This is the fourth re-incarnation of the CQ pool patches proposed by Sagi and Christoph. I have started with the patches that Sagi last submitted and built the CQ pool as a new API for acquiring shared CQs. The main change from Sagi's last proposal is that I have simplified the method that ULP drivers interact with the CQ pool. Instead of calling ib_alloc_cq they now call ib_cq_pool_get but use the CQ in the same manner that they did before. This allows for a much easier transition to using shared CQs by the ULP and makes it easier to deal with IB_POLL_DIRECT contexts. Certain types of actions on CQs have been prevented on shared CQs in order to prevent one user from harming another. Our ULPs often want to make smart decisions on completion vector affinitization when using multiple completion queues spread on multiple cpu cores. We can see examples for this in iser, srp, nvme-rdma.
Yamin, didn't you promise to adjust other ulps as well in the next post?
