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Diffstat (limited to 'mm/memcontrol.c')
-rw-r--r--mm/memcontrol.c48
1 files changed, 31 insertions, 17 deletions
diff --git a/mm/memcontrol.c b/mm/memcontrol.c
index ae052b5e3315..175ec51c346d 100644
--- a/mm/memcontrol.c
+++ b/mm/memcontrol.c
@@ -1816,22 +1816,13 @@ static void drain_all_stock(struct mem_cgroup *root_memcg)
mutex_unlock(&percpu_charge_mutex);
}
-static int memcg_cpu_hotplug_callback(struct notifier_block *nb,
- unsigned long action,
- void *hcpu)
+static int memcg_hotplug_cpu_dead(unsigned int cpu)
{
- int cpu = (unsigned long)hcpu;
struct memcg_stock_pcp *stock;
- if (action == CPU_ONLINE)
- return NOTIFY_OK;
-
- if (action != CPU_DEAD && action != CPU_DEAD_FROZEN)
- return NOTIFY_OK;
-
stock = &per_cpu(memcg_stock, cpu);
drain_stock(stock);
- return NOTIFY_OK;
+ return 0;
}
static void reclaim_high(struct mem_cgroup *memcg,
@@ -1917,6 +1908,15 @@ retry:
current->flags & PF_EXITING))
goto force;
+ /*
+ * Prevent unbounded recursion when reclaim operations need to
+ * allocate memory. This might exceed the limits temporarily,
+ * but we prefer facilitating memory reclaim and getting back
+ * under the limit over triggering OOM kills in these cases.
+ */
+ if (unlikely(current->flags & PF_MEMALLOC))
+ goto force;
+
if (unlikely(task_in_memcg_oom(current)))
goto nomem;
@@ -2145,6 +2145,8 @@ struct memcg_kmem_cache_create_work {
struct work_struct work;
};
+static struct workqueue_struct *memcg_kmem_cache_create_wq;
+
static void memcg_kmem_cache_create_func(struct work_struct *w)
{
struct memcg_kmem_cache_create_work *cw =
@@ -2176,7 +2178,7 @@ static void __memcg_schedule_kmem_cache_create(struct mem_cgroup *memcg,
cw->cachep = cachep;
INIT_WORK(&cw->work, memcg_kmem_cache_create_func);
- schedule_work(&cw->work);
+ queue_work(memcg_kmem_cache_create_wq, &cw->work);
}
static void memcg_schedule_kmem_cache_create(struct mem_cgroup *memcg,
@@ -5765,16 +5767,28 @@ __setup("cgroup.memory=", cgroup_memory);
/*
* subsys_initcall() for memory controller.
*
- * Some parts like hotcpu_notifier() have to be initialized from this context
- * because of lock dependencies (cgroup_lock -> cpu hotplug) but basically
- * everything that doesn't depend on a specific mem_cgroup structure should
- * be initialized from here.
+ * Some parts like memcg_hotplug_cpu_dead() have to be initialized from this
+ * context because of lock dependencies (cgroup_lock -> cpu hotplug) but
+ * basically everything that doesn't depend on a specific mem_cgroup structure
+ * should be initialized from here.
*/
static int __init mem_cgroup_init(void)
{
int cpu, node;
- hotcpu_notifier(memcg_cpu_hotplug_callback, 0);
+#ifndef CONFIG_SLOB
+ /*
+ * Kmem cache creation is mostly done with the slab_mutex held,
+ * so use a special workqueue to avoid stalling all worker
+ * threads in case lots of cgroups are created simultaneously.
+ */
+ memcg_kmem_cache_create_wq =
+ alloc_ordered_workqueue("memcg_kmem_cache_create", 0);
+ BUG_ON(!memcg_kmem_cache_create_wq);
+#endif
+
+ cpuhp_setup_state_nocalls(CPUHP_MM_MEMCQ_DEAD, "mm/memctrl:dead", NULL,
+ memcg_hotplug_cpu_dead);
for_each_possible_cpu(cpu)
INIT_WORK(&per_cpu_ptr(&memcg_stock, cpu)->work,