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 EC872C433F5 for ; Wed, 20 Oct 2021 13:53:23 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id 662026128B for ; Wed, 20 Oct 2021 13:53:23 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.4.1 mail.kernel.org 662026128B Authentication-Results: mail.kernel.org; dmarc=fail (p=quarantine dis=none) header.from=virtuozzo.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=kvack.org Received: by kanga.kvack.org (Postfix) id EEDD3900002; Wed, 20 Oct 2021 09:53:22 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id E9EF86B0072; Wed, 20 Oct 2021 09:53:22 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id D8B68900002; Wed, 20 Oct 2021 09:53:22 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0065.hostedemail.com [216.40.44.65]) by kanga.kvack.org (Postfix) with ESMTP id C5A496B0071 for ; Wed, 20 Oct 2021 09:53:22 -0400 (EDT) Received: from smtpin39.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay03.hostedemail.com (Postfix) with ESMTP id 7CEF68249980 for ; Wed, 20 Oct 2021 13:53:22 +0000 (UTC) X-FDA: 78716957844.39.1A3D159 Received: from relay.sw.ru (relay.sw.ru [185.231.240.75]) by imf16.hostedemail.com (Postfix) with ESMTP id 34D50F00008F for ; Wed, 20 Oct 2021 13:53:19 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=virtuozzo.com; s=relay; h=Content-Type:MIME-Version:Date:Message-ID:From: Subject; bh=rwHiENVsU+PAyCq6R1IGWsHjEjN7UJ7KRwgz3+7hO5Y=; b=TXtVaBAvdC04JlrqI NKpx1GC690M5p+aueGyGido9fpz0EtSupAgjPy2+2FCv/K9yxQ5YAFhVhpRuduJnse480vwpxvco9 f+Zm8GCu8Rv71SX6ne3seHmN7MS4qLdk25HFf5+oG9eozcYhOPv4UjskRhZFiB0wy5UCtSLcbJMlE =; Received: from [172.29.1.17] by relay.sw.ru with esmtp (Exim 4.94.2) (envelope-from ) id 1mdC1q-006bpi-TY; Wed, 20 Oct 2021 16:53:14 +0300 Subject: Re: [PATCH memcg 1/3] mm: do not firce global OOM from inside dying tasks To: Michal Hocko Cc: Johannes Weiner , Vladimir Davydov , Andrew Morton , Roman Gushchin , Uladzislau Rezki , Vlastimil Babka , Shakeel Butt , Mel Gorman , Tetsuo Handa , cgroups@vger.kernel.org, linux-mm@kvack.org, linux-kernel@vger.kernel.org, kernel@openvz.org References: <2c13c739-7282-e6f4-da0a-c0b69e68581e@virtuozzo.com> From: Vasily Averin Message-ID: Date: Wed, 20 Oct 2021 16:52:53 +0300 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:78.0) Gecko/20100101 Thunderbird/78.13.0 MIME-Version: 1.0 In-Reply-To: Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: 7bit X-Stat-Signature: cn3x4fs9s7ni13rdmstqwtno1s93qz9h X-Rspamd-Server: rspam05 X-Rspamd-Queue-Id: 34D50F00008F Authentication-Results: imf16.hostedemail.com; dkim=pass header.d=virtuozzo.com header.s=relay header.b=TXtVaBAv; spf=pass (imf16.hostedemail.com: domain of vvs@virtuozzo.com designates 185.231.240.75 as permitted sender) smtp.mailfrom=vvs@virtuozzo.com; dmarc=pass (policy=quarantine) header.from=virtuozzo.com X-HE-Tag: 1634737999-160119 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 20.10.2021 15:33, Michal Hocko wrote: > s@firce@force@ > > On Wed 20-10-21 15:12:19, Vasily Averin wrote: >> There is no sense to force global OOM if current task is dying. > > This really begs for much more information. Feel free to get an > inspiration from my previous attempt to achieve something similar. > In minimum it is important to mention that the OOM killer is already > handled at the page allocator level for the global OOM and at the > charging level for the memcg one. Both have much more information > about the scope of allocation/charge request. This means that either the > OOM killer has been invoked properly and didn't lead to the allocation > success or it has been skipped because it couldn't have been invoked. > In both cases triggering it from here is pointless and even harmful. > > Another argument is that it is more reasonable to let killed task die > rather than hit the oom killer and retry the allocation. Thank you, I'll update patch description later, this time I would like to clarify patch content. >> Signed-off-by: Vasily Averin >> --- >> mm/oom_kill.c | 3 +++ >> 1 file changed, 3 insertions(+) >> >> diff --git a/mm/oom_kill.c b/mm/oom_kill.c >> index 831340e7ad8b..1deef8c7a71b 100644 >> --- a/mm/oom_kill.c >> +++ b/mm/oom_kill.c >> @@ -1137,6 +1137,9 @@ void pagefault_out_of_memory(void) >> if (mem_cgroup_oom_synchronize(true)) >> return; >> >> + if (fatal_signal_pending(current)) >> + return; >> + >> if (!mutex_trylock(&oom_lock)) >> return; >> out_of_memory(&oc); >> -- >> 2.32.0 >