Hi Christoph, Sagi, On Tue, Dec 8, 2015 at 2:21 AM, Christoph Hellwig <hch@xxxxxx> wrote:+static void ib_cq_poll_work(struct work_struct *work) +{ + struct ib_cq *cq = container_of(work, struct ib_cq, work); + int completed; + + completed = __ib_process_cq(cq, IB_POLL_BUDGET_WORKQUEUE); + if (completed >= IB_POLL_BUDGET_WORKQUEUE || + ib_req_notify_cq(cq, IB_POLL_FLAGS) > 0) + queue_work(ib_comp_wq, &cq->work); +}In above code, Let says completion is added in a time window where ib_process_cq is completed (CQ is diarmed in hw at that point) and ib_req_notify_cq is yet to be called. Provider vendor driver say mlx4 or mlx5 as specific case always returns ib_req_notify_cq = 0. Will it result into a missed notification? (so queue_work is not done).
If we have not drained the CQ (consumed budget or more) the second condition (ib_req_notify_cq) will not be invoked. We are only rearming the CQ when we drained it completely. So I don't see how we can end up with missed notifications. -- To unsubscribe from this list: send the line "unsubscribe linux-rdma" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
