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=-1.1 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, DKIM_VALID_AU,FREEMAIL_FORGED_FROMDOMAIN,FREEMAIL_FROM, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS autolearn=ham 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 44A5AC282CE for ; Thu, 23 May 2019 01:25:06 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id C9C5220B1F for ; Thu, 23 May 2019 01:25:04 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b="cj5+AGFc" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org C9C5220B1F Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=gmail.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=owner-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix) id AB2106B0003; Wed, 22 May 2019 21:25:04 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id A62BD6B0006; Wed, 22 May 2019 21:25:04 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 94FF46B0007; Wed, 22 May 2019 21:25:04 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from mail-it1-f199.google.com (mail-it1-f199.google.com [209.85.166.199]) by kanga.kvack.org (Postfix) with ESMTP id 71E916B0003 for ; Wed, 22 May 2019 21:25:04 -0400 (EDT) Received: by mail-it1-f199.google.com with SMTP id k8so3907633itd.4 for ; Wed, 22 May 2019 18:25:04 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:dkim-signature:mime-version:references :in-reply-to:from:date:message-id:subject:to:cc; bh=DwrwlKuIdoVYrJdyb0eyY3233BEFJTf1xEwDvRn1qmE=; b=kjQRTXGHTfUlYd3Nm3GuU6rHmWGK3Jaw3hNLrlHVBnnI52JE5ZPIIvFHXymG1hLYtA b5HZ/9qySg3mKhYdQsej1F7iClMnlaT7pFOQQ2VgCoHhjvuwgbcZEhkliYTBKRmRITn1 jd/A50VUGwCB4g6UX7EqwODmehq12p5dCbBwmCVsrb0cK056gUpfyi5f91bfzBKAmH4A sY69Kc82fQwly5LERVf8ErZ6lWlEb4+THle84ASO2nKViBiDPRE1qYjH0x6l754oe5B/ s1pFc0iDLeyb5Hr5ARz3ReLaJ3wgngJXxA1cMQ226cjsOZZkUZzaNXjv23rQWTfdERvd O5NA== X-Gm-Message-State: APjAAAVa1T+6qoAhXES6IUO5afhJ6MaxIo1sVeM1drD5kZiB8Fz9zXWM AVGYRgboK80hma4+pV3j2BK3pGLfKN9JyYZM3xOwY5D/32prFQBO2nu2k2tMomxHfj8qhxjSjoh ia2AEKSHYlWuqqWhRTjWNVtmVE10/UKu6tLtMr0s0JxsLhzNONvXqwu7TIegAbYcSfQ== X-Received: by 2002:a05:660c:492:: with SMTP id a18mr10962445itk.48.1558574704206; Wed, 22 May 2019 18:25:04 -0700 (PDT) X-Received: by 2002:a05:660c:492:: with SMTP id a18mr10962401itk.48.1558574703429; Wed, 22 May 2019 18:25:03 -0700 (PDT) ARC-Seal: i=1; a=rsa-sha256; t=1558574703; cv=none; d=google.com; s=arc-20160816; b=mzxmk9AzVdDQ4IuRQcuMHxYHzna5TgVJhMoobzhIXjBQSwXtyprue2Pj0ZuvOpuUKh wdiF0Zen/XbaEXk2Fu7pRjsoVCel53BMU2Fvsgww6c68tByTBcKkabGphMG3Eel1NxMq fylX5QOtpkVqwRES+HurgU/w0FhXMD/PSiRUiYd+9ecW9knvHYLe7veBMs04Z1YAof8W RIkA5fdARWdoKTZyDdpXqijSkavCa6Msulw73hACM2MwqKNyoZ6IF8DvYuatBNJrH565 EU9Ut3CvP2mMKnAoqRU2gqEM/VXvGCcCpN31gul+FMO4MxKEAynCtcZc62p2ywpppl/a CBEQ== ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=arc-20160816; h=cc:to:subject:message-id:date:from:in-reply-to:references :mime-version:dkim-signature; bh=DwrwlKuIdoVYrJdyb0eyY3233BEFJTf1xEwDvRn1qmE=; b=iOQ6bxeRM7Uh2ibJJuJEiYFRA+/Y5r9pN4a0/8XMwkF0aybrNslPKBiUy/QaaTxQHh XliAsbd+odZQMnRq1L7iD5bK0q7y1A6SZCszmrKFdSNV+a8PAL76oFp8IWfRwbqTGypx MF/a0XCfEWaiKaQj7RCI8p6hd87pdmkoTrXa404+Oi05u05y7M8oYVuh/RmbpVc9ZMGR oYalXXFj/Ti5hamVSHrsEjQ2QKln3Y/IRXUB64REfI1dr5sUU3BE8i4LbIm7L1cvVA+v ZfBPp53dqVJQTfl1Rx6/2XJfsfTHNH/2IArSh00sLPAbmJgmd+t2N4XvmVbObO7bNC16 u8EA== ARC-Authentication-Results: i=1; mx.google.com; dkim=pass header.i=@gmail.com header.s=20161025 header.b=cj5+AGFc; spf=pass (google.com: domain of laoar.shao@gmail.com designates 209.85.220.65 as permitted sender) smtp.mailfrom=laoar.shao@gmail.com; dmarc=pass (p=NONE sp=QUARANTINE dis=NONE) header.from=gmail.com Received: from mail-sor-f65.google.com (mail-sor-f65.google.com. [209.85.220.65]) by mx.google.com with SMTPS id h1sor10443409ior.20.2019.05.22.18.25.03 for (Google Transport Security); Wed, 22 May 2019 18:25:03 -0700 (PDT) Received-SPF: pass (google.com: domain of laoar.shao@gmail.com designates 209.85.220.65 as permitted sender) client-ip=209.85.220.65; Authentication-Results: mx.google.com; dkim=pass header.i=@gmail.com header.s=20161025 header.b=cj5+AGFc; spf=pass (google.com: domain of laoar.shao@gmail.com designates 209.85.220.65 as permitted sender) smtp.mailfrom=laoar.shao@gmail.com; dmarc=pass (p=NONE sp=QUARANTINE dis=NONE) header.from=gmail.com DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=mime-version:references:in-reply-to:from:date:message-id:subject:to :cc; bh=DwrwlKuIdoVYrJdyb0eyY3233BEFJTf1xEwDvRn1qmE=; b=cj5+AGFcIJ6mMVhY0Grxcklza0OvOObx9vT0xDujcgfRz774kcxwmlGOk6zNARoWxi A+PveCNSxbLF3BodTEUNUcGiKkqQoukA983GWFtTgtufkHdiUhiYANsAon4WWmi/dlC2 iQ2rDNPsdNbVUBfmzws6xTkyZ0aLHV/LfOVtGk6obeYJns7fQ6CjAHpRLirXekyWsDHD TvQGd4oNOztziWnMPEbE24edV+MssyM8rxz+RhtRWYkDcNMp6rFtnO5uHZLDruNI41by hJo6PNJPtB9KAekGNoOTmE89PbjP9tIbw/ylrYT2X8bLdY0G1JnXQAF7MS9pUsl/YAqJ jZ0Q== X-Google-Smtp-Source: APXvYqxErFwLeE1PTEpKDqML7Cqul0fImhXrqEeKAf47KdF58aPbu2rSfqa9mY9LQ/9Gj6zfA5CZf1sX6MEePssFroI= X-Received: by 2002:a05:6602:2049:: with SMTP id z9mr26907713iod.46.1558574703020; Wed, 22 May 2019 18:25:03 -0700 (PDT) MIME-Version: 1.0 References: <1557649528-11676-1-git-send-email-laoar.shao@gmail.com> <20190522123314.e17fc708ff6548b9b621d6ad@linux-foundation.org> In-Reply-To: <20190522123314.e17fc708ff6548b9b621d6ad@linux-foundation.org> From: Yafang Shao Date: Thu, 23 May 2019 09:24:26 +0800 Message-ID: Subject: Re: [PATCH v2] mm/vmscan: expose cgroup_ino for memcg reclaim tracepoints To: Andrew Morton Cc: Dmitry Dolgov <9erthalion6@gmail.com>, Michal Hocko , shaoyafang@didiglobal.com, Linux MM Content-Type: text/plain; charset="UTF-8" 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 Thu, May 23, 2019 at 3:33 AM Andrew Morton wrote: > > On Sun, 12 May 2019 16:25:28 +0800 Yafang Shao wrote: > > > We can use the exposed cgroup_ino to trace specified cgroup. > > > > For example, > > step 1, get the inode of the specified cgroup > > $ ls -di /tmp/cgroupv2/foo > > step 2, set this inode into tracepoint filter to trace this cgroup only > > (assume the inode is 11) > > $ cd /sys/kernel/debug/tracing/events/vmscan/ > > $ echo 'cgroup_ino == 11' > mm_vmscan_memcg_reclaim_begin/filter > > $ echo 'cgroup_ino == 11' > mm_vmscan_memcg_reclaim_end/filter > > Seems straightforward enough. > > But please explain the value of such a change. What is wrong with the > current situation and how does this change improve things? A simple > use-case scenario would be good. > > I can guess why it is beneficial, but I'd rather not guess! > Got it. The reason I made this change is to trace a specific container. Sometimes there're lots of containers on one host. Some of them are not important at all, so we don't care whether them are under memory pressure. While some of them are important, so we want't to know if these containers are doing memcg reclaim and how long this relaim takes. Without this change, we don't know the memcg reclaim happend in which container. Thanks Yafang