On Fri, Jul 26, 2019 at 10:07 AM Joel Fernandes <joel@xxxxxxxxxxxxxxxxx> wrote:
>
> On Fri, Jul 26, 2019 at 09:22:26AM -0700, Suren Baghdasaryan wrote:
> > This adds testing for polling on pidfd of a process being killed. Test runs
> > 10000 iterations by default to stress test pidfd polling functionality.
> > It accepts an optional command-line parameter to override the number or
> > iterations to run.
> > Specifically, it tests for:
> > - pidfd_open on a child process succeeds
> > - pidfd_send_signal on a child process succeeds
> > - polling on pidfd succeeds and returns exactly one event
> > - returned event is POLLIN
> > - event is received within 3 secs of the process being killed
> >
> > 10000 iterations was chosen because of the race condition being tested
> > which is not consistently reproducible but usually is revealed after less
> > than 2000 iterations.
> > Reveals race fixed by commit b191d6491be6 ("pidfd: fix a poll race when setting exit_state")
> >
> > Signed-off-by: Suren Baghdasaryan <surenb@xxxxxxxxxx>
> > ---
>
> > + close(pidfd);
> > + // Wait for child to prevent zombies
>
> Comment style should be /* */, but I think Christian would be kind enough to
> fix that when he applies the patch so shouldn't need a resend.
Agrh! That's what I get for constantly switching between kernel and
userspace development :\
Christian please let me know if I should respin this or you can fix it
when taking this patch.
Thanks!
>
> Thanks Suren and Christian!
>
> Reviewed-by: Joel Fernandes (Google) <joel@xxxxxxxxxxxxxxxxx>
>
