The charging path currently starts out with OOM condition checks when OOM is the rarest possible case. Rearrange this code to run OOM/task dying checks only after trying the percpu charge and the res_counter charge and bail out before entering reclaim. Attempting a charge does not hurt an (oom-)killed task as much as every charge attempt having to check OOM conditions. Also, only check __GFP_NOFAIL when the charge would actually fail. Signed-off-by: Johannes Weiner <hannes@xxxxxxxxxxx> --- mm/memcontrol.c | 31 ++++++++++++++++--------------- 1 file changed, 16 insertions(+), 15 deletions(-) diff --git a/mm/memcontrol.c b/mm/memcontrol.c index 75dfeb8fa98b..6ce59146fec7 100644 --- a/mm/memcontrol.c +++ b/mm/memcontrol.c @@ -2598,21 +2598,6 @@ static int mem_cgroup_try_charge(struct mem_cgroup *memcg, if (mem_cgroup_is_root(memcg)) goto done; - /* - * Unlike in global OOM situations, memcg is not in a physical - * memory shortage. Allow dying and OOM-killed tasks to - * bypass the last charges so that they can exit quickly and - * free their memory. - */ - if (unlikely(test_thread_flag(TIF_MEMDIE) || - fatal_signal_pending(current))) - goto bypass; - - if (unlikely(task_in_memcg_oom(current))) - goto nomem; - - if (gfp_mask & __GFP_NOFAIL) - oom = false; retry: if (consume_stock(memcg, nr_pages)) goto done; @@ -2634,6 +2619,19 @@ retry: goto retry; } + /* + * Unlike in global OOM situations, memcg is not in a physical + * memory shortage. Allow dying and OOM-killed tasks to + * bypass the last charges so that they can exit quickly and + * free their memory. + */ + if (unlikely(test_thread_flag(TIF_MEMDIE) || + fatal_signal_pending(current))) + goto bypass; + + if (unlikely(task_in_memcg_oom(current))) + goto nomem; + if (!(gfp_mask & __GFP_WAIT)) goto nomem; @@ -2662,6 +2660,9 @@ retry: if (mem_cgroup_wait_acct_move(mem_over_limit)) goto retry; + if (gfp_mask & __GFP_NOFAIL) + goto bypass; + if (fatal_signal_pending(current)) goto bypass; -- 1.9.2 -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@xxxxxxxxx. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: <a href=mailto:"dont@xxxxxxxxx";> email@xxxxxxxxx </a>