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 C6A76C433F5 for ; Wed, 23 Feb 2022 12:50:09 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id 078D38D0002; Wed, 23 Feb 2022 07:50:09 -0500 (EST) Received: by kanga.kvack.org (Postfix, from userid 40) id 001BE8D0001; Wed, 23 Feb 2022 07:50:08 -0500 (EST) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id DE4358D0002; Wed, 23 Feb 2022 07:50:08 -0500 (EST) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0018.hostedemail.com [216.40.44.18]) by kanga.kvack.org (Postfix) with ESMTP id CBCBA8D0001 for ; Wed, 23 Feb 2022 07:50:08 -0500 (EST) Received: from smtpin18.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay02.hostedemail.com (Postfix) with ESMTP id 85FDC9526B for ; Wed, 23 Feb 2022 12:50:08 +0000 (UTC) X-FDA: 79174027296.18.06E73F2 Received: from outbound-smtp23.blacknight.com (outbound-smtp23.blacknight.com [81.17.249.191]) by imf08.hostedemail.com (Postfix) with ESMTP id CD036160009 for ; Wed, 23 Feb 2022 12:50:07 +0000 (UTC) Received: from mail.blacknight.com (pemlinmail05.blacknight.ie [81.17.254.26]) by outbound-smtp23.blacknight.com (Postfix) with ESMTPS id DC35FBEBDA for ; Wed, 23 Feb 2022 12:50:04 +0000 (GMT) Received: (qmail 528 invoked from network); 23 Feb 2022 12:50:04 -0000 Received: from unknown (HELO techsingularity.net) (mgorman@techsingularity.net@[84.203.17.223]) by 81.17.254.9 with ESMTPSA (AES256-SHA encrypted, authenticated); 23 Feb 2022 12:50:04 -0000 Date: Wed, 23 Feb 2022 12:50:02 +0000 From: Mel Gorman To: Shuang Zhai 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: Re: [PATCH v4 1/1] mm: vmscan: Reduce throttling due to a failure to make progress' Message-ID: <20220223125002.GE4423@techsingularity.net> References: <20220215144924.GS3366@techsingularity.net> <20220222172731.31949-1-szhai2@cs.rochester.edu> MIME-Version: 1.0 Content-Type: text/plain; charset=iso-8859-15 Content-Disposition: inline In-Reply-To: <20220222172731.31949-1-szhai2@cs.rochester.edu> User-Agent: Mutt/1.10.1 (2018-07-13) X-Rspamd-Server: rspam04 X-Rspamd-Queue-Id: CD036160009 X-Stat-Signature: kpri1zt5wxkbitug37qd353shbay1you Authentication-Results: imf08.hostedemail.com; dkim=none; spf=pass (imf08.hostedemail.com: domain of mgorman@techsingularity.net designates 81.17.249.191 as permitted sender) smtp.mailfrom=mgorman@techsingularity.net; dmarc=none X-Rspam-User: X-HE-Tag: 1645620607-917937 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 Tue, Feb 22, 2022 at 12:27:31PM -0500, Shuang Zhai wrote: > Mel Gorman wrote: > > On Mon, Feb 14, 2022 at 04:10:50PM -0500, Shuang Zhai wrote: > > > 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. > > > > > > > Am I correct in thinging that this only happens with MGLRU? > > Sorry about the confusion and let me clarify on this. The regression happens > on upstream Linux with the default page replacement mechanism. Ok, the fio command for me simply exits with an error and even if it didn't the test machine I have with persistent memory does not have enough pmem to trigger memory reclaim issues with fio. Can you do the following please? # echo 1 > vmscan/mm_vmscan_throttled/enable # cat /sys/kernel/debug/tracing/trace_pipe > trace.out and run the test? Compress trace.out with xz and send it to me by mail. If the trace is too large, send as much as you can. -- Mel Gorman SUSE Labs