Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755837AbZCNLva (ORCPT ); Sat, 14 Mar 2009 07:51:30 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1752984AbZCNLvS (ORCPT ); Sat, 14 Mar 2009 07:51:18 -0400 Received: from mx3.mail.elte.hu ([157.181.1.138]:42898 "EHLO mx3.mail.elte.hu" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752854AbZCNLvS (ORCPT ); Sat, 14 Mar 2009 07:51:18 -0400 Date: Sat, 14 Mar 2009 12:51:05 +0100 From: Ingo Molnar To: Paul Mackerras Cc: Peter Zijlstra , linux-kernel@vger.kernel.org, Thomas Gleixner Subject: Re: [PATCH] perfcounters: Make s/w counters in a group only count when group is on Message-ID: <20090314115105.GC3805@elte.hu> References: <18873.48668.562126.113618@cargo.ozlabs.ibm.com> <1236939816.22914.3714.camel@twins> <18874.20538.785519.824803@cargo.ozlabs.ibm.com> <1236948283.22447.36.camel@twins> <18874.57621.950179.972863@cargo.ozlabs.ibm.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <18874.57621.950179.972863@cargo.ozlabs.ibm.com> User-Agent: Mutt/1.5.18 (2008-05-17) X-ELTE-VirusStatus: clean X-ELTE-SpamScore: -1.5 X-ELTE-SpamLevel: X-ELTE-SpamCheck: no X-ELTE-SpamVersion: ELTE 2.0 X-ELTE-SpamCheck-Details: score=-1.5 required=5.9 tests=BAYES_00 autolearn=no SpamAssassin version=3.2.5 -1.5 BAYES_00 BODY: Bayesian spam probability is 0 to 1% [score: 0.0000] Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 624 Lines: 20 * Paul Mackerras wrote: > Peter Zijlstra writes: > > > The issue I have with your approach is two-fold: > > - it breaks the symmetry between software and hardware counters by > > treating them differently. > > So... I was about to restore that symmetry by implementing > lazy PMU context switching. [...] That would be _really_ neat to have. Ingo -- 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/