On Thu, Oct 13, 2022 at 05:44:49PM +0800, Chao Leng wrote:
> + rcu = kvmalloc(count * sizeof(*rcu), GFP_KERNEL);
> + if (rcu) {
> + list_for_each_entry(q, &set->tag_list, tag_set_list) {
> + if (blk_queue_noquiesced(q))
> + continue;
> +
> + init_rcu_head(&rcu[i].head);
> + init_completion(&rcu[i].completion);
> + call_srcu(q->srcu, &rcu[i].head, wakeme_after_rcu);
> + i++;
> + }
> +
> + for (i = 0; i < count; i++) {
> + wait_for_completion(&rcu[i].completion);
> + destroy_rcu_head(&rcu[i].head);
> + }
> + kvfree(rcu);
> + } else {
> + list_for_each_entry(q, &set->tag_list, tag_set_list)
> + synchronize_srcu(q->srcu);
> + }
Having to allocate a struct rcu_synchronize for each of the potentially
many queues here is a bit sad.
Pull just explained the start_poll_synchronize_rcu interfaces at ALPSS
last week, so I wonder if something like that would also be feasible
for SRCU, as that would come in really handy here.
