_memcg = memcg;
+ page->mem_cgroup = memcg;
- css_put(&memcg->css);
- return (ret == 0);
+ return 0;
}
-void __memcg_kmem_commit_charge(struct page *page, struct mem_cgroup *memcg,
- int order)
+int __memcg_kmem_charge(struct page *page, gfp_t gfp, int order)
{
- VM_BUG_ON(mem_cgroup_is_root(memcg));
+ struct mem_cgroup *memcg;
+ int ret;
- /* The page allocation failed. Revert */
- if (!page) {
- memcg_uncharge_kmem(memcg, 1 << order);
- return;
- }
- page->mem_cgroup = memcg;
+ memcg = get_mem_cgroup_from_mm(current->mm);
+ ret = __memcg_kmem_charge_memcg(page, gfp, order, memcg);
+ css_put(&memcg->css);
+ return ret;
}
-void __memcg_kmem_uncharge_pages(struct page *page, int order)
+void __memcg_kmem_uncharge(struct page *page, int order)
{
struct mem_cgroup *memcg = page->mem_cgroup;
+ unsigned int nr_pages = 1 << order;
if (!memcg)
return;
VM_BUG_ON_PAGE(mem_cgroup_is_root(memcg), page);
- memcg_uncharge_kmem(memcg, 1 << order);
- page->mem_cgroup = NULL;
-}
-
-struct mem_cgroup *__mem_cgroup_from_kmem(void *ptr)
-{
- struct mem_cgroup *memcg = NULL;
- struct kmem_cache *cachep;
- struct page *page;
-
- page = virt_to_head_page(ptr);
- if (PageSlab(page)) {
- cachep = page->slab_cache;
- if (!is_root_cache(cachep))
- memcg = cachep->memcg_params.memcg;
- } else
- /* page allocated by alloc_kmem_pages */
- memcg = page->mem_cgroup;
+ page_counter_uncharge(&memcg->kmem, nr_pages);
+ page_counter_uncharge(&memcg->memory, nr_pages);
+ if (do_swap_account)
+ page_counter_uncharge(&memcg->memsw, nr_pages);
- return memcg;
+ page->mem_cgroup = NULL;
+ css_put_many(&memcg->css, nr_pages);
}
#endif /* CONFIG_MEMCG_KMEM */
enum mem_cgroup_stat_index idx)
{
struct mem_cgroup *iter;
- long val = 0;
+ unsigned 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)
+static unsigned long mem_cgroup_usage(struct mem_cgroup *memcg, bool swap)
{
- u64 val;
+ unsigned long val;
if (mem_cgroup_is_root(memcg)) {
val = tree_stat(memcg, MEM_CGROUP_STAT_CACHE);
else
val = page_counter_read(&memcg->memsw);
}
- return val << PAGE_SHIFT;
+ return val;
}
enum {
switch (MEMFILE_ATTR(cft->private)) {
case RES_USAGE:
if (counter == &memcg->memory)
- return mem_cgroup_usage(memcg, false);
+ return (u64)mem_cgroup_usage(memcg, false) * PAGE_SIZE;
if (counter == &memcg->memsw)
- return mem_cgroup_usage(memcg, true);
+ return (u64)mem_cgroup_usage(memcg, true) * PAGE_SIZE;
return (u64)page_counter_read(counter) * PAGE_SIZE;
case RES_LIMIT:
return (u64)counter->limit * PAGE_SIZE;
* of course permitted.
*/
mutex_lock(&memcg_create_mutex);
- if (cgroup_has_tasks(memcg->css.cgroup) ||
+ if (cgroup_is_populated(memcg->css.cgroup) ||
(memcg->use_hierarchy && memcg_has_children(memcg)))
err = -EBUSY;
mutex_unlock(&memcg_create_mutex);
for (i = 0; i < MEM_CGROUP_STAT_NSTATS; i++) {
if (i == MEM_CGROUP_STAT_SWAP && !do_swap_account)
continue;
- seq_printf(m, "%s %ld\n", mem_cgroup_stat_names[i],
+ seq_printf(m, "%s %lu\n", mem_cgroup_stat_names[i],
mem_cgroup_read_stat(memcg, i) * PAGE_SIZE);
}
(u64)memsw * PAGE_SIZE);
for (i = 0; i < MEM_CGROUP_STAT_NSTATS; i++) {
- long long val = 0;
+ unsigned long long val = 0;
if (i == MEM_CGROUP_STAT_SWAP && !do_swap_account)
continue;
for_each_mem_cgroup_tree(mi, memcg)
val += mem_cgroup_read_stat(mi, i) * PAGE_SIZE;
- seq_printf(m, "total_%s %lld\n", mem_cgroup_stat_names[i], val);
+ seq_printf(m, "total_%s %llu\n", mem_cgroup_stat_names[i], val);
}
for (i = 0; i < MEM_CGROUP_EVENTS_NSTATS; i++) {
swap_buffers:
/* Swap primary and spare array */
thresholds->spare = thresholds->primary;
- /* If all events are unregistered, free the spare array */
- if (!new) {
- kfree(thresholds->spare);
- thresholds->spare = NULL;
- }
rcu_assign_pointer(thresholds->primary, new);
/* To be sure that nobody uses thresholds */
synchronize_rcu();
+
+ /* If all events are unregistered, free the spare array */
+ if (!new) {
+ kfree(thresholds->spare);
+ thresholds->spare = NULL;
+ }
unlock:
mutex_unlock(&memcg->thresholds_lock);
}
list_add(&event->list, &memcg->oom_notify);
/* already in OOM ? */
- if (atomic_read(&memcg->under_oom))
+ if (memcg->under_oom)
eventfd_signal(eventfd, 1);
spin_unlock(&memcg_oom_lock);
struct mem_cgroup *memcg = mem_cgroup_from_css(seq_css(sf));
seq_printf(sf, "oom_kill_disable %d\n", memcg->oom_kill_disable);
- seq_printf(sf, "under_oom %d\n", (bool)atomic_read(&memcg->under_oom));
+ seq_printf(sf, "under_oom %d\n", (bool)memcg->under_oom);
return 0;
}
}
#endif
+#ifdef CONFIG_CGROUP_WRITEBACK
+
+struct list_head *mem_cgroup_cgwb_list(struct mem_cgroup *memcg)
+{
+ return &memcg->cgwb_list;
+}
+
+static int memcg_wb_domain_init(struct mem_cgroup *memcg, gfp_t gfp)
+{
+ return wb_domain_init(&memcg->cgwb_domain, gfp);
+}
+
+static void memcg_wb_domain_exit(struct mem_cgroup *memcg)
+{
+ wb_domain_exit(&memcg->cgwb_domain);
+}
+
+static void memcg_wb_domain_size_changed(struct mem_cgroup *memcg)
+{
+ wb_domain_size_changed(&memcg->cgwb_domain);
+}
+
+struct wb_domain *mem_cgroup_wb_domain(struct bdi_writeback *wb)
+{
+ struct mem_cgroup *memcg = mem_cgroup_from_css(wb->memcg_css);
+
+ if (!memcg->css.parent)
+ return NULL;
+
+ return &memcg->cgwb_domain;
+}
+
+/**
+ * mem_cgroup_wb_stats - retrieve writeback related stats from its memcg
+ * @wb: bdi_writeback in question
+ * @pfilepages: out parameter for number of file pages
+ * @pheadroom: out parameter for number of allocatable pages according to memcg
+ * @pdirty: out parameter for number of dirty pages
+ * @pwriteback: out parameter for number of pages under writeback
+ *
+ * Determine the numbers of file, headroom, dirty, and writeback pages in
+ * @wb's memcg. File, dirty and writeback are self-explanatory. Headroom
+ * is a bit more involved.
+ *
+ * A memcg's headroom is "min(max, high) - used". In the hierarchy, the
+ * headroom is calculated as the lowest headroom of itself and the
+ * ancestors. Note that this doesn't consider the actual amount of
+ * available memory in the system. The caller should further cap
+ * *@pheadroom accordingly.
+ */
+void mem_cgroup_wb_stats(struct bdi_writeback *wb, unsigned long *pfilepages,
+ unsigned long *pheadroom, unsigned long *pdirty,
+ unsigned long *pwriteback)
+{
+ struct mem_cgroup *memcg = mem_cgroup_from_css(wb->memcg_css);
+ struct mem_cgroup *parent;
+
+ *pdirty = mem_cgroup_read_stat(memcg, MEM_CGROUP_STAT_DIRTY);
+
+ /* this should eventually include NR_UNSTABLE_NFS */
+ *pwriteback = mem_cgroup_read_stat(memcg, MEM_CGROUP_STAT_WRITEBACK);
+ *pfilepages = mem_cgroup_nr_lru_pages(memcg, (1 << LRU_INACTIVE_FILE) |
+ (1 << LRU_ACTIVE_FILE));
+ *pheadroom = PAGE_COUNTER_MAX;
+
+ while ((parent = parent_mem_cgroup(memcg))) {
+ unsigned long ceiling = min(memcg->memory.limit, memcg->high);
+ unsigned long used = page_counter_read(&memcg->memory);
+
+ *pheadroom = min(*pheadroom, ceiling - min(ceiling, used));
+ memcg = parent;
+ }
+}
+
+#else /* CONFIG_CGROUP_WRITEBACK */
+
+static int memcg_wb_domain_init(struct mem_cgroup *memcg, gfp_t gfp)
+{
+ return 0;
+}
+
+static void memcg_wb_domain_exit(struct mem_cgroup *memcg)
+{
+}
+
+static void memcg_wb_domain_size_changed(struct mem_cgroup *memcg)
+{
+}
+
+#endif /* CONFIG_CGROUP_WRITEBACK */
+
/*
* DO NOT USE IN NEW FILES.
*
{
.name = "cgroup.event_control", /* XXX: for compat */
.write = memcg_write_event_control,
- .flags = CFTYPE_NO_PREFIX,
- .mode = S_IWUGO,
+ .flags = CFTYPE_NO_PREFIX | CFTYPE_WORLD_WRITABLE,
},
{
.name = "swappiness",
memcg->stat = alloc_percpu(struct mem_cgroup_stat_cpu);
if (!memcg->stat)
goto out_free;
- spin_lock_init(&memcg->pcp_counter_lock);
+
+ if (memcg_wb_domain_init(memcg, GFP_KERNEL))
+ goto out_free_stat;
+
return memcg;
+out_free_stat:
+ free_percpu(memcg->stat);
out_free:
kfree(memcg);
return NULL;
free_mem_cgroup_per_zone_info(memcg, node);
free_percpu(memcg->stat);
+ memcg_wb_domain_exit(memcg);
kfree(memcg);
}
/* root ? */
if (parent_css == NULL) {
root_mem_cgroup = memcg;
+ mem_cgroup_root_css = &memcg->css;
page_counter_init(&memcg->memory, NULL);
memcg->high = PAGE_COUNTER_MAX;
memcg->soft_limit = PAGE_COUNTER_MAX;
#ifdef CONFIG_MEMCG_KMEM
memcg->kmemcg_id = -1;
#endif
-
+#ifdef CONFIG_CGROUP_WRITEBACK
+ INIT_LIST_HEAD(&memcg->cgwb_list);
+#endif
return &memcg->css;
free_out:
vmpressure_cleanup(&memcg->vmpressure);
memcg_deactivate_kmem(memcg);
+
+ wb_memcg_offline(memcg);
+}
+
+static void mem_cgroup_css_released(struct cgroup_subsys_state *css)
+{
+ struct mem_cgroup *memcg = mem_cgroup_from_css(css);
+
+ invalidate_reclaim_iterators(memcg);
}
static void mem_cgroup_css_free(struct cgroup_subsys_state *css)
memcg->low = 0;
memcg->high = PAGE_COUNTER_MAX;
memcg->soft_limit = PAGE_COUNTER_MAX;
+ memcg_wb_domain_size_changed(memcg);
}
#ifdef CONFIG_MMU
{
int ret;
- /* Try a single bulk charge without reclaim first */
- ret = try_charge(mc.to, GFP_KERNEL & ~__GFP_WAIT, count);
+ /* Try a single bulk charge without reclaim first, kswapd may wake */
+ ret = try_charge(mc.to, GFP_KERNEL & ~__GFP_DIRECT_RECLAIM, count);
if (!ret) {
mc.precharge += count;
return ret;
}
- if (ret == -EINTR) {
- cancel_charge(root_mem_cgroup, count);
- return ret;
- }
/* Try charges one by one with reclaim */
while (count--) {
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)
return ret;
mc.precharge++;
{
unsigned long flags;
int ret;
+ bool anon;
VM_BUG_ON(from == to);
VM_BUG_ON_PAGE(PageLRU(page), page);
goto out;
/*
- * Prevent mem_cgroup_migrate() from looking at page->mem_cgroup
- * of its source page while we change it: page migration takes
- * both pages off the LRU, but page cache replacement doesn't.
+ * Prevent mem_cgroup_replace_page() from looking at
+ * page->mem_cgroup of its source page while we change it.
*/
if (!trylock_page(page))
goto out;
if (page->mem_cgroup != from)
goto out_unlock;
+ anon = PageAnon(page);
+
spin_lock_irqsave(&from->move_lock, flags);
- if (!PageAnon(page) && page_mapped(page)) {
+ if (!anon && 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);
}
+ /*
+ * move_lock grabbed above and caller set from->moving_account, so
+ * mem_cgroup_update_page_stat() will serialize updates to PageDirty.
+ * So mapping should be stable for dirty pages.
+ */
+ if (!anon && PageDirty(page)) {
+ struct address_space *mapping = page_mapping(page);
+
+ if (mapping_cap_account_dirty(mapping)) {
+ __this_cpu_sub(from->stat->count[MEM_CGROUP_STAT_DIRTY],
+ nr_pages);
+ __this_cpu_add(to->stat->count[MEM_CGROUP_STAT_DIRTY],
+ nr_pages);
+ }
+ }
+
if (PageWriteback(page)) {
__this_cpu_sub(from->stat->count[MEM_CGROUP_STAT_WRITEBACK],
nr_pages);
spin_unlock(&mc.lock);
}
-static int mem_cgroup_can_attach(struct cgroup_subsys_state *css,
- struct cgroup_taskset *tset)
+static int mem_cgroup_can_attach(struct cgroup_taskset *tset)
{
- struct task_struct *p = cgroup_taskset_first(tset);
- int ret = 0;
- struct mem_cgroup *memcg = mem_cgroup_from_css(css);
+ struct cgroup_subsys_state *css;
+ struct mem_cgroup *memcg;
+ struct mem_cgroup *from;
+ struct task_struct *leader, *p;
+ struct mm_struct *mm;
unsigned long move_flags;
+ int ret = 0;
+
+ /* charge immigration isn't supported on the default hierarchy */
+ if (cgroup_subsys_on_dfl(memory_cgrp_subsys))
+ return 0;
+
+ /*
+ * Multi-process migrations only happen on the default hierarchy
+ * where charge immigration is not used. Perform charge
+ * immigration if @tset contains a leader and whine if there are
+ * multiple.
+ */
+ p = NULL;
+ cgroup_taskset_for_each_leader(leader, css, tset) {
+ WARN_ON_ONCE(p);
+ p = leader;
+ memcg = mem_cgroup_from_css(css);
+ }
+ if (!p)
+ return 0;
/*
* We are now commited to this value whatever it is. Changes in this
* So we need to save it, and keep it going.
*/
move_flags = READ_ONCE(memcg->move_charge_at_immigrate);
- if (move_flags) {
- struct mm_struct *mm;
- struct mem_cgroup *from = mem_cgroup_from_task(p);
+ if (!move_flags)
+ return 0;
- VM_BUG_ON(from == memcg);
+ from = mem_cgroup_from_task(p);
- mm = get_task_mm(p);
- if (!mm)
- return 0;
- /* We move charges only when we move a owner of the mm */
- if (mm->owner == p) {
- VM_BUG_ON(mc.from);
- VM_BUG_ON(mc.to);
- VM_BUG_ON(mc.precharge);
- VM_BUG_ON(mc.moved_charge);
- VM_BUG_ON(mc.moved_swap);
-
- spin_lock(&mc.lock);
- mc.from = from;
- mc.to = memcg;
- mc.flags = move_flags;
- spin_unlock(&mc.lock);
- /* We set mc.moving_task later */
-
- ret = mem_cgroup_precharge_mc(mm);
- if (ret)
- mem_cgroup_clear_mc();
- }
- mmput(mm);
+ VM_BUG_ON(from == memcg);
+
+ mm = get_task_mm(p);
+ if (!mm)
+ return 0;
+ /* We move charges only when we move a owner of the mm */
+ if (mm->owner == p) {
+ VM_BUG_ON(mc.from);
+ VM_BUG_ON(mc.to);
+ VM_BUG_ON(mc.precharge);
+ VM_BUG_ON(mc.moved_charge);
+ VM_BUG_ON(mc.moved_swap);
+
+ spin_lock(&mc.lock);
+ mc.from = from;
+ mc.to = memcg;
+ mc.flags = move_flags;
+ spin_unlock(&mc.lock);
+ /* We set mc.moving_task later */
+
+ ret = mem_cgroup_precharge_mc(mm);
+ if (ret)
+ mem_cgroup_clear_mc();
}
+ mmput(mm);
return ret;
}
-static void mem_cgroup_cancel_attach(struct cgroup_subsys_state *css,
- struct cgroup_taskset *tset)
+static void mem_cgroup_cancel_attach(struct cgroup_taskset *tset)
{
if (mc.to)
mem_cgroup_clear_mc();
atomic_dec(&mc.from->moving_account);
}
-static void mem_cgroup_move_task(struct cgroup_subsys_state *css,
- struct cgroup_taskset *tset)
+static void mem_cgroup_move_task(struct cgroup_taskset *tset)
{
- struct task_struct *p = cgroup_taskset_first(tset);
+ struct cgroup_subsys_state *css;
+ struct task_struct *p = cgroup_taskset_first(tset, &css);
struct mm_struct *mm = get_task_mm(p);
if (mm) {
mem_cgroup_clear_mc();
}
#else /* !CONFIG_MMU */
-static int mem_cgroup_can_attach(struct cgroup_subsys_state *css,
- struct cgroup_taskset *tset)
+static int mem_cgroup_can_attach(struct cgroup_taskset *tset)
{
return 0;
}
-static void mem_cgroup_cancel_attach(struct cgroup_subsys_state *css,
- struct cgroup_taskset *tset)
+static void mem_cgroup_cancel_attach(struct cgroup_taskset *tset)
{
}
-static void mem_cgroup_move_task(struct cgroup_subsys_state *css,
- struct cgroup_taskset *tset)
+static void mem_cgroup_move_task(struct cgroup_taskset *tset)
{
}
#endif
* guarantees that @root doesn't have any children, so turning it
* on for the root memcg is enough.
*/
- if (cgroup_on_dfl(root_css->cgroup))
+ if (cgroup_subsys_on_dfl(memory_cgrp_subsys))
root_mem_cgroup->use_hierarchy = true;
else
root_mem_cgroup->use_hierarchy = false;
static u64 memory_current_read(struct cgroup_subsys_state *css,
struct cftype *cft)
{
- return mem_cgroup_usage(mem_cgroup_from_css(css), false);
+ struct mem_cgroup *memcg = mem_cgroup_from_css(css);
+
+ return (u64)page_counter_read(&memcg->memory) * PAGE_SIZE;
}
static int memory_low_show(struct seq_file *m, void *v)
memcg->high = high;
+ memcg_wb_domain_size_changed(memcg);
return nbytes;
}
if (err)
return err;
+ memcg_wb_domain_size_changed(memcg);
return nbytes;
}
static struct cftype memory_files[] = {
{
.name = "current",
+ .flags = CFTYPE_NOT_ON_ROOT,
.read_u64 = memory_current_read,
},
{
{
.name = "events",
.flags = CFTYPE_NOT_ON_ROOT,
+ .file_offset = offsetof(struct mem_cgroup, events_file),
.seq_show = memory_events_show,
},
{ } /* terminate */
.css_alloc = mem_cgroup_css_alloc,
.css_online = mem_cgroup_css_online,
.css_offline = mem_cgroup_css_offline,
+ .css_released = mem_cgroup_css_released,
.css_free = mem_cgroup_css_free,
.css_reset = mem_cgroup_css_reset,
.can_attach = mem_cgroup_can_attach,
.early_init = 0,
};
-/**
- * mem_cgroup_events - count memory events against a cgroup
- * @memcg: the memory cgroup
- * @idx: the event index
- * @nr: the number of events to account for
- */
-void mem_cgroup_events(struct mem_cgroup *memcg,
- enum mem_cgroup_events_index idx,
- unsigned int nr)
-{
- this_cpu_add(memcg->stat->events[idx], nr);
-}
-
/**
* mem_cgroup_low - check if memory consumption is below the normal range
* @root: the highest ancestor to consider
* the page lock, which serializes swap cache removal, which
* in turn serializes uncharging.
*/
+ VM_BUG_ON_PAGE(!PageLocked(page), page);
if (page->mem_cgroup)
goto out;
+
+ if (do_swap_account) {
+ swp_entry_t ent = { .val = page_private(page), };
+ unsigned short id = lookup_swap_cgroup_id(ent);
+
+ rcu_read_lock();
+ memcg = mem_cgroup_from_id(id);
+ if (memcg && !css_tryget_online(&memcg->css))
+ memcg = NULL;
+ rcu_read_unlock();
+ }
}
if (PageTransHuge(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_migrate - migrate a charge to another page
+ * mem_cgroup_replace_page - migrate a charge to another page
* @oldpage: currently charged page
* @newpage: page to transfer the charge to
- * @lrucare: either or 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.
+ * Either or both pages might be on the LRU already.
*/
-void mem_cgroup_migrate(struct page *oldpage, struct page *newpage,
- bool lrucare)
+void mem_cgroup_replace_page(struct page *oldpage, struct page *newpage)
{
struct mem_cgroup *memcg;
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 (newpage->mem_cgroup)
return;
- /*
- * Swapcache readahead pages can get migrated before being
- * charged, and migration from compaction can happen to an
- * uncharged page when the PFN walker finds a page that
- * reclaim just put back on the LRU but has not released yet.
- */
+ /* Swapcache readahead pages can get replaced before being charged */
memcg = oldpage->mem_cgroup;
if (!memcg)
return;
- if (lrucare)
- lock_page_lru(oldpage, &isolated);
-
+ lock_page_lru(oldpage, &isolated);
oldpage->mem_cgroup = NULL;
+ unlock_page_lru(oldpage, isolated);
- if (lrucare)
- unlock_page_lru(oldpage, isolated);
-
- commit_charge(newpage, memcg, lrucare);
+ commit_charge(newpage, memcg, true);
}
/*
if (!mem_cgroup_is_root(memcg))
page_counter_uncharge(&memcg->memory, 1);
+ /*
+ * Interrupts should be disabled here because the caller holds the
+ * mapping->tree_lock lock which is taken with interrupts-off. It is
+ * important here to have the interrupts disabled because it is the
+ * only synchronisation we have for udpating the per-CPU variables.
+ */
local_lock_irqsave(event_lock, flags);
- /* Caller disabled preemption with mapping->tree_lock */
+#ifndef CONFIG_PREEMPT_RT_BASE
+ VM_BUG_ON(!irqs_disabled());
+#endif
mem_cgroup_charge_statistics(memcg, page, -1);
memcg_check_events(memcg, page);
local_unlock_irqrestore(event_lock, flags);
Code Review / kvmfornfv.git / blobdiff