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 Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by smtp.lore.kernel.org (Postfix) with ESMTP id 66E3AC433EF for ; Mon, 14 Feb 2022 21:11:19 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id 7F2A96B0075; Mon, 14 Feb 2022 16:11:18 -0500 (EST) Received: by kanga.kvack.org (Postfix, from userid 40) id 7A1D16B007B; Mon, 14 Feb 2022 16:11:18 -0500 (EST) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 66A016B007D; Mon, 14 Feb 2022 16:11:18 -0500 (EST) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0126.hostedemail.com [216.40.44.126]) by kanga.kvack.org (Postfix) with ESMTP id 5A56F6B0075 for ; Mon, 14 Feb 2022 16:11:18 -0500 (EST) Received: from smtpin31.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay02.hostedemail.com (Postfix) with ESMTP id 22668884BD for ; Mon, 14 Feb 2022 21:11:18 +0000 (UTC) X-FDA: 79142631036.31.5A27406 Received: from slate.cs.rochester.edu (slate.cs.rochester.edu [128.151.167.14]) by imf15.hostedemail.com (Postfix) with SMTP id ADDDDA0005 for ; Mon, 14 Feb 2022 21:11:17 +0000 (UTC) Received: from node1x10a.cs.rochester.edu (node1x10a.cs.rochester.edu [192.5.53.74]) by slate.cs.rochester.edu (8.14.7/8.14.7) with ESMTP id 21ELAx5P010783 (version=TLSv1/SSLv3 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=NO); Mon, 14 Feb 2022 16:10:59 -0500 Received: from node1x10a.cs.rochester.edu (localhost [127.0.0.1]) by node1x10a.cs.rochester.edu (8.15.2/8.15.1) with ESMTP id 21ELAxL3031113; Mon, 14 Feb 2022 16:10:59 -0500 Received: (from szhai2@localhost) by node1x10a.cs.rochester.edu (8.15.2/8.15.1/Submit) id 21ELAuk4031106; Mon, 14 Feb 2022 16:10:56 -0500 From: Shuang Zhai To: mgorman@techsingularity.net Cc: akpm@linux-foundation.org, djwong@kernel.org, efault@gmx.de, hakavlad@inbox.lv, linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org, linux-mm@kvack.org, mhocko@suse.com, regressions@lists.linux.dev, riel@surriel.com, vbabka@suse.cz Subject: [PATCH v4 1/1] mm: vmscan: Reduce throttling due to a failure to make progress Date: Mon, 14 Feb 2022 16:10:50 -0500 Message-Id: <20220214211050.31049-1-szhai2@cs.rochester.edu> X-Mailer: git-send-email 2.21.3 In-Reply-To: <20211202150614.22440-1-mgorman@techsingularity.net> References: <20211202150614.22440-1-mgorman@techsingularity.net> MIME-Version: 1.0 X-Rspamd-Server: rspam01 X-Rspamd-Queue-Id: ADDDDA0005 X-Stat-Signature: 65hsd5ytgdde3a7dg8ku8w9uwr4hc1or X-Rspam-User: Authentication-Results: imf15.hostedemail.com; dkim=none; dmarc=fail reason="No valid SPF, No valid DKIM" header.from=rochester.edu (policy=none); spf=none (imf15.hostedemail.com: domain of szhai2@cs.rochester.edu has no SPF policy when checking 128.151.167.14) smtp.mailfrom=szhai2@cs.rochester.edu X-HE-Tag: 1644873077-805271 Content-Transfer-Encoding: quoted-printable 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: Hi Mel, Mel Gorman wrote: > > Mike Galbraith, Alexey Avramov and Darrick Wong all reported similar > problems due to reclaim throttling for excessive lengths of time. > In Alexey's case, a memory hog that should go OOM quickly stalls for > several minutes before stalling. In Mike and Darrick's cases, a small > memcg environment stalled excessively even though the system had enough > memory overall. > I recently found a regression when I tested MGLRU with fio on Linux 5.16-rc6 [1]. After this patch was applied, I re-ran the test with Linux 5.16, but the regression has not been fixed yet.=20 The workload is to let fio perform random access on files with buffered IO. The total file size is 2x the memory size. Files are stored on pmem. For each configuration, I ran fio 10 times and reported the average and the standard deviation. Fio command =3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D $ numactl --cpubind=3D0 --membind=3D0 fio --name=3Drandread \ --directory=3D/mnt/pmem/ --size=3D{10G, 5G} --io_size=3D1000TB \ --time_based --numjobs=3D{40, 80} --ioengine=3Dio_uring \ --ramp_time=3D20m --runtime=3D10m --iodepth=3D128 \ --iodepth_batch_submit=3D32 --iodepth_batch_complete=3D32 \ --rw=3Drandread --random_distribution=3Drandom \ --direct=3D0 --norandommap --group_reporting Results in throughput (MB/s): =3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D= =3D=3D=3D=3D +------------+------+-------+------+-------+----------+-------+ | Jobs / CPU | 5.15 | stdev | 5.16 | stdev | 5.17-rc3 | stdev | +------------+------+-------+------+-------+----------+-------+ | 1 | 8411 | 75 | 7459 | 38 | 7331 | 36 | +------------+------+-------+------+-------+----------+-------+ | 2 | 8417 | 54 | 7491 | 41 | 7383 | 15 | +------------+------+-------+------+-------+----------+-------+ [1] https://lore.kernel.org/linux-mm/20220105024423.26409-1-szhai2@cs.roc= hester.edu/ Thanks! Shuang