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: Tzvetomir Stoyanov (VMware) <tz.stoyanov@gmail.com>
Acked-by: Jiri 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: Arnaldo Carvalho de Melo <acme@redhat.com>
This commit is contained in:
Tzvetomir Stoyanov (VMware) 2022-02-21 12:26:28 +02:00 committed by Arnaldo Carvalho de Melo
parent 41415b8a97
commit 56dce86819
5 changed files with 62 additions and 8 deletions

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@ -62,6 +62,7 @@ SYNOPSIS
struct perf_thread_map; struct perf_thread_map;
struct perf_thread_map *perf_thread_map__new_dummy(void); 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); 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); char *perf_thread_map__comm(struct perf_thread_map *map, int idx);

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@ -8,6 +8,7 @@
struct perf_thread_map; 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_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 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); LIBPERF_API char *perf_thread_map__comm(struct perf_thread_map *map, int idx);

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@ -12,6 +12,7 @@ LIBPERF_0.0.1 {
perf_cpu_map__empty; perf_cpu_map__empty;
perf_cpu_map__max; perf_cpu_map__max;
perf_cpu_map__has; perf_cpu_map__has;
perf_thread_map__new_array;
perf_thread_map__new_dummy; perf_thread_map__new_dummy;
perf_thread_map__set_pid; perf_thread_map__set_pid;
perf_thread_map__comm; perf_thread_map__comm;

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@ -11,9 +11,43 @@ static int libperf_print(enum libperf_print_level level,
return vfprintf(stderr, fmt, ap); 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) int test_threadmap(int argc, char **argv)
{ {
struct perf_thread_map *threads; struct perf_thread_map *threads;
pid_t thr_array[THREADS_NR];
int i;
__T_START; __T_START;
@ -27,6 +61,13 @@ int test_threadmap(int argc, char **argv)
perf_thread_map__put(threads); perf_thread_map__put(threads);
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; __T_END;
return tests_failed == 0 ? 0 : -1; return tests_failed == 0 ? 0 : -1;
} }

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@ -42,16 +42,26 @@ char *perf_thread_map__comm(struct perf_thread_map *map, int idx)
return map->map[idx].comm; return map->map[idx].comm;
} }
struct perf_thread_map *perf_thread_map__new_array(int nr_threads, pid_t *array)
{
struct perf_thread_map *threads = thread_map__alloc(nr_threads);
int i;
if (!threads)
return NULL;
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) struct perf_thread_map *perf_thread_map__new_dummy(void)
{ {
struct perf_thread_map *threads = thread_map__alloc(1); return perf_thread_map__new_array(1, NULL);
if (threads != NULL) {
perf_thread_map__set_pid(threads, 0, -1);
threads->nr = 1;
refcount_set(&threads->refcnt, 1);
}
return threads;
} }
static void perf_thread_map__delete(struct perf_thread_map *threads) static void perf_thread_map__delete(struct perf_thread_map *threads)