Commit a7ac67ea authored by Peter Zijlstra's avatar Peter Zijlstra Committed by Ingo Molnar
Browse files

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: default avatarPeter Zijlstra <a.p.zijlstra@chello.nl>
Link: http://lkml.kernel.org/n/tip-2crpvsx3cqu67q3zqjbnlpsc@git.kernel.org


Signed-off-by: default avatarIngo Molnar <mingo@elte.hu>
parent a8b0ca17

arch/x86/kernel/cpu/perf_event_intel_ds.c

+1 −1
Original line number Diff line number Diff line
@@ -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++) {

include/linux/perf_event.h

+1 −3
Original line number Diff line number Diff line
@@ -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);

kernel/events/core.c

+20 −6
Original line number Diff line number Diff line
@@ -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;

kernel/events/ring_buffer.c

+1 −18
Original line number Diff line number Diff line
@@ -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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