From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753639Ab1KJScJ (ORCPT ); Thu, 10 Nov 2011 13:32:09 -0500 Received: from casper.infradead.org ([85.118.1.10]:53080 "EHLO casper.infradead.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750965Ab1KJScH convert rfc822-to-8bit (ORCPT ); Thu, 10 Nov 2011 13:32:07 -0500 Subject: Re: [PATCH] perf_events: fix and improve x86 event scheduling From: Peter Zijlstra To: Stephane Eranian Cc: linux-kernel@vger.kernel.org, robert.richter@amd.com, mingo@elte.hu, ming.m.lin@intel.com, ak@linux.intel.com Date: Thu, 10 Nov 2011 19:31:50 +0100 In-Reply-To: References: <20111107110149.GA5177@quad> <1320935860.13800.25.camel@twins> Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: 8BIT X-Mailer: Evolution 3.0.3- Message-ID: <1320949910.13800.35.camel@twins> Mime-Version: 1.0 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Thu, 2011-11-10 at 16:09 +0100, Stephane Eranian wrote: > What are the configs for which you have failures on Intel? > Continuing to use Core2 as an example platform: cycles,cycles,instructions,instructions They all have weight 3, yet the masks are not the same, it'll assign them like: pmc0, pmc1, fp-instructions, fail Counter rotation will make sure the next attempt looks like: instructions,cycles,cycles,instructions Which will work correctly since it'll do: pmc0, pmc1, fp-cycles, fp-instructions. Its usually not a really big deal, but I ran into it few months ago and noticed it because the scaled values weren't what I was expecting them to be, took me a while to figure out wth happened.