Re: [RFC,PATCH] use rcu for fasync_lock

[OGAWA Hirofumi]

Manfred Spraul <manfred@xxxxxxxxxxxxxxxx> writes:

>  void kill_fasync(struct fasync_struct **fp, int sig, int band)
>  {
> -	read_lock(&fasync_lock);
> +	rcu_read_lock();
>  	__kill_fasync(*fp, sig, band);
> -	read_unlock(&fasync_lock);
> +	rcu_read_unlock();
>  }

Usually *fp is NULL, I think. So what about the following test?

void kill_fasync(struct fasync_struct **fp, int sig, int band)
{
	if (*fp) {
		rcu_read_lock();
		__kill_fasync(*fp, sig, band);
		rcu_read_unlock();
	}
}

Or use inline function for testing *fp.
-- 
OGAWA Hirofumi <hirofumi@xxxxxxxxxxxxxxxxxx>
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