[PATCH 3/8] perf sched: Fix memory leaks in 'perf sched map'

Namhyung Kim posted 8 patches 3 months, 1 week ago
[PATCH 3/8] perf sched: Fix memory leaks in 'perf sched map'
Posted by Namhyung Kim 3 months, 1 week ago
It maintains per-cpu pointers for the current thread but it doesn't
release the refcounts.

Signed-off-by: Namhyung Kim <namhyung@kernel.org>
---
 tools/perf/builtin-sched.c | 31 ++++++++++++++++++++-----------
 1 file changed, 20 insertions(+), 11 deletions(-)

diff --git a/tools/perf/builtin-sched.c b/tools/perf/builtin-sched.c
index fa4052e040201105..b73989fb6acef8d6 100644
--- a/tools/perf/builtin-sched.c
+++ b/tools/perf/builtin-sched.c
@@ -1634,6 +1634,7 @@ static int map_switch_event(struct perf_sched *sched, struct evsel *evsel,
 	const char *color = PERF_COLOR_NORMAL;
 	char stimestamp[32];
 	const char *str;
+	int ret = -1;
 
 	BUG_ON(this_cpu.cpu >= MAX_CPUS || this_cpu.cpu < 0);
 
@@ -1664,17 +1665,20 @@ static int map_switch_event(struct perf_sched *sched, struct evsel *evsel,
 	sched_in = map__findnew_thread(sched, machine, -1, next_pid);
 	sched_out = map__findnew_thread(sched, machine, -1, prev_pid);
 	if (sched_in == NULL || sched_out == NULL)
-		return -1;
+		goto out;
 
 	tr = thread__get_runtime(sched_in);
-	if (tr == NULL) {
-		thread__put(sched_in);
-		return -1;
-	}
+	if (tr == NULL)
+		goto out;
+
+	thread__put(sched->curr_thread[this_cpu.cpu]);
+	thread__put(sched->curr_out_thread[this_cpu.cpu]);
 
 	sched->curr_thread[this_cpu.cpu] = thread__get(sched_in);
 	sched->curr_out_thread[this_cpu.cpu] = thread__get(sched_out);
 
+	ret = 0;
+
 	str = thread__comm_str(sched_in);
 	new_shortname = 0;
 	if (!tr->shortname[0]) {
@@ -1769,12 +1773,10 @@ static int map_switch_event(struct perf_sched *sched, struct evsel *evsel,
 	color_fprintf(stdout, color, "\n");
 
 out:
-	if (sched->map.task_name)
-		thread__put(sched_out);
-
+	thread__put(sched_out);
 	thread__put(sched_in);
 
-	return 0;
+	return ret;
 }
 
 static int process_sched_switch_event(const struct perf_tool *tool,
@@ -3556,10 +3558,10 @@ static int perf_sched__map(struct perf_sched *sched)
 
 	sched->curr_out_thread = calloc(MAX_CPUS, sizeof(*(sched->curr_out_thread)));
 	if (!sched->curr_out_thread)
-		return rc;
+		goto out_free_curr_thread;
 
 	if (setup_cpus_switch_event(sched))
-		goto out_free_curr_thread;
+		goto out_free_curr_out_thread;
 
 	if (setup_map_cpus(sched))
 		goto out_free_cpus_switch_event;
@@ -3590,7 +3592,14 @@ static int perf_sched__map(struct perf_sched *sched)
 out_free_cpus_switch_event:
 	free_cpus_switch_event(sched);
 
+out_free_curr_out_thread:
+	for (int i = 0; i < MAX_CPUS; i++)
+		thread__put(sched->curr_out_thread[i]);
+	zfree(&sched->curr_out_thread);
+
 out_free_curr_thread:
+	for (int i = 0; i < MAX_CPUS; i++)
+		thread__put(sched->curr_thread[i]);
 	zfree(&sched->curr_thread);
 	return rc;
 }
-- 
2.50.0.727.gbf7dc18ff4-goog
Re: [PATCH 3/8] perf sched: Fix memory leaks in 'perf sched map'
Posted by Ian Rogers 3 months ago
On Wed, Jul 2, 2025 at 6:49 PM Namhyung Kim <namhyung@kernel.org> wrote:
>
> It maintains per-cpu pointers for the current thread but it doesn't
> release the refcounts.
>
> Signed-off-by: Namhyung Kim <namhyung@kernel.org>

Reviewed-by: Ian Rogers <irogers@google.com>

Thanks,
Ian

> ---
>  tools/perf/builtin-sched.c | 31 ++++++++++++++++++++-----------
>  1 file changed, 20 insertions(+), 11 deletions(-)
>
> diff --git a/tools/perf/builtin-sched.c b/tools/perf/builtin-sched.c
> index fa4052e040201105..b73989fb6acef8d6 100644
> --- a/tools/perf/builtin-sched.c
> +++ b/tools/perf/builtin-sched.c
> @@ -1634,6 +1634,7 @@ static int map_switch_event(struct perf_sched *sched, struct evsel *evsel,
>         const char *color = PERF_COLOR_NORMAL;
>         char stimestamp[32];
>         const char *str;
> +       int ret = -1;
>
>         BUG_ON(this_cpu.cpu >= MAX_CPUS || this_cpu.cpu < 0);
>
> @@ -1664,17 +1665,20 @@ static int map_switch_event(struct perf_sched *sched, struct evsel *evsel,
>         sched_in = map__findnew_thread(sched, machine, -1, next_pid);
>         sched_out = map__findnew_thread(sched, machine, -1, prev_pid);
>         if (sched_in == NULL || sched_out == NULL)
> -               return -1;
> +               goto out;
>
>         tr = thread__get_runtime(sched_in);
> -       if (tr == NULL) {
> -               thread__put(sched_in);
> -               return -1;
> -       }
> +       if (tr == NULL)
> +               goto out;
> +
> +       thread__put(sched->curr_thread[this_cpu.cpu]);
> +       thread__put(sched->curr_out_thread[this_cpu.cpu]);
>
>         sched->curr_thread[this_cpu.cpu] = thread__get(sched_in);
>         sched->curr_out_thread[this_cpu.cpu] = thread__get(sched_out);
>
> +       ret = 0;
> +
>         str = thread__comm_str(sched_in);
>         new_shortname = 0;
>         if (!tr->shortname[0]) {
> @@ -1769,12 +1773,10 @@ static int map_switch_event(struct perf_sched *sched, struct evsel *evsel,
>         color_fprintf(stdout, color, "\n");
>
>  out:
> -       if (sched->map.task_name)
> -               thread__put(sched_out);
> -
> +       thread__put(sched_out);
>         thread__put(sched_in);
>
> -       return 0;
> +       return ret;
>  }
>
>  static int process_sched_switch_event(const struct perf_tool *tool,
> @@ -3556,10 +3558,10 @@ static int perf_sched__map(struct perf_sched *sched)
>
>         sched->curr_out_thread = calloc(MAX_CPUS, sizeof(*(sched->curr_out_thread)));
>         if (!sched->curr_out_thread)
> -               return rc;
> +               goto out_free_curr_thread;
>
>         if (setup_cpus_switch_event(sched))
> -               goto out_free_curr_thread;
> +               goto out_free_curr_out_thread;
>
>         if (setup_map_cpus(sched))
>                 goto out_free_cpus_switch_event;
> @@ -3590,7 +3592,14 @@ static int perf_sched__map(struct perf_sched *sched)
>  out_free_cpus_switch_event:
>         free_cpus_switch_event(sched);
>
> +out_free_curr_out_thread:
> +       for (int i = 0; i < MAX_CPUS; i++)
> +               thread__put(sched->curr_out_thread[i]);
> +       zfree(&sched->curr_out_thread);
> +
>  out_free_curr_thread:
> +       for (int i = 0; i < MAX_CPUS; i++)
> +               thread__put(sched->curr_thread[i]);
>         zfree(&sched->curr_thread);
>         return rc;
>  }
> --
> 2.50.0.727.gbf7dc18ff4-goog
>