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 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id C8F81C433EF for ; Tue, 19 Oct 2021 08:49:42 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id 5D22A61212 for ; Tue, 19 Oct 2021 08:49:42 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.4.1 mail.kernel.org 5D22A61212 Authentication-Results: mail.kernel.org; dmarc=fail (p=quarantine dis=none) header.from=suse.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=kvack.org Received: by kanga.kvack.org (Postfix) id ED39B900003; Tue, 19 Oct 2021 04:49:41 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id E83EB6B0071; Tue, 19 Oct 2021 04:49:41 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id D72B4900003; Tue, 19 Oct 2021 04:49:41 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0156.hostedemail.com [216.40.44.156]) by kanga.kvack.org (Postfix) with ESMTP id CAA186B006C for ; Tue, 19 Oct 2021 04:49:41 -0400 (EDT) Received: from smtpin40.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay02.hostedemail.com (Postfix) with ESMTP id 870FC3C675 for ; Tue, 19 Oct 2021 08:49:41 +0000 (UTC) X-FDA: 78712563762.40.23C71E5 Received: from smtp-out2.suse.de (smtp-out2.suse.de [195.135.220.29]) by imf08.hostedemail.com (Postfix) with ESMTP id EE7AC30000AB for ; Tue, 19 Oct 2021 08:49:37 +0000 (UTC) Received: from relay2.suse.de (relay2.suse.de [149.44.160.134]) by smtp-out2.suse.de (Postfix) with ESMTP id 337A11FCA3; Tue, 19 Oct 2021 08:49:40 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=suse.com; s=susede1; t=1634633380; h=from:from:reply-to:date:date:message-id:message-id:to:to:cc:cc: mime-version:mime-version:content-type:content-type: in-reply-to:in-reply-to:references:references; bh=XPwmj/o6n9ykv9XbtNvWH5jIFBBxobggF5mrBJrzaOI=; b=CziZ8O745mlkeu314jrm3XHnf3nMStZFP21MvFp8qAH3CeVI8ZEssk6h4spttaOLGBn+V4 GY4QKYFX8SBEAuigRErLE1YypTQh0h4wf6PGqCMFRKXhiAuj+syDyugIiT4DGDhvGfHz2r zVXG7CncMJv59I36BTIdl91S37t0zCY= Received: from suse.cz (unknown [10.100.201.86]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by relay2.suse.de (Postfix) with ESMTPS id 05932A3B84; Tue, 19 Oct 2021 08:49:39 +0000 (UTC) Date: Tue, 19 Oct 2021 10:49:37 +0200 From: Michal Hocko To: Vasily Averin Cc: Johannes Weiner , Vladimir Davydov , Andrew Morton , Roman Gushchin , Uladzislau Rezki , Vlastimil Babka , Shakeel Butt , Mel Gorman , cgroups@vger.kernel.org, linux-mm@kvack.org, linux-kernel@vger.kernel.org, kernel@openvz.org Subject: Re: [PATCH memcg 0/1] false global OOM triggered by memcg-limited task Message-ID: References: <9d10df01-0127-fb40-81c3-cc53c9733c3e@virtuozzo.com> <6b751abe-aa52-d1d8-2631-ec471975cc3a@virtuozzo.com> <339ae4b5-6efd-8fc2-33f1-2eb3aee71cb2@virtuozzo.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <339ae4b5-6efd-8fc2-33f1-2eb3aee71cb2@virtuozzo.com> X-Rspamd-Queue-Id: EE7AC30000AB Authentication-Results: imf08.hostedemail.com; dkim=pass header.d=suse.com header.s=susede1 header.b=CziZ8O74; spf=pass (imf08.hostedemail.com: domain of mhocko@suse.com designates 195.135.220.29 as permitted sender) smtp.mailfrom=mhocko@suse.com; dmarc=pass (policy=quarantine) header.from=suse.com X-Stat-Signature: p5o1ax5j9fnzyunakq3fsr99wwdyx7rt X-Rspamd-Server: rspam05 X-HE-Tag: 1634633377-928739 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 Tue 19-10-21 09:30:18, Vasily Averin wrote: [...] > With my patch ("memcg: prohibit unconditional exceeding the limit of dying tasks") try_charge_memcg() can fail: > a) due to fatal signal > b) when mem_cgroup_oom -> mem_cgroup_out_of_memory -> out_of_memory() returns false (when select_bad_process() found nothing) > > To handle a) we can follow to your suggestion and skip excution of out_of_memory() in pagefault_out_of memory() > To handle b) we can go to retry: if mem_cgroup_oom() return OOM_FAILED. How is b) possible without current being killed? Do we allow remote charging? > However all these cases can be successfully handled by my new patch > "memcg: prevent false global OOM triggered by memcg limited task" > and I think it is better solution. I have already replied to your approach in other email. Sorry our replies have crossed. -- Michal Hocko SUSE Labs