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

[Samuel Thibault]

Justus Winter, le Wed 24 Jul 2013 08:30:52 +0200, a écrit :
>   the processes below 100 that are
>   not marked as essential by Guillems patch are:
> 
>   exec,

That one should be easy.

> /sbin/init, term, pflocal, mach-defpager, null, procfs,
>   proxy-defpager, tmpfs, storeio

Most of which are translators.

>   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?

> * As Markus pointed out in his critique of Guillems patch, any user
>   can mark any process as essential, this is probably not what we
>   want. Restricting this to root seems easy though.

Yes, and I agree.

Samuel