From 56dce868198cd01b023e05d72bbbba7c87cc384d Mon Sep 17 00:00:00 2001
From: "Tzvetomir Stoyanov (VMware)" <tz.stoyanov@gmail.com>
Date: Mon, 21 Feb 2022 12:26:28 +0200
Subject: [PATCH] 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>
---
tools/lib/perf/Documentation/libperf.txt | 1 +
tools/lib/perf/include/perf/threadmap.h | 1 +
tools/lib/perf/libperf.map | 1 +
tools/lib/perf/tests/test-threadmap.c | 41 ++++++++++++++++++++++++
tools/lib/perf/threadmap.c | 24 ++++++++++----
5 files changed, 61 insertions(+), 7 deletions(-)
diff --git a/tools/lib/perf/Documentation/libperf.txt b/tools/lib/perf/Documentation/libperf.txt
index a21f733b95b17..a8f1a237931b1 100644
--- a/tools/lib/perf/Documentation/libperf.txt
+++ b/tools/lib/perf/Documentation/libperf.txt
@@ -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);
diff --git a/tools/lib/perf/include/perf/threadmap.h b/tools/lib/perf/include/perf/threadmap.h
index 58f7fbdce4463..8b40e7777cea7 100644
--- a/tools/lib/perf/include/perf/threadmap.h
+++ b/tools/lib/perf/include/perf/threadmap.h
@@ -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);
diff --git a/tools/lib/perf/libperf.map b/tools/lib/perf/libperf.map
index 6fa0d651576b6..190b56ae923ad 100644
--- a/tools/lib/perf/libperf.map
+++ b/tools/lib/perf/libperf.map
@@ -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;
diff --git a/tools/lib/perf/tests/test-threadmap.c b/tools/lib/perf/tests/test-threadmap.c
index 5e2a0291e94c2..f728ad7002bb9 100644
--- a/tools/lib/perf/tests/test-threadmap.c
+++ b/tools/lib/perf/tests/test-threadmap.c
@@ -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;
}
diff --git a/tools/lib/perf/threadmap.c b/tools/lib/perf/threadmap.c
index 84fa07c79d007..07968f3ea0931 100644
--- a/tools/lib/perf/threadmap.c
+++ b/tools/lib/perf/threadmap.c
@@ -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;
+
+ 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);
- if (threads != NULL) {
- perf_thread_map__set_pid(threads, 0, -1);
- threads->nr = 1;
- 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) {
--
2.30.2