On Wed, May 27, 2020 at 11:34:53AM +0300, Yamin Friedman wrote:
> +struct ib_cq *ib_cq_pool_get(struct ib_device *dev, unsigned int nr_cqe,
> + int comp_vector_hint,
> + enum ib_poll_context poll_ctx)
> +{
> + static unsigned int default_comp_vector;
> + unsigned int vector, num_comp_vectors;
> + struct ib_cq *cq, *found = NULL;
> + int ret;
> +
> + if (poll_ctx > IB_POLL_LAST_POOL_TYPE) {
> + WARN_ON_ONCE(poll_ctx > IB_POLL_LAST_POOL_TYPE);
> + return ERR_PTR(-EINVAL);
> + }
> +
> + num_comp_vectors = min_t(int, dev->num_comp_vectors,
> + num_online_cpus());
> + /* Project the affinty to the device completion vector range */
> + if (comp_vector_hint < 0)
> + vector = default_comp_vector++ % num_comp_vectors;
This should not be touching this shared data without some concurrency
management, I changed it to this:
if (comp_vector_hint < 0) {
comp_vector_hint =
(READ_ONCE(default_comp_vector) + 1) % num_comp_vectors;
WRITE_ONCE(default_comp_vector, comp_vector_hint);
}
vector = comp_vector_hint % num_comp_vectors;
Jason
