Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932736Ab3EOOUu (ORCPT ); Wed, 15 May 2013 10:20:50 -0400 Received: from mail-oa0-f44.google.com ([209.85.219.44]:49261 "EHLO mail-oa0-f44.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932700Ab3EOOUr (ORCPT ); Wed, 15 May 2013 10:20:47 -0400 MIME-Version: 1.0 In-Reply-To: <20130503170007.GA30733@dyad.programming.kicks-ass.net> References: <20130503121122.931661809@chello.nl> <20130503121256.083340271@chello.nl> <20130503143507.GP19487@tassilo.jf.intel.com> <20130503170007.GA30733@dyad.programming.kicks-ass.net> Date: Wed, 15 May 2013 16:20:46 +0200 Message-ID: Subject: Re: [PATCH 1/3] perf, x86: Blacklist all MEM_*_RETIRED events for IVB From: Stephane Eranian To: Peter Zijlstra Cc: Andi Kleen , Peter Zijlstra , Ingo Molnar , LKML Content-Type: text/plain; charset=UTF-8 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1257 Lines: 31 Hi, Based on our testing, it appears the corruption occurs only when the MEM_* events are used and only on the sibling counter. In other words, if HT0 has MEM_* in cntr0, then HT1 cntr0 cannot be used, otherwise whatever is there may get corrupted. So I think we could enhance Andi's initial patch to handle this case instead of blacklist those events. They are very important events. On Fri, May 3, 2013 at 7:00 PM, Peter Zijlstra wrote: > On Fri, May 03, 2013 at 07:35:07AM -0700, Andi Kleen wrote: >> On Fri, May 03, 2013 at 02:11:23PM +0200, Peter Zijlstra wrote: >> > Errata BV98 states that all MEM_*_RETIRED events corrupt the counter >> > value of the SMT sibling's counters. Blacklist these events >> >> I disagree with this patch. This is just overkill and not needed >> at all. > > Then give me a patch that both completely describes the problem and ensures > isolation so that no counters get corrupted (and isn't too invasive). > > So far you've failed on both counts. > > -- 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/