On 09/22/2017 07:42 AM, Shuah Khan wrote:
Hi John/Greg,
On 09/21/2017 02:10 PM, Shuah Khan wrote:
do_timer_oneshot() uses select() as a timer with FD_SETSIZE and readfs
is cleared with FD_ZERO without FD_SET.
When stdout and stderr are redirected, the test hangs in select forever.
Fix the problem calling select() with readfds empty and nfds zero. This
is sufficient for using select() for timer.
With this fix "./set-timer-lat > /dev/null 2>&1" no longer hangs.
Signed-off-by: Shuah Khan <shuahkh@xxxxxxxxxxxxxxx>
---
tools/testing/selftests/timers/set-timer-lat.c | 4 +---
1 file changed, 1 insertion(+), 3 deletions(-)
diff --git a/tools/testing/selftests/timers/set-timer-lat.c b/tools/testing/selftests/timers/set-timer-lat.c
index ab2fe225e051..3c248f0dc0d5 100644
--- a/tools/testing/selftests/timers/set-timer-lat.c
+++ b/tools/testing/selftests/timers/set-timer-lat.c
@@ -229,7 +229,6 @@ int do_timer_oneshot(int clock_id, int flags)
timer_t tm1;
const int interval = 0;
struct timeval timeout;
- fd_set fds;
int err;
err = setup_timer(clock_id, flags, interval, &tm1);
@@ -238,9 +237,8 @@ int do_timer_oneshot(int clock_id, int flags)
memset(&timeout, 0, sizeof(timeout));
timeout.tv_sec = 5;
- FD_ZERO(&fds);
do {
- err = select(FD_SETSIZE, &fds, NULL, NULL, &timeout);
+ err = select(0, NULL, NULL, NULL, &timeout);
} while (err == -1 && errno == EINTR);
timer_delete(tm1);
I assume you are good with this fix. I plan to apply it to linux-kselftest fixes
today. Please let me know if you have any objections.
thanks,
-- Shuah
Thanks for looking into this.
Acked-by: Greg Hackmann <ghackmann@xxxxxxxxxx>
--
To unsubscribe from this list: send the line "unsubscribe linux-kselftest" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
