From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752100Ab3JFJK7 (ORCPT ); Sun, 6 Oct 2013 05:10:59 -0400 Received: from mail-ea0-f180.google.com ([209.85.215.180]:57003 "EHLO mail-ea0-f180.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751570Ab3JFJK5 (ORCPT ); Sun, 6 Oct 2013 05:10:57 -0400 Date: Sun, 6 Oct 2013 11:10:54 +0200 From: Ingo Molnar To: Peter Zijlstra Cc: Adrian Hunter , hpa@zytor.com, linux-kernel@vger.kernel.org, tglx@linutronix.de, linux-tip-commits@vger.kernel.org Subject: Re: [tip:perf/core] perf/x86: Clean up cap_user_time* setting Message-ID: <20131006091054.GA4342@gmail.com> References: <524F097A.9010506@intel.com> <20131004185539.GT15690@laptop.programming.kicks-ass.net> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20131004185539.GT15690@laptop.programming.kicks-ass.net> User-Agent: Mutt/1.5.21 (2010-09-15) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org * Peter Zijlstra wrote: > On Fri, Oct 04, 2013 at 09:31:22PM +0300, Adrian Hunter wrote: > > On 4/10/2013 8:31 p.m., tip-bot for Peter Zijlstra wrote: > > >Commit-ID: d8b11a0cbd1c66ce283eb9dabe0498dfa6483f32 > > >Gitweb: http://git.kernel.org/tip/d8b11a0cbd1c66ce283eb9dabe0498dfa6483f32 > > >Author: Peter Zijlstra > > >AuthorDate: Thu, 3 Oct 2013 16:00:14 +0200 > > >Committer: Ingo Molnar > > >CommitDate: Fri, 4 Oct 2013 09:58:55 +0200 > > > > > >perf/x86: Clean up cap_user_time* setting > > > > > >Currently the cap_user_time_zero capability has different tests than > > >cap_user_time; even though they expose the exact same data. > > > > > >Switch from CONSTANT && NONSTOP to sched_clock_stable to also deal > > >with multi cabinet machines and drop the tsc_disabled() check.. non of > > >this will work sanely without tsc anyway. > > > > Unfortunately in the case that TSC is disabled, sched_clock is still > > reported as stable, which means removing the tsc_disabled() check breaks > > the capability bit. e.g. > > I'm wanting to hear from the x86 people on why we have this absurd knob > to begin with; but I'm tempted to simply disable all of perf if you > touch it. I'm fully with you, please zap the 'notsc' boot option - it's an ancient relic, if any box is still broken with the TSC on we want to hear about it and fix it! Thanks, Ingo