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-rw-r--r--mm/memcontrol.c54
1 files changed, 38 insertions, 16 deletions
diff --git a/mm/memcontrol.c b/mm/memcontrol.c
index 0b1a32cbd74d..c39a177bb641 100644
--- a/mm/memcontrol.c
+++ b/mm/memcontrol.c
@@ -359,7 +359,7 @@ enum charge_type {
static void mem_cgroup_get(struct mem_cgroup *mem);
static void mem_cgroup_put(struct mem_cgroup *mem);
static struct mem_cgroup *parent_mem_cgroup(struct mem_cgroup *mem);
-static void drain_all_stock_async(void);
+static void drain_all_stock_async(struct mem_cgroup *mem);
static struct mem_cgroup_per_zone *
mem_cgroup_zoneinfo(struct mem_cgroup *mem, int nid, int zid)
@@ -1671,7 +1671,7 @@ static int mem_cgroup_hierarchical_reclaim(struct mem_cgroup *root_mem,
if (victim == root_mem) {
loop++;
if (loop >= 1)
- drain_all_stock_async();
+ drain_all_stock_async(root_mem);
if (loop >= 2) {
/*
* If we have not been able to reclaim
@@ -1934,9 +1934,11 @@ struct memcg_stock_pcp {
struct mem_cgroup *cached; /* this never be root cgroup */
unsigned int nr_pages;
struct work_struct work;
+ unsigned long flags;
+#define FLUSHING_CACHED_CHARGE (0)
};
static DEFINE_PER_CPU(struct memcg_stock_pcp, memcg_stock);
-static atomic_t memcg_drain_count;
+static DEFINE_MUTEX(percpu_charge_mutex);
/*
* Try to consume stocked charge on this cpu. If success, one page is consumed
@@ -1984,6 +1986,7 @@ static void drain_local_stock(struct work_struct *dummy)
{
struct memcg_stock_pcp *stock = &__get_cpu_var(memcg_stock);
drain_stock(stock);
+ clear_bit(FLUSHING_CACHED_CHARGE, &stock->flags);
}
/*
@@ -2008,26 +2011,45 @@ static void refill_stock(struct mem_cgroup *mem, unsigned int nr_pages)
* expects some charges will be back to res_counter later but cannot wait for
* it.
*/
-static void drain_all_stock_async(void)
+static void drain_all_stock_async(struct mem_cgroup *root_mem)
{
- int cpu;
- /* This function is for scheduling "drain" in asynchronous way.
- * The result of "drain" is not directly handled by callers. Then,
- * if someone is calling drain, we don't have to call drain more.
- * Anyway, WORK_STRUCT_PENDING check in queue_work_on() will catch if
- * there is a race. We just do loose check here.
+ int cpu, curcpu;
+ /*
+ * If someone calls draining, avoid adding more kworker runs.
*/
- if (atomic_read(&memcg_drain_count))
+ if (!mutex_trylock(&percpu_charge_mutex))
return;
/* Notify other cpus that system-wide "drain" is running */
- atomic_inc(&memcg_drain_count);
get_online_cpus();
+ /*
+ * Get a hint for avoiding draining charges on the current cpu,
+ * which must be exhausted by our charging. It is not required that
+ * this be a precise check, so we use raw_smp_processor_id() instead of
+ * getcpu()/putcpu().
+ */
+ curcpu = raw_smp_processor_id();
for_each_online_cpu(cpu) {
struct memcg_stock_pcp *stock = &per_cpu(memcg_stock, cpu);
- schedule_work_on(cpu, &stock->work);
+ struct mem_cgroup *mem;
+
+ if (cpu == curcpu)
+ continue;
+
+ mem = stock->cached;
+ if (!mem)
+ continue;
+ if (mem != root_mem) {
+ if (!root_mem->use_hierarchy)
+ continue;
+ /* check whether "mem" is under tree of "root_mem" */
+ if (!css_is_ancestor(&mem->css, &root_mem->css))
+ continue;
+ }
+ if (!test_and_set_bit(FLUSHING_CACHED_CHARGE, &stock->flags))
+ schedule_work_on(cpu, &stock->work);
}
put_online_cpus();
- atomic_dec(&memcg_drain_count);
+ mutex_unlock(&percpu_charge_mutex);
/* We don't wait for flush_work */
}
@@ -2035,9 +2057,9 @@ static void drain_all_stock_async(void)
static void drain_all_stock_sync(void)
{
/* called when force_empty is called */
- atomic_inc(&memcg_drain_count);
+ mutex_lock(&percpu_charge_mutex);
schedule_on_each_cpu(drain_local_stock);
- atomic_dec(&memcg_drain_count);
+ mutex_unlock(&percpu_charge_mutex);
}
/*