From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1757310AbZKWL5Y (ORCPT ); Mon, 23 Nov 2009 06:57:24 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1757188AbZKWL5X (ORCPT ); Mon, 23 Nov 2009 06:57:23 -0500 Received: from hera.kernel.org ([140.211.167.34]:39351 "EHLO hera.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1757055AbZKWL5W (ORCPT ); Mon, 23 Nov 2009 06:57:22 -0500 Date: Mon, 23 Nov 2009 11:54:54 GMT From: tip-bot for Peter Zijlstra Cc: linux-kernel@vger.kernel.org, paulus@samba.org, hpa@zytor.com, mingo@redhat.com, fweisbec@gmail.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, fweisbec@gmail.com, a.p.zijlstra@chello.nl, tglx@linutronix.de, mingo@elte.hu In-Reply-To: <20091123103819.842455480@chello.nl> References: <20091123103819.842455480@chello.nl> To: linux-tip-commits@vger.kernel.org Subject: [tip:perf/core] perf_events: Fix __perf_event_exit_task() vs. update_event_times() locking Message-ID: Git-Commit-ID: f67218c3e93abaf0f480bb94b53d234853ffe4de 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: f67218c3e93abaf0f480bb94b53d234853ffe4de Gitweb: http://git.kernel.org/tip/f67218c3e93abaf0f480bb94b53d234853ffe4de Author: Peter Zijlstra AuthorDate: Mon, 23 Nov 2009 11:37:27 +0100 Committer: Ingo Molnar CommitDate: Mon, 23 Nov 2009 11:49:57 +0100 perf_events: Fix __perf_event_exit_task() vs. update_event_times() locking Move the update_event_times() call in __perf_event_exit_task() into list_del_event() because that holds the proper lock (ctx->lock) and seems a more natural place to do the last time update. Signed-off-by: Peter Zijlstra Cc: Paul Mackerras Cc: Frederic Weisbecker LKML-Reference: <20091123103819.842455480@chello.nl> Signed-off-by: Ingo Molnar --- kernel/perf_event.c | 78 +++++++++++++++++++++++++------------------------- 1 files changed, 39 insertions(+), 39 deletions(-) diff --git a/kernel/perf_event.c b/kernel/perf_event.c index 8be2574..50f11b5 100644 --- a/kernel/perf_event.c +++ b/kernel/perf_event.c @@ -246,6 +246,44 @@ static void perf_unpin_context(struct perf_event_context *ctx) put_ctx(ctx); } +static inline u64 perf_clock(void) +{ + return cpu_clock(smp_processor_id()); +} + +/* + * Update the record of the current time in a context. + */ +static void update_context_time(struct perf_event_context *ctx) +{ + u64 now = perf_clock(); + + ctx->time += now - ctx->timestamp; + ctx->timestamp = now; +} + +/* + * Update the total_time_enabled and total_time_running fields for a event. + */ +static void update_event_times(struct perf_event *event) +{ + struct perf_event_context *ctx = event->ctx; + u64 run_end; + + if (event->state < PERF_EVENT_STATE_INACTIVE || + event->group_leader->state < PERF_EVENT_STATE_INACTIVE) + return; + + event->total_time_enabled = ctx->time - event->tstamp_enabled; + + if (event->state == PERF_EVENT_STATE_INACTIVE) + run_end = event->tstamp_stopped; + else + run_end = ctx->time; + + event->total_time_running = run_end - event->tstamp_running; +} + /* * Add a event from the lists for its context. * Must be called with ctx->mutex and ctx->lock held. @@ -294,6 +332,7 @@ list_del_event(struct perf_event *event, struct perf_event_context *ctx) if (event->group_leader != event) event->group_leader->nr_siblings--; + update_event_times(event); event->state = PERF_EVENT_STATE_OFF; /* @@ -454,44 +493,6 @@ retry: spin_unlock_irq(&ctx->lock); } -static inline u64 perf_clock(void) -{ - return cpu_clock(smp_processor_id()); -} - -/* - * Update the record of the current time in a context. - */ -static void update_context_time(struct perf_event_context *ctx) -{ - u64 now = perf_clock(); - - ctx->time += now - ctx->timestamp; - ctx->timestamp = now; -} - -/* - * Update the total_time_enabled and total_time_running fields for a event. - */ -static void update_event_times(struct perf_event *event) -{ - struct perf_event_context *ctx = event->ctx; - u64 run_end; - - if (event->state < PERF_EVENT_STATE_INACTIVE || - event->group_leader->state < PERF_EVENT_STATE_INACTIVE) - return; - - event->total_time_enabled = ctx->time - event->tstamp_enabled; - - if (event->state == PERF_EVENT_STATE_INACTIVE) - run_end = event->tstamp_stopped; - else - run_end = ctx->time; - - event->total_time_running = run_end - event->tstamp_running; -} - /* * Update total_time_enabled and total_time_running for all events in a group. */ @@ -4931,7 +4932,6 @@ __perf_event_exit_task(struct perf_event *child_event, { struct perf_event *parent_event; - update_event_times(child_event); perf_event_remove_from_context(child_event); parent_event = child_event->parent;