From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755487AbbIDDMk (ORCPT ); Thu, 3 Sep 2015 23:12:40 -0400 Received: from e39.co.us.ibm.com ([32.97.110.160]:47902 "EHLO e39.co.us.ibm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752511AbbIDDJp (ORCPT ); Thu, 3 Sep 2015 23:09:45 -0400 X-Helo: d03dlp03.boulder.ibm.com X-MailFrom: sukadev@linux.vnet.ibm.com X-RcptTo: sparclinux@vger.kernel.org From: Sukadev Bhattiprolu To: Peter Zijlstra , Ingo Molnar , Arnaldo Carvalho de Melo , Michael Ellerman Cc: , linuxppc-dev@lists.ozlabs.org, linux-s390@vger.kernel.org, sparclinux@vger.kernel.org Subject: [[PATCH v6 03/10] perf: Split perf_event_read() and perf_event_count() Date: Thu, 3 Sep 2015 20:07:46 -0700 Message-Id: <1441336073-22750-4-git-send-email-sukadev@linux.vnet.ibm.com> X-Mailer: git-send-email 1.7.9.5 In-Reply-To: <1441336073-22750-1-git-send-email-sukadev@linux.vnet.ibm.com> References: <1441336073-22750-1-git-send-email-sukadev@linux.vnet.ibm.com> X-TM-AS-MML: disable X-Content-Scanned: Fidelis XPS MAILER x-cbid: 15090403-0033-0000-0000-000005BFDF09 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org perf_event_read() does two things: - call the PMU to read/update the counter value, and - compute the total count of the event and its children Not all callers need both. perf_event_reset() for instance needs the first piece but doesn't need the second. Similarly, when we implement the ability to read a group of events using the transaction interface, we would need the two pieces done independently. Break up perf_event_read() and have it just read/update the counter and have the callers compute the total count if necessary. Signed-off-by: Sukadev Bhattiprolu --- kernel/events/core.c | 14 ++++++++------ 1 file changed, 8 insertions(+), 6 deletions(-) diff --git a/kernel/events/core.c b/kernel/events/core.c index e221432..01ede6b 100644 --- a/kernel/events/core.c +++ b/kernel/events/core.c @@ -3275,7 +3275,7 @@ u64 perf_event_read_local(struct perf_event *event) return val; } -static u64 perf_event_read(struct perf_event *event) +static void perf_event_read(struct perf_event *event) { /* * If event is enabled and currently active on a CPU, update the @@ -3301,8 +3301,6 @@ static u64 perf_event_read(struct perf_event *event) update_event_times(event); raw_spin_unlock_irqrestore(&ctx->lock, flags); } - - return perf_event_count(event); } /* @@ -3818,14 +3816,18 @@ u64 perf_event_read_value(struct perf_event *event, u64 *enabled, u64 *running) *running = 0; mutex_lock(&event->child_mutex); - total += perf_event_read(event); + + perf_event_read(event); + total += perf_event_count(event); + *enabled += event->total_time_enabled + atomic64_read(&event->child_total_time_enabled); *running += event->total_time_running + atomic64_read(&event->child_total_time_running); list_for_each_entry(child, &event->child_list, child_list) { - total += perf_event_read(child); + perf_event_read(child); + total += perf_event_count(child); *enabled += child->total_time_enabled; *running += child->total_time_running; } @@ -3985,7 +3987,7 @@ static unsigned int perf_poll(struct file *file, poll_table *wait) static void _perf_event_reset(struct perf_event *event) { - (void)perf_event_read(event); + perf_event_read(event); local64_set(&event->count, 0); perf_event_update_userpage(event); } -- 1.7.9.5