diff --git a/mm/memcontrol.c b/mm/memcontrol.c index 0140629b7cb20e..0cc7ee52d6bda9 100644 --- a/mm/memcontrol.c +++ b/mm/memcontrol.c @@ -2214,6 +2214,9 @@ static void drain_stock(struct memcg_stock_pcp *stock) { struct mem_cgroup *old = stock->cached; + if (!old) + return; + if (stock->nr_pages) { page_counter_uncharge(&old->memory, stock->nr_pages); if (do_memsw_account()) @@ -2221,6 +2224,8 @@ static void drain_stock(struct memcg_stock_pcp *stock) css_put_many(&old->css, stock->nr_pages); stock->nr_pages = 0; } + + css_put(&old->css); stock->cached = NULL; } @@ -2256,6 +2261,7 @@ static void refill_stock(struct mem_cgroup *memcg, unsigned int nr_pages) stock = this_cpu_ptr(&memcg_stock); if (stock->cached != memcg) { /* reset if necessary */ drain_stock(stock); + css_get(&memcg->css); stock->cached = memcg; } stock->nr_pages += nr_pages;