Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755296Ab2JVOzp (ORCPT ); Mon, 22 Oct 2012 10:55:45 -0400 Received: from mail-la0-f46.google.com ([209.85.215.46]:47685 "EHLO mail-la0-f46.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755183Ab2JVOzn (ORCPT ); Mon, 22 Oct 2012 10:55:43 -0400 MIME-Version: 1.0 In-Reply-To: <20121022135358.GJ2095@tassilo.jf.intel.com> References: <1350912052-10066-1-git-send-email-eranian@google.com> <1350912052-10066-2-git-send-email-eranian@google.com> <20121022135358.GJ2095@tassilo.jf.intel.com> Date: Mon, 22 Oct 2012 16:55:41 +0200 Message-ID: Subject: Re: [PATCH v2 1/2] perf tools: add event modifier to request exclusive PMU access From: Stephane Eranian To: Andi Kleen Cc: LKML , Peter Zijlstra , "mingo@elte.hu" , Arnaldo Carvalho de Melo , Jiri Olsa Content-Type: text/plain; charset=UTF-8 X-System-Of-Record: true Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1285 Lines: 36 On Mon, Oct 22, 2012 at 3:53 PM, Andi Kleen wrote: > On Mon, Oct 22, 2012 at 03:20:51PM +0200, Stephane Eranian wrote: >> This patch adds the x modifier for events. It allows users to >> request exclusive PMU access (attr->exclusive): >> >> perf stat -e cycles:x ...... >> or >> perf stat -e cpu/cycles/x .... >> >> Exclusive mode is a feature of perf_events which was not yet >> supported by the perf tool. Some events may require exclusive >> PMU access (like on Intel SandyBridge). > > You probably should add it also to be readable from sysfs > Not sure I understand what you mean here. x is not a HW property, this is a perf_event feature. It should NOT be exposed in /sys/device/cpu/format/. But maybe you're talking about a generic event exports in /sys/device/cpu/events. But why would I expose prec_dist there. And under what name? > (like I did with precise in my haswell patchkit) > > Then the SNB version of instructions-p can just force this > without the user having to do anything special. > > -Andi -- 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/