From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-yw1-f69.google.com (mail-yw1-f69.google.com [209.85.161.69]) by kanga.kvack.org (Postfix) with ESMTP id 136B18E0002 for ; Wed, 2 Jan 2019 16:18:34 -0500 (EST) Received: by mail-yw1-f69.google.com with SMTP id l7so22828806ywh.16 for ; Wed, 02 Jan 2019 13:18:34 -0800 (PST) Received: from mail-sor-f65.google.com (mail-sor-f65.google.com. [209.85.220.65]) by mx.google.com with SMTPS id f124sor6985064ywe.27.2019.01.02.13.18.33 for (Google Transport Security); Wed, 02 Jan 2019 13:18:33 -0800 (PST) MIME-Version: 1.0 References: <1546459533-36247-1-git-send-email-yang.shi@linux.alibaba.com> <1546459533-36247-2-git-send-email-yang.shi@linux.alibaba.com> In-Reply-To: <1546459533-36247-2-git-send-email-yang.shi@linux.alibaba.com> From: Shakeel Butt Date: Wed, 2 Jan 2019 13:18:21 -0800 Message-ID: Subject: Re: [PATCH 1/3] doc: memcontrol: fix the obsolete content about force empty Content-Type: text/plain; charset="UTF-8" Sender: owner-linux-mm@kvack.org List-ID: To: Yang Shi Cc: Michal Hocko , Johannes Weiner , Andrew Morton , Linux MM , LKML On Wed, Jan 2, 2019 at 12:07 PM Yang Shi wrote: > > We don't do page cache reparent anymore when offlining memcg, so update > force empty related content accordingly. > > Cc: Michal Hocko > Cc: Johannes Weiner > Signed-off-by: Yang Shi Reviewed-by: Shakeel Butt > --- > Documentation/cgroup-v1/memory.txt | 7 ++++--- > 1 file changed, 4 insertions(+), 3 deletions(-) > > diff --git a/Documentation/cgroup-v1/memory.txt b/Documentation/cgroup-v1/memory.txt > index 3682e99..8e2cb1d 100644 > --- a/Documentation/cgroup-v1/memory.txt > +++ b/Documentation/cgroup-v1/memory.txt > @@ -70,7 +70,7 @@ Brief summary of control files. > memory.soft_limit_in_bytes # set/show soft limit of memory usage > memory.stat # show various statistics > memory.use_hierarchy # set/show hierarchical account enabled > - memory.force_empty # trigger forced move charge to parent > + memory.force_empty # trigger forced page reclaim > memory.pressure_level # set memory pressure notifications > memory.swappiness # set/show swappiness parameter of vmscan > (See sysctl's vm.swappiness) > @@ -459,8 +459,9 @@ About use_hierarchy, see Section 6. > the cgroup will be reclaimed and as many pages reclaimed as possible. > > The typical use case for this interface is before calling rmdir(). > - Because rmdir() moves all pages to parent, some out-of-use page caches can be > - moved to the parent. If you want to avoid that, force_empty will be useful. > + Though rmdir() offlines memcg, but the memcg may still stay there due to > + charged file caches. Some out-of-use page caches may keep charged until > + memory pressure happens. If you want to avoid that, force_empty will be useful. > > Also, note that when memory.kmem.limit_in_bytes is set the charges due to > kernel pages will still be seen. This is not considered a failure and the > -- > 1.8.3.1 > 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=-14.6 required=3.0 tests=DKIMWL_WL_MED,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH, MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_PASS,USER_IN_DEF_DKIM_WL 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 6B457C43387 for ; Wed, 2 Jan 2019 21:18:35 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id 004D52075B for ; Wed, 2 Jan 2019 21:18:34 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=google.com header.i=@google.com header.b="kOUhQs6h" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 004D52075B Authentication-Results: mail.kernel.org; dmarc=fail (p=reject dis=none) header.from=google.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=owner-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix) id 6340B8E0046; Wed, 2 Jan 2019 16:18:34 -0500 (EST) Received: by kanga.kvack.org (Postfix, from userid 40) id 5B9B28E0002; Wed, 2 Jan 2019 16:18:34 -0500 (EST) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 45A5C8E0046; Wed, 2 Jan 2019 16:18:34 -0500 (EST) X-Delivered-To: linux-mm@kvack.org Received: from mail-yw1-f69.google.com (mail-yw1-f69.google.com [209.85.161.69]) by kanga.kvack.org (Postfix) with ESMTP id 136B18E0002 for ; Wed, 2 Jan 2019 16:18:34 -0500 (EST) Received: by mail-yw1-f69.google.com with SMTP id l7so22828806ywh.16 for ; Wed, 02 Jan 2019 13:18:34 -0800 (PST) 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=2stP9UFtPAKH3/LwOn4Ye9NZzNGkHMYFwKnAD6NZC3E=; b=agIUR2pk3quNq3OcUXUGDEBg53h+exmWndG3rkyTuEOx1XulBv4q9J+sox++SFRIxe 6L0PpbTqwcjze5xHjMZ/CtD9qj0+7mHEp2qO5S9BfzWQ7FdQ2u6JrboVyEpdu+TXNmsF szaHodWtsEwPWYY0FlmO1NAfyWDyrRe9cewxTI3+ENRyYo0rBTWFITnML7em+H747Fvw eFPErWzsN6C3XZIwFkk9iUEDKejNLbNQ5rFhSVSDp1P7wQIPbCX0fm/bFKx4l93j/vw+ 2oUyfCgePJSzl49K7SdCPP9rIKl7HZ2s/9OjllGMhA0CMwhqdssPVjQ+hhxpgDvekT4U vq4A== X-Gm-Message-State: AJcUukeX28SMD5Mvaf0HbEbbYIWsw9bJABZSkzXjjWl1TcAuSaMd5f6W LYNao/x3nXeRl61TIcLrqSpxYSNYZzC5AMW49pcJjVA30z2ystvTRrQG1Gy66tNVYmmLHWOlfuE 5bRqwlPmIEK8LQddJ2Mx6D4jRSFVzf82F2HY4RstUzpmfWvdFXqpQoYXoohDfdoZE2MpnRuu12C vH2y56DeQmapbEz/akcRvCaOBavTdcTI0r9OACTRtn9nrHy3Jrz4u3XHIN3MKzDcSv0B1oHV/nm anLDFmghqS6klJA9cvRv+iNkldUTwRvBiU/LBKNlwFDwwdQjZ07Z08HroX7GecZAnvhe3KhKo66 h4aqCjkmRM8Wbf4F568bRyIqZxshQyc9mWwqeHRhreiGuAWsB+qT2mXDJEtn63mbqkqPp83pO9b l X-Received: by 2002:a25:5f0a:: with SMTP id t10mr38356557ybb.203.1546463913815; Wed, 02 Jan 2019 13:18:33 -0800 (PST) X-Received: by 2002:a25:5f0a:: with SMTP id t10mr38356534ybb.203.1546463913147; Wed, 02 Jan 2019 13:18:33 -0800 (PST) ARC-Seal: i=1; a=rsa-sha256; t=1546463913; cv=none; d=google.com; s=arc-20160816; b=vkQBooXXLHDiySTrJ5unfwj5MsQYK/rBXugh5WvW4bPoCOm5SQW1YzAYDHuEy6wdbW T3NlTXm+kYmnSMIHIKUZnFyS17R2Ca4Z306D8VTDmvMvo7y73kvGfVqPwJ7I5nNweygp ncKZrLnxAQGvKX53c4gzqgp9DMJkiZB8GcxzwOtnggRCdIh0XSE4lG7T+V9ecMHEPMt1 1usLKd38sDJiEgKyM/yrWid7tGdlTy5nsqnq8HQuDpDFhPtNodtPUZPvI68JRrraCzf2 55fvR8r6zhTq68cDn6qgGQf1DAec3WEJ0Bfv+11o2GSsi+9jYCt2Kfvh444LSfPcmyC0 1fbA== 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=2stP9UFtPAKH3/LwOn4Ye9NZzNGkHMYFwKnAD6NZC3E=; b=CyImJrvVsOr0QkFIKk0mFkA9zqFdi4Jj3Dr4nqtcWBYwLJn6HDnW8u3QRHk3HuU7i6 7PLczmpr4zBMzolJtACuaWewBrrtIYnBVk+eJVU2cthsn7gUkK3qSjFi2zxehjhisfkY 5bVs/2WbKHVjkF2jYK97UUlhZ7gKJWueKYTtU2+APyRAztvB8PI+cCz2JqzXnKp30P2U p2YNSJ8d8F0Vk3us53tWu2ZKde992JoAlLe+Ao8+zfpXXyPaSk+3LnbyVyI9kKZJ2gjL 7DYtpWtN3B3d4QdfXpSHFM+BWqGQOPfxZFKt72g2eiGcmj454pai4afaSoHGg67Dd3Pu OxlQ== ARC-Authentication-Results: i=1; mx.google.com; dkim=pass header.i=@google.com header.s=20161025 header.b=kOUhQs6h; spf=pass (google.com: domain of shakeelb@google.com designates 209.85.220.65 as permitted sender) smtp.mailfrom=shakeelb@google.com; dmarc=pass (p=REJECT sp=REJECT dis=NONE) header.from=google.com Received: from mail-sor-f65.google.com (mail-sor-f65.google.com. [209.85.220.65]) by mx.google.com with SMTPS id f124sor6985064ywe.27.2019.01.02.13.18.33 for (Google Transport Security); Wed, 02 Jan 2019 13:18:33 -0800 (PST) Received-SPF: pass (google.com: domain of shakeelb@google.com designates 209.85.220.65 as permitted sender) client-ip=209.85.220.65; Authentication-Results: mx.google.com; dkim=pass header.i=@google.com header.s=20161025 header.b=kOUhQs6h; spf=pass (google.com: domain of shakeelb@google.com designates 209.85.220.65 as permitted sender) smtp.mailfrom=shakeelb@google.com; dmarc=pass (p=REJECT sp=REJECT dis=NONE) header.from=google.com DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20161025; h=mime-version:references:in-reply-to:from:date:message-id:subject:to :cc; bh=2stP9UFtPAKH3/LwOn4Ye9NZzNGkHMYFwKnAD6NZC3E=; b=kOUhQs6h4jhZE8Kh+U6zRjNcWfD5sr/T49F6y9WimfogeFHtF0GGdh8jjyqX03XLx5 0vTrglcvnn1h0LPCyiKLUyYCRKxsXdgSNb7Nz5U++evrIA3ZT4DLbCC9HOdkk2EbFAwO 5iHNtjls7Vt3YIzINaVlmiiqcXkHRKv6c5QaEsEoKGHem8qiq9pxW5Q8F2+g9Jd6pf9X nk3KaTMcNhObMJ4VflMSeNfzyv6Fet7szZtgXIN7CoO75YBpe+hQObSPe+rdmc/RKsQn D3R6Ch3qXRXtadJRfWAn9PNBsceFvyD1vlPXxwpsDdcyErmfNB5fx2pNc8eA8ExBOJfZ 6G7w== X-Google-Smtp-Source: AFSGD/WeHteSWiTWipjnMVwfeXXIYWceoEsVLF5g0YXiF+BcfqAimEQTjK7InaWTmRnpKaLSJ7ubnMApdjUlVoWHi/A= X-Received: by 2002:a81:c144:: with SMTP id e4mr46830352ywl.409.1546463912552; Wed, 02 Jan 2019 13:18:32 -0800 (PST) MIME-Version: 1.0 References: <1546459533-36247-1-git-send-email-yang.shi@linux.alibaba.com> <1546459533-36247-2-git-send-email-yang.shi@linux.alibaba.com> In-Reply-To: <1546459533-36247-2-git-send-email-yang.shi@linux.alibaba.com> From: Shakeel Butt Date: Wed, 2 Jan 2019 13:18:21 -0800 Message-ID: Subject: Re: [PATCH 1/3] doc: memcontrol: fix the obsolete content about force empty To: Yang Shi Cc: Michal Hocko , Johannes Weiner , Andrew Morton , Linux MM , LKML 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: Message-ID: <20190102211821.T4R7FmuBpLNE6SpOXjRR7kzJLIM4-yhBfWooQXFM2Tg@z> On Wed, Jan 2, 2019 at 12:07 PM Yang Shi wrote: > > We don't do page cache reparent anymore when offlining memcg, so update > force empty related content accordingly. > > Cc: Michal Hocko > Cc: Johannes Weiner > Signed-off-by: Yang Shi Reviewed-by: Shakeel Butt > --- > Documentation/cgroup-v1/memory.txt | 7 ++++--- > 1 file changed, 4 insertions(+), 3 deletions(-) > > diff --git a/Documentation/cgroup-v1/memory.txt b/Documentation/cgroup-v1/memory.txt > index 3682e99..8e2cb1d 100644 > --- a/Documentation/cgroup-v1/memory.txt > +++ b/Documentation/cgroup-v1/memory.txt > @@ -70,7 +70,7 @@ Brief summary of control files. > memory.soft_limit_in_bytes # set/show soft limit of memory usage > memory.stat # show various statistics > memory.use_hierarchy # set/show hierarchical account enabled > - memory.force_empty # trigger forced move charge to parent > + memory.force_empty # trigger forced page reclaim > memory.pressure_level # set memory pressure notifications > memory.swappiness # set/show swappiness parameter of vmscan > (See sysctl's vm.swappiness) > @@ -459,8 +459,9 @@ About use_hierarchy, see Section 6. > the cgroup will be reclaimed and as many pages reclaimed as possible. > > The typical use case for this interface is before calling rmdir(). > - Because rmdir() moves all pages to parent, some out-of-use page caches can be > - moved to the parent. If you want to avoid that, force_empty will be useful. > + Though rmdir() offlines memcg, but the memcg may still stay there due to > + charged file caches. Some out-of-use page caches may keep charged until > + memory pressure happens. If you want to avoid that, force_empty will be useful. > > Also, note that when memory.kmem.limit_in_bytes is set the charges due to > kernel pages will still be seen. This is not considered a failure and the > -- > 1.8.3.1 >