#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",
};
*/
bool use_hierarchy;
+ /* protected by memcg_oom_lock */
bool oom_lock;
- atomic_t under_oom;
- atomic_t oom_wakeups;
+ int under_oom;
int swappiness;
/* OOM-Killer disable */
* 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)
atomic_t numainfo_updating;
#endif
+#ifdef CONFIG_CGROUP_WRITEBACK
+ struct list_head cgwb_list;
+ struct wb_domain cgwb_domain;
+#endif
+
/* List of events which userspace want to receive */
struct list_head event_list;
spinlock_t event_list_lock;
return &memcg->css;
}
+/**
+ * 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_on_dfl(memcg->css.cgroup))
+ memcg = root_mem_cgroup;
+
+ rcu_read_unlock();
+ return &memcg->css;
+}
+
static struct mem_cgroup_per_zone *
mem_cgroup_page_zoneinfo(struct mem_cgroup *memcg, struct page *page)
{
long val = 0;
int cpu;
- get_online_cpus();
- for_each_online_cpu(cpu)
+ 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();
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;
}
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);
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(chosen, gfp_mask, order, points, totalpages,
+ memcg, NULL, "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)
return memcg;
}
+EXPORT_SYMBOL(mem_cgroup_begin_page_stat);
/**
* mem_cgroup_end_page_stat - finish a page state statistics transaction
rcu_read_unlock();
}
+EXPORT_SYMBOL(mem_cgroup_end_page_stat);
/**
* mem_cgroup_update_page_stat - update page state statistics
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;
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
+ * @pavail: out parameter for number of available pages
+ * @pdirty: out parameter for number of dirty pages
+ * @pwriteback: out parameter for number of pages under writeback
+ *
+ * Determine the numbers of available, dirty, and writeback pages in @wb's
+ * memcg. Dirty and writeback are self-explanatory. Available is a bit
+ * more involved.
+ *
+ * A memcg's headroom is "min(max, high) - used". The available memory is
+ * calculated as the lowest headroom of itself and the ancestors plus the
+ * number of pages already being used for file pages. Note that this
+ * doesn't consider the actual amount of available memory in the system.
+ * The caller should further cap *@pavail accordingly.
+ */
+void mem_cgroup_wb_stats(struct bdi_writeback *wb, unsigned long *pavail,
+ unsigned long *pdirty, unsigned long *pwriteback)
+{
+ struct mem_cgroup *memcg = mem_cgroup_from_css(wb->memcg_css);
+ struct mem_cgroup *parent;
+ unsigned long head_room = PAGE_COUNTER_MAX;
+ unsigned long file_pages;
+
+ *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);
+
+ file_pages = mem_cgroup_nr_lru_pages(memcg, (1 << LRU_INACTIVE_FILE) |
+ (1 << LRU_ACTIVE_FILE));
+ while ((parent = parent_mem_cgroup(memcg))) {
+ unsigned long ceiling = min(memcg->memory.limit, memcg->high);
+ unsigned long used = page_counter_read(&memcg->memory);
+
+ head_room = min(head_room, ceiling - min(ceiling, used));
+ memcg = parent;
+ }
+
+ *pavail = file_pages + head_room;
+}
+
+#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.
*
memcg->stat = alloc_percpu(struct mem_cgroup_stat_cpu);
if (!memcg->stat)
goto out_free;
+
+ if (memcg_wb_domain_init(memcg, GFP_KERNEL))
+ goto out_free_stat;
+
spin_lock_init(&memcg->pcp_counter_lock);
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_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
{
unsigned long flags;
int ret;
+ bool anon;
VM_BUG_ON(from == to);
VM_BUG_ON_PAGE(PageLRU(page), page);
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);
memcg->high = high;
+ memcg_wb_domain_size_changed(memcg);
return nbytes;
}
if (err)
return err;
+ memcg_wb_domain_size_changed(memcg);
return nbytes;
}
projects / cascardo / linux.git / blobdiff