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=-5.2 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS,USER_AGENT_SANE_1 autolearn=unavailable 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 00CA7C7618F for ; Sat, 27 Jul 2019 01:58:16 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id 92F6A2173C for ; Sat, 27 Jul 2019 01:58:15 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 92F6A2173C Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=redhat.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=owner-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix) id E8E056B0003; Fri, 26 Jul 2019 21:58:14 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id E3DA08E0003; Fri, 26 Jul 2019 21:58:14 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id D056F8E0002; Fri, 26 Jul 2019 21:58:14 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from mail-qk1-f199.google.com (mail-qk1-f199.google.com [209.85.222.199]) by kanga.kvack.org (Postfix) with ESMTP id B0A7A6B0003 for ; Fri, 26 Jul 2019 21:58:14 -0400 (EDT) Received: by mail-qk1-f199.google.com with SMTP id m198so46567853qke.22 for ; Fri, 26 Jul 2019 18:58:14 -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:organization:message-id:date:user-agent :mime-version:in-reply-to:content-transfer-encoding:content-language; bh=c7CB+rfFECYt0ajTPN6miUrq6o9XtuXTa3aW8yoJHuo=; b=XR9GgAVlkScFuEpDMfzUAK8TVbfil0y806+9GQc629hY2xWt5wQ9IVWXsN5vCsWbAk q85TJmncH6Y9mttxyIaaHVpt17X4k3HLYj42PhE42AaRmT2s9T04pLjALHc6afejEGul U7jecpzE0wx0xY76R/y3JwaKEQas2u1lt4v2zRMC4di3/jr/o/8SeBVOlEyyGtCPxKzQ xaqje7x1xpeG9ycl8jffRsd+aHNvTBOeOIOXJ5WKiHg74DJ8YaTR73UfY8mvfbYojgal 5+yo26FC4OFOwGevYsUlftBUYqaKliLDKRH5HiXESPGKaY3jehfX/GGFc5vZKWF4FGND A1eA== X-Original-Authentication-Results: mx.google.com; spf=pass (google.com: domain of longman@redhat.com designates 209.132.183.28 as permitted sender) smtp.mailfrom=longman@redhat.com; dmarc=pass (p=NONE sp=NONE dis=NONE) header.from=redhat.com X-Gm-Message-State: APjAAAVy+HKwhCQtWoxqPswaSI1ChXiZMFAlll2h2eETL6LEZxhYczxu LH3KJhgNT90czMjfOgBG8CHzly2AbKvXgb1iS8Snqyiz7Ed3R7GLrvXUPjkHQgoOczdgHKlqEVG ox9pjM6kURZxJNDlB1uRi03ZB+HMqP6iS0ZD/X+U5uBRfaT09l0rNci9fkyIQx3hJPw== X-Received: by 2002:a05:620a:1228:: with SMTP id v8mr20628308qkj.357.1564192694417; Fri, 26 Jul 2019 18:58:14 -0700 (PDT) X-Google-Smtp-Source: APXvYqxXQSb9E7KizFx8SkvwqOpGxmffAD+luTdV9Isyrpux2ssMMVPhLiaV7MKoynA6/nNlHow5 X-Received: by 2002:a05:620a:1228:: with SMTP id v8mr20628285qkj.357.1564192693782; Fri, 26 Jul 2019 18:58:13 -0700 (PDT) ARC-Seal: i=1; a=rsa-sha256; t=1564192693; cv=none; d=google.com; s=arc-20160816; b=BsDXo7cl2tcZ8Kqpyyb4R9NybFUZqA3LMG5u7dYQ3LPjySBsseQhq59ZcYxISrvUjI nFtWfHjVxI9nSzdYwqnL+U8B1EN+hkgMkvoxgHW+jLB5t+DfcyL+wgwy6Ivh820PeR+u v/3fzW5r5RomiF5PZ3SZVGN/RJzX0N6e0zMnCdzrIy/dZWKX9PHDjsVodcqiap6f/PgJ yEaW8W8abr6q3kX02trxNWEp/A4NPk/4SzDzw6k6pmu0c03IvkhVCBQu6tsLIP0WZ5P+ 5pIXQBIF95XzoEwNfeWeN826wX2/Ek5+T6+UQpmDeSlLcdOnjmpvPsd/Q0ip33NJ6FgE mQTQ== ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=arc-20160816; h=content-language:content-transfer-encoding:in-reply-to:mime-version :user-agent:date:message-id:organization:from:references:cc:to :subject; bh=c7CB+rfFECYt0ajTPN6miUrq6o9XtuXTa3aW8yoJHuo=; b=m+W5jhPWsrYCOkhNr9fQoHUoOkHGBdW30bx19sF1d++7oCKV6kGI7jrbe9yiKhG+Ct MLooU5arXn1KJRN+r9LLNXeArZCEId2Vyqalp7WceW/QhFDmC8yXOBDwurwHUfAhpmuy aoVema0fitzrZOWPPmaT89SypIsjht1fdoXkujrBs0o76gZtToBhRRMDgOlZy5bHGNgb X0FOgMM7+ftzVdps96HEs3DrgSLhFWsc90VCpb+vWvKjUXGtY10gksWYKZzEa8KT/alt Fg5s5JTVwMRcUctEeV6t49LvLM/abdXqDCfm5XT7koALqN+fevV4EcROJp7VN2bJDAlt ui6w== ARC-Authentication-Results: i=1; mx.google.com; spf=pass (google.com: domain of longman@redhat.com designates 209.132.183.28 as permitted sender) smtp.mailfrom=longman@redhat.com; dmarc=pass (p=NONE sp=NONE dis=NONE) header.from=redhat.com Received: from mx1.redhat.com (mx1.redhat.com. [209.132.183.28]) by mx.google.com with ESMTPS id w15si36809286qvc.73.2019.07.26.18.58.13 for (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Fri, 26 Jul 2019 18:58:13 -0700 (PDT) Received-SPF: pass (google.com: domain of longman@redhat.com designates 209.132.183.28 as permitted sender) client-ip=209.132.183.28; Authentication-Results: mx.google.com; spf=pass (google.com: domain of longman@redhat.com designates 209.132.183.28 as permitted sender) smtp.mailfrom=longman@redhat.com; dmarc=pass (p=NONE sp=NONE dis=NONE) header.from=redhat.com Received: from smtp.corp.redhat.com (int-mx03.intmail.prod.int.phx2.redhat.com [10.5.11.13]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mx1.redhat.com (Postfix) with ESMTPS id D2AA03082141; Sat, 27 Jul 2019 01:58:12 +0000 (UTC) Received: from llong.remote.csb (ovpn-124-85.rdu2.redhat.com [10.10.124.85]) by smtp.corp.redhat.com (Postfix) with ESMTP id E001C60A35; Sat, 27 Jul 2019 01:58:11 +0000 (UTC) Subject: Re: [PATCH] sched/core: Don't use dying mm as active_mm for kernel threads To: Peter Zijlstra , Ingo Molnar Cc: linux-kernel@vger.kernel.org, linux-mm@kvack.org, Andrew Morton , Phil Auld References: <20190726234541.3771-1-longman@redhat.com> From: Waiman Long Organization: Red Hat Message-ID: Date: Fri, 26 Jul 2019 21:58:11 -0400 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:60.0) Gecko/20100101 Thunderbird/60.7.2 MIME-Version: 1.0 In-Reply-To: <20190726234541.3771-1-longman@redhat.com> Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: 7bit Content-Language: en-US X-Scanned-By: MIMEDefang 2.79 on 10.5.11.13 X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.5.110.42]); Sat, 27 Jul 2019 01:58:12 +0000 (UTC) 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 7/26/19 7:45 PM, Waiman Long wrote: > It was found that a dying mm_struct where the owning task has exited can > stay on as active_mm of kernel threads as long as no other user tasks > run on those CPUs that use it as active_mm. This prolongs the life time > of dying mm holding up memory and other resources that cannot be freed. > > Fix that by forcing the kernel threads to use init_mm as the active_mm > if the previous active_mm is dying. > > Signed-off-by: Waiman Long > --- > kernel/sched/core.c | 13 +++++++++++-- > mm/init-mm.c | 2 ++ > 2 files changed, 13 insertions(+), 2 deletions(-) Sorry, I didn't realize that mm->owner depends on CONFIG_MEMCG. I will need to refresh the patch and send out v2 when I am done testing. Cheers, Longman