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=-2.3 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, 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 8CABFC43331 for ; Thu, 7 Nov 2019 17:48:11 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id A3C8921882 for ; Thu, 7 Nov 2019 17:48:10 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=cmpxchg-org.20150623.gappssmtp.com header.i=@cmpxchg-org.20150623.gappssmtp.com header.b="G8fRkvwV" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org A3C8921882 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=cmpxchg.org Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=owner-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix) id 4A4176B0003; Thu, 7 Nov 2019 12:48:10 -0500 (EST) Received: by kanga.kvack.org (Postfix, from userid 40) id 47BA26B0005; Thu, 7 Nov 2019 12:48:10 -0500 (EST) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 36AD76B0007; Thu, 7 Nov 2019 12:48:10 -0500 (EST) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0110.hostedemail.com [216.40.44.110]) by kanga.kvack.org (Postfix) with ESMTP id 203F96B0003 for ; Thu, 7 Nov 2019 12:48:10 -0500 (EST) Received: from smtpin04.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay04.hostedemail.com (Postfix) with SMTP id B734B45AB for ; Thu, 7 Nov 2019 17:48:09 +0000 (UTC) X-FDA: 76130215098.04.crack37_81568965fbd49 X-HE-Tag: crack37_81568965fbd49 X-Filterd-Recvd-Size: 6479 Received: from mail-pg1-f195.google.com (mail-pg1-f195.google.com [209.85.215.195]) by imf13.hostedemail.com (Postfix) with ESMTP for ; Thu, 7 Nov 2019 17:48:08 +0000 (UTC) Received: by mail-pg1-f195.google.com with SMTP id 29so2506213pgm.6 for ; Thu, 07 Nov 2019 09:48:08 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=cmpxchg-org.20150623.gappssmtp.com; s=20150623; h=date:from:to:cc:subject:message-id:references:mime-version :content-disposition:in-reply-to:user-agent; bh=YQHzfatweJlvu9QRgWqn6mLupzORKF19rwgbns+H/Ko=; b=G8fRkvwVCgK+5AnZZD/V83YvXyFilTUx9GafaEg/RlOfkWwhafnHdqdNeGKXLF/H6K FDoIV9FDSYGiZwaMLLnBtT4HOWe9rvBSeoXdkoOt977x30UGwRbKIQD62Y3e0SHPGkJE zj18IxkktF05wkCUiif3Tune+pTbQR19EfTWV8nDz4Wk+HvNaFZ82cJrX2VmWcejNZCG /iA/y8UqcJOl8F5Lh91S8tMoq40Go993jzHkeaTYmeYHGrX9dqqW6SRh5BZnroMcF8Jn BD77+M4HBjqEt44AKkO6oPWfH6+/na5b+Omr1i/uNPazTemCNSqER5sX4i6vu+vqbhQq hrYw== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:date:from:to:cc:subject:message-id:references :mime-version:content-disposition:in-reply-to:user-agent; bh=YQHzfatweJlvu9QRgWqn6mLupzORKF19rwgbns+H/Ko=; b=HDacWY3vUXHe7kAp3GHayQHlKp/Ym6F2aacwbrGhs1em5MnFK1eRo0aetSSq44tJa8 XMch+/+eMJJYUWSN7mMgO0YsNJ3s4L6xfqS++fCD9S5vVrfbkGOHeKFWWBD0OqhCfka+ SZ7yGPCZFSvmBh29eO9pDzSoGP7renbowzxV72WakViFwLD1loRzNbJnUh8MuXF6vKxZ QgIGRX5YkJKAGyb5REjWGCHiis+6qKigbrkon2mZs+EMKbw6NNCeC1jp5rwvszmzp5Y8 Ts7LJob99SnT2/sXw2QzMlPhfrSp1Nnp3xDbXzTRmQGignOtD0wm6hZ2mT9Kfw7Ojjk1 DkIQ== X-Gm-Message-State: APjAAAUVWIyXKRIlyWPQCjg8BrfSGS8HOM1PSlPDdht6//GTgWIySqD3 GJj4LjcYfu9U11Spi9fNHIt10w== X-Google-Smtp-Source: APXvYqzAqvPs1jX+juk9qWnYhY1RhnF/vPkdqQeAI9VIRBxgjUBTjIXOsZmOImIrN/73qLNmV/iXGQ== X-Received: by 2002:a63:6f47:: with SMTP id k68mr5759534pgc.92.1573148887304; Thu, 07 Nov 2019 09:48:07 -0800 (PST) Received: from localhost ([199.201.64.133]) by smtp.gmail.com with ESMTPSA id t12sm3323606pgv.45.2019.11.07.09.48.05 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Thu, 07 Nov 2019 09:48:06 -0800 (PST) Date: Thu, 7 Nov 2019 09:45:55 -0800 From: Johannes Weiner To: Shakeel Butt Cc: Andrew Morton , Andrey Ryabinin , Suren Baghdasaryan , Michal Hocko , Linux MM , Cgroups , LKML , Kernel Team Subject: Re: [PATCH 00/11] mm: fix page aging across multiple cgroups Message-ID: <20191107174555.GA116752@cmpxchg.org> References: <20190603210746.15800-1-hannes@cmpxchg.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.12.2 (2019-09-21) 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 Wed, Nov 06, 2019 at 06:50:25PM -0800, Shakeel Butt wrote: > On Mon, Jun 3, 2019 at 2:59 PM Johannes Weiner wrote: > > > > When applications are put into unconfigured cgroups for memory > > accounting purposes, the cgrouping itself should not change the > > behavior of the page reclaim code. We expect the VM to reclaim the > > coldest pages in the system. But right now the VM can reclaim hot > > pages in one cgroup while there is eligible cold cache in others. > > > > This is because one part of the reclaim algorithm isn't truly cgroup > > hierarchy aware: the inactive/active list balancing. That is the part > > that is supposed to protect hot cache data from one-off streaming IO. > > > > The recursive cgroup reclaim scheme will scan and rotate the physical > > LRU lists of each eligible cgroup at the same rate in a round-robin > > fashion, thereby establishing a relative order among the pages of all > > those cgroups. However, the inactive/active balancing decisions are > > made locally within each cgroup, so when a cgroup is running low on > > cold pages, its hot pages will get reclaimed - even when sibling > > cgroups have plenty of cold cache eligible in the same reclaim run. > > > > For example: > > > > [root@ham ~]# head -n1 /proc/meminfo > > MemTotal: 1016336 kB > > > > [root@ham ~]# ./reclaimtest2.sh > > Establishing 50M active files in cgroup A... > > Hot pages cached: 12800/12800 workingset-a > > Linearly scanning through 18G of file data in cgroup B: > > real 0m4.269s > > user 0m0.051s > > sys 0m4.182s > > Hot pages cached: 134/12800 workingset-a > > > > Can you share reclaimtest2.sh as well? Maybe a selftest to > monitor/test future changes. I wish it were more portable, but it really only does what it says in the log output, in a pretty hacky way, with all parameters hard-coded to my test environment: --- #!/bin/bash # this should protect workingset-a from workingset-b set -e #set -x echo Establishing 50M active files in cgroup A... rmdir /cgroup/workingset-a 2>/dev/null || true mkdir /cgroup/workingset-a echo $$ > /cgroup/workingset-a/cgroup.procs rm -f workingset-a dd of=workingset-a bs=1M count=0 seek=50 2>/dev/null >/dev/null cat workingset-a > /dev/null cat workingset-a > /dev/null cat workingset-a > /dev/null cat workingset-a > /dev/null cat workingset-a > /dev/null cat workingset-a > /dev/null cat workingset-a > /dev/null cat workingset-a > /dev/null echo -n "Hot pages cached: " ./mincore workingset-a echo -n Linearly scanning through 2G of file data cgroup B: rmdir /cgroup/workingset-b >/dev/null || true mkdir /cgroup/workingset-b echo $$ > /cgroup/workingset-b/cgroup.procs rm -f workingset-b dd of=workingset-b bs=1M count=0 seek=2048 2>/dev/null >/dev/null time ( cat workingset-b > /dev/null cat workingset-b > /dev/null cat workingset-b > /dev/null cat workingset-b > /dev/null cat workingset-b > /dev/null cat workingset-b > /dev/null cat workingset-b > /dev/null cat workingset-b > /dev/null ) echo -n "Hot pages cached: " ./mincore workingset-a