From mboxrd@z Thu Jan 1 00:00:00 1970 From: Arjan van de Ven Subject: Re: [patch 0/3] [Announcement] Performance Counters for Linux Date: Thu, 4 Dec 2008 23:02:06 -0800 Message-ID: <20081204230206.6e083d51@infradead.org> References: <20081204225345.654705757@linutronix.de> <18744.29747.728320.652642@cargo.ozlabs.ibm.com> <20081205063131.GB12785@elte.hu> Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Return-path: Received: from casper.infradead.org ([85.118.1.10]:45524 "EHLO casper.infradead.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751888AbYLEHA6 (ORCPT ); Fri, 5 Dec 2008 02:00:58 -0500 In-Reply-To: <20081205063131.GB12785@elte.hu> Sender: linux-arch-owner@vger.kernel.org List-ID: To: Ingo Molnar Cc: Paul Mackerras , Thomas Gleixner , LKML , linux-arch@vger.kernel.org, Andrew Morton , Stephane Eranian , Eric Dumazet , Robert Richter , Peter Anvin , Peter Zijlstra , Steven Rostedt , David Miller On Fri, 5 Dec 2008 07:31:31 +0100 Ingo Molnar wrote: > Btw., i'm curious, why would we want to do that? It skews the results > if the task continues executing and counters stop. To get the highest > quality profiling output the counters should follow the true state of > the task that is profiled - and events should be passed to the > monitoring task asynchronously. The _events_ can contain precise > coupled information > - but the counters should continue. btw stopping the task on counter overflow is an issue for things that want to self profile, like JITs -- Arjan van de Ven Intel Open Source Technology Centre For development, discussion and tips for power savings, visit http://www.lesswatts.org