[tip:perf/core] perf: Shrink hw_perf_event

tip-bot for Peter Zijlstra
2010-09-09T19:50:12Z

Commit-ID: fa407f35e0298d841e4088f95a7f9cf6e725c6d5
Gitweb: http://git.kernel.org/tip/fa407f35e0298d841e4088f95a7f9cf6e725c6d5
Author: Peter Zijlstra <a.p.zijlstra@chello.nl>
AuthorDate: Thu, 24 Jun 2010 12:35:12 +0200
Committer: Ingo Molnar <mingo@elte.hu>
CommitDate: Thu, 9 Sep 2010 20:46:30 +0200

perf: Shrink hw_perf_event

Use hw_perf_event::period_left instead of hw_perf_event::remaining
and win back 8 bytes.

Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: paulus <paulus@samba.org>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
LKML-Reference: <new-submission>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
---
include/linux/perf_event.h | 1 -
kernel/perf_event.c | 13 ++++++-------
2 files changed, 6 insertions(+), 8 deletions(-)

diff --git a/include/linux/perf_event.h b/include/linux/perf_event.h
index bf85733..8cafa15 100644
--- a/include/linux/perf_event.h
+++ b/include/linux/perf_event.h
@@ -529,7 +529,6 @@ struct hw_perf_event {
int last_cpu;
};
struct { /* software */
- s64 remaining;
struct hrtimer hrtimer;
};
#ifdef CONFIG_HAVE_HW_BREAKPOINT
diff --git a/kernel/perf_event.c b/kernel/perf_event.c
index 8ef4ba3..1a6cdbf 100644
--- a/kernel/perf_event.c
+++ b/kernel/perf_event.c
@@ -4800,14 +4800,13 @@ static void perf_swevent_start_hrtimer(struct perf_event *event)
hrtimer_init(&hwc->hrtimer, CLOCK_MONOTONIC, HRTIMER_MODE_REL);
hwc->hrtimer.function = perf_swevent_hrtimer;
if (hwc->sample_period) {
- u64 period;
+ s64 period = local64_read(&hwc->period_left);

- if (hwc->remaining) {
- if (hwc->remaining < 0)
+ if (period) {
+ if (period < 0)
period = 10000;
- else
- period = hwc->remaining;
- hwc->remaining = 0;
+
+ local64_set(&hwc->period_left, 0);
} else {
period = max_t(u64, 10000, hwc->sample_period);
}
@@ -4823,7 +4822,7 @@ static void perf_swevent_cancel_hrtimer(struct perf_event *event)

if (hwc->sample_period) {
ktime_t remaining = hrtimer_get_remaining(&hwc->hrtimer);
- hwc->remaining = ktime_to_ns(remaining);
+ local64_set(&hwc->period_left, ktime_to_ns(remaining));

hrtimer_cancel(&hwc->hrtimer);
}