From 01db7fbf5487505b887fbd6a03c51f2adc952196 Mon Sep 17 00:00:00 2001 From: Shuah Khan Date: Thu, 21 Sep 2017 13:46:01 -0600 Subject: selftests: timers: set-timer-lat: fix hang when std out/err are redirected 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 Acked-by: Greg Hackmann Signed-off-by: Shuah Khan --- tools/testing/selftests/timers/set-timer-lat.c | 4 +--- 1 file changed, 1 insertion(+), 3 deletions(-) (limited to 'tools/testing/selftests/timers/set-timer-lat.c') diff --git a/tools/testing/selftests/timers/set-timer-lat.c b/tools/testing/selftests/timers/set-timer-lat.c index 9c92b7bd5641..ea1af5dbc7b6 100644 --- a/tools/testing/selftests/timers/set-timer-lat.c +++ b/tools/testing/selftests/timers/set-timer-lat.c @@ -228,7 +228,6 @@ 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); @@ -237,9 +236,8 @@ 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); -- cgit v1.2.3 From eefd95e1f3d47b90dc768e9ebc77d390c4f34809 Mon Sep 17 00:00:00 2001 From: Shuah Khan Date: Thu, 21 Sep 2017 13:05:18 -0600 Subject: selftests: timers: set-timer-lat: Fix hang when testing unsupported alarms When timer_create() fails on a bootime or realtime clock, setup_timer() returns 0 as if timer has been set. Callers wait forever for the timer to expire. This hang is seen on a system that doesn't have support for: CLOCK_REALTIME_ALARM ABSTIME missing CAP_WAKE_ALARM? : [UNSUPPORTED] Test hangs waiting for a timer that hasn't been set to expire. Fix setup_timer() to return 1, add handling in callers to detect the unsupported case and return 0 without waiting to not fail the test. Signed-off-by: Shuah Khan --- tools/testing/selftests/timers/set-timer-lat.c | 9 ++++++--- 1 file changed, 6 insertions(+), 3 deletions(-) (limited to 'tools/testing/selftests/timers/set-timer-lat.c') diff --git a/tools/testing/selftests/timers/set-timer-lat.c b/tools/testing/selftests/timers/set-timer-lat.c index ea1af5dbc7b6..50da45437daa 100644 --- a/tools/testing/selftests/timers/set-timer-lat.c +++ b/tools/testing/selftests/timers/set-timer-lat.c @@ -143,7 +143,8 @@ int setup_timer(int clock_id, int flags, int interval, timer_t *tm1) printf("%-22s %s missing CAP_WAKE_ALARM? : [UNSUPPORTED]\n", clockstring(clock_id), flags ? "ABSTIME":"RELTIME"); - return 0; + /* Indicate timer isn't set, so caller doesn't wait */ + return 1; } printf("%s - timer_create() failed\n", clockstring(clock_id)); return -1; @@ -213,8 +214,9 @@ int do_timer(int clock_id, int flags) int err; err = setup_timer(clock_id, flags, interval, &tm1); + /* Unsupported case - return 0 to not fail the test */ if (err) - return err; + return err == 1 ? 0 : err; while (alarmcount < 5) sleep(1); @@ -231,8 +233,9 @@ int do_timer_oneshot(int clock_id, int flags) int err; err = setup_timer(clock_id, flags, interval, &tm1); + /* Unsupported case - return 0 to not fail the test */ if (err) - return err; + return err == 1 ? 0 : err; memset(&timeout, 0, sizeof(timeout)); timeout.tv_sec = 5; -- cgit v1.2.3