Re: [PATCH] Bsdacct: stir up comments around acct_process.

[Randy Dunlap <randy.dunlap@oracle.com>]

On Fri, 16 May 2008 14:54:59 +0400 Pavel Emelyanov wrote:

> Fix the one describing what this function is and add one
> more - about locking absence around pid namespaces loop.
> 
> Signed-off-by: Pavel Emelyanov <xemul@openvz.org>
> 
> ---
> 
> diff --git a/kernel/acct.c b/kernel/acct.c
> index 0feba97..d7b670c 100644
> --- a/kernel/acct.c
> +++ b/kernel/acct.c
> @@ -657,7 +657,8 @@ static void acct_process_in_ns(struct pid_namespace *ns)
>  }
>  
>  /**
> - * acct_process - now just a wrapper around do_acct_process
> + * acct_process - now just a wrapper around acct_process_in_ns,
> + * which int turn is a wrapper around do_acct_process.

            in

>   *
>   * handles process accounting for an exiting task
>   */
> @@ -665,6 +666,11 @@ void acct_process(void)
>  {
>  	struct pid_namespace *ns;
>  
> +	/*
> +	 * This loop is safe lockless, since current it still

                                                     is still

> +	 * alive and holds its namespace, which in turn holds
> +	 * its parent.
> +	 */
>  	for (ns = task_active_pid_ns(current); ns != NULL; ns = ns->parent)
>  		acct_process_in_ns(ns);
>  }

---
~Randy