Re: [PATCH] proc: array: drop stale FIXME about RCU in task_sig()

[Oleg Nesterov]

On 02/15, Jaime Saguillo Revilla wrote:
> task_sig() already wraps the SigQ rlimit read in an explicit RCU
> read-side critical section. Drop the stale FIXME comment and keep using
> task_ucounts() for the ucounts access.
> 
> No functional change.
> 
> Signed-off-by: Jaime Saguillo Revilla <jaime.saguillo@xxxxxxxxx>
> ---
>  fs/proc/array.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/fs/proc/array.c b/fs/proc/array.c
> index f447e734612a..90fb0c6b5f99 100644
> --- a/fs/proc/array.c
> +++ b/fs/proc/array.c
> @@ -280,7 +280,7 @@ static inline void task_sig(struct seq_file *m, struct task_struct *p)
>  		blocked = p->blocked;
>  		collect_sigign_sigcatch(p, &ignored, &caught);
>  		num_threads = get_nr_threads(p);
> -		rcu_read_lock();  /* FIXME: is this correct? */
> +		rcu_read_lock();
>  		qsize = get_rlimit_value(task_ucounts(p), UCOUNT_RLIMIT_SIGPENDING);

I think that task_ucounts/rcu interaction need cleanups, I'll try to do
this next week(s)...

But as for this change I agree: the code is correct and "FIXME' adds the
unnecessary confusion.

Acked-by: Oleg Nesterov <oleg@xxxxxxxxxx>