Re: kill (0, SIGSTOP) is freezing the system (was: /hurd/init and /hurd/proc)

[Samuel Thibault]

Justus Winter, le Fri 26 Jul 2013 13:24:49 +0200, a écrit :
> > >   I'm not sure about how important it is not to freeze anyone of them,
> > >   but at least procfs must not be stopped b/c killall5 wants to
> > >   iterate over /proc.
> > 
> > And /proc might not even be started yet, so exec need to be unfrozen at
> > least, to start it. Perhaps killall5.c could have a Hurd-specific
> > function to use libps to identify procfs and let it continue.
> > 
> > > But it would surely be nice not to freeze filesystem translators, and
> > > probably the pagers and the term translators.
> > 
> > So should perhaps translators be marked as such and avoided?
> 
> So you are saying that any translator started by root should be
> considered essential?

For instance, yes.

> A more explicit variant would be to let translators set themself as
> essential, would you prefer that?

That should work too.  I'd tend to prefer that.

That said, we don't want to mix up "essential" as it happens to be now
(whenever it crashes, init crashes the whole system) with "essential" as
we want it to have (do not kill it on killall -1).

Samuel