Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751362Ab3HSLRF (ORCPT ); Mon, 19 Aug 2013 07:17:05 -0400 Received: from mx1.redhat.com ([209.132.183.28]:10479 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751233Ab3HSLRE (ORCPT ); Mon, 19 Aug 2013 07:17:04 -0400 Date: Mon, 19 Aug 2013 13:16:16 +0200 From: Jiri Olsa To: Stephane Eranian Cc: Andi Kleen , Peter Zijlstra , LKML , Corey Ashford , Frederic Weisbecker , Paul Mackerras , Ingo Molnar , Arnaldo Carvalho de Melo Subject: Re: [PATCH 1/2] perf x86: Make intel_pmu_enable_all to enable only active events Message-ID: <20130819111616.GA1145@krava.brq.redhat.com> References: <1376411952-16718-1-git-send-email-jolsa@redhat.com> <1376411952-16718-2-git-send-email-jolsa@redhat.com> <20130815114040.GR24092@twins.programming.kicks-ass.net> <20130815135314.GE19750@two.firstfloor.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: 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 Content-Length: 980 Lines: 23 On Mon, Aug 19, 2013 at 11:16:54AM +0200, Stephane Eranian wrote: > On Thu, Aug 15, 2013 at 3:53 PM, Andi Kleen wrote: > >> > >> I think its a NOP; this is the global ctrl register but > >> intel_pmu_disable_event() writes PERFEVTSELx.EN = 0, so even if you > >> enable it in the global mask, the event should still be disabled. > > > > Yes the hardware ANDs the various enable bits in the different > > registers. > > > Andi is correct. There is a logical AND between GLOBAL_CTRL and > the individual PERFEVTCTL.EN bits. If the EN bit is zero, then the > counter does not count. That also applies to fixed counters. right, peter mentioned I could have seen already queded NMI comming in for that event.. jirka -- 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/