[PATCH 6/7] perf/bench-futex, requeue: Robustify futex_wait() handling
From: Davidlohr Bueso <dave@stgolabs.net>
Date: 2021-08-09 04:33:36
Also in:
lkml
Subsystem:
futex subsystem, performance events subsystem, the rest · Maintainers:
Thomas Gleixner, Ingo Molnar, Peter Zijlstra, Arnaldo Carvalho de Melo, Namhyung Kim, Linus Torvalds
Do not assume success and account for EAGAIN or any other return value, however unlikely. Signed-off-by: Davidlohr Bueso <redacted> --- tools/perf/bench/futex-requeue.c | 15 ++++++++++++++- 1 file changed, 14 insertions(+), 1 deletion(-)
diff --git a/tools/perf/bench/futex-requeue.c b/tools/perf/bench/futex-requeue.c
index 80f40ee92b53..e4892ba6864f 100644
--- a/tools/perf/bench/futex-requeue.c
+++ b/tools/perf/bench/futex-requeue.c@@ -76,6 +76,8 @@ static void print_summary(void) static void *workerfn(void *arg __maybe_unused) { + int ret; + pthread_mutex_lock(&thread_lock); threads_starting--; if (!threads_starting)
@@ -83,7 +85,18 @@ static void *workerfn(void *arg __maybe_unused) pthread_cond_wait(&thread_worker, &thread_lock); pthread_mutex_unlock(&thread_lock); - futex_wait(&futex1, 0, NULL, futex_flag); + while (1) { + ret = futex_wait(&futex1, 0, NULL, futex_flag); + if (!ret) + break; + + if (ret && errno != EAGAIN) { + if (!params.silent) + warn("futex_wait"); + break; + } + } + return NULL; }
--
2.26.2