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 X-Spam-Level: X-Spam-Status: No, score=-5.3 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS, USER_AGENT_SANE_1 autolearn=no autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id A2B4CC433E9 for ; Tue, 26 Jan 2021 18:06:25 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 714D822273 for ; Tue, 26 Jan 2021 18:06:25 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2394011AbhAZSFc (ORCPT ); Tue, 26 Jan 2021 13:05:32 -0500 Received: from outbound-smtp25.blacknight.com ([81.17.249.193]:52332 "EHLO outbound-smtp25.blacknight.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1732054AbhAZJSe (ORCPT ); Tue, 26 Jan 2021 04:18:34 -0500 Received: from mail.blacknight.com (pemlinmail02.blacknight.ie [81.17.254.11]) by outbound-smtp25.blacknight.com (Postfix) with ESMTPS id 92E9ECAD1F for ; Tue, 26 Jan 2021 09:17:40 +0000 (GMT) Received: (qmail 31365 invoked from network); 26 Jan 2021 09:17:40 -0000 Received: from unknown (HELO techsingularity.net) (mgorman@techsingularity.net@[84.203.22.4]) by 81.17.254.9 with ESMTPSA (AES256-SHA encrypted, authenticated); 26 Jan 2021 09:17:40 -0000 Date: Tue, 26 Jan 2021 09:17:37 +0000 From: Mel Gorman To: Tibor Bana Cc: valdis.kletnieks@vt.edu, Jan Kara , Pavel Machek , kernel list , Andrew Morton , vbabka@suse.cz, aarcange@redhat.com, rientjes@google.com, mhocko@kernel.org, zi.yan@cs.rutgers.edu, hannes@cmpxchg.org Subject: Re: [regression -next0117] What is kcompactd and why is he eating 100% of my cpu? Message-ID: <20210126091737.GA3592@techsingularity.net> References: <20190126200005.GB27513@amd> <12171.1548557813@turing-police.cc.vt.edu> <20190127141556.GB9565@techsingularity.net> <20190127160027.GA9340@amd> <13417.1548624994@turing-police.cc.vt.edu> <20190128091627.GA27972@quack2.suse.cz> <14875.1548810399@turing-police.cc.vt.edu> <9618.1548822577@turing-police.cc.vt.edu> <20190130104020.GE9565@techsingularity.net> <20210125195438.c8d0e7980da0c2931d4f3056@gmail.com> MIME-Version: 1.0 Content-Type: text/plain; charset=iso-8859-15 Content-Disposition: inline In-Reply-To: <20210125195438.c8d0e7980da0c2931d4f3056@gmail.com> User-Agent: Mutt/1.10.1 (2018-07-13) Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Mon, Jan 25, 2021 at 07:54:38PM +0100, Tibor Bana wrote: > Greetings! > > I don't know if it still actual, but I am strugling with this problem right now and searching the internet for solutions. > I read the thread and saw that you are strugling to reproduce the problem, and I can reproduce it almost every day. > > - Install vmware player, and a linux guest. > - Configure the virtual machine to have a good amount of memory and cpu > - run resource intensive tasks on the guest > - when the host used up almost it's all memory and start to reuse caches kcompactd will kick in. > > As I know the problem is related to transparent huge pages, but I tried to disable it. > Today I saw the problem again and kcompactd shown an interesting status in top. It hasn't used any memory, all zeroes but it used up one core completely. > > My machine is a core-i7 with 4 physical cores and hyper threading and 24GB Memory > 5.9.11-arch2-1 #1 SMP PREEMPT Sat, 28 Nov 2020 02:07:22 +0000 x86_64 GNU/Linux > > Hope this can help, to point out the problem. > Is 5.10.10 affected because it included two patches related to halting compaction that are relevant. d20bdd571ee5c9966191568527ecdb1bd4b52368 mm/compaction: stop isolation if too many pages are isolated and we have pages to migrate 38935861d85a4d9a353d1dd5a156c97700e2765d mm/compaction: count pages and stop correctly during page isolation -- Mel Gorman SUSE Labs