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 37D26C433F5 for ; Wed, 1 Dec 2021 15:12:23 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id 5A1E56B008A; Wed, 1 Dec 2021 10:08:53 -0500 (EST) Received: by kanga.kvack.org (Postfix, from userid 40) id 550ED6B008C; Wed, 1 Dec 2021 10:08:53 -0500 (EST) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 41A976B0092; Wed, 1 Dec 2021 10:08:53 -0500 (EST) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0154.hostedemail.com [216.40.44.154]) by kanga.kvack.org (Postfix) with ESMTP id 2D6A16B008A for ; Wed, 1 Dec 2021 10:08:53 -0500 (EST) Received: from smtpin26.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay01.hostedemail.com (Postfix) with ESMTP id E68F01812E1F3 for ; Wed, 1 Dec 2021 15:08:42 +0000 (UTC) X-FDA: 78869557284.26.E8BB86A Received: from outbound-smtp01.blacknight.com (outbound-smtp01.blacknight.com [81.17.249.7]) by imf22.hostedemail.com (Postfix) with ESMTP id 8B21FD0AC for ; Wed, 1 Dec 2021 15:06:17 +0000 (UTC) Received: from mail.blacknight.com (pemlinmail03.blacknight.ie [81.17.254.16]) by outbound-smtp01.blacknight.com (Postfix) with ESMTPS id 8F022C4B01 for ; Wed, 1 Dec 2021 15:06:15 +0000 (GMT) Received: (qmail 6766 invoked from network); 1 Dec 2021 15:06:15 -0000 Received: from unknown (HELO techsingularity.net) (mgorman@techsingularity.net@[84.203.17.29]) by 81.17.254.9 with ESMTPSA (AES256-SHA encrypted, authenticated); 1 Dec 2021 15:06:15 -0000 Date: Wed, 1 Dec 2021 15:06:13 +0000 From: Mel Gorman To: Mike Galbraith Cc: Alexey Avramov , Andrew Morton , Michal Hocko , Vlastimil Babka , Rik van Riel , Darrick Wong , regressions@lists.linux.dev, Linux-fsdevel , Linux-MM , LKML Subject: Re: [PATCH 1/1] mm: vmscan: Reduce throttling due to a failure to make progress Message-ID: <20211201150613.GV3366@techsingularity.net> References: <20211125151853.8540-1-mgorman@techsingularity.net> <20211127011246.7a8ac7b8@mail.inbox.lv> <20211129150117.GO3366@techsingularity.net> <20211201010348.31e99637@mail.inbox.lv> <20211130172754.GS3366@techsingularity.net> <20211201130155.GT3366@techsingularity.net> <2899c7841c8afc23b329230bd940692ffd586f63.camel@gmx.de> MIME-Version: 1.0 Content-Type: text/plain; charset=iso-8859-15 Content-Disposition: inline In-Reply-To: <2899c7841c8afc23b329230bd940692ffd586f63.camel@gmx.de> User-Agent: Mutt/1.10.1 (2018-07-13) X-Rspamd-Server: rspam04 X-Rspamd-Queue-Id: 8B21FD0AC X-Stat-Signature: 57idw77knh775xkqxbw9p7tg3wi63u1a Authentication-Results: imf22.hostedemail.com; dkim=none; spf=pass (imf22.hostedemail.com: domain of mgorman@techsingularity.net designates 81.17.249.7 as permitted sender) smtp.mailfrom=mgorman@techsingularity.net; dmarc=none X-HE-Tag: 1638371177-12196 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, Dec 01, 2021 at 02:52:01PM +0100, Mike Galbraith wrote: > On Wed, 2021-12-01 at 13:01 +0000, Mel Gorman wrote: > > On Tue, Nov 30, 2021 at 06:59:58PM +0100, Mike Galbraith wrote: > > > On Tue, 2021-11-30 at 17:27 +0000, Mel Gorman wrote: > > > > > > > > Obviously a fairly different experience and most likely due to > > > > the > > > > underlying storage. > > > > > > I bet a virtual nickle this is the sore spot. > > > > > > > You win a virtual nickle! > > I'm rich I'm rich... oh dang, virtual. > > I went back to 5.15, and confirmed that wait_iff_congested() did not > ever sleep with the try to eat /dev/zero load. Nor did it with insane > overcommit swap storm from hell with as much IO going on as my little > box is capable of generating, making the surrounding congestion bits > look.. down right expendable. > wait_iff_congested was broken once the block layer stopped tracking congestion and became a glorified cond_resched() in most cases. This is why the series aimed to remove the reliance on congestion_wait/wait_iff_congested. -- Mel Gorman SUSE Labs