Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754152Ab2EXI7b (ORCPT ); Thu, 24 May 2012 04:59:31 -0400 Received: from mail-lpp01m010-f46.google.com ([209.85.215.46]:58521 "EHLO mail-lpp01m010-f46.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752391Ab2EXI73 (ORCPT ); Thu, 24 May 2012 04:59:29 -0400 MIME-Version: 1.0 In-Reply-To: <1337846873.9783.66.camel@laptop> References: <1337828525-1789-1-git-send-email-namhyung.kim@lge.com> <1337844471.9783.48.camel@laptop> <1337845936.9783.57.camel@laptop> <1337846272.9783.59.camel@laptop> <1337846873.9783.66.camel@laptop> Date: Thu, 24 May 2012 10:59:27 +0200 Message-ID: Subject: Re: [PATCH] perf, x86: Make cycles:p working on SNB From: Stephane Eranian To: Peter Zijlstra Cc: Namhyung Kim , Ingo Molnar , Namhyung Kim , Arnaldo Carvalho de Melo , Paul Mackerras , LKML 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: 1431 Lines: 29 On Thu, May 24, 2012 at 10:07 AM, Peter Zijlstra wrote: > On Thu, 2012-05-24 at 10:00 +0200, Stephane Eranian wrote: >> On Thu, May 24, 2012 at 9:57 AM, Peter Zijlstra wrote: >> > On Thu, 2012-05-24 at 09:52 +0200, Peter Zijlstra wrote: >> >> >> >> OK, so how about I queue the below and if the u-code updates gets >> >> released before this hits Linus' tree we'll make it all go away ;-) >> >> >> > Also, I suspect the u-code update might make INST_RETIRED.ANY_P >> > available on SNB again voiding the need to use a different encoding. But >> > we'll cross that bridge when we'll get to it. >> >> The PREC_DIST is by design, it is not a work-around of any sort. >> It is an attempt at getting a better distribution of samples when sampling >> with inst_retired. > > Oh completely agreed, note that my patch used UOPS_RETIRED.ALL. Only > Namhyung used PREC_DIST, mostly I suspect because he's not stared at all > these manuals for long yet ;-) > PREC_DIST is only meaningful when used with PEBS. This is where it improves the sample distribution (compensation some of the PEBS shadow effect). Otherwise, you still habe INST_RETIRED:ANY_P. -- 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/