On 07/25, Christian Brauner wrote: > > On Thu, Jul 25, 2019 at 12:35:44PM +0200, Oleg Nesterov wrote: > > > > I have to admit this feature looks a bit exotic to me... > > It might look like it from the kernels perspective but from the feedback > on this when presenting on this userspace has real usecases for this. OK... but then perhaps we can make PF_WAIT_PID more flexible. Say, we can add the new WXXX wait option and change eligible_child() if ((p->flags & PF_WAIT_PID) && (wo->options & WXXX)) return 0; this way the parent can tell waitid() whether the PF_WAIT_PID tasks should be filtered or not. And if we do this we can even add PR_SET_WAIT_PID/PR_CLR_WAIT_PID instead of the new CLONE_ flag. Oleg.
