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=-8.4 required=3.0 tests=DKIMWL_WL_MED,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI, SPF_HELO_NONE,SPF_PASS,USER_IN_DEF_DKIM_WL 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 E3473C2BB1D for ; Tue, 17 Mar 2020 19:01:00 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id 9BC8720674 for ; Tue, 17 Mar 2020 19:01:00 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=google.com header.i=@google.com header.b="OwjZi9Xd" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 9BC8720674 Authentication-Results: mail.kernel.org; dmarc=fail (p=reject dis=none) header.from=google.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=owner-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix) id 224C66B0005; Tue, 17 Mar 2020 15:01:00 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id 1D7446B0006; Tue, 17 Mar 2020 15:01:00 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 112F46B0007; Tue, 17 Mar 2020 15:01:00 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0107.hostedemail.com [216.40.44.107]) by kanga.kvack.org (Postfix) with ESMTP id EEDC26B0005 for ; Tue, 17 Mar 2020 15:00:59 -0400 (EDT) Received: from smtpin14.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay03.hostedemail.com (Postfix) with ESMTP id D1A72824556B for ; Tue, 17 Mar 2020 19:00:59 +0000 (UTC) X-FDA: 76605771438.14.tent26_5fef47dd92000 X-HE-Tag: tent26_5fef47dd92000 X-Filterd-Recvd-Size: 3877 Received: from mail-lj1-f196.google.com (mail-lj1-f196.google.com [209.85.208.196]) by imf07.hostedemail.com (Postfix) with ESMTP for ; Tue, 17 Mar 2020 19:00:59 +0000 (UTC) Received: by mail-lj1-f196.google.com with SMTP id y17so2971327ljk.12 for ; Tue, 17 Mar 2020 12:00:59 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20161025; h=mime-version:references:in-reply-to:from:date:message-id:subject:to :cc; bh=Y0VT78F3dxvDrSDRU0usDCfY5N57Y8ZF/aY+SJ6VytM=; b=OwjZi9XdTCjPbZ21iUQ+IU6Y08aeWbK57bHoTZtarsLaihwXamXErvGEo5E5/lfKQi JA0/JuuWsaMWjZsm2kvtbqaBaKj8T079+Yc5qX6+8BIheZJ69AlxqQfOHW2R04ErokWz qZ1JaoSphttl82iL+gNmJz/GLhogkmpLchnAEXx26muc/dAoSBImwlxEiMevGb0t4C4c bT4wrzepziqNgpVPnQtwgpGC3THGNnsgGrJj9GkpZ32OsQZ1kzLAjGyjmRtaVWL5RKs2 06iaqxrEbgrz3QY1Uz1TCI6cA7I20q+3SYGou+DxBiFMstmHXJZCUc3iRzYKcT+rmgx5 4koQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:mime-version:references:in-reply-to:from:date :message-id:subject:to:cc; bh=Y0VT78F3dxvDrSDRU0usDCfY5N57Y8ZF/aY+SJ6VytM=; b=BZXm2piXNI/nlVyuipPKqg+7FIod2NLFgBlktES+x74BeXiCUVzHX+snP372FCHdLm k1062fNBfXTm/Ihnl7vbUPCOPCzX3aABk13uZVYjuOI+yF6cZi/Zxe2ygW62JZamO9pJ 7tozrWow38+KnCrW46qZz9IKdEC2jSPGBMENqDzmjIi2V0/Up/8uxB/bVirliMKl3MNy cGEEAhMFQ4Nk4AEncAa0cHC5qsJWxLW/rTDSAuuilTnLXXJLghbRrNknZI6Sn/08JfoK nrKQJ9tCK5rVVROl2Yq/VXcuNpjBUYB5bHb8F3SnOM28Vyx0hYPfQQlPPmtUuxYXOMja lMtg== X-Gm-Message-State: ANhLgQ2oAb1nWhw34RQrwRCIFiBEDUxgLOtUSMUaty6vyl/sAUDGd8kk 9E6tOQH/QGwVUx056bBYh2BN6pMBiTyxWI5abDZzrw== X-Google-Smtp-Source: ADFU+vubEo1FoPiUFrFFOhisoKyjnOC4/HwIRLoy2w6txWLdz8YeKk8qBtOEaqefkrRGIstTHEo3U9SETX3VzvSur+M= X-Received: by 2002:a2e:b0f7:: with SMTP id h23mr141835ljl.56.1584471656937; Tue, 17 Mar 2020 12:00:56 -0700 (PDT) MIME-Version: 1.0 References: <20200310221938.GF8447@dhcp22.suse.cz> In-Reply-To: From: Ami Fischman Date: Tue, 17 Mar 2020 12:00:45 -0700 Message-ID: Subject: Re: [patch] mm, oom: make a last minute check to prevent unnecessary memcg oom kills To: Robert Kolchmeyer Cc: David Rientjes , Michal Hocko , Andrew Morton , Vlastimil Babka , linux-kernel@vger.kernel.org, linux-mm@kvack.org Content-Type: text/plain; charset="UTF-8" X-Bogosity: Ham, tests=bogofilter, spamicity=0.009161, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: On Tue, Mar 17, 2020 at 11:26 AM Robert Kolchmeyer wrote: > > On Tue, Mar 10, 2020 at 3:54 PM David Rientjes wrote: > > > > Robert, could you elaborate on the user-visible effects of this issue that > > caused it to initially get reported? > > Ami (now cc'ed) knows more, but here is my understanding. Robert's description of the mechanics we observed is accurate. We discovered this regression in the oom-killer's behavior when attempting to upgrade our system. The fraction of the system that went unhealthy due to this issue was approximately equal to the _sum_ of all other causes of unhealth, which are many and varied, but each of which contribute only a small amount of unhealth. This issue forced a rollback to the previous kernel where we ~never see this behavior, returning our unhealth levels to the previous background levels. Cheers, -a