| Message ID | 20240123211130.190553-1-aurelien@aurel32.net |
|---|---|
| State | New |
| Headers | show |
| Series | tst-epoll: increase waiting time before sending signal to the child | expand |
On Jan 23 2024, Aurelien Jarno wrote: > When running the testsuite in parallel, for instance running make -j > $(nproc) check, from time to time tst-epoll fails with a timeout. It > happens because it sometimes takes a bit more than 10ms for the process > to get cloned and blocked by the syscall. In that case the signal is > sent to early, and the test fails with a timeout. This happens even on > fast hosts. > > This patch increases the waiting time to 100ms to make it more reliable. > It corresponds to 20% of the epoll wait time, so there is still some > margin on that side. Can this be synchronized properly? A racy test is worthless.
On 23/01/24 19:23, Andreas Schwab wrote: > On Jan 23 2024, Aurelien Jarno wrote: > >> When running the testsuite in parallel, for instance running make -j >> $(nproc) check, from time to time tst-epoll fails with a timeout. It >> happens because it sometimes takes a bit more than 10ms for the process >> to get cloned and blocked by the syscall. In that case the signal is >> sent to early, and the test fails with a timeout. This happens even on >> fast hosts. >> >> This patch increases the waiting time to 100ms to make it more reliable. >> It corresponds to 20% of the epoll wait time, so there is still some >> margin on that side. > > Can this be synchronized properly? A racy test is worthless. > Maybe either: static pthread_barrier_t *barrier; shared_data = support_shared_allocate (sizeof (*shared_data)); { pthread_barrierattr_t attr; xpthread_barrierattr_init (&attr); xpthread_barrierattr_setpshared (&attr, PTHREAD_PROCESS_SHARED); xpthread_barrier_init (barrier, &attr, 2); xpthread_barrierattr_destroy (&attr); } /* Child. */ xpthread_barrier_wait (&barrier); epoll_ctl (...) /* Parent. */ xpthread_barrier_wait (&barrier); kill (...) Or: /* Parent. */ support_process_state_wait (pid, support_process_state_sleeping); kill (...)
diff --git a/sysdeps/unix/sysv/linux/tst-epoll.c b/sysdeps/unix/sysv/linux/tst-epoll.c index 3b38beae6e..39953c0a08 100644 --- a/sysdeps/unix/sysv/linux/tst-epoll.c +++ b/sysdeps/unix/sysv/linux/tst-epoll.c @@ -98,7 +98,7 @@ test_epoll_basic (epoll_wait_check_t epoll_wait_check) xclose (fds[1][1]); /* Wait some time so child is blocked on the syscall. */ - nanosleep (&(struct timespec) {0, 10000000}, NULL); + nanosleep (&(struct timespec) {0, 100000000}, NULL); TEST_COMPARE (kill (p, SIGUSR1), 0); int e = epoll_wait_check (efd, &event, 1, 500000000, &ss);