Re: RFC [patch 13/34] PID Virtualization Define new task_pid api

[Serge E. Hallyn]

Quoting Arjan van de Ven (arjan@xxxxxxxxxxxxx):
> On Tue, 2006-01-17 at 08:33 -0600, Serge Hallyn wrote:
> > plain text document attachment (BC-define-pid-handlers)
> > Actually define the task_pid() and task_tgid() functions.  Also
> > replace pid with __pid so as to make sure any missed accessors are
> > caught.
> 
> This question was asked a few times before without satisfactory answer:
> *WHY* this abstraction.
> There is *NO* point. Really. 
> 
> (And if the answer is "but we want to play tricks later", just make a
> current->realpid or whatever, but leave current->pid be the virtual pid.
> Your abstraction helps NOTHING there. Zero Nada Noppes).

The virtual pid is different depending on who is asking.  So simply
storing current->realpid and current->pid isn't helpful, as we would
still need to call a function when a pid crosses user->kernel boundary.

However we could make the patch far less invasive by skipping the
task_pid() macro altogether.  Switching current->pid to current->__pid
was to make sure we catch any ->pid accesses which we may have missed,
during compilation.

Is that approach (keeping task->pid as the real pid and dropping the
task_pid() macro) preferred by all?

-serge

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