From: Davidlohr Bueso <dave@stgolabs.net>
Date: Fri, 8 May 2015 18:38:00 +0000 (-0700)
Subject: perf bench futex: Handle spurious wakeups
X-Git-Url: https://git.stricted.de/?a=commitdiff_plain;h=598adc5c9c1cfd3f154f6d9df72b38eda63e306e;p=GitHub%2FLineageOS%2FG12%2Fandroid_kernel_amlogic_linux-4.9.git

perf bench futex: Handle spurious wakeups

Wrap futex_wait around a loop and catch for EINTR.

Either a spurious wakeup occurred or a signal interrupted is, either way
we need to block again.

Signed-off-by: Davidlohr Bueso <dbueso@suse.de>
Cc: Davidlohr Bueso <dbueso@suse.de>
Link: http://lkml.kernel.org/r/1431110280-20231-2-git-send-email-dave@stgolabs.net
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
---

diff --git a/tools/perf/bench/futex-wake.c b/tools/perf/bench/futex-wake.c
index 929f762be47e..e5e41d3bdce7 100644
--- a/tools/perf/bench/futex-wake.c
+++ b/tools/perf/bench/futex-wake.c
@@ -60,7 +60,12 @@ 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) {
+		if (futex_wait(&futex1, 0, NULL, futex_flag) != EINTR)
+			break;
+	}
+
+	pthread_exit(NULL);
 	return NULL;
 }