Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756439Ab2EOKuF (ORCPT ); Tue, 15 May 2012 06:50:05 -0400 Received: from merlin.infradead.org ([205.233.59.134]:55609 "EHLO merlin.infradead.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752682Ab2EOKuD convert rfc822-to-8bit (ORCPT ); Tue, 15 May 2012 06:50:03 -0400 Message-ID: <1337078996.27694.26.camel@twins> Subject: Re: Perf events warning.. From: Peter Zijlstra To: Linus Torvalds Cc: Ingo Molnar , Arnaldo Carvalho de Melo , linux-kernel@vger.kernel.org Date: Tue, 15 May 2012 12:49:56 +0200 In-Reply-To: References: <1337034048.27020.137.camel@laptop> Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7BIT X-Mailer: Evolution 3.2.2- Mime-Version: 1.0 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1089 Lines: 25 On Mon, 2012-05-14 at 15:25 -0700, Linus Torvalds wrote: > On Mon, May 14, 2012 at 3:20 PM, Peter Zijlstra wrote: > > > > So far I can't make any of the things I came up stick. You ran something > > simple like: 'perf record -e cycles:pp -F 20000 make test' ? Or did you > > do something more interesting? > > It was not much more complex than that. > > It did use "make -j64 test" to make the load a *bit* more interesting > (and go noticeably faster), but other than that you got it. OK, that limits the scope of crazy scenarios I have to consider, still no immediate clue though.. I think I've found a possible race, but I can't make it work with that workload. I've also let your workload run for 2+ hours in trying to reproduce, but no luck, it must be a very narrow window indeed. I'll keep prodding at it.. -- 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/