From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755250Ab0CJNNx (ORCPT ); Wed, 10 Mar 2010 08:13:53 -0500 Received: from hera.kernel.org ([140.211.167.34]:43063 "EHLO hera.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752611Ab0CJNNu (ORCPT ); Wed, 10 Mar 2010 08:13:50 -0500 Date: Wed, 10 Mar 2010 13:13:12 GMT From: tip-bot for Peter Zijlstra Cc: linux-kernel@vger.kernel.org, hpa@zytor.com, mingo@redhat.com, acme@infradead.org, a.p.zijlstra@chello.nl, tglx@linutronix.de, mingo@elte.hu Reply-To: mingo@redhat.com, hpa@zytor.com, linux-kernel@vger.kernel.org, a.p.zijlstra@chello.nl, acme@infradead.org, tglx@linutronix.de, mingo@elte.hu In-Reply-To: References: To: linux-tip-commits@vger.kernel.org Subject: [tip:perf/urgent] perf, x86: Fix double enable calls Message-ID: Git-Commit-ID: f3d46b2e6fa57547f9884330798792afc83f4b04 X-Mailer: tip-git-log-daemon MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Disposition: inline X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.2.3 (hera.kernel.org [127.0.0.1]); Wed, 10 Mar 2010 13:13:12 +0000 (UTC) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Commit-ID: f3d46b2e6fa57547f9884330798792afc83f4b04 Gitweb: http://git.kernel.org/tip/f3d46b2e6fa57547f9884330798792afc83f4b04 Author: Peter Zijlstra AuthorDate: Sat, 6 Mar 2010 13:24:58 +0100 Committer: Ingo Molnar CommitDate: Wed, 10 Mar 2010 13:22:35 +0100 perf, x86: Fix double enable calls hw_perf_enable() would enable already enabled events. This causes problems with code that assumes that ->enable/->disable calls are balanced (like the LBR code does). What happens is that events that were already running and left in place would get enabled again. Avoid this by only enabling new events that match their previous assignment. Signed-off-by: Peter Zijlstra Cc: Arnaldo Carvalho de Melo Cc: paulus@samba.org Cc: eranian@google.com Cc: robert.richter@amd.com Cc: fweisbec@gmail.com LKML-Reference: Signed-off-by: Ingo Molnar --- arch/x86/kernel/cpu/perf_event.c | 4 ++++ 1 files changed, 4 insertions(+), 0 deletions(-) diff --git a/arch/x86/kernel/cpu/perf_event.c b/arch/x86/kernel/cpu/perf_event.c index 045cc0b..1d665a0 100644 --- a/arch/x86/kernel/cpu/perf_event.c +++ b/arch/x86/kernel/cpu/perf_event.c @@ -835,6 +835,10 @@ void hw_perf_enable(void) event = cpuc->event_list[i]; hwc = &event->hw; + if (i < n_running && + match_prev_assignment(hwc, cpuc, i)) + continue; + if (hwc->idx == -1) x86_assign_hw_event(event, cpuc, i);