From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail.linuxfoundation.org ([140.211.169.12]:56752 "EHLO mail.linuxfoundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752239AbbHSQUb (ORCPT ); Wed, 19 Aug 2015 12:20:31 -0400 Subject: Patch "perf: Fix running time accounting" has been added to the 4.1-stable tree To: peterz@infradead.org, gregkh@linuxfoundation.org, shli@fb.com, tglx@linutronix.de, vincent.weaver@maine.edu Cc: , From: Date: Wed, 19 Aug 2015 09:20:30 -0700 Message-ID: <14400012304717@kroah.com> MIME-Version: 1.0 Content-Type: text/plain; charset=ANSI_X3.4-1968 Content-Transfer-Encoding: 8bit Sender: stable-owner@vger.kernel.org List-ID: This is a note to let you know that I've just added the patch titled perf: Fix running time accounting to the 4.1-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary The filename of the patch is: perf-fix-running-time-accounting.patch and it can be found in the queue-4.1 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let know about it. >>From 00a2916f7f82c348a2a94dbb572874173bc308a3 Mon Sep 17 00:00:00 2001 From: Peter Zijlstra Date: Mon, 27 Jul 2015 10:35:07 +0200 Subject: perf: Fix running time accounting From: Peter Zijlstra commit 00a2916f7f82c348a2a94dbb572874173bc308a3 upstream. A recent fix to the shadow timestamp inadvertly broke the running time accounting. We must not update the running timestamp if we fail to schedule the event, the event will not have ran. This can (and did) result in negative total runtime because the stopped timestamp was before the running timestamp (we 'started' but never stopped the event -- because it never really started we didn't have to stop it either). Reported-and-Tested-by: Vince Weaver Fixes: 72f669c0086f ("perf: Update shadow timestamp before add event") Signed-off-by: Peter Zijlstra (Intel) Cc: Shaohua Li Signed-off-by: Thomas Gleixner Signed-off-by: Greg Kroah-Hartman --- kernel/events/core.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) --- a/kernel/events/core.c +++ b/kernel/events/core.c @@ -1886,8 +1886,6 @@ event_sched_in(struct perf_event *event, perf_pmu_disable(event->pmu); - event->tstamp_running += tstamp - event->tstamp_stopped; - perf_set_shadow_time(event, ctx, tstamp); perf_log_itrace_start(event); @@ -1899,6 +1897,8 @@ event_sched_in(struct perf_event *event, goto out; } + event->tstamp_running += tstamp - event->tstamp_stopped; + if (!is_software_event(event)) cpuctx->active_oncpu++; if (!ctx->nr_active++) Patches currently in stable-queue which might be from peterz@infradead.org are queue-4.1/perf-fix-perf_event_ioc_period-migration-race.patch queue-4.1/ipc-sem.c-update-correct-memory-barriers.patch queue-4.1/perf-fix-fasync-handling-on-inherited-events.patch queue-4.1/perf-fix-double-free-of-the-aux-buffer.patch queue-4.1/perf-fix-running-time-accounting.patch