Commit 56dce868 authored by Tzvetomir Stoyanov (VMware)'s avatar Tzvetomir Stoyanov (VMware) Committed by Arnaldo Carvalho de Melo
Browse files

libperf: Add API for allocating new thread map array 



The existing API perf_thread_map__new_dummy() allocates new thread map
for one thread. I couldn't find a way to reallocate the map with more
threads, or to allocate a new map for more than one thread.

Having multiple threads in a thread map is essential for some use cases.
That's why a new API is proposed, which allocates a new thread map for
given number of threads: perf_thread_map__new_array()

Signed-off-by: default avatarTzvetomir Stoyanov (VMware) <tz.stoyanov@gmail.com>
Acked-by: default avatarJiri Olsa <jolsa@kernel.org>
Cc: Ian Rogers <irogers@google.com>
Link: https://lore.kernel.org/linux-perf-users/20220221102628.43904-1-tz.stoyanov@gmail.com


Signed-off-by: default avatarArnaldo Carvalho de Melo <acme@redhat.com>
parent 41415b8a

tools/lib/perf/Documentation/libperf.txt

+1 −0
Original line number Diff line number Diff line
@@ -62,6 +62,7 @@ SYNOPSIS 
  struct perf_thread_map;



  struct perf_thread_map *perf_thread_map__new_dummy(void);

  struct perf_thread_map *perf_thread_map__new_array(int nr_threads, pid_t *array);



  void perf_thread_map__set_pid(struct perf_thread_map *map, int idx, pid_t pid);

  char *perf_thread_map__comm(struct perf_thread_map *map, int idx);

tools/lib/perf/include/perf/threadmap.h

+1 −0
Original line number Diff line number Diff line
@@ -8,6 +8,7 @@ 
struct perf_thread_map;



LIBPERF_API struct perf_thread_map *perf_thread_map__new_dummy(void);

LIBPERF_API struct perf_thread_map *perf_thread_map__new_array(int nr_threads, pid_t *array);



LIBPERF_API void perf_thread_map__set_pid(struct perf_thread_map *map, int idx, pid_t pid);

LIBPERF_API char *perf_thread_map__comm(struct perf_thread_map *map, int idx);

tools/lib/perf/libperf.map

+1 −0
Original line number Diff line number Diff line
@@ -12,6 +12,7 @@ LIBPERF_0.0.1 { 
		perf_cpu_map__empty;

		perf_cpu_map__max;

		perf_cpu_map__has;

		perf_thread_map__new_array;

		perf_thread_map__new_dummy;

		perf_thread_map__set_pid;

		perf_thread_map__comm;

tools/lib/perf/tests/test-threadmap.c

+41 −0
Original line number Diff line number Diff line
@@ -11,9 +11,43 @@ static int libperf_print(enum libperf_print_level level, 
	return vfprintf(stderr, fmt, ap);

}



static int test_threadmap_array(int nr, pid_t *array)

{

	struct perf_thread_map *threads;

	int i;



	threads = perf_thread_map__new_array(nr, array);

	__T("Failed to allocate new thread map", threads);



	__T("Unexpected number of threads", perf_thread_map__nr(threads) == nr);



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

		__T("Unexpected initial value of thread",

		    perf_thread_map__pid(threads, i) == (array ? array[i] : -1));

	}



	for (i = 1; i < nr; i++)

		perf_thread_map__set_pid(threads, i, i * 100);



	__T("Unexpected value of thread 0",

	    perf_thread_map__pid(threads, 0) == (array ? array[0] : -1));



	for (i = 1; i < nr; i++) {

		__T("Unexpected thread value",

		    perf_thread_map__pid(threads, i) == i * 100);

	}



	perf_thread_map__put(threads);



	return 0;

}



#define THREADS_NR	10

int test_threadmap(int argc, char **argv)

{

	struct perf_thread_map *threads;

	pid_t thr_array[THREADS_NR];

	int i;



	__T_START;
@@ -27,6 +61,13 @@ int test_threadmap(int argc, char **argv) 
	perf_thread_map__put(threads);

	perf_thread_map__put(threads);



	test_threadmap_array(THREADS_NR, NULL);



	for (i = 0; i < THREADS_NR; i++)

		thr_array[i] = i + 100;



	test_threadmap_array(THREADS_NR, thr_array);



	__T_END;

	return tests_failed == 0 ? 0 : -1;

}

tools/lib/perf/threadmap.c

+17 −7
Original line number Diff line number Diff line
@@ -42,18 +42,28 @@ char *perf_thread_map__comm(struct perf_thread_map *map, int idx) 
	return map->map[idx].comm;

}



struct perf_thread_map *perf_thread_map__new_dummy(void)

struct perf_thread_map *perf_thread_map__new_array(int nr_threads, pid_t *array)

{

	struct perf_thread_map *threads = thread_map__alloc(1);

	struct perf_thread_map *threads = thread_map__alloc(nr_threads);

	int i;



	if (!threads)

		return NULL;



	if (threads != NULL) {

		perf_thread_map__set_pid(threads, 0, -1);

		threads->nr = 1;

	for (i = 0; i < nr_threads; i++)

		perf_thread_map__set_pid(threads, i, array ? array[i] : -1);



	threads->nr = nr_threads;

	refcount_set(&threads->refcnt, 1);

	}



	return threads;

}



struct perf_thread_map *perf_thread_map__new_dummy(void)

{

	return perf_thread_map__new_array(1, NULL);

}



static void perf_thread_map__delete(struct perf_thread_map *threads)

{

	if (threads) {