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 vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 57AD4C433FE for ; Mon, 14 Feb 2022 22:11:46 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231736AbiBNWLw (ORCPT ); Mon, 14 Feb 2022 17:11:52 -0500 Received: from mxb-00190b01.gslb.pphosted.com ([23.128.96.19]:57004 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230197AbiBNWLv (ORCPT ); Mon, 14 Feb 2022 17:11:51 -0500 X-Greylist: delayed 3597 seconds by postgrey-1.37 at lindbergh.monkeyblade.net; Mon, 14 Feb 2022 14:11:42 PST Received: from slate.cs.rochester.edu (slate.cs.rochester.edu [128.151.167.14]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 1082EB820A; Mon, 14 Feb 2022 14:11:41 -0800 (PST) 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 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 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. 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 =========== $ numactl --cpubind=0 --membind=0 fio --name=randread \ --directory=/mnt/pmem/ --size={10G, 5G} --io_size=1000TB \ --time_based --numjobs={40, 80} --ioengine=io_uring \ --ramp_time=20m --runtime=10m --iodepth=128 \ --iodepth_batch_submit=32 --iodepth_batch_complete=32 \ --rw=randread --random_distribution=random \ --direct=0 --norandommap --group_reporting Results in throughput (MB/s): ============================= +------------+------+-------+------+-------+----------+-------+ | 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.rochester.edu/ Thanks! Shuang