[Devel] Re: [PATCH 1/13] Round up the API

[Serge E. Hallyn]

Quoting Pavel Emelianov (xemul at openvz.org):
> Serge E. Hallyn wrote:
> > Quoting Eric W. Biederman (ebiederm at xmission.com):
> >> "Serge E. Hallyn" <serue at us.ibm.com> writes:
> >>
> >>> Quoting Pavel Emelianov (xemul at openvz.org):
> >>>> The set of functions process_session, task_session, process_group
> >>>> and task_pgrp is confusing, as the names can be mixed with each other
> >>>> when looking at the code for a long time.
> >>>>
> >>>> The proposals are to
> >>>> * equip the functions that return the integer with _nr suffix to
> >>>>   represent that fact,
> >>>> * and to make all functions work with task (not process) by making
> >>>>   the common prefix of the same name.
> >>>>
> >>>> For monotony the routines signal_session() and set_signal_session()
> >>>> are replaced with task_session_nr() and set_task_session(), especially
> >>>> since they are only used with the explicit task->signal dereference.
> >>>>
> >>>> I've sent this before, but Andrew didn't include it, so I resend it
> >>>> as the part of this set.
> >>>>
> >>>> Signed-off-by: Pavel Emelianov <xemul at openvz.org>
> >>>> Acked-by: Serge E. Hallyn <serue at us.ibm.com>
> >>> Yup, I still like this patch.
> >> I'm borderline.  Less error prone interfaces sound good, less
> >> duplication of information sounds good.  Changing the names of
> >> historical function may be change for the sake of change and
> >> thus noise.
> >>
> >> However if we are going to go this far I think we need to remove
> >> the numeric pid cache from the task_struct.
> > 
> > You mean tsk->pid?
> > 
> > I agree, especially in Suka's version.  Not sure it applies to Pavel's
> > version, though since the "real"/global pid is still stored only in
> > tsk->pid, right?
> 
> No. All objects that have pid (task_struct, signal_struct and pid (struct))
> have two ids after this patch - virtual one and global one.

(Yes, so wouldn't removing task->pid be pretty detrimental?)

Could you outline how you would extend this to 3 levels?  Would you just
add a 'vpid2' etc to the struct pid?

thanks,
-serge