From 7f822c24c2b32a9feafb33e3b9a9e23ef4278c2c Mon Sep 17 00:00:00 2001 From: Tejun Heo Date: Thu, 5 Nov 2015 18:46:20 -0800 Subject: [PATCH] memcg: drop unnecessary cold-path tests from __memcg_kmem_bypass() __memcg_kmem_bypass() decides whether a kmem allocation should be bypassed to the root memcg. Some conditions that it tests are valid criteria regarding who should be held accountable; however, there are a couple unnecessary tests for cold paths - __GFP_FAIL and fatal_signal_pending(). The previous patch updated try_charge() to handle both __GFP_FAIL and dying tasks correctly and the only thing these two tests are doing is making accounting less accurate and sprinkling tests for cold path conditions in the hot paths. There's nothing meaningful gained by these extra tests. This patch removes the two unnecessary tests from __memcg_kmem_bypass(). Signed-off-by: Tejun Heo Reviewed-by: Vladimir Davydov Acked-by: Michal Hocko Cc: Johannes Weiner Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- include/linux/memcontrol.h | 14 -------------- 1 file changed, 14 deletions(-) diff --git a/include/linux/memcontrol.h b/include/linux/memcontrol.h index d8174e8d6ab4..641bb60dd7db 100644 --- a/include/linux/memcontrol.h +++ b/include/linux/memcontrol.h @@ -781,24 +781,10 @@ static inline bool __memcg_kmem_bypass(gfp_t gfp) { if (!memcg_kmem_enabled()) return true; - if (gfp & __GFP_NOACCOUNT) return true; - /* - * __GFP_NOFAIL allocations will move on even if charging is not - * possible. Therefore we don't even try, and have this allocation - * unaccounted. We could in theory charge it forcibly, but we hope - * those allocations are rare, and won't be worth the trouble. - */ - if (gfp & __GFP_NOFAIL) - return true; if (in_interrupt() || (!current->mm) || (current->flags & PF_KTHREAD)) return true; - - /* If the test is dying, just let it go. */ - if (unlikely(fatal_signal_pending(current))) - return true; - return false; } -- 2.20.1