From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755769Ab1KUTEH (ORCPT ); Mon, 21 Nov 2011 14:04:07 -0500 Received: from mail-gx0-f174.google.com ([209.85.161.174]:53201 "EHLO mail-gx0-f174.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752660Ab1KUTED (ORCPT ); Mon, 21 Nov 2011 14:04:03 -0500 MIME-Version: 1.0 In-Reply-To: References: <1321901536.28118.20.camel@twins> Date: Mon, 21 Nov 2011 20:04:02 +0100 Message-ID: Subject: Re: [tip:perf/urgent] perf/x86: Enable raw event access to Intel offcore events From: Stephane Eranian To: Vince Weaver Cc: Peter Zijlstra , mingo@redhat.com, hpa@zytor.com, linux-kernel@vger.kernel.org, tglx@linutronix.de, mingo@elte.hu 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 Vince, On Mon, Nov 21, 2011 at 8:01 PM, Vince Weaver wrote: > On Mon, 21 Nov 2011, Peter Zijlstra wrote: >> On Mon, 2011-11-21 at 13:24 -0500, Vince Weaver wrote: > >> > Now I'll have to find something else >> > to complain about, probably the scedulability issue introduced with the >> > NMI watchdog. >> >> But you can disable that thing, right? >> >> echo 0 > /proc/sys/kernel/nmi_watchdog; >> >> or so should do the trick. > > yes, if the user running PAPI has root. > > That's unfortunately not always the case, and sometimes people want to > have both the NMI watchdog operating and use PAPI simultaneously. > I don't understand why you have a problem with NMI watchdog. Multiplexing allows you to still measure more events than there are counters. > We have a workaround, but it currently disables kernel multiplexing and a > few other nice features. > > Vince > vweaver1@eecs.utk.edu > >