Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755583Ab3HANfy (ORCPT ); Thu, 1 Aug 2013 09:35:54 -0400 Received: from merlin.infradead.org ([205.233.59.134]:39078 "EHLO merlin.infradead.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754005Ab3HANfx (ORCPT ); Thu, 1 Aug 2013 09:35:53 -0400 Date: Thu, 1 Aug 2013 15:35:49 +0200 From: Peter Zijlstra To: Jiri Olsa Cc: Frederic Weisbecker , LKML , Namhyung Kim , Ingo Molnar , Arnaldo Carvalho de Melo , Stephane Eranian Subject: Re: [PATCH 6/8] perf: Account freq events per cpu Message-ID: <20130801133549.GC27162@twins.programming.kicks-ass.net> References: <1374539466-4799-1-git-send-email-fweisbec@gmail.com> <1374539466-4799-7-git-send-email-fweisbec@gmail.com> <20130801124658.GC1032@krava.brq.redhat.com> <20130801133155.GB27162@twins.programming.kicks-ass.net> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20130801133155.GB27162@twins.programming.kicks-ass.net> User-Agent: Mutt/1.5.21 (2012-12-30) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 709 Lines: 15 On Thu, Aug 01, 2013 at 03:31:55PM +0200, Peter Zijlstra wrote: > the branch_stack thing tests ATTACH_TASK, which should also be good, but > leaves me wonder wth they do for those that are attached to tasks. Ah found it, in intel_pmu_lbr_enable() we test cpuc->lbr_context against event->ctx and wipe the LBR if they differ, that should indeed avoid the leak but isn't sufficient to guarantee sane data as the context swap for inherited counters can foil this. -- 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/