Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1757409AbYKUT2y (ORCPT ); Fri, 21 Nov 2008 14:28:54 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1754318AbYKUT2q (ORCPT ); Fri, 21 Nov 2008 14:28:46 -0500 Received: from smtp-out.google.com ([216.239.45.13]:29770 "EHLO smtp-out.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753039AbYKUT2p (ORCPT ); Fri, 21 Nov 2008 14:28:45 -0500 DomainKey-Signature: a=rsa-sha1; s=beta; d=google.com; c=nofws; q=dns; h=subject:from:to:cc:in-reply-to:references:content-type: organization:date:message-id:mime-version:x-mailer:content-transfer-encoding; b=MaaSH0bezOraDdElfCw+N8iZMk/IId4Lr/Nyuf7DpVaWBOos+q9DL/I9e507FHXEV wdJugdFfKfGqdQ5Tph46g== Subject: Re: regression introduced by - timers: fix itimer/many thread hang From: Frank Mayhar To: Petr Tesarik Cc: Peter Zijlstra , Christoph Lameter , Doug Chapman , mingo@elte.hu, roland@redhat.com, adobriyan@gmail.com, akpm@linux-foundation.org, linux-kernel In-Reply-To: <200811211942.43848.ptesarik@suse.cz> References: <1224694989.8431.23.camel@oberon> <1226015568.2186.20.camel@bobble.smo.corp.google.com> <1226053744.7803.5851.camel@twins> <200811211942.43848.ptesarik@suse.cz> Content-Type: text/plain Organization: Google, Inc. Date: Fri, 21 Nov 2008 11:26:03 -0800 Message-Id: <1227295563.21605.13.camel@bobble.smo.corp.google.com> Mime-Version: 1.0 X-Mailer: Evolution 2.6.1 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 888 Lines: 20 On Fri, 2008-11-21 at 19:42 +0100, Petr Tesarik wrote: > This is just not true. I've seen a very real example of a lockup with a very > sane number of threads (one per CPU), but on a very large machine (1024 CPUs > IIRC). The application set per-process CPU profiling with an interval of 1 > tick, which translates to 1024 timers firing off with each tick... > > Well, yes, that was broken, too, but that's the way one quite popular FORTRAN > compiler works... Petr, have you tried the fix in the latest kernel? Does it help? I'm intensely curious to know how it affected your runs. -- Frank Mayhar Google, Inc. -- 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/