From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-2.3 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,USER_AGENT_SANE_1 autolearn=no autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id C727EC54FD0 for ; Mon, 27 Apr 2020 05:03:28 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id 4AEAB2075B for ; Mon, 27 Apr 2020 05:03:27 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 4AEAB2075B Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=I-love.SAKURA.ne.jp Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=owner-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix) id 71B018E0005; Mon, 27 Apr 2020 01:03:27 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id 6CBD48E0001; Mon, 27 Apr 2020 01:03:27 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 5E1DE8E0005; Mon, 27 Apr 2020 01:03:27 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0198.hostedemail.com [216.40.44.198]) by kanga.kvack.org (Postfix) with ESMTP id 471928E0001 for ; Mon, 27 Apr 2020 01:03:27 -0400 (EDT) Received: from smtpin17.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay02.hostedemail.com (Postfix) with ESMTP id F10EB499616 for ; Mon, 27 Apr 2020 05:03:26 +0000 (UTC) X-FDA: 76752441612.17.value65_754e5f9a6e356 X-HE-Tag: value65_754e5f9a6e356 X-Filterd-Recvd-Size: 2818 Received: from www262.sakura.ne.jp (www262.sakura.ne.jp [202.181.97.72]) by imf46.hostedemail.com (Postfix) with ESMTP for ; Mon, 27 Apr 2020 05:03:25 +0000 (UTC) Received: from fsav305.sakura.ne.jp (fsav305.sakura.ne.jp [153.120.85.136]) by www262.sakura.ne.jp (8.15.2/8.15.2) with ESMTP id 03R53HRg000862; Mon, 27 Apr 2020 14:03:17 +0900 (JST) (envelope-from penguin-kernel@I-love.SAKURA.ne.jp) Received: from www262.sakura.ne.jp (202.181.97.72) by fsav305.sakura.ne.jp (F-Secure/fsigk_smtp/550/fsav305.sakura.ne.jp); Mon, 27 Apr 2020 14:03:17 +0900 (JST) X-Virus-Status: clean(F-Secure/fsigk_smtp/550/fsav305.sakura.ne.jp) Received: from [192.168.1.9] (M106072142033.v4.enabler.ne.jp [106.72.142.33]) (authenticated bits=0) by www262.sakura.ne.jp (8.15.2/8.15.2) with ESMTPSA id 03R53GLu000850 (version=TLSv1.2 cipher=DHE-RSA-AES256-SHA bits=256 verify=NO); Mon, 27 Apr 2020 14:03:17 +0900 (JST) (envelope-from penguin-kernel@I-love.SAKURA.ne.jp) Subject: Re: [patch] mm, oom: stop reclaiming if GFP_ATOMIC will start failing soon To: David Rientjes Cc: Andrew Morton , Vlastimil Babka , linux-mm@kvack.org, linux-kernel@vger.kernel.org References: <20200425172706.26b5011293e8dc77b1dccaf3@linux-foundation.org> From: Tetsuo Handa Message-ID: Date: Mon, 27 Apr 2020 14:03:15 +0900 User-Agent: Mozilla/5.0 (Windows NT 6.3; WOW64; rv:68.0) Gecko/20100101 Thunderbird/68.7.0 MIME-Version: 1.0 In-Reply-To: Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: 7bit X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: On 2020/04/27 12:12, David Rientjes wrote: > Tetsuo: the specific allocation that triggers a page allocation failure is > not interesting; we have tens of thousands of examples. Each example is > simply the unlucky last GFP_ATOMIC allocation that fails; the interesting > point is the amount of free memory. In other words, when free memory is > below ALLOC_HIGH watermarks, we assume that we have depleted memory > reserves *faster* than when user allocations started to fail. In the > interest of userspace being responsive, we should oom kill here. My interest is, which function (and which process if process context) is [ab]using GFP_ATOMIC (or __GFP_MEMALLOC) allocations enough to hit memory allocation failure. GFP_NOWAIT (or __GFP_NOMEMALLOC) could be used if that allocation can't sleep and can't shortly recover free memory.