Re: [PATCH v3 5/8] perf: Split perf_event_read_value()
From: Peter Zijlstra <peterz@infradead.org>
Date: 2015-07-16 21:12:32
Also in:
linux-s390, lkml, sparclinux
On Tue, Jul 14, 2015 at 08:01:52PM -0700, Sukadev Bhattiprolu wrote:
Move the part of perf_event_read_value() that computes the event counts and event times into a new function, perf_event_compute(). This would allow us to call perf_event_compute() independently. Signed-off-by: Sukadev Bhattiprolu <redacted> Changelog[v3] Rather than move perf_event_read() into callers and then rename, just move the computations into a separate function (redesign to address comment from Peter Zijlstra). ---
Changelog[] bits go here, below the '---' where they get discarded.
quoted hunk ↗ jump to hunk
kernel/events/core.c | 37 ++++++++++++++++++++++++------------- 1 file changed, 24 insertions(+), 13 deletions(-)diff --git a/kernel/events/core.c b/kernel/events/core.c index 44fb89d..b1e9a42 100644 --- a/kernel/events/core.c +++ b/kernel/events/core.c@@ -3704,6 +3704,29 @@ static int perf_release(struct inode *inode, struct file *file) return 0; } +static u64 perf_event_compute(struct perf_event *event, u64 *enabled, + u64 *running)
This is a horrible name, 'compute' what?
+{
+ struct perf_event *child;
+ u64 total;
+
+ 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);
+lockdep_assert_held(&event->child_mutex);
+ list_for_each_entry(child, &event->child_list, child_list) {
+ perf_event_read(child);
+ total += perf_event_count(child);
+ *enabled += child->total_time_enabled;
+ *running += child->total_time_running;
+ }
+
+ return total;
+}
+
/*
* Remove all orphanes events from the context.
*/