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=-5.8 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI, SPF_HELO_NONE,SPF_PASS 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 9BD47C433DB for ; Tue, 16 Feb 2021 12:37:31 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 58D5D64DDA for ; Tue, 16 Feb 2021 12:37:31 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229979AbhBPMhP (ORCPT ); Tue, 16 Feb 2021 07:37:15 -0500 Received: from mail.zx2c4.com ([104.131.123.232]:41916 "EHLO mail.zx2c4.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229970AbhBPMhI (ORCPT ); Tue, 16 Feb 2021 07:37:08 -0500 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=zx2c4.com; s=20210105; t=1613478985; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: in-reply-to:in-reply-to:references:references; bh=zvWPHeRu5Ta1ITtaL534RRLVGoWOubmd/7MZ9yEeUuQ=; b=RztHKShYzf7YfqsFFHTiHt5XfOXMGAQWWz4aq25hqQR7BL2pEWME2ODedVDqAgZQfipe7S 7083DgElJ+0Ye50xK5cbZuWUO5tQOruU8TxJFZqy0moj/h1MQVFMMmUeSXlPNOVNuOgWg4 GzIWcuSv/otj0byrIY1Euv0l7PXSK2M= Received: by mail.zx2c4.com (ZX2C4 Mail Server) with ESMTPSA id f12447e9 (TLSv1.3:AEAD-AES256-GCM-SHA384:256:NO); Tue, 16 Feb 2021 12:36:25 +0000 (UTC) Date: Tue, 16 Feb 2021 13:36:22 +0100 From: "Jason A. Donenfeld" To: Tibor Bana Cc: Mel Gorman , 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: 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=utf-8 Content-Disposition: inline In-Reply-To: <20210125195438.c8d0e7980da0c2931d4f3056@gmail.com> 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 Another anecdote: 5.11.0, 64 gigs of ram. If I run QEMU/KVM for a VM with 16 gigs at the same time as a VMware VM with 16 gigs of ram, kcompact goes wild and both VMs get really slow. The key here is running KVM at the same time as VMware.