From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-io0-f197.google.com (mail-io0-f197.google.com [209.85.223.197]) by kanga.kvack.org (Postfix) with ESMTP id 11CF56B0033 for ; Fri, 3 Nov 2017 10:08:46 -0400 (EDT) Received: by mail-io0-f197.google.com with SMTP id f20so8798812ioj.2 for ; Fri, 03 Nov 2017 07:08:46 -0700 (PDT) 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 b7si2230763itj.17.2017.11.03.07.08.43 for (version=TLS1 cipher=AES128-SHA bits=128/128); Fri, 03 Nov 2017 07:08:44 -0700 (PDT) Subject: Re: [PATCH] mm,page_alloc: Update comment for last second allocation attempt. From: Tetsuo Handa References: <201711022015.BBE95844.QOHtJFMLFOOSVF@I-love.SAKURA.ne.jp> <1509716789-7218-1-git-send-email-penguin-kernel@I-love.SAKURA.ne.jp> <20171103135739.svmtesmgynshjuth@dhcp22.suse.cz> In-Reply-To: <20171103135739.svmtesmgynshjuth@dhcp22.suse.cz> Message-Id: <201711032308.GHE78150.LQOFOtVFFJMHSO@I-love.SAKURA.ne.jp> Date: Fri, 3 Nov 2017 23:08:35 +0900 Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Sender: owner-linux-mm@kvack.org List-ID: To: mhocko@kernel.org Cc: akpm@linux-foundation.org, linux-mm@kvack.org, linux-kernel@vger.kernel.org, aarcange@redhat.com, hannes@cmpxchg.org Michal Hocko wrote: > On Fri 03-11-17 22:46:29, Tetsuo Handa wrote: > [...] > > diff --git a/mm/page_alloc.c b/mm/page_alloc.c > > index c274960..547e9cb 100644 > > --- a/mm/page_alloc.c > > +++ b/mm/page_alloc.c > > @@ -3312,11 +3312,10 @@ void warn_alloc(gfp_t gfp_mask, nodemask_t *nodemask, const char *fmt, ...) > > } > > > > /* > > - * 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. > > + * This allocation attempt must not depend on __GFP_DIRECT_RECLAIM && > > + * !__GFP_NORETRY allocation which will never fail due to oom_lock > > + * already held. And since this allocation attempt does not sleep, > > + * there is no reason we must use high watermark here. > > */ > > page = get_page_from_freelist((gfp_mask | __GFP_HARDWALL) & > > ~__GFP_DIRECT_RECLAIM, order, > > Which patch does this depend on? This patch is preparation for "mm,oom: Move last second allocation to inside the OOM killer." patch in order to use changelog close to what you suggested. That is, I will move this comment and get_page_from_freelist() together to alloc_pages_before_oomkill(), after we recorded why using ALLOC_WMARK_HIGH. -- 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