Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753344AbYJ1KEb (ORCPT ); Tue, 28 Oct 2008 06:04:31 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1751883AbYJ1KEX (ORCPT ); Tue, 28 Oct 2008 06:04:23 -0400 Received: from mx2.mail.elte.hu ([157.181.151.9]:58487 "EHLO mx2.mail.elte.hu" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751518AbYJ1KEW (ORCPT ); Tue, 28 Oct 2008 06:04:22 -0400 Date: Tue, 28 Oct 2008 11:04:03 +0100 From: Ingo Molnar To: Arjan van de Ven Cc: "Frank Ch. Eigler" , linux-kernel@vger.kernel.org, Steven Rostedt , Peter Zijlstra , lenb@kernel.org Subject: Re: PATCH] ftrace: Add a C/P state tracer to help power optimization Message-ID: <20081028100403.GC15734@elte.hu> References: <20081006102640.481acd23@infradead.org> <20081027155920.GS5704@elte.hu> <20081027110522.6cb7b142@infradead.org> <20081027140630.521f933d@infradead.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20081027140630.521f933d@infradead.org> 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,DNS_FROM_SECURITYSAGE autolearn=no SpamAssassin version=3.2.3 -1.5 BAYES_00 BODY: Bayesian spam probability is 0 to 1% [score: 0.0000] 0.0 DNS_FROM_SECURITYSAGE RBL: Envelope sender in blackholes.securitysage.com Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1101 Lines: 38 * Arjan van de Ven wrote: > On Mon, 27 Oct 2008 15:47:30 -0400 > fche@redhat.com (Frank Ch. Eigler) wrote: > > > > > Arjan van de Ven writes: > > > > > [...] > > > --- a/arch/x86/kernel/cpu/cpufreq/acpi-cpufreq.c > > > +++ b/arch/x86/kernel/cpu/cpufreq/acpi-cpufreq.c > > > [...] > > > @@ -427,6 +429,8 @@ static int acpi_cpufreq_target(struct > > > cpufreq_policy *policy, } > > > } > > > > > > + trace_power_mark(&it, POWER_PSTATE, next_perf_state); > > > + > > > switch (data->cpu_feature) { > > > case SYSTEM_INTEL_MSR_CAPABLE: > > > cmd.type = SYSTEM_INTEL_MSR_CAPABLE; > > > [...] > > > > Is there some reason that this doesn't use tracepoints instead > > of such a single-backend hook? > > because it's a ton simpler this way? do simple things simpe and all > that.... correct. 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/