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 B31BBC433F5 for ; Wed, 24 Nov 2021 10:53:18 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S241625AbhKXK40 (ORCPT ); Wed, 24 Nov 2021 05:56:26 -0500 Received: from outbound-smtp34.blacknight.com ([46.22.139.253]:53913 "EHLO outbound-smtp34.blacknight.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S233895AbhKXK4Y (ORCPT ); Wed, 24 Nov 2021 05:56:24 -0500 Received: from mail.blacknight.com (pemlinmail01.blacknight.ie [81.17.254.10]) by outbound-smtp34.blacknight.com (Postfix) with ESMTPS id 5515E20B4 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) Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 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