On Tue, 2017-08-01 at 19:49 -0700, Stephen Hemminger wrote:
> Split the TCP congestion ops structure into const and mutable portions.
> Put the list pointers, key and a copy of the flags in new tcp_congestion_entry
> structure.
...
> -void tcp_unregister_congestion_control(struct tcp_congestion_ops *ca)
> +void tcp_unregister_congestion_control(const struct tcp_congestion_ops *ca)
> {
> + struct tcp_congestion_entry *e;
> +
> spin_lock(&tcp_cong_list_lock);
> - list_del_rcu(&ca->list);
> + list_for_each_entry_rcu(e, &tcp_cong_list, list) {
> + if (e->ops == ca) {
> + list_del_rcu(&e->list);
> + kfree_rcu(e, rcu);
> + break;
> + }
> + }
> spin_unlock(&tcp_cong_list_lock);
>
Since you switched to kfree_rcu(), you could remove the
synchronize_rcu() from tcp_unregister_congestion_control()
Otherwise, no need for kfree_rcu() and the rcu head added in struct
tcp_congestion_entry :
- You could do a kfree() after the synchronize_rcu().
Also, I am not convinced this would be a good move, since you added an
extra structure which is not const anyway.
