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

[Linus Torvalds]

On Wed, Jul 24, 2019 at 7:47 AM Christian Brauner <christian@xxxxxxxxxx> wrote:
>
> 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