[tip:perf/core] perf: Remove the perf_output_begin(.sample) argument

From: tip-bot for Peter Zijlstra
Date: Fri Jul 01 2011 - 11:22:16 EST

Commit-ID: a7ac67ea021b4603095d2aa458bc41641238f22c
Gitweb: http://git.kernel.org/tip/a7ac67ea021b4603095d2aa458bc41641238f22c
Author: Peter Zijlstra <a.p.zijlstra@xxxxxxxxx>
AuthorDate: Mon, 27 Jun 2011 16:47:16 +0200
Committer: Ingo Molnar <mingo@xxxxxxx>
CommitDate: Fri, 1 Jul 2011 11:06:35 +0200

perf: Remove the perf_output_begin(.sample) argument

Since only samples call perf_output_sample() its much saner (and more
correct) to put the sample logic in there than in the
perf_output_begin()/perf_output_end() pair.

Saves a useless argument, reduces conditionals and shrinks
struct perf_output_handle, win!

Signed-off-by: Peter Zijlstra <a.p.zijlstra@xxxxxxxxx>
Link: http://lkml.kernel.org/n/tip-2crpvsx3cqu67q3zqjbnlpsc@xxxxxxxxxxxxxx
Signed-off-by: Ingo Molnar <mingo@xxxxxxx>
---
arch/x86/kernel/cpu/perf_event_intel_ds.c | 2 +-
include/linux/perf_event.h | 4 +---
kernel/events/core.c | 26 ++++++++++++++++++++------
kernel/events/ring_buffer.c | 19 +------------------
4 files changed, 23 insertions(+), 28 deletions(-)

diff --git a/arch/x86/kernel/cpu/perf_event_intel_ds.c b/arch/x86/kernel/cpu/perf_event_intel_ds.c
index 0941f93..1b1ef3a 100644
--- a/arch/x86/kernel/cpu/perf_event_intel_ds.c
+++ b/arch/x86/kernel/cpu/perf_event_intel_ds.c
@@ -340,7 +340,7 @@ static int intel_pmu_drain_bts_buffer(void)
*/
perf_prepare_sample(&header, &data, event, &regs);

- if (perf_output_begin(&handle, event, header.size * (top - at), 1))
+ if (perf_output_begin(&handle, event, header.size * (top - at)))
return 1;

for (; at < top; at++) {
diff --git a/include/linux/perf_event.h b/include/linux/perf_event.h
index 0946a8b..771b0b2 100644
--- a/include/linux/perf_event.h
+++ b/include/linux/perf_event.h
@@ -925,7 +925,6 @@ struct perf_output_handle {
unsigned long size;
void *addr;
int page;
- int sample;
};

#ifdef CONFIG_PERF_EVENTS
@@ -1117,8 +1116,7 @@ extern void perf_bp_event(struct perf_event *event, void *data);
#endif

extern int perf_output_begin(struct perf_output_handle *handle,
- struct perf_event *event, unsigned int size,
- int sample);
+ struct perf_event *event, unsigned int size);
extern void perf_output_end(struct perf_output_handle *handle);
extern void perf_output_copy(struct perf_output_handle *handle,
const void *buf, unsigned int len);
diff --git a/kernel/events/core.c b/kernel/events/core.c
index dbd1ca7..81de28d 100644
--- a/kernel/events/core.c
+++ b/kernel/events/core.c
@@ -3928,6 +3928,20 @@ void perf_output_sample(struct perf_output_handle *handle,
perf_output_put(handle, raw);
}
}
+
+ if (!event->attr.watermark) {
+ int wakeup_events = event->attr.wakeup_events;
+
+ if (wakeup_events) {
+ struct ring_buffer *rb = handle->rb;
+ int events = local_inc_return(&rb->events);
+
+ if (events >= wakeup_events) {
+ local_sub(wakeup_events, &rb->events);
+ local_inc(&rb->wakeup);
+ }
+ }
+ }
}

void perf_prepare_sample(struct perf_event_header *header,
@@ -3984,7 +3998,7 @@ static void perf_event_output(struct perf_event *event,

perf_prepare_sample(&header, data, event, regs);

- if (perf_output_begin(&handle, event, header.size, 1))
+ if (perf_output_begin(&handle, event, header.size))
goto exit;

perf_output_sample(&handle, &header, data, event);
@@ -4024,7 +4038,7 @@ perf_event_read_event(struct perf_event *event,
int ret;

perf_event_header__init_id(&read_event.header, &sample, event);
- ret = perf_output_begin(&handle, event, read_event.header.size, 0);
+ ret = perf_output_begin(&handle, event, read_event.header.size);
if (ret)
return;

@@ -4067,7 +4081,7 @@ static void perf_event_task_output(struct perf_event *event,
perf_event_header__init_id(&task_event->event_id.header, &sample, event);

ret = perf_output_begin(&handle, event,
- task_event->event_id.header.size, 0);
+ task_event->event_id.header.size);
if (ret)
goto out;

@@ -4204,7 +4218,7 @@ static void perf_event_comm_output(struct perf_event *event,

perf_event_header__init_id(&comm_event->event_id.header, &sample, event);
ret = perf_output_begin(&handle, event,
- comm_event->event_id.header.size, 0);
+ comm_event->event_id.header.size);

if (ret)
goto out;
@@ -4351,7 +4365,7 @@ static void perf_event_mmap_output(struct perf_event *event,

perf_event_header__init_id(&mmap_event->event_id.header, &sample, event);
ret = perf_output_begin(&handle, event,
- mmap_event->event_id.header.size, 0);
+ mmap_event->event_id.header.size);
if (ret)
goto out;

@@ -4546,7 +4560,7 @@ static void perf_log_throttle(struct perf_event *event, int enable)
perf_event_header__init_id(&throttle_event.header, &sample, event);

ret = perf_output_begin(&handle, event,
- throttle_event.header.size, 0);
+ throttle_event.header.size);
if (ret)
return;

diff --git a/kernel/events/ring_buffer.c b/kernel/events/ring_buffer.c
index 8b3b736..a2a2920 100644
--- a/kernel/events/ring_buffer.c
+++ b/kernel/events/ring_buffer.c
@@ -98,8 +98,7 @@ out:
}

int perf_output_begin(struct perf_output_handle *handle,
- struct perf_event *event, unsigned int size,
- int sample)
+ struct perf_event *event, unsigned int size)
{
struct ring_buffer *rb;
unsigned long tail, offset, head;
@@ -124,7 +123,6 @@ int perf_output_begin(struct perf_output_handle *handle,

handle->rb = rb;
handle->event = event;
- handle->sample = sample;

if (!rb->nr_pages)
goto out;
@@ -192,21 +190,6 @@ void perf_output_copy(struct perf_output_handle *handle,

void perf_output_end(struct perf_output_handle *handle)
{
- struct perf_event *event = handle->event;
- struct ring_buffer *rb = handle->rb;
-
- if (handle->sample && !event->attr.watermark) {
- int wakeup_events = event->attr.wakeup_events;
-
- if (wakeup_events) {
- int events = local_inc_return(&rb->events);
- if (events >= wakeup_events) {
- local_sub(wakeup_events, &rb->events);
- local_inc(&rb->wakeup);
- }
- }
- }
-
perf_output_put_handle(handle);
rcu_read_unlock();
}
--
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