From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-pg0-f71.google.com (mail-pg0-f71.google.com [74.125.83.71]) by kanga.kvack.org (Postfix) with ESMTP id 0A21C6B0260 for ; Thu, 7 Dec 2017 07:39:29 -0500 (EST) Received: by mail-pg0-f71.google.com with SMTP id f8so5099660pgs.9 for ; Thu, 07 Dec 2017 04:39:29 -0800 (PST) Received: from www262.sakura.ne.jp (www262.sakura.ne.jp. [2001:e42:101:1:202:181:97:72]) by mx.google.com with ESMTPS id w16si2279429plp.416.2017.12.07.04.39.27 for (version=TLS1 cipher=AES128-SHA bits=128/128); Thu, 07 Dec 2017 04:39:27 -0800 (PST) From: Tetsuo Handa Subject: [PATCH] mm,oom: use ALLOC_OOM for OOM victim's last second allocation Date: Thu, 7 Dec 2017 20:42:20 +0900 Message-Id: <1512646940-3388-1-git-send-email-penguin-kernel@I-love.SAKURA.ne.jp> Sender: owner-linux-mm@kvack.org List-ID: To: akpm@linux-foundation.org Cc: linux-mm@kvack.org, Tetsuo Handa , Andrea Arcangeli , David Rientjes , Johannes Weiner , Manish Jaggi , Michal Hocko , Oleg Nesterov , Vladimir Davydov Manish Jaggi noticed that running LTP oom01/oom02 ltp tests with high core count causes random kernel panics when an OOM victim which consumed memory in a way the OOM reaper does not help was selected by the OOM killer [1]. Since commit 696453e66630ad45 ("mm, oom: task_will_free_mem should skip oom_reaped tasks") changed task_will_free_mem(current) in out_of_memory() to return false as soon as MMF_OOM_SKIP is set, many threads sharing the victim's mm were not able to try allocation from memory reserves after the OOM reaper gave up reclaiming memory. Therefore, this patch allows OOM victims to use ALLOC_OOM watermark for last second allocation attempt. [1] http://lkml.kernel.org/r/e6c83a26-1d59-4afd-55cf-04e58bdde188@caviumnetworks.com Fixes: 696453e66630ad45 ("mm, oom: task_will_free_mem should skip oom_reaped tasks") Signed-off-by: Tetsuo Handa Reported-by: Manish Jaggi Acked-by: Michal Hocko Cc: Michal Hocko Cc: Oleg Nesterov Cc: Vladimir Davydov Cc: David Rientjes Cc: Andrea Arcangeli Cc: Johannes Weiner --- mm/page_alloc.c | 39 +++++++++++++++++++++++++++++---------- 1 file changed, 29 insertions(+), 10 deletions(-) diff --git a/mm/page_alloc.c b/mm/page_alloc.c index 73f5d45..5d054a4 100644 --- a/mm/page_alloc.c +++ b/mm/page_alloc.c @@ -3309,6 +3309,10 @@ void warn_alloc(gfp_t gfp_mask, nodemask_t *nodemask, const char *fmt, ...) return page; } +static struct page *alloc_pages_before_oomkill(gfp_t gfp_mask, + unsigned int order, + const struct alloc_context *ac); + static inline struct page * __alloc_pages_may_oom(gfp_t gfp_mask, unsigned int order, const struct alloc_context *ac, unsigned long *did_some_progress) @@ -3334,16 +3338,7 @@ void warn_alloc(gfp_t gfp_mask, nodemask_t *nodemask, const char *fmt, ...) return NULL; } - /* - * Go through the zonelist yet one more time, keep very high watermark - * here, this is only to catch a parallel oom killing, we must fail if - * we're still under heavy pressure. But make sure that this reclaim - * attempt shall not depend on __GFP_DIRECT_RECLAIM && !__GFP_NORETRY - * allocation which will never fail due to oom_lock already held. - */ - page = get_page_from_freelist((gfp_mask | __GFP_HARDWALL) & - ~__GFP_DIRECT_RECLAIM, order, - ALLOC_WMARK_HIGH|ALLOC_CPUSET, ac); + page = alloc_pages_before_oomkill(gfp_mask, order, ac); if (page) goto out; @@ -3755,6 +3750,30 @@ bool gfp_pfmemalloc_allowed(gfp_t gfp_mask) return !!__gfp_pfmemalloc_flags(gfp_mask); } +static struct page *alloc_pages_before_oomkill(gfp_t gfp_mask, + unsigned int order, + const struct alloc_context *ac) +{ + /* + * Go through the zonelist yet one more time, keep very high watermark + * here, this is only to catch a parallel oom killing, we must fail if + * we're still under heavy pressure. But make sure that this reclaim + * attempt shall not depend on __GFP_DIRECT_RECLAIM && !__GFP_NORETRY + * allocation which will never fail due to oom_lock already held. + * Also, make sure that OOM victims can try ALLOC_OOM watermark + * in case they haven't tried ALLOC_OOM watermark. + */ + int alloc_flags = ALLOC_CPUSET | ALLOC_WMARK_HIGH; + int reserve_flags; + + gfp_mask |= __GFP_HARDWALL; + gfp_mask &= ~__GFP_DIRECT_RECLAIM; + reserve_flags = __gfp_pfmemalloc_flags(gfp_mask); + if (reserve_flags) + alloc_flags = reserve_flags; + return get_page_from_freelist(gfp_mask, order, alloc_flags, ac); +} + /* * Checks whether it makes sense to retry the reclaim to make a forward progress * for the given allocation request. -- 1.8.3.1 -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: email@kvack.org