From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755326AbZKUNoV (ORCPT ); Sat, 21 Nov 2009 08:44:21 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1755227AbZKUNoR (ORCPT ); Sat, 21 Nov 2009 08:44:17 -0500 Received: from hera.kernel.org ([140.211.167.34]:60999 "EHLO hera.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754788AbZKUNoO (ORCPT ); Sat, 21 Nov 2009 08:44:14 -0500 Date: Sat, 21 Nov 2009 13:43:32 GMT From: tip-bot for Peter Zijlstra Cc: linux-kernel@vger.kernel.org, paulus@samba.org, hpa@zytor.com, mingo@redhat.com, a.p.zijlstra@chello.nl, tglx@linutronix.de, mingo@elte.hu Reply-To: mingo@redhat.com, hpa@zytor.com, paulus@samba.org, linux-kernel@vger.kernel.org, a.p.zijlstra@chello.nl, tglx@linutronix.de, mingo@elte.hu In-Reply-To: <20091120212509.102316434@chello.nl> References: <20091120212509.102316434@chello.nl> To: linux-tip-commits@vger.kernel.org Subject: [tip:perf/core] perf: Fix time locking Message-ID: Git-Commit-ID: 2b8988c9f7defe319cffe0cd362a7cd356c86f62 X-Mailer: tip-git-log-daemon MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Disposition: inline Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Commit-ID: 2b8988c9f7defe319cffe0cd362a7cd356c86f62 Gitweb: http://git.kernel.org/tip/2b8988c9f7defe319cffe0cd362a7cd356c86f62 Author: Peter Zijlstra AuthorDate: Fri, 20 Nov 2009 22:19:54 +0100 Committer: Ingo Molnar CommitDate: Sat, 21 Nov 2009 14:11:39 +0100 perf: Fix time locking Most sites updating ctx->time and event times do so under ctx->lock, make sure they all do. This was made possible by removing the __perf_event_read() call from __perf_event_sync_stat(), which already had this lock taken. Signed-off-by: Peter Zijlstra Cc: Paul Mackerras LKML-Reference: <20091120212509.102316434@chello.nl> Signed-off-by: Ingo Molnar --- kernel/perf_event.c | 9 +++++++++ 1 files changed, 9 insertions(+), 0 deletions(-) diff --git a/kernel/perf_event.c b/kernel/perf_event.c index 028619d..fdfae88 100644 --- a/kernel/perf_event.c +++ b/kernel/perf_event.c @@ -1526,8 +1526,11 @@ static void __perf_event_read(void *info) if (ctx->task && cpuctx->task_ctx != ctx) return; + spin_lock(&ctx->lock); update_context_time(ctx); update_event_times(event); + spin_unlock(&ctx->lock); + event->pmu->read(event); } @@ -1541,7 +1544,13 @@ static u64 perf_event_read(struct perf_event *event) smp_call_function_single(event->oncpu, __perf_event_read, event, 1); } else if (event->state == PERF_EVENT_STATE_INACTIVE) { + struct perf_event_context *ctx = event->ctx; + unsigned long flags; + + spin_lock_irqsave(&ctx->lock, flags); + update_context_time(ctx); update_event_times(event); + spin_unlock_irqrestore(&ctx->lock, flags); } return atomic64_read(&event->count);