diff options
| -rw-r--r-- | rts/posix/itimer/Pthread.c | 16 |
1 files changed, 12 insertions, 4 deletions
diff --git a/rts/posix/itimer/Pthread.c b/rts/posix/itimer/Pthread.c index d4b0342795..dd36137b72 100644 --- a/rts/posix/itimer/Pthread.c +++ b/rts/posix/itimer/Pthread.c @@ -122,10 +122,18 @@ static void *itimer_thread_func(void *_handle_tick) while (!exited) { if (USE_TIMERFD_FOR_ITIMER) { - if (read(timerfd, &nticks, sizeof(nticks)) != sizeof(nticks)) { - if (errno != EINTR) { - barf("Itimer: read(timerfd) failed: %s", strerror(errno)); - } + ssize_t r = read(timerfd, &nticks, sizeof(nticks)); + if ((r == 0) && (errno == 0)) { + /* r == 0 is expected only for non-blocking fd (in which case + * errno should be EAGAIN) but we use a blocking fd. + * + * Due to a kernel bug (cf https://lkml.org/lkml/2019/8/16/335) + * on some platforms we could see r == 0 and errno == 0. + */ + IF_DEBUG(scheduler, debugBelch("read(timerfd) returned 0 with errno=0. This is a known kernel bug. We just ignore it.")); + } + else if (r != sizeof(nticks) && errno != EINTR) { + barf("Itimer: read(timerfd) failed with %s and returned %zd", strerror(errno), r); } } else { if (rtsSleep(itimer_interval) != 0) { |