From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from e36.co.us.ibm.com (e36.co.us.ibm.com [32.97.110.154]) (using TLSv1 with cipher CAMELLIA256-SHA (256/256 bits)) (No client certificate requested) by lists.ozlabs.org (Postfix) with ESMTPS id EBF511A17B4 for ; Fri, 4 Sep 2015 13:09:45 +1000 (AEST) Received: from /spool/local by e36.co.us.ibm.com with IBM ESMTP SMTP Gateway: Authorized Use Only! Violators will be prosecuted for from ; Thu, 3 Sep 2015 21:09:43 -0600 Received: from b03cxnp07028.gho.boulder.ibm.com (b03cxnp07028.gho.boulder.ibm.com [9.17.130.15]) by d03dlp02.boulder.ibm.com (Postfix) with ESMTP id DA4313E40047 for ; Thu, 3 Sep 2015 21:09:40 -0600 (MDT) Received: from d03av04.boulder.ibm.com (d03av04.boulder.ibm.com [9.17.195.170]) by b03cxnp07028.gho.boulder.ibm.com (8.14.9/8.14.9/NCO v10.0) with ESMTP id t8436jY345613096 for ; Thu, 3 Sep 2015 20:06:45 -0700 Received: from d03av04.boulder.ibm.com (loopback [127.0.0.1]) by d03av04.boulder.ibm.com (8.14.4/8.14.4/NCO v10.0 AVout) with ESMTP id t8439ed1005011 for ; Thu, 3 Sep 2015 21:09:40 -0600 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> 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> List-Id: Linux on PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , 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