From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752736AbbLGGss (ORCPT ); Mon, 7 Dec 2015 01:48:48 -0500 Received: from mail-wm0-f52.google.com ([74.125.82.52]:36389 "EHLO mail-wm0-f52.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751220AbbLGGsr (ORCPT ); Mon, 7 Dec 2015 01:48:47 -0500 Date: Mon, 7 Dec 2015 07:48:41 +0100 From: Ingo Molnar To: Peter Zijlstra Cc: vincent.weaver@maine.edu, jolsa@redhat.com, torvalds@linux-foundation.org, eranian@google.com, tglx@linutronix.de, acme@redhat.com, ak@linux.intel.com, linux-kernel@vger.kernel.org, hpa@zytor.com, linux-tip-commits@vger.kernel.org, Arnaldo Carvalho de Melo Subject: Re: [tip:perf/core] perf/x86: Use INST_RETIRED.PREC_DIST for cycles: ppp Message-ID: <20151207064841.GA29761@gmail.com> References: <1448929689-13771-2-git-send-email-andi@firstfloor.org> <20151206131102.GA12167@gmail.com> <20151206220651.GM17308@twins.programming.kicks-ass.net> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20151206220651.GM17308@twins.programming.kicks-ass.net> User-Agent: Mutt/1.5.23 (2014-03-12) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org * Peter Zijlstra wrote: > On Sun, Dec 06, 2015 at 02:11:02PM +0100, Ingo Molnar wrote: > > > Also, I'm not convinced we need a new 'ppp' qualifier for any of this, why not > > just replace 'pp' with this event - 'pp' is meant to be our most precise > > event. > > I requested this because the PREC_DIST events can only be scheduled on a single > counter, whereas the existing :pp events can be had on all 4. > > This mean you can have 2 concurrent :pp users (without RR), but not :ppp. Ok. Will tooling do the right thing? I.e. will the first user of 'perf top' get :ppp automatically, while the second one falls back to :pp? Thanks, Ingo