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=-2.5 required=3.0 tests=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 DD137C5B57D for ; Tue, 2 Jul 2019 21:27:11 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id A0DB0218A3 for ; Tue, 2 Jul 2019 21:27:11 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org A0DB0218A3 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=i-love.sakura.ne.jp Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=owner-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix) id 338576B0003; Tue, 2 Jul 2019 17:27:11 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id 2C28D8E0003; Tue, 2 Jul 2019 17:27:11 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 13C538E0001; Tue, 2 Jul 2019 17:27:11 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from mail-pg1-f200.google.com (mail-pg1-f200.google.com [209.85.215.200]) by kanga.kvack.org (Postfix) with ESMTP id CEB976B0003 for ; Tue, 2 Jul 2019 17:27:10 -0400 (EDT) Received: by mail-pg1-f200.google.com with SMTP id d3so183078pgc.9 for ; Tue, 02 Jul 2019 14:27:10 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-original-authentication-results:x-gm-message-state:subject:to:cc :references:from:message-id:date:user-agent:mime-version:in-reply-to :content-language:content-transfer-encoding; bh=3A2JKYyF6Wow+uyBjAseYYHmwKeOnuwwqwzbEFG4G9s=; b=KpIkfmUlpkoIxmuULtGtwcsjUC8VWKXyMkfZCosqEZqFtXcJDAylDE55dwDE6HffL7 05AgEhwCVNaMS0qD6ERygDNOfCvsJOTOsSTY7en7fk8CrjkCi84VAW4Aijg/a1zmE9A3 hM/fss6GhU0rbLaceJ3F6YxtD1UQS5/MGe2gEcua7nQbb/vN7KoqcZKuG52WHYcnD2On Kq6OZYIluddFsKVemDVLJ1y4VfRWpkJ9faNxndfnQqMvHgf879KQ0f0j30cbZ1O0x8sp stihSaS8QDK0rQa2s/BaLonpOWnLWVo34yLDbBCo4lr0eQL+Dw+84sLeG+/Gq02BShO7 T2sA== X-Original-Authentication-Results: mx.google.com; spf=pass (google.com: best guess record for domain of penguin-kernel@i-love.sakura.ne.jp designates 202.181.97.72 as permitted sender) smtp.mailfrom=penguin-kernel@i-love.sakura.ne.jp X-Gm-Message-State: APjAAAV1zoAT76oYy/o1OvXUsKNiH85U8GOA//PZeBV+MrTidbb0DsN1 AhqmHO3JPPjwVKEYoi5GhWIfJkZszEk3ckxB6v1RAQfOVhH9BLooc6f4JJUbRs49A2saJEv0Lej i4NogVUGp9tT02M8/AMZDJxMyK0E9tXZGyHNdvhQnBEylxYAFl2qra8pSESee9e3skQ== X-Received: by 2002:a17:902:8b82:: with SMTP id ay2mr35151693plb.164.1562102830406; Tue, 02 Jul 2019 14:27:10 -0700 (PDT) X-Google-Smtp-Source: APXvYqyuP+utd0cm3A4N3hpvL0YPzOZ8VD+OF56xRxzmfdz5ykM/6+HGhYUnUHyL4NdwNV9l4wUF X-Received: by 2002:a17:902:8b82:: with SMTP id ay2mr35151655plb.164.1562102829796; Tue, 02 Jul 2019 14:27:09 -0700 (PDT) ARC-Seal: i=1; a=rsa-sha256; t=1562102829; cv=none; d=google.com; s=arc-20160816; b=p7QQYKrWz/ulaaXvqFyXB+/zX/OIOrgM6ojfKivGXqV3HHyWU9jo2YPpHqDsfwOT9K rPW+O1dXiFs3m6kff1fmnD44QUiCYhyT/SEe+d+k2GaDPjZwqoZpWqoRB5zjjzI3N+qF Nx7c18nkQhSt7mz4cv6yhJ/iFcUWRqvwXHDTiDsu04hIIMVU+WFzST5TZk0X0YDrQEC6 O8P3HVoIFrmcvVt9fBisFwYCkELUda56fcllBtEJLi5vvIsOlmbLpVzspguFWQ3nGtXG /luRWyw9yT16KyYwTYh6bzZRQ4VWb/JFD+c8Hf87PCQZ3gSdiUAvnzKWLuHm0y2HEwYf yGFQ== ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=arc-20160816; h=content-transfer-encoding:content-language:in-reply-to:mime-version :user-agent:date:message-id:from:references:cc:to:subject; bh=3A2JKYyF6Wow+uyBjAseYYHmwKeOnuwwqwzbEFG4G9s=; b=0BhcYMBW4yqSH0zw4U2CfDVCQ2/6tpkdn3Mozth+AOHhnqe9yYysOvndD1aqc+dlwa idw+YzUJ1m1CDqNlNMTnOg972qOauRYPWClYzBPDpQ+gunFvvXcGkS4GbpZ1aqp1Vp5O LqRQFJSGDwJXIyOXEfxnhtSvipTktwBfW7JGxhPV8J994vD8wCN1aV/tVhkA7C582+sR ZT1QJjTL9UfAFw1GzAHr+kUtUPe214z3fhM/svc7daPP3QFXQR9sD2AxFM8+NedF2be0 rco4I7drFusOZq0Ir4GNVl2I88H1q0rU1boxg+A880ynx+tcVIvHr6qQVDwq072PidyQ y6Sg== ARC-Authentication-Results: i=1; mx.google.com; spf=pass (google.com: best guess record for domain of penguin-kernel@i-love.sakura.ne.jp designates 202.181.97.72 as permitted sender) smtp.mailfrom=penguin-kernel@i-love.sakura.ne.jp Received: from www262.sakura.ne.jp (www262.sakura.ne.jp. [202.181.97.72]) by mx.google.com with ESMTPS id w9si37587plp.118.2019.07.02.14.27.09 for (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Tue, 02 Jul 2019 14:27:09 -0700 (PDT) Received-SPF: pass (google.com: best guess record for domain of penguin-kernel@i-love.sakura.ne.jp designates 202.181.97.72 as permitted sender) client-ip=202.181.97.72; Authentication-Results: mx.google.com; spf=pass (google.com: best guess record for domain of penguin-kernel@i-love.sakura.ne.jp designates 202.181.97.72 as permitted sender) smtp.mailfrom=penguin-kernel@i-love.sakura.ne.jp Received: from fsav302.sakura.ne.jp (fsav302.sakura.ne.jp [153.120.85.133]) by www262.sakura.ne.jp (8.15.2/8.15.2) with ESMTP id x62LR2VM045843; Wed, 3 Jul 2019 06:27:02 +0900 (JST) (envelope-from penguin-kernel@i-love.sakura.ne.jp) Received: from www262.sakura.ne.jp (202.181.97.72) by fsav302.sakura.ne.jp (F-Secure/fsigk_smtp/530/fsav302.sakura.ne.jp); Wed, 03 Jul 2019 06:27:02 +0900 (JST) X-Virus-Status: clean(F-Secure/fsigk_smtp/530/fsav302.sakura.ne.jp) Received: from [192.168.1.8] (softbank126012062002.bbtec.net [126.12.62.2]) (authenticated bits=0) by www262.sakura.ne.jp (8.15.2/8.15.2) with ESMTPSA id x62LQvFp045817 (version=TLSv1.2 cipher=AES256-SHA bits=256 verify=NO); Wed, 3 Jul 2019 06:27:02 +0900 (JST) (envelope-from penguin-kernel@i-love.sakura.ne.jp) Subject: Re: [PATCH] mm: mempolicy: don't select exited threads as OOM victims To: Michal Hocko Cc: Shakeel Butt , linux-mm@kvack.org References: <1561807474-10317-1-git-send-email-penguin-kernel@I-love.SAKURA.ne.jp> <20190701111708.GP6376@dhcp22.suse.cz> <15099126-5d0f-51eb-7134-46c5c2db3bf0@i-love.sakura.ne.jp> <20190701131736.GX6376@dhcp22.suse.cz> <20190701134859.GZ6376@dhcp22.suse.cz> <20190701140434.GA6376@dhcp22.suse.cz> <20190701141647.GB6376@dhcp22.suse.cz> <0d81f46e-0b5f-0792-637f-fa88468f33cf@i-love.sakura.ne.jp> <20190702135148.GF978@dhcp22.suse.cz> From: Tetsuo Handa Message-ID: <0c26d2d5-19b1-7915-e47e-60d86a946d09@i-love.sakura.ne.jp> Date: Wed, 3 Jul 2019 06:26:55 +0900 User-Agent: Mozilla/5.0 (Windows NT 6.3; WOW64; rv:60.0) Gecko/20100101 Thunderbird/60.7.2 MIME-Version: 1.0 In-Reply-To: <20190702135148.GF978@dhcp22.suse.cz> Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: 7bit 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 2019/07/02 22:51, Michal Hocko wrote: >>> I do not see any strong reason to keep the current ordering. OOM victim >>> check is trivial so it shouldn't add a visible overhead for few >>> unkillable tasks that we might encounter. >>> >> >> Yes if we can tolerate that there can be only one OOM victim for !memcg OOM events >> (because an OOM victim in a different OOM context will hit "goto abort;" path). > > You are right. Considering that we now have a guarantee of a forward > progress then this should be tolerateable (a victim in a disjoint > numaset will go away and other one can go ahead and trigger its own > OOM). But it might take very long period before MMF_OOM_SKIP is set by the OOM reaper or exit_mmap(). Until MMF_OOM_SKIP is set, OOM events from disjoint numaset can't make forward progress.