Re: [RESEND][RFC PATCH v2] waitfd

Davide Libenzi
2009-01-07T21:06:03Z

On Wed, 7 Jan 2009, Ingo Molnar wrote:

>
> * Roland McGrath <roland@redhat.com> wrote:
>
> > New syscall should have gone to linux-api, I think.
> >
> > Do we really need another one for this? How about using signalfd plus
> > setting the child's exit_signal to a queuing (SIGRTMIN+n) signal instead
> > of SIGCHLD? It's slightly more magical for the userland process to know
> > to do that (fork -> clone SIGRTMIN). But compared to adding a syscall
> > we don't really have to add, maybe better.
>
> hm, i think it's cleaner conceptually than trying to wrap this into
> signalfd. Since we already have:
>
> #define __NR_signalfd 321
> #define __NR_timerfd_create 322
> #define __NR_timerfd_settime 325
> #define __NR_timerfd_gettime 326
> #define __NR_signalfd4 327
>
> is one more really such an issue?

And what did eventfd do to you? :)
I partially agree with Roland (and I stated this during Casey's first
post), this can be achieved in a not too troublesome way already.
A new dedicated interface is easier for the challenged userspace coder,
but I dunno if it's worth the new code (although it does have little
footprint). Both ways are fine from my POV.

- Davide