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 1ADEAC433EF for ; Wed, 20 Oct 2021 13:53:24 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id F21BB6128B for ; Wed, 20 Oct 2021 13:53:23 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230298AbhJTNzg (ORCPT ); Wed, 20 Oct 2021 09:55:36 -0400 Received: from relay.sw.ru ([185.231.240.75]:46986 "EHLO relay.sw.ru" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230160AbhJTNzf (ORCPT ); Wed, 20 Oct 2021 09:55:35 -0400 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 Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 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 >