Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S934577Ab0GOTuJ (ORCPT ); Thu, 15 Jul 2010 15:50:09 -0400 Received: from mail-bw0-f46.google.com ([209.85.214.46]:53598 "EHLO mail-bw0-f46.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S934528Ab0GOTuE (ORCPT ); Thu, 15 Jul 2010 15:50:04 -0400 DomainKey-Signature: a=rsa-sha1; c=nofws; d=gmail.com; s=gamma; h=mime-version:sender:in-reply-to:references:date :x-google-sender-auth:message-id:subject:from:to:cc:content-type; b=jnpAqoeeUYt5Syy6W+p/yjkAVZxIMWA8whZrkv5Ed//J8kRDR0rIh1A67YU+bfCpsl oUAyNrHZxr98f5cJc53u6v9ZGDvIkE/rTEvG5RviRkvnxKAydGN7M/UEQKT5Kzs/c27z O5OmP9bwIXLKcJ82eBkG9NhtcqH3/xTZNGDS0= MIME-Version: 1.0 In-Reply-To: <20100715191638.GA3694@brouette> References: <1279100846.8592.53.camel@e102109-lin.cambridge.arm.com> <4C3D89AC.4040303@cs.helsinki.fi> <1279205891.6664.46.camel@e102109-lin.cambridge.arm.com> <4C3F2F52.2050101@cs.helsinki.fi> <20100715162805.GA10240@brouette> <20100715191638.GA3694@brouette> Date: Thu, 15 Jul 2010 22:50:02 +0300 X-Google-Sender-Auth: jvgbtA00PFRnOgeKMo0JTuiTPxY Message-ID: Subject: Re: kmemleak, cpu usage jump out of nowhere From: Pekka Enberg To: Damien Wyart Cc: Zeno Davatz , Catalin Marinas , linux-kernel@vger.kernel.org, Andrew Morton , x86@kernel.org, mingo@elte.hu, yinghai@kernel.org, Peter Zijlstra Content-Type: text/plain; charset=ISO-8859-1 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1731 Lines: 33 On Thu, Jul 15, 2010 at 10:16 PM, Damien Wyart wrote: >> > > I also did not have anymore hangs and random bad moods of my CPUs >> > > that all of a sudden grab 100% of all 8 cores of my CPU power across >> > > my machine since I disabled >> > > CONFIG_NO_BOOTMEM: > >> * Pekka Enberg [2010-07-15 18:54]: >> > Interesting. Damien, does disabling CONFIG_NO_BOOTMEM fix you problem too? > >> I will test in the coming hours, and report back tomorrow... Just >> recompiled 2.6.35-rc5-git1 with this option disabled. > > For now, I can't reproduce the problem with CONFIG_NO_BOOTMEM disabled ; > with the option and rc5 the problem was happening quite quickly after > boot and normal use of the machine. So it seems I can confirme what Zeno > has seen and I hope this will give a hint to debug the problem. I guess > this has not been reported that much because many testers might not have > enabled CONFIG_NO_BOOTMEM... Maybe the scheduler folks could test their > benchmark with a kernel having this option enabled? To be honest, the bug is bit odd. It's related to boot-time memory allocator changes but yet it seems to manifest itself as a scheduling problem. So if you have some spare time and want to speed up the debugging process, please test v2.6.34 and v2.6.35-rc1 with CONFIG_NO_BOOTMEM and if former is good and latter is bad, try to see if you can identify the offending commit with "git bisect." Pekka -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/