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 6B99FC433F5 for ; Wed, 24 Nov 2021 10:53:42 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id D5FDA6B0081; Wed, 24 Nov 2021 05:53:26 -0500 (EST) Received: by kanga.kvack.org (Postfix, from userid 40) id D0D246B0080; Wed, 24 Nov 2021 05:53:26 -0500 (EST) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id BFCC26B0081; Wed, 24 Nov 2021 05:53:26 -0500 (EST) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0203.hostedemail.com [216.40.44.203]) by kanga.kvack.org (Postfix) with ESMTP id B2AFC6B007E for ; Wed, 24 Nov 2021 05:53:26 -0500 (EST) Received: from smtpin08.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay05.hostedemail.com (Postfix) with ESMTP id 7534C18113284 for ; Wed, 24 Nov 2021 10:53:16 +0000 (UTC) X-FDA: 78843511992.08.9C57452 Received: from outbound-smtp22.blacknight.com (outbound-smtp22.blacknight.com [81.17.249.190]) by imf12.hostedemail.com (Postfix) with ESMTP id D5D6F10003D0 for ; Wed, 24 Nov 2021 10:53:15 +0000 (UTC) Received: from mail.blacknight.com (pemlinmail01.blacknight.ie [81.17.254.10]) by outbound-smtp22.blacknight.com (Postfix) with ESMTPS id 5363DBB0BC for ; Wed, 24 Nov 2021 10:53:14 +0000 (GMT) Received: (qmail 23874 invoked from network); 24 Nov 2021 10:53:14 -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); 24 Nov 2021 10:53:14 -0000 Date: Wed, 24 Nov 2021 10:53:11 +0000 From: Mel Gorman To: Vlastimil Babka Cc: "Darrick J. Wong" , Andrew Morton , NeilBrown , Theodore Ts'o , Andreas Dilger , Matthew Wilcox , Michal Hocko , Dave Chinner , Rik van Riel , Johannes Weiner , Jonathan Corbet , Linux-MM , Linux-fsdevel , LKML Subject: Re: [PATCH 3/8] mm/vmscan: Throttle reclaim when no progress is being made Message-ID: <20211124105311.GF3366@techsingularity.net> References: <20211022144651.19914-1-mgorman@techsingularity.net> <20211022144651.19914-4-mgorman@techsingularity.net> <20211124011912.GA265983@magnolia> <20211124103221.GD3366@techsingularity.net> MIME-Version: 1.0 Content-Type: text/plain; charset=iso-8859-15 Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.10.1 (2018-07-13) X-Rspamd-Server: rspam06 X-Rspamd-Queue-Id: D5D6F10003D0 X-Stat-Signature: t38xttwkcr3cgsffkwfqu5tbjdhmhw8r Authentication-Results: imf12.hostedemail.com; dkim=none; spf=pass (imf12.hostedemail.com: domain of mgorman@techsingularity.net designates 81.17.249.190 as permitted sender) smtp.mailfrom=mgorman@techsingularity.net; dmarc=none X-HE-Tag: 1637751195-233922 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, Nov 24, 2021 at 11:43:05AM +0100, Vlastimil Babka wrote: > >> Any thoughts? For now I can just hack around this by skipping > >> reclaim_throttle if cgroup_reclaim() == true, but that's probably not > >> the correct fix. :) > >> > > > > No, it wouldn't be but a possibility is throttling for only 1 jiffy if > > reclaiming within a memcg and the zone is balanced overall. > > > > The interruptible part should just be the patch below. I need to poke at > > the cgroup limit part a bit > > As the throttle timeout is short anyway, will the TASK_UNINTERRUPTIBLE vs > TASK_INTERRUPTIBLE make a difference for the (ability to kill? AFAIU > typically this inability to kill is because of a loop that doesn't check for > fatal_signal_pending(). > Yep, and the fatal_signal_pending() is lacking within reclaim in general but I'm undecided on how much that should change in the context of reclaim throttling but at minimum, I don't want the signal delivery to be masked or delayed. -- Mel Gorman SUSE Labs