On Sat, Mar 14, 2015 at 09:30:29PM +0100, Oleg Nesterov wrote: > On 03/14, Josh Triplett wrote: > > > > What I was proposing was that a task that isn't yet dead, but that is > > going to be autoreaped, is not eligible for waiting either. All the > > various wait* familiy of system calls should pretend it doesn't exist at > > all, because returning an autoreaped task from a wait* call introduces a > > race condition if the parent tries to *do* anything with the returned > > PID. If you launch a process with CLONE_FD, you need to manage it > > exclusively with that fd, not with the wait* family of system calls. > > > > That also implies that the child-stop and child-continued mechanisms > > (do_notify_parent_cldstop, WSTOPPED, WCONTINUED) should ignore the task > > too. In the future there could be a flag to clone4 that lets you get > > stop and continue notifications through the file descriptor. > > So far I strongly disagree, and I think that "autoreap" feature should > not depend on CLONE_FD. After reading your other mail and thinking about this, I agree that the two can be separated; see my othermail for the details. > Plus we should also discuss the reparenting. Ok, let me leave this > discussion until I read 0/4 at least. I think you can safely wait for v2 of the last patch, though the first four patches should be almost completely identical in v2. - Josh Triplett -- To unsubscribe from this list: send the line "unsubscribe linux-api" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
