From cd8fad3a6e19fc835ffb0fa251b239b03ceb74b0 Mon Sep 17 00:00:00 2001 From: Namhyung Kim Date: Wed, 2 Jul 2025 18:49:38 -0700 Subject: [PATCH] perf sched: Fix thread leaks in 'perf sched timehist' [ Upstream commit e2eb59260c4f6bac403491d0112891766b8650d1 ] Add missing thread__put() after machine__findnew_thread() or timehist_get_thread(). Also idle threads' last_thread should be refcounted properly. Fixes: 699b5b920db04a6f ("perf sched timehist: Save callchain when entering idle") Reviewed-by: Ian Rogers Tested-by: Ian Rogers Link: https://lore.kernel.org/r/20250703014942.1369397-5-namhyung@kernel.org Signed-off-by: Namhyung Kim Signed-off-by: Sasha Levin --- tools/perf/builtin-sched.c | 48 +++++++++++++++++++++++++++++--------- 1 file changed, 37 insertions(+), 11 deletions(-) diff --git a/tools/perf/builtin-sched.c b/tools/perf/builtin-sched.c index b73989fb6acef..83b5a85a91b7f 100644 --- a/tools/perf/builtin-sched.c +++ b/tools/perf/builtin-sched.c @@ -2313,8 +2313,10 @@ static void save_task_callchain(struct perf_sched *sched, return; } - if (!sched->show_callchain || sample->callchain == NULL) + if (!sched->show_callchain || sample->callchain == NULL) { + thread__put(thread); return; + } cursor = get_tls_callchain_cursor(); @@ -2323,10 +2325,12 @@ static void save_task_callchain(struct perf_sched *sched, if (verbose > 0) pr_err("Failed to resolve callchain. Skipping\n"); + thread__put(thread); return; } callchain_cursor_commit(cursor); + thread__put(thread); while (true) { struct callchain_cursor_node *node; @@ -2403,8 +2407,17 @@ static void free_idle_threads(void) return; for (i = 0; i < idle_max_cpu; ++i) { - if ((idle_threads[i])) - thread__delete(idle_threads[i]); + struct thread *idle = idle_threads[i]; + + if (idle) { + struct idle_thread_runtime *itr; + + itr = thread__priv(idle); + if (itr) + thread__put(itr->last_thread); + + thread__delete(idle); + } } free(idle_threads); @@ -2441,7 +2454,7 @@ static struct thread *get_idle_thread(int cpu) } } - return idle_threads[cpu]; + return thread__get(idle_threads[cpu]); } static void save_idle_callchain(struct perf_sched *sched, @@ -2496,7 +2509,8 @@ static struct thread *timehist_get_thread(struct perf_sched *sched, if (itr == NULL) return NULL; - itr->last_thread = thread; + thread__put(itr->last_thread); + itr->last_thread = thread__get(thread); /* copy task callchain when entering to idle */ if (evsel__intval(evsel, sample, "next_pid") == 0) @@ -2567,6 +2581,7 @@ static void timehist_print_wakeup_event(struct perf_sched *sched, /* show wakeup unless both awakee and awaker are filtered */ if (timehist_skip_sample(sched, thread, evsel, sample) && timehist_skip_sample(sched, awakened, evsel, sample)) { + thread__put(thread); return; } @@ -2583,6 +2598,8 @@ static void timehist_print_wakeup_event(struct perf_sched *sched, printf("awakened: %s", timehist_get_commstr(awakened)); printf("\n"); + + thread__put(thread); } static int timehist_sched_wakeup_ignore(const struct perf_tool *tool __maybe_unused, @@ -2611,8 +2628,10 @@ static int timehist_sched_wakeup_event(const struct perf_tool *tool, return -1; tr = thread__get_runtime(thread); - if (tr == NULL) + if (tr == NULL) { + thread__put(thread); return -1; + } if (tr->ready_to_run == 0) tr->ready_to_run = sample->time; @@ -2622,6 +2641,7 @@ static int timehist_sched_wakeup_event(const struct perf_tool *tool, !perf_time__skip_sample(&sched->ptime, sample->time)) timehist_print_wakeup_event(sched, evsel, sample, machine, thread); + thread__put(thread); return 0; } @@ -2649,6 +2669,7 @@ static void timehist_print_migration_event(struct perf_sched *sched, if (timehist_skip_sample(sched, thread, evsel, sample) && timehist_skip_sample(sched, migrated, evsel, sample)) { + thread__put(thread); return; } @@ -2676,6 +2697,7 @@ static void timehist_print_migration_event(struct perf_sched *sched, printf(" cpu %d => %d", ocpu, dcpu); printf("\n"); + thread__put(thread); } static int timehist_migrate_task_event(const struct perf_tool *tool, @@ -2695,8 +2717,10 @@ static int timehist_migrate_task_event(const struct perf_tool *tool, return -1; tr = thread__get_runtime(thread); - if (tr == NULL) + if (tr == NULL) { + thread__put(thread); return -1; + } tr->migrations++; tr->migrated = sample->time; @@ -2706,6 +2730,7 @@ static int timehist_migrate_task_event(const struct perf_tool *tool, timehist_print_migration_event(sched, evsel, sample, machine, thread); } + thread__put(thread); return 0; } @@ -2728,10 +2753,10 @@ static void timehist_update_task_prio(struct evsel *evsel, return; tr = thread__get_runtime(thread); - if (tr == NULL) - return; + if (tr != NULL) + tr->prio = next_prio; - tr->prio = next_prio; + thread__put(thread); } static int timehist_sched_change_event(const struct perf_tool *tool, @@ -2743,7 +2768,7 @@ static int timehist_sched_change_event(const struct perf_tool *tool, struct perf_sched *sched = container_of(tool, struct perf_sched, tool); struct perf_time_interval *ptime = &sched->ptime; struct addr_location al; - struct thread *thread; + struct thread *thread = NULL; struct thread_runtime *tr = NULL; u64 tprev, t = sample->time; int rc = 0; @@ -2867,6 +2892,7 @@ out: evsel__save_time(evsel, sample->time, sample->cpu); + thread__put(thread); addr_location__exit(&al); return rc; } -- 2.47.3