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 9DF25C433EF for ; Wed, 23 Feb 2022 12:50:13 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S240584AbiBWMuj (ORCPT ); Wed, 23 Feb 2022 07:50:39 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:42124 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231601AbiBWMuh (ORCPT ); Wed, 23 Feb 2022 07:50:37 -0500 Received: from outbound-smtp59.blacknight.com (outbound-smtp59.blacknight.com [46.22.136.243]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 8BF50A88AE for ; Wed, 23 Feb 2022 04:50:06 -0800 (PST) Received: from mail.blacknight.com (pemlinmail05.blacknight.ie [81.17.254.26]) by outbound-smtp59.blacknight.com (Postfix) with ESMTPS id EBDBCFAB02 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) Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 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