[PATCH 0/1] signals: kill block_all_signals() and unblock_all_signals()

[Oleg Nesterov]

On 05/26, Dave Airlie wrote:
>
> On 26 May 2015 at 02:50, Oleg Nesterov <oleg at redhat.com> wrote:
> > AAAAOn 05/25, Richard Weinberger wrote:
> >>
> >> Is this functionality still in use/needed?
> >
> > All I can say it doesn't work.
> >
> >> Otherwise we could get rid of block_all_signals() and unpuzzle the signaling
> >> code a bit. :-)
> >
> > Yes. I do not even remember when I reported this the first time. Perhaps
> > more than 10 years ago.
> >
> > See the last attempt in 2011: https://lkml.org/lkml/2011/7/12/263
> > I copied this email below.
> >
> > Dave. Lets finally kill this horror? I am going to send a patch unless
> > you stop me ;)
>
> There were follow up on that thread 4 years ago, but we are probably
> at the stage where this thing can die,

Heh.

I tried to kill this horror so many years, and forgot to send the patch
after you finally blessed it ;)

Could you please review?

> I suspect any hw using it has died out, and any new hardware won't be
> doing evil things with drm locks

even if it does, let me repeat that block_all_signals() simply do not
work. At all. if ->notifier() returns 0, this thread will burn CPU until
SIGCONT or SIGKILL. Or it will stop anyway if multi-threaded.

Oleg.