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charset="utf-8" The signal race that exists in perf_sched__schedstat_record() also affects perf_sched__schedstat_live(). A very short-lived workload can exit and deliver SIGCHLD before pause() is entered, causing an indefinite hang. Apply the same fix: block SIGCHLD before starting the workload and replace pause() with sigsuspend() to atomically unblock and wait. Assisted-by: Claude:claude-opus-4.6 Signed-off-by: Swapnil Sapkal --- tools/perf/builtin-sched.c | 9 +++++++-- 1 file changed, 7 insertions(+), 2 deletions(-) diff --git a/tools/perf/builtin-sched.c b/tools/perf/builtin-sched.c index eb3702d98fd1..1d8f4ceda1eb 100644 --- a/tools/perf/builtin-sched.c +++ b/tools/perf/builtin-sched.c @@ -4655,6 +4655,7 @@ static int perf_sched__schedstat_live(struct perf_sch= ed *sched, int argc, const char **argv) { struct cpu_domain_map **cd_map =3D NULL; + sigset_t sigchld_mask, oldmask; struct target target =3D {}; u32 __maybe_unused md; struct evlist *evlist; @@ -4666,6 +4667,10 @@ static int perf_sched__schedstat_live(struct perf_sc= hed *sched, signal(SIGCHLD, sighandler); signal(SIGTERM, sighandler); =20 + sigemptyset(&sigchld_mask); + sigaddset(&sigchld_mask, SIGCHLD); + sigprocmask(SIG_BLOCK, &sigchld_mask, &oldmask); + evlist =3D evlist__new(); if (!evlist) return -ENOMEM; @@ -4707,8 +4712,8 @@ static int perf_sched__schedstat_live(struct perf_sch= ed *sched, if (argc) evlist__start_workload(evlist); =20 - /* wait for signal */ - pause(); + sigsuspend(&oldmask); + sigprocmask(SIG_SETMASK, &oldmask, NULL); =20 if (reset) { err =3D disable_sched_schedstat(); --=20 2.43.0