diff options
| -rw-r--r-- | mm/memcontrol.c | 12 |
1 files changed, 10 insertions, 2 deletions
diff --git a/mm/memcontrol.c b/mm/memcontrol.c index f4ec4e7ca4cd..930de9437271 100644 --- a/mm/memcontrol.c +++ b/mm/memcontrol.c @@ -2091,6 +2091,7 @@ struct memcg_stock_pcp { #define FLUSHING_CACHED_CHARGE (0) }; static DEFINE_PER_CPU(struct memcg_stock_pcp, memcg_stock); +static DEFINE_MUTEX(percpu_charge_mutex); /* * Try to consume stocked charge on this cpu. If success, one page is consumed @@ -2197,8 +2198,7 @@ static void drain_all_stock(struct mem_cgroup *root_mem, bool sync) for_each_online_cpu(cpu) { struct memcg_stock_pcp *stock = &per_cpu(memcg_stock, cpu); - if (mem_cgroup_same_or_subtree(root_mem, stock->cached) && - test_bit(FLUSHING_CACHED_CHARGE, &stock->flags)) + if (test_bit(FLUSHING_CACHED_CHARGE, &stock->flags)) flush_work(&stock->work); } out: @@ -2213,14 +2213,22 @@ out: */ static void drain_all_stock_async(struct mem_cgroup *root_mem) { + /* + * If someone calls draining, avoid adding more kworker runs. + */ + if (!mutex_trylock(&percpu_charge_mutex)) + return; drain_all_stock(root_mem, false); + mutex_unlock(&percpu_charge_mutex); } /* This is a synchronous drain interface. */ static void drain_all_stock_sync(struct mem_cgroup *root_mem) { /* called when force_empty is called */ + mutex_lock(&percpu_charge_mutex); drain_all_stock(root_mem, true); + mutex_unlock(&percpu_charge_mutex); } /* |