Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753953AbZD2M4W (ORCPT ); Wed, 29 Apr 2009 08:56:22 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1752199AbZD2M4M (ORCPT ); Wed, 29 Apr 2009 08:56:12 -0400 Received: from mx3.mail.elte.hu ([157.181.1.138]:41544 "EHLO mx3.mail.elte.hu" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751604AbZD2M4L (ORCPT ); Wed, 29 Apr 2009 08:56:11 -0400 Date: Wed, 29 Apr 2009 14:55:56 +0200 From: Ingo Molnar To: Paul Mackerras Cc: Peter Zijlstra , Robert Richter , LKML Subject: Re: [PATCH 04/29] x86/perfcounters: rework pmc_amd_save_disable_all() and pmc_amd_restore_all() Message-ID: <20090429125556.GA31500@elte.hu> References: <1241002046-8832-1-git-send-email-robert.richter@amd.com> <1241002046-8832-5-git-send-email-robert.richter@amd.com> <1241003260.8021.236.camel@laptop> <20090429111159.GJ2373@elte.hu> <18936.18732.35199.647196@cargo.ozlabs.ibm.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <18936.18732.35199.647196@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=3.2.3 -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: 935 Lines: 27 * Paul Mackerras wrote: > Ingo Molnar wrote: > > > Could we remove the disable-all facility altogether and make the > > core code NMI-safe? The current approach wont scale on CPUs that > > dont have global-disable features. > > > > disable-all was arguably a hack i introduced and which spread > > too far. Can you see a conceptual need for it? > > If you're talking about hw_perf_save_disable / hw_perf_restore, > please don't get rid of those. I use them to batch up counter > enable/disable operations so I only have to compute the PMU config > once for each batch rather than every time an individual counter > is enabled or disabled. ok, sure. 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/