From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S933515Ab0I0Tvi (ORCPT ); Mon, 27 Sep 2010 15:51:38 -0400 Received: from ist.d-labs.de ([213.239.218.44]:53168 "EHLO mx01.d-labs.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S933389Ab0I0Tvh (ORCPT ); Mon, 27 Sep 2010 15:51:37 -0400 Date: Mon, 27 Sep 2010 21:51:35 +0200 From: Florian Mickler To: tmhikaru@gmail.com Newsgroups: gmane.linux.kernel Cc: Greg KH , linux-kernel@vger.kernel.org Subject: Re: Linux 2.6.35.6 Message-ID: <20100927215135.3d11d587@schatten.dmk.lab> In-Reply-To: <20100927163208.GA4892@roll> References: <20100927003608.GA20395@kroah.com> <20100927163208.GA4892@roll> X-Newsreader: Claws Mail 3.7.6cvs31 (GTK+ 2.20.1; x86_64-unknown-linux-gnu) Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Mon, 27 Sep 2010 12:32:08 -0400 tmhikaru@gmail.com wrote: > I'm not exactly sure what's going on here and I'd like some help > figuring out what is. For some inexplicable reason, ever since I started > using the 2.6.35.x series with the 2.6.35.3 release, my loadaverages tend to > bounce anywhere from as low to .2 to 1.5 - constantly, while the machine > seems idle. Consistently, there are no programs in D state in ps aux output, > no cpu hogging programs running in top, nothing I can see that should > explain the bizzarely high load average. *Something* is wrong beyond the > mere loadaverage numbers going crazy however, since timed runs of kernel > compiles done with my distro's kernel and 2.6.35.5 show that while there is > no *apparent* use of cpu or disk showing in vmstat while the machine is > idle, the compiles on the newer kernel are taking approximately twice as > long as before. Now, while I could try to figure out what patch started the > problem, I think it would be a better idea for me to make sure I'm looking > for the actual problem in the right place. Therefore, I know that cpu use, > disk I/O, and the kernel can drive the load average up. Of these things, cpu > use and disk I/O are trackable in top/ps output (eg, a process in D state is > waiting on the disk to do something and can't sleep.) but I don't know if > there's any easy way to determine if the kernel itself is doing something > that's driving up the load average. It's perplexing me that I can see the > loadaverage constantly bouncing about but can't seem to find any reason why > it is doing so. I can't comment on the bouncing part, but increased load average is partly bisected down in Bug 16525 (unexpected high load since 2.6.35 Bug 16525)[1]. Maybe you are seeing something similiar? > > If you have any tips or recommendations on what I should use to > investigate this further, please let me know. Once I have ensured to my own > satisfaction that I'm not doing something bizzare that's screwing up my > machine, I'll make a detailed bug report and start on figuring out how to > use git bisect. > > Tim McGrath >