On Fri, Jul 24, 2015 at 04:26:00PM -0400, Chuck Lever wrote: > Basically RPC work flow stopped because an RPC reply never > arrived. Oh, that is what I expect to see.. Remebmer the cq upcall is edge triggered, so if you leave stuff in the cq then you don't get another upcall until another CQE is added. If adding another CQE is somehow contingent on the CQE left behind then the scheme deadlocks. The CQE is not lost because calling ib_poll_cq from outside the upcall will return it. To confirm lost you need to see ib_poll_cq return no results and confirm an expected CQE is missing. The driver is expected to avoid racing with the upcall and guarentee new CQEs will trigger no matter how many CQEs are consumed by the ULP. So, as Steve said, if the ULP leaves CQEs behind then it must do something to guarantee that ib_poll_cq is eventually called to collect them, or not care about forward progress on the CQ. Does that make sense and explain what you saw? If yes, I recommend revising the commit and comment language. CQEs are not lost, only the upcall isn't happening. Jason -- 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
