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=-0.8 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_NONE, SPF_PASS 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 64EFBC2BB1D for ; Thu, 12 Mar 2020 22:32:41 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id 26FB5206FA for ; Thu, 12 Mar 2020 22:32:41 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=kernel.org header.i=@kernel.org header.b="2u1oozTC" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 26FB5206FA Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=linux-foundation.org Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=owner-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix) id AB6D76B0005; Thu, 12 Mar 2020 18:32:40 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id A3FED6B0006; Thu, 12 Mar 2020 18:32:40 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 92FF16B0007; Thu, 12 Mar 2020 18:32:40 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0216.hostedemail.com [216.40.44.216]) by kanga.kvack.org (Postfix) with ESMTP id 781396B0005 for ; Thu, 12 Mar 2020 18:32:40 -0400 (EDT) Received: from smtpin16.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay05.hostedemail.com (Postfix) with ESMTP id 2E4DA1833820B for ; Thu, 12 Mar 2020 22:32:40 +0000 (UTC) X-FDA: 76588160880.16.dock20_3458d0261ad40 X-HE-Tag: dock20_3458d0261ad40 X-Filterd-Recvd-Size: 2758 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by imf13.hostedemail.com (Postfix) with ESMTP for ; Thu, 12 Mar 2020 22:32:39 +0000 (UTC) Received: from localhost.localdomain (c-73-231-172-41.hsd1.ca.comcast.net [73.231.172.41]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 9CBE920637; Thu, 12 Mar 2020 22:32:38 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1584052358; bh=Lza2wvGcb07HstOGtM3uhmYGNmaJ9AzJsigH30FF04c=; h=Date:From:To:Cc:Subject:In-Reply-To:References:From; b=2u1oozTCjgkspj5iC+6D6dBZcbBYV0TdViO75UI0pVKxRdVf6Yf6B4BTFuO9ld+3c FWyX5qGQKQEAa+V2jnHQ7SjZ+sx9hTOKyZ3zlops4671t8fqYEwGRPRLTbWhnm9JHW ARFpFWy5RudMAXMCwm65x/vy1QbG2Yolwf7LkPvo= Date: Thu, 12 Mar 2020 15:32:38 -0700 From: Andrew Morton To: David Rientjes Cc: Tetsuo Handa , Vlastimil Babka , Michal Hocko , linux-kernel@vger.kernel.org, linux-mm@kvack.org Subject: Re: [patch] mm, oom: prevent soft lockup on memcg oom for UP systems Message-Id: <20200312153238.c8d25ea6994b54a2c4d5ae1f@linux-foundation.org> In-Reply-To: References: <993e7783-60e9-ba03-b512-c829b9e833fd@i-love.sakura.ne.jp> <202003120012.02C0CEUB043533@www262.sakura.ne.jp> X-Mailer: Sylpheed 3.5.1 (GTK+ 2.24.31; x86_64-pc-linux-gnu) Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII 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 Thu, 12 Mar 2020 11:07:15 -0700 (PDT) David Rientjes wrote: > On Thu, 12 Mar 2020, Tetsuo Handa wrote: > > > > On Thu, 12 Mar 2020, Tetsuo Handa wrote: > > > > > If you have an alternate patch to try, we can test it. But since this > > > > > cond_resched() is needed anyway, I'm not sure it will change the result. > > > > > > > > schedule_timeout_killable(1) is an alternate patch to try; I don't think > > > > that this cond_resched() is needed anyway. > > > > > > > > > > You are suggesting schedule_timeout_killable(1) in shrink_node_memcgs()? > > > > > > > Andrew Morton also mentioned whether cond_resched() in shrink_node_memcgs() > > is enough. But like you mentioned, > > > > It passes our testing because this is where the allocator is looping while > the victim is trying to exit if only it could be scheduled. What happens if the allocator has SCHED_FIFO?