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=-2.3 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS, USER_AGENT_SANE_1 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 EE9CAC433FF for ; Wed, 7 Aug 2019 21:12:49 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id C150C217D9 for ; Wed, 7 Aug 2019 21:12:49 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=cmpxchg-org.20150623.gappssmtp.com header.i=@cmpxchg-org.20150623.gappssmtp.com header.b="rZ0i7K+4" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1730454AbfHGVMs (ORCPT ); Wed, 7 Aug 2019 17:12:48 -0400 Received: from mail-pg1-f178.google.com ([209.85.215.178]:46783 "EHLO mail-pg1-f178.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1729714AbfHGVMs (ORCPT ); Wed, 7 Aug 2019 17:12:48 -0400 Received: by mail-pg1-f178.google.com with SMTP id w3so5614160pgt.13 for ; Wed, 07 Aug 2019 14:12:48 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=cmpxchg-org.20150623.gappssmtp.com; s=20150623; h=date:from:to:cc:subject:message-id:references:mime-version :content-disposition:in-reply-to:user-agent; bh=HDsbOqdqt6WL/tNlrJsj+N++Ozhrzy+jd8MDoupW4xM=; b=rZ0i7K+4dO7YAgZr7g3eTN78Jx4YSreaML2nif7MCjeuCG2DcmetfvCHzYeNrxmOvI GgNIgk9auMbqEEL4L2Dq9xyLKXeJMKWWeLM4AqNXM7Br7+IG2anIx5/oI+zxEGfohjvB v1zGLGk/Qlid4kz6oWC1tVPUNHQkwN67sJEI0W3zw1nH6nLbmXJXLircrwcOItO9oRbX TvYbSjDDcgzXn5vO5RhaOWZo/FQL/WpG6HO+tCEHlomMbyhrislSd4//md2/z6bniBmJ 8ZWDyU7PRL4sXRr65HxiDpbWjxA2+qAgo6lB/V7mYpK7VZHAmXLX/usE4cNGwbcvxUml yhRQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:date:from:to:cc:subject:message-id:references :mime-version:content-disposition:in-reply-to:user-agent; bh=HDsbOqdqt6WL/tNlrJsj+N++Ozhrzy+jd8MDoupW4xM=; b=m0xn9NNlparYS5cdfO6aSWkc8YUzCu0Lck8GAiRWeSjU39sVLRCyDdAFmJBzDgCFZ/ EWyRPyXkGIs5tdQM9ysYzbnI7SaMR7suuksjDUjDS7DSj1I+SjhJ2+LE+Tuc2vFgCFcF +ENqiSdGAgDBq0gjveLSqSnfe8gFNHT4Ds8N5vNIxyfrxtDemqBCoK0UFK9cfWmrrZ6d a9K/qBmJV5PCOJIcpw5XMHl9FPXf755Q5Tm6LYihMpgucY1FfhPzUbBY/ZBxK1/v7P91 yAUWTz176RRaL6LCDBG4UXGlRovxa7zlOK7QsC3m93ef7igFjKMC6LEOUv991FCLxyJw NX/Q== X-Gm-Message-State: APjAAAUwY6HpFs7XTWTDTspjfjJh5JO+3CXbMaCx6i01OPSNSR6fnrrP Z/+5bjjb7Uvw4ZzfNThAYG54Jg== X-Google-Smtp-Source: APXvYqzHU2Qv90JaGiam0/j3y7qiJAsqUy0QsTn9ntikZSQbDjZ92rTTHkhUSHGxO7ewruuC5ndDhw== X-Received: by 2002:a63:2b84:: with SMTP id r126mr9751854pgr.308.1565212367528; Wed, 07 Aug 2019 14:12:47 -0700 (PDT) Received: from localhost ([2620:10d:c091:500::1:f7c1]) by smtp.gmail.com with ESMTPSA id u16sm24716337pgm.83.2019.08.07.14.12.46 (version=TLS1_3 cipher=AEAD-AES256-GCM-SHA384 bits=256/256); Wed, 07 Aug 2019 14:12:46 -0700 (PDT) Date: Wed, 7 Aug 2019 17:12:45 -0400 From: Johannes Weiner To: Michal Hocko Cc: Suren Baghdasaryan , Vlastimil Babka , "Artem S. Tashkinov" , Andrew Morton , LKML , linux-mm Subject: Re: Let's talk about the elephant in the room - the Linux kernel's inability to gracefully handle low memory pressure Message-ID: <20190807211245.GA11071@cmpxchg.org> References: <20190805193148.GB4128@cmpxchg.org> <398f31f3-0353-da0c-fc54-643687bb4774@suse.cz> <20190806142728.GA12107@cmpxchg.org> <20190806143608.GE11812@dhcp22.suse.cz> <20190806220150.GA22516@cmpxchg.org> <20190807075927.GO11812@dhcp22.suse.cz> <20190807205138.GA24222@cmpxchg.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20190807205138.GA24222@cmpxchg.org> User-Agent: Mutt/1.12.0 (2019-05-25) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Wed, Aug 07, 2019 at 04:51:42PM -0400, Johannes Weiner wrote: > Per default, the OOM killer will engage after 15 seconds of at least > 80% memory pressure. These values are tunable via sysctls > vm.thrashing_oom_period and vm.thrashing_oom_level. Let's go with this: Per default, the OOM killer will engage after 15 seconds of at least 80% memory pressure. From experience, at 80% the user is experiencing multi-second reaction times. 15 seconds is chosen to be long enough to not OOM kill a short-lived spike that might resolve itself, yet short enough for users to not press the reset button just yet.