Commit f6e70715 authored by Namhyung Kim's avatar Namhyung Kim Committed by Ingo Molnar
Browse files

perf/core: Introduce perf_prepare_header() 



Factor out perf_prepare_header() so that it can call
perf_prepare_sample() without a header if not needed.

Also it checks the filtered_sample_type to avoid duplicate
work when perf_prepare_sample() is called twice (or more).

Suggested-by: default avatarPeter Zijlstr <peterz@infradead.org>
Signed-off-by: default avatarNamhyung Kim <namhyung@kernel.org>
Signed-off-by: default avatarIngo Molnar <mingo@kernel.org>
Tested-by: default avatarJiri Olsa <jolsa@kernel.org>
Acked-by: default avatarJiri Olsa <jolsa@kernel.org>
Acked-by: default avatarSong Liu <song@kernel.org>
Acked-by: default avatarPeter Zijlstra <peterz@infradead.org>
Link: https://lore.kernel.org/r/20230118060559.615653-8-namhyung@kernel.org
parent a7c8d0da

arch/s390/kernel/perf_cpum_sf.c

+2 −1
Original line number Diff line number Diff line
@@ -672,7 +672,8 @@ static void cpumsf_output_event_pid(struct perf_event *event, 
	/* Protect callchain buffers, tasks */

	rcu_read_lock();



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

	perf_prepare_sample(data, event, regs);

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

	if (perf_output_begin(&handle, data, event, header.size))

		goto out;

arch/x86/events/intel/ds.c

+2 −1
Original line number Diff line number Diff line
@@ -807,7 +807,8 @@ int intel_pmu_drain_bts_buffer(void) 
	 * the sample.

	 */

	rcu_read_lock();

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

	perf_prepare_sample(&data, event, &regs);

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



	if (perf_output_begin(&handle, &data, event,

			      header.size * (top - base - skip)))

include/linux/perf_event.h

+15 −1
Original line number Diff line number Diff line
@@ -1250,6 +1250,17 @@ static inline void perf_sample_save_brstack(struct perf_sample_data *data, 
	data->sample_flags |= PERF_SAMPLE_BRANCH_STACK;

}



static inline u32 perf_sample_data_size(struct perf_sample_data *data,

					struct perf_event *event)

{

	u32 size = sizeof(struct perf_event_header);



	size += event->header_size + event->id_header_size;

	size += data->dyn_size;



	return size;

}



/*

 * Clear all bitfields in the perf_branch_entry.

 * The to and from fields are not cleared because they are
@@ -1271,7 +1282,10 @@ extern void perf_output_sample(struct perf_output_handle *handle, 
			       struct perf_event_header *header,

			       struct perf_sample_data *data,

			       struct perf_event *event);

extern void perf_prepare_sample(struct perf_event_header *header,

extern void perf_prepare_sample(struct perf_sample_data *data,

				struct perf_event *event,

				struct pt_regs *regs);

extern void perf_prepare_header(struct perf_event_header *header,

				struct perf_sample_data *data,

				struct perf_event *event,

				struct pt_regs *regs);

kernel/events/core.c

+24 −14
Original line number Diff line number Diff line
@@ -7568,20 +7568,13 @@ static __always_inline u64 __cond_set(u64 flags, u64 s, u64 d) 
	return d * !!(flags & s);

}



void perf_prepare_sample(struct perf_event_header *header,

			 struct perf_sample_data *data,

void perf_prepare_sample(struct perf_sample_data *data,

			 struct perf_event *event,

			 struct pt_regs *regs)

{

	u64 sample_type = event->attr.sample_type;

	u64 filtered_sample_type;



	header->type = PERF_RECORD_SAMPLE;

	header->size = sizeof(*header) + event->header_size + event->id_header_size;



	header->misc = 0;

	header->misc |= perf_misc_flags(regs);



	/*

	 * Add the sample flags that are dependent to others.  And clear the

	 * sample flags that have already been done by the PMU driver.
@@ -7595,6 +7588,12 @@ void perf_prepare_sample(struct perf_event_header *header, 
					   PERF_SAMPLE_REGS_USER);

	filtered_sample_type &= ~data->sample_flags;



	if (filtered_sample_type == 0) {

		/* Make sure it has the correct data->type for output */

		data->type = event->attr.sample_type;

		return;

	}



	__perf_event_header__init_id(data, event, filtered_sample_type);



	if (filtered_sample_type & PERF_SAMPLE_IP) {
@@ -7646,9 +7645,10 @@ void perf_prepare_sample(struct perf_event_header *header, 
		 * up the rest of the sample size.

		 */

		u16 stack_size = event->attr.sample_stack_user;

		u16 header_size = perf_sample_data_size(data, event);

		u16 size = sizeof(u64);



		stack_size = perf_sample_ustack_size(stack_size, header->size,

		stack_size = perf_sample_ustack_size(stack_size, header_size,

						     data->regs_user.regs);



		/*
@@ -7733,8 +7733,9 @@ void perf_prepare_sample(struct perf_event_header *header, 


	if (filtered_sample_type & PERF_SAMPLE_AUX) {

		u64 size;

		u16 header_size = perf_sample_data_size(data, event);



		header->size += sizeof(u64); /* size */

		header_size += sizeof(u64); /* size */



		/*

		 * Given the 16bit nature of header::size, an AUX sample can
@@ -7742,17 +7743,25 @@ void perf_prepare_sample(struct perf_event_header *header, 
		 * Make sure this doesn't happen by using up to U16_MAX bytes

		 * per sample in total (rounded down to 8 byte boundary).

		 */

		size = min_t(size_t, U16_MAX - header->size,

		size = min_t(size_t, U16_MAX - header_size,

			     event->attr.aux_sample_size);

		size = rounddown(size, 8);

		size = perf_prepare_sample_aux(event, data, size);



		WARN_ON_ONCE(size + header->size > U16_MAX);

		WARN_ON_ONCE(size + header_size > U16_MAX);

		data->dyn_size += size + sizeof(u64); /* size above */

		data->sample_flags |= PERF_SAMPLE_AUX;

	}

}



	header->size += data->dyn_size;

void perf_prepare_header(struct perf_event_header *header,

			 struct perf_sample_data *data,

			 struct perf_event *event,

			 struct pt_regs *regs)

{

	header->type = PERF_RECORD_SAMPLE;

	header->size = perf_sample_data_size(data, event);

	header->misc = perf_misc_flags(regs);



	/*

	 * If you're adding more sample types here, you likely need to do
@@ -7781,7 +7790,8 @@ __perf_event_output(struct perf_event *event, 
	/* protect the callchain buffers */

	rcu_read_lock();



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

	perf_prepare_sample(data, event, regs);

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



	err = output_begin(&handle, data, event, header.size);

	if (err)