On Fri, 15 Mar 2019 at 13:15, Li Wang <liwang@redhat.com> wrote:
>
>
>
> On Thu, Mar 14, 2019 at 9:59 PM Cyril Hrubis <chrubis@suse.cz> wrote:
>>
>> Hi!
>> > I am not sure how we would manage actual "msec_timeout" in case we get
>> > EINTR and need to retry again as we may need to take care of elapsed
>> > time till we receive asynchronous signal.
>>
>> I would have just restarted the timeout after we got signal, the worst case
>> that can happen is that in an unlikely case we will send a signals fast enough
>
>
> Maybe we can print something useful there at least for friendly debugging if that unlikely case happens.
>>
>> so that the checkpoint will never timeout. But even then the test library will
>> timeout and would kill the process anyways.
>>
>> Another option is to switch checkpoints so that they use absolute timeout and
>> pass clock_gettime() + msec_timeout as timeout.
>>
>> I would go for something as simple as:
>>
>> diff --git a/lib/tst_checkpoint.c b/lib/tst_checkpoint.c
>> index 5455d0378..5e5b11496 100644
>> --- a/lib/tst_checkpoint.c
>> +++ b/lib/tst_checkpoint.c
>> @@ -85,6 +85,7 @@ void tst_checkpoint_init(const char *file, const int lineno,
>> int tst_checkpoint_wait(unsigned int id, unsigned int msec_timeout)
>> {
>> struct timespec timeout;
>> + int ret;
>>
>> if (id >= tst_max_futexes) {
>> errno = EOVERFLOW;
>> @@ -94,8 +95,12 @@ int tst_checkpoint_wait(unsigned int id, unsigned int msec_timeout)
>> timeout.tv_sec = msec_timeout/1000;
>> timeout.tv_nsec = (msec_timeout%1000) * 1000000;
>>
>> - return syscall(SYS_futex, &tst_futexes[id], FUTEX_WAIT,
>> - tst_futexes[id], &timeout);
>> + do {
>> + ret = syscall(SYS_futex, &tst_futexes[id], FUTEX_WAIT,
>> + tst_futexes[id], &timeout);
>
> if (ret == -1 && errno == EINTR)
> tst_res(TWARN | TERRNO, "FUTEX_WAIT operation was interrupted by a signal, retry again");
>
I am not sure if this warning message is desired for test-cases which
needs to wait on checkpoints irrespective of signals like this
tgkill01 test-case.
-Sumit
>> + } while (ret == -1 && errno == EINTR);
>> +
>> + return ret;
>> }
>>
>> --
>> Cyril Hrubis
>> chrubis@suse.cz
>
>
>
> --
> Regards,
> Li Wang