Re: [PATCH 1/2] kill_something_info: misc cleanups

[Oleg Nesterov <oleg@tv-sign.ru>]

On 12/16, Eric W. Biederman wrote:
>
> Oleg Nesterov <oleg@tv-sign.ru> writes:
> 
> > On top of
> > 	signal-rewrite-kill_something_info-so-it-uses-newer-helpers.patch
> >
> > - Factor out sending PIDTYPE_PGID wide signals.
> >
> > - Use is_init(p) instead of "p->pid > 1". We don't hash idle threads anymore,
> >   no need to worry about p->pid == 0.
> 
> 
> I do not believe is_init is the proper function here.

Ok. How about child_reaper() for now? "p->pid == 1" doesn't look good either.

>                                                        In the presence
> of multiple pid namespaces

In that case we should use something else than for_each_process() to filter
out task from different namespaces, no?

>                             the intention is for is_init to catch all of
> the special handling (except signal behavior) for the init process.
>
> That way when we have multiple processes with pid == 1 we know which
> one we care about.

I must admit, I don't understand what is the purpose of pid namespace.
The current implementation looks incomplete. For example, mk_pid()
takes pid_namespace into account, but find_pid() (and thus attach_pid())
does not. Shouldn't pid_hash[] live in the "struct pid_namespace" ?

Oleg.