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Commit 0e2e63dd authored by Peter Zijlstra's avatar Peter Zijlstra Committed by Ingo Molnar
Browse files

perf-record: Share per-cpu buffers 



It seems a waste of space to create a buffer per
event, share it per-cpu.

Signed-off-by: default avatarPeter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Steven Rostedt <rostedt@goodmis.org>
LKML-Reference: <20100521090710.634824884@chello.nl>
Signed-off-by: default avatarIngo Molnar <mingo@elte.hu>
parent 57adc51d

tools/perf/builtin-record.c

+28 −24
Original line number Diff line number Diff line
@@ -82,7 +82,7 @@ struct mmap_data { 
	unsigned int		prev;

};



static struct mmap_data		*mmap_array[MAX_NR_CPUS][MAX_COUNTERS];

static struct mmap_data		mmap_array[MAX_NR_CPUS];



static unsigned long mmap_read_head(struct mmap_data *md)

{
@@ -365,20 +365,31 @@ static void create_counter(int counter, int cpu) 
		if (group && group_fd == -1)

			group_fd = fd[nr_cpu][counter][thread_index];



		event_array[nr_poll].fd = fd[nr_cpu][counter][thread_index];

		event_array[nr_poll].events = POLLIN;

		nr_poll++;



		mmap_array[nr_cpu][counter][thread_index].counter = counter;

		mmap_array[nr_cpu][counter][thread_index].prev = 0;

		mmap_array[nr_cpu][counter][thread_index].mask = mmap_pages*page_size - 1;

		mmap_array[nr_cpu][counter][thread_index].base = mmap(NULL, (mmap_pages+1)*page_size,

		if (counter || thread_index) {

			ret = ioctl(fd[nr_cpu][counter][thread_index],

					PERF_EVENT_IOC_SET_OUTPUT,

					fd[nr_cpu][0][0]);

			if (ret) {

				error("failed to set output: %d (%s)\n", errno,

						strerror(errno));

				exit(-1);

			}

		} else {

			mmap_array[nr_cpu].counter = counter;

			mmap_array[nr_cpu].prev = 0;

			mmap_array[nr_cpu].mask = mmap_pages*page_size - 1;

			mmap_array[nr_cpu].base = mmap(NULL, (mmap_pages+1)*page_size,

				PROT_READ|PROT_WRITE, MAP_SHARED, fd[nr_cpu][counter][thread_index], 0);

		if (mmap_array[nr_cpu][counter][thread_index].base == MAP_FAILED) {

			if (mmap_array[nr_cpu].base == MAP_FAILED) {

				error("failed to mmap with %d (%s)\n", errno, strerror(errno));

				exit(-1);

			}



			event_array[nr_poll].fd = fd[nr_cpu][counter][thread_index];

			event_array[nr_poll].events = POLLIN;

			nr_poll++;

		}



		if (filter != NULL) {

			ret = ioctl(fd[nr_cpu][counter][thread_index],

					PERF_EVENT_IOC_SET_FILTER, filter);
@@ -477,16 +488,11 @@ static struct perf_event_header finished_round_event = { 


static void mmap_read_all(void)

{

	int i, counter, thread;

	int i;



	for (i = 0; i < nr_cpu; i++) {

		for (counter = 0; counter < nr_counters; counter++) {

			for (thread = 0; thread < thread_num; thread++) {

				if (mmap_array[i][counter][thread].base)

					mmap_read(&mmap_array[i][counter][thread]);

			}



		}

		if (mmap_array[i].base)

			mmap_read(&mmap_array[i]);

	}



	if (perf_header__has_feat(&session->header, HEADER_TRACE_INFO))
@@ -861,9 +867,7 @@ int cmd_record(int argc, const char **argv, const char *prefix __used) 
	for (i = 0; i < MAX_NR_CPUS; i++) {

		for (j = 0; j < MAX_COUNTERS; j++) {

			fd[i][j] = malloc(sizeof(int)*thread_num);

			mmap_array[i][j] = zalloc(

				sizeof(struct mmap_data)*thread_num);

			if (!fd[i][j] || !mmap_array[i][j])

			if (!fd[i][j])

				return -ENOMEM;

		}

	}