From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754792Ab1BGVQG (ORCPT ); Mon, 7 Feb 2011 16:16:06 -0500 Received: from cantor2.suse.de ([195.135.220.15]:46072 "EHLO mx2.suse.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754524Ab1BGVQD (ORCPT ); Mon, 7 Feb 2011 16:16:03 -0500 Date: Mon, 7 Feb 2011 22:16:01 +0100 From: Michal Hocko To: Andrea Arcangeli Cc: LKML , linux-mm@kvack.org Subject: Re: khugepaged eating 100%CPU Message-ID: <20110207211601.GA25665@tiehlicka.suse.cz> References: <20110207210517.GA24837@tiehlicka.suse.cz> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20110207210517.GA24837@tiehlicka.suse.cz> User-Agent: Mutt/1.5.20 (2009-06-14) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Mon 07-02-11 22:06:54, Michal Hocko wrote: > Hi Andrea, > > I am currently running into an issue when khugepaged is running 100% on > one of my CPUs for a long time (at least one hour as I am writing the > email). The kernel is the clean 2.6.38-rc3 (i386) vanilla kernel. > > I have tried to disable defrag but it didn't help (I haven't rebooted > after setting the value). I am not sure what information is helpful and > also not sure whether I am able to reproduce it after restart (it is the > first time I can see this problem) so sorry for the poor report. > > Here is some basic info which might be useful (config and sysrq+t are > attached): > ========= And I have just realized that I forgot about the daemon stack: # cat /proc/573/stack [] shrink_zone+0x1b9/0x455 [] do_try_to_free_pages+0x9d/0x301 [] try_to_free_pages+0xb3/0x104 [] __alloc_pages_nodemask+0x358/0x589 [] khugepaged+0x13f/0xc60 [] kthread+0x67/0x6c [] kernel_thread_helper+0x6/0x10 [] 0xffffffff -- Michal Hocko SUSE Labs SUSE LINUX s.r.o. Lihovarska 1060/12 190 00 Praha 9 Czech Republic