Re: [PATCH 4/4] pidns: Use task_active_pid_ns where appropriate

From: Alexey Dobriyan
Date: Mon Jan 31 2011 - 06:26:48 EST


On Mon, Jan 31, 2011 at 12:25 PM, Daniel Lezcano <daniel.lezcano@xxxxxxx> wrote:
> The expressions tsk->nsproxy->pid_ns and task_active_pid_ns
> aka ns_of_pid(task_pid(tsk)) should have the same number of
> cache line misses with the practical difference that
> ns_of_pid(task_pid(tsk)) is released later in a processes life.
>
> Furthermore by using task_active_pid_ns it becomes trivial
> to write an unshare implementation for the the pid namespace.
>
> So I have used task_active_pid_ns everywhere I can.

Yet current->nsproxy->pid_ns is way clearer.
Because live current always has pid_ns.

This task_active_pid_ns() is misnamed(?) because it does matter only
for dead tasks?

> -               current->nsproxy->pid_ns->last_pid);
> +               task_active_pid_ns(current)->last_pid);

I thought of doing exactly opposite patch :-)
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