Re: [PATCH 2/5] pidfd: add pidfd_wait()

On July 24, 2019 7:45:38 PM GMT+02:00, Linus Torvalds [off-list ref] wrote:

On Wed, Jul 24, 2019 at 7:47 AM Christian Brauner
[off-list ref] wrote:

quoted

This adds the pidfd_wait() syscall.

I despise this patch.

Why can't this just be a new P_PIDFD flag, and then use
"waitid(P_PIDFD, pidfd, ...);"

Yes, yes, yes, I realize that "pidfd" is of type "int", and waitid()
takes an argument of type pid_t, but it's the same type in the end,
and it does seem like the whole *point* of "waitid()" is that
"idtype_t idtype" which tells you what kind of ID you're passing it.

              Linus

Well in that case we could add P_PIDFD.
But then I would like to _only_ enable it for waitid(). How's that sound?

Christian