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 <shua...@osg.samsung.com>
> ---
> 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
