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perf: Remove the perf_output_begin(.sample) argument

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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@chello.nl>
Link: http://lkml.kernel.org/n/tip-2crpvsx3cqu67q3zqjbnlpsc@git.kernel.org
Signed-off-by: Ingo Molnar <mingo@elte.hu>
This commit is contained in:
Peter Zijlstra 2011-06-27 16:47:16 +02:00 committed by Ingo Molnar
parent a8b0ca17b8
commit a7ac67ea02
4 changed files with 23 additions and 28 deletions
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2
arch/x86/kernel/cpu/perf_event_intel_ds.c
View File

@ -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++) {

4
include/linux/perf_event.h
View File

@ -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);

26
kernel/events/core.c
View File

@ -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;

19
kernel/events/ring_buffer.c
View File

@ -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();
}