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=-2.2 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,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 A0289C606AC for ; Mon, 8 Jul 2019 12:15:13 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id 6174C2064A for ; Mon, 8 Jul 2019 12:15:13 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 6174C2064A 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 D8CB48E0010; Mon, 8 Jul 2019 08:15:12 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id D3E4F8E0002; Mon, 8 Jul 2019 08:15:12 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id C2BA58E0010; Mon, 8 Jul 2019 08:15:12 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from mail-qt1-f199.google.com (mail-qt1-f199.google.com [209.85.160.199]) by kanga.kvack.org (Postfix) with ESMTP id A28B18E0002 for ; Mon, 8 Jul 2019 08:15:12 -0400 (EDT) Received: by mail-qt1-f199.google.com with SMTP id e32so4787985qtc.7 for ; Mon, 08 Jul 2019 05:15:12 -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:date:from:to :cc:subject:message-id:references:mime-version:content-disposition :in-reply-to:user-agent; bh=zuc2UGoulORVltkjy8YEdyUMHEcx1/3ATLZEvtOe3FI=; b=QIFij3sZuPd2NmVhB11S3dBMacx7OOFL43XFfl5/EsBxJf8mX3jk+kq0f9DgiJ+Yis eMLzNw7IvPH1GG2FxgvlyZZ8S31PxuB/q5kegItElsP4RvoPMSZsVIf35lQqyhj0ABEs sx/59UFApiNBQD95hUdTx2lokinwXyYJKiLepq9910oVBmB7l2Vp2c0RhJKwK9vuiZY/ 87AmdIZZq4N8JdGuoxfF9unvMVvVG1ixJaYds22R7IQeCMvDU+750KVExydJyBezqaSj 6LF/NIfSrRDX9W0QTTsZX2ogSN6Ab88ydXrqdJw1csJ1eNinceKU2Th2l/Won1S7sdVC MJwA== X-Original-Authentication-Results: mx.google.com; spf=pass (google.com: domain of bfoster@redhat.com designates 209.132.183.28 as permitted sender) smtp.mailfrom=bfoster@redhat.com; dmarc=pass (p=NONE sp=NONE dis=NONE) header.from=redhat.com X-Gm-Message-State: APjAAAUnShhTlA1mg5wcsxGJK+LeIh4L9ew2bH/DDHFiV2rdG2e9k3YW 0R0LLULUbWCfSkg9Ukg5afX8oMJAqQUVnE/wIvW8IHm0luex3ch5wGkl3KUAebGqysaQIIX4OmN v0cIciWpWN9kEYZSAQ6KuMD0LCmKy7uMU3o75sswt81JVSZS0Mf7c9hFRJc6ae8O2sw== X-Received: by 2002:ac8:30d2:: with SMTP id w18mr13841697qta.296.1562588112401; Mon, 08 Jul 2019 05:15:12 -0700 (PDT) X-Google-Smtp-Source: APXvYqyRtK7+YU3L0TPJfdi9uLN4+Hfv1Mz3HPrAsbgG9oYCwBZ22mDg+eZiCmQSPjznDkWsHuze X-Received: by 2002:ac8:30d2:: with SMTP id w18mr13841623qta.296.1562588111411; Mon, 08 Jul 2019 05:15:11 -0700 (PDT) ARC-Seal: i=1; a=rsa-sha256; t=1562588111; cv=none; d=google.com; s=arc-20160816; b=FavPLLzPgsgMN8BG5PRzwsxiQg8mVG7wJ/EXrZkiXkBdleiMFqEUybifTv2y219oON SsoQhka8cNTsBv0vWJvekhbYQ7s3vMSkPB53cUMWEHd4f3Lewj1Xhs7jjjjpDg+4vTbX Pw3tUOeuTV1QSB8euNqh8lbm9yDk+a6w7VP/Myv2Um9K0bB4M+1YAACes2MvY9HgsFfm IGp18axOQgSCfB0gzgqPoKikbE/C9zH4v3vMnsXmrcwjRh/MGrkmoR8ibw3RGWER7Ff6 Uio1f5gXlG8yfLJZGpGajXHzw7/WPcFsiXJTpbobou5Hvy1TywUnyG+rlA/P1zn8D2Fr mBqQ== ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=arc-20160816; h=user-agent:in-reply-to:content-disposition:mime-version:references :message-id:subject:cc:to:from:date; bh=zuc2UGoulORVltkjy8YEdyUMHEcx1/3ATLZEvtOe3FI=; b=egCuTMwrd/iymRqLxtFCeeqftkyciDGXlhL0ACDaID7Xs0aHXbmIq9xcVWCZcTyCvB HfQOhYFlwXA+/JWS29mfWS8Qa+wV/fUy+SL1ISxJobO+zfa9byTuk7tIJtYlcl1MUfi2 5cY4mej/WF0G5zR+inc/JN5xUqbhxT99VuI2f/K2FyoeyVuT8T6ZUTZXIUq8AmJcn8VZ JSDXmzvZHA9cnBfRQWtQBs4iNaXIiKnRITiQeuZFCXyWXtw/+ehiXpk10beDTYL9FC82 8LQT+iLtdSvPWgUfhQLNYZMtkLLUvBaiwB9+soTBfC+2kRWt1xvnwLEWOW9qMz1/vcjB NPbg== ARC-Authentication-Results: i=1; mx.google.com; spf=pass (google.com: domain of bfoster@redhat.com designates 209.132.183.28 as permitted sender) smtp.mailfrom=bfoster@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 j24si9978789qtj.383.2019.07.08.05.15.11 for (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Mon, 08 Jul 2019 05:15:11 -0700 (PDT) Received-SPF: pass (google.com: domain of bfoster@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 bfoster@redhat.com designates 209.132.183.28 as permitted sender) smtp.mailfrom=bfoster@redhat.com; dmarc=pass (p=NONE sp=NONE dis=NONE) header.from=redhat.com Received: from smtp.corp.redhat.com (int-mx04.intmail.prod.int.phx2.redhat.com [10.5.11.14]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mx1.redhat.com (Postfix) with ESMTPS id 44BE57CBA0; Mon, 8 Jul 2019 12:15:05 +0000 (UTC) Received: from bfoster (dhcp-41-2.bos.redhat.com [10.18.41.2]) by smtp.corp.redhat.com (Postfix) with ESMTPS id C53E75D9E5; Mon, 8 Jul 2019 12:15:01 +0000 (UTC) Date: Mon, 8 Jul 2019 08:15:00 -0400 From: Brian Foster To: Dave Chinner Cc: Yafang Shao , Michal Hocko , Andrew Morton , Linux MM , Johannes Weiner , Vladimir Davydov , Shakeel Butt , Yafang Shao , linux-xfs@vger.kernel.org Subject: Re: [PATCH] mm, memcg: support memory.{min, low} protection in cgroup v1 Message-ID: <20190708121459.GB51396@bfoster> References: <1562310330-16074-1-git-send-email-laoar.shao@gmail.com> <20190705090902.GF8231@dhcp22.suse.cz> <20190705111043.GJ8231@dhcp22.suse.cz> <20190705151045.GI37448@bfoster> <20190705235222.GE7689@dread.disaster.area> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20190705235222.GE7689@dread.disaster.area> User-Agent: Mutt/1.11.3 (2019-02-01) X-Scanned-By: MIMEDefang 2.79 on 10.5.11.14 X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.5.110.26]); Mon, 08 Jul 2019 12:15:10 +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 Sat, Jul 06, 2019 at 09:52:22AM +1000, Dave Chinner wrote: > On Fri, Jul 05, 2019 at 11:10:45AM -0400, Brian Foster wrote: > > cc linux-xfs > > > > On Fri, Jul 05, 2019 at 10:33:04PM +0800, Yafang Shao wrote: > > > On Fri, Jul 5, 2019 at 7:10 PM Michal Hocko wrote: > > > > > > > > On Fri 05-07-19 17:41:44, Yafang Shao wrote: > > > > > On Fri, Jul 5, 2019 at 5:09 PM Michal Hocko wrote: > > > > [...] > > > > > > Why cannot you move over to v2 and have to stick with v1? > > > > > Because the interfaces between cgroup v1 and cgroup v2 are changed too > > > > > much, which is unacceptable by our customer. > > > > > > > > Could you be more specific about obstacles with respect to interfaces > > > > please? > > > > > > > > > > Lots of applications will be changed. > > > Kubernetes, Docker and some other applications which are using cgroup v1, > > > that will be a trouble, because they are not maintained by us. > > > > > > > > It may take long time to use cgroup v2 in production envrioment, per > > > > > my understanding. > > > > > BTW, the filesystem on our servers is XFS, but the cgroup v2 > > > > > writeback throttle is not supported on XFS by now, that is beyond my > > > > > comprehension. > > > > > > > > Are you sure? I would be surprised if v1 throttling would work while v2 > > > > wouldn't. As far as I remember it is v2 writeback throttling which > > > > actually works. The only throttling we have for v1 is reclaim based one > > > > which is a huge hammer. > > > > -- > > > > > > We did it in cgroup v1 in our kernel. > > > But the upstream still don't support it in cgroup v2. > > > So my real question is why upstream can't support such an import file system ? > > > Do you know which companies besides facebook are using cgroup v2 in > > > their product enviroment? > > > > > > > I think the original issue with regard to XFS cgroupv2 writeback > > throttling support was that at the time the XFS patch was proposed, > > there wasn't any test coverage to prove that the code worked (and the > > original author never followed up). That has since been resolved and > > Christoph has recently posted a new patch [1], which appears to have > > been accepted by the maintainer. > > I don't think the validation issue has been resolved. > > i.e. we still don't have regression tests that ensure it keeps > working it in future, or that it works correctly in any specific > distro setting/configuration. The lack of repeatable QoS validation > infrastructure was the reason I never merged support for this in the > first place. > > So while the (simple) patch to support it has been merged now, > there's no guarantee that it will work as expected or continue to do > so over the long run as nobody upstream or in distro land has a way > of validating that it is working correctly. > > From that perspective, it is still my opinion that one-off "works > for me" testing isn't sufficient validation for a QoS feature that > people will use to implement SLAs with $$$ penalities attached to > QoS failures.... > We do have an fstest to cover the accounting bits (which is what the fs is responsible for). Christoph also sent a patch[1] to enable that on XFS. I'm sure there's plenty of room for additional/broader test coverage, of course... Brian [1] https://marc.info/?l=fstests&m=156138385006173&w=2 > Cheers, > > Dave. > -- > Dave Chinner > david@fromorbit.com >