Re: And now for something _totally_ different: Linux v2.6.22-rc5

Nicholas Miell
2007-06-17T19:26:58Z

On Sun, 2007-06-17 at 10:01 -0700, Davide Libenzi wrote:
> On Sun, 17 Jun 2007, Nicholas Miell wrote:
>
> > On Sat, 2007-06-16 at 20:33 -0700, Linus Torvalds wrote:
> > > In a stunning turn of events, I've actually been able to make another -rc
> > > release despite all the discussion (*cough*flaming*cough*) about other
> > > issues, and we now have a brand-spanking-new Linux 2.6.22-rc5 release
> > > out there!
> > >
> >
> > signalfd still has the broken behavior w.r.t. signal delivery to
> > threads.
> >
> > Is this going to get fixed before 2.6.22 proper is released, or should
> > it just be disabled entirely so no userspace apps grow to depend on
> > current wrong behavior?
>
> At the moment, with Ben's patch applied, signalfd can see all group-sent
> signals, and locally-directed thread signals.

But there's still no way for multiple threads to read from a single
signalfd and get their own thread-specific signals in addition to
process-wide signals, right? I think this was agreed to be the least
surprising behavior.

> Linus, we can leave this as is, or we can use the ququed-signalfd that was
> implemented in the first versions of signalfd. In such case, since
> signalfd hooks to the sighand, all signals will be visible to signalfd and
> they will not compete against dequeue_signal with the tasks. So there will
> be no races in the queue retrieval. The issue that remained to be solved
> was a simple way to limit memory allocated by the queue.
> What do you prefer?
>
>
>
> - Davide

--
Nicholas Miell <nmiell@comcast.net>