3.14-rc2 XFS backtrace because irqs_disabled.

[Oleg Nesterov]

On 02/12, Linus Torvalds wrote:
>
> On Wed, Feb 12, 2014 at 1:14 PM, Al Viro <viro at zeniv.linux.org.uk> wrote:
> >
> > Umm...  What if we delay __sigqueue_free()?  After all, that's where the
> > fat sucker normally comes from.  That way we might get away with much
> > smaller structure on stack...
>
> Sounds like the RightThing(tm) to do to me, and I don't see why it
> wouldn't work.

Probably... I'll try to reply tomorrow.

> We'd have to teach each user of "dequeue_signal()" to free the siginfo
> thing.

And we should be careful with SIGQUEUE_PREALLOC, at least
collect_signal() should not do list_del_init()... Plus we need to
handle the SEND_SIG_FORCED-like case.

Oleg.