From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756571Ab1GAPUn (ORCPT ); Fri, 1 Jul 2011 11:20:43 -0400 Received: from hera.kernel.org ([140.211.167.34]:57441 "EHLO hera.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1756527Ab1GAPUl (ORCPT ); Fri, 1 Jul 2011 11:20:41 -0400 Date: Fri, 1 Jul 2011 15:20:27 GMT From: tip-bot for Eric B Munson Message-ID: Cc: linux-kernel@vger.kernel.org, hpa@zytor.com, mingo@redhat.com, a.p.zijlstra@chello.nl, tglx@linutronix.de, mingo@elte.hu, emunson@mgebm.net Reply-To: mingo@redhat.com, hpa@zytor.com, linux-kernel@vger.kernel.org, a.p.zijlstra@chello.nl, tglx@linutronix.de, emunson@mgebm.net, mingo@elte.hu In-Reply-To: <1308932786-5111-1-git-send-email-emunson@mgebm.net> References: <1308932786-5111-1-git-send-email-emunson@mgebm.net> To: linux-tip-commits@vger.kernel.org Subject: [tip:perf/core] events: Ensure that timers are updated without requiring read() call Git-Commit-ID: 0d6412085b7ff58612af52e51ffa864f0df4b8fd X-Mailer: tip-git-log-daemon Robot-ID: Robot-Unsubscribe: Contact to get blacklisted from these emails 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]); Fri, 01 Jul 2011 15:20:28 +0000 (UTC) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Commit-ID: 0d6412085b7ff58612af52e51ffa864f0df4b8fd Gitweb: http://git.kernel.org/tip/0d6412085b7ff58612af52e51ffa864f0df4b8fd Author: Eric B Munson AuthorDate: Fri, 24 Jun 2011 12:26:26 -0400 Committer: Ingo Molnar CommitDate: Fri, 1 Jul 2011 11:06:34 +0200 events: Ensure that timers are updated without requiring read() call The event tracing infrastructure exposes two timers which should be updated each time the value of the counter is updated. Currently, these counters are only updated when userspace calls read() on the fd associated with an event. This means that counters which are read via the mmap'd page exclusively never have their timers updated. This patch adds ensures that the timers are updated each time the values in the mmap'd page are updated. Signed-off-by: Eric B Munson Signed-off-by: Peter Zijlstra Link: http://lkml.kernel.org/r/1308932786-5111-1-git-send-email-emunson@mgebm.net Signed-off-by: Ingo Molnar --- kernel/events/core.c | 15 +++++++++++++-- 1 files changed, 13 insertions(+), 2 deletions(-) diff --git a/kernel/events/core.c b/kernel/events/core.c index c851d70..270e32f 100644 --- a/kernel/events/core.c +++ b/kernel/events/core.c @@ -3372,8 +3372,19 @@ void perf_event_update_userpage(struct perf_event *event) { struct perf_event_mmap_page *userpg; struct ring_buffer *rb; + u64 enabled, running; rcu_read_lock(); + /* + * compute total_time_enabled, total_time_running + * based on snapshot values taken when the event + * was last scheduled in. + * + * we cannot simply called update_context_time() + * because of locking issue as we can be called in + * NMI context + */ + calc_timer_values(event, &enabled, &running); rb = rcu_dereference(event->rb); if (!rb) goto unlock; @@ -3392,10 +3403,10 @@ void perf_event_update_userpage(struct perf_event *event) if (event->state == PERF_EVENT_STATE_ACTIVE) userpg->offset -= local64_read(&event->hw.prev_count); - userpg->time_enabled = event->total_time_enabled + + userpg->time_enabled = enabled + atomic64_read(&event->child_total_time_enabled); - userpg->time_running = event->total_time_running + + userpg->time_running = running + atomic64_read(&event->child_total_time_running); barrier();