At 12:34 PM 5/19/2008, Tom Tucker wrote: >When adapters have differing IRD limits, the RDMA transport will fail to >connect properly. The RDMA transport should use the client's advertised >inbound read limit when computing it's outbound read limit. For iWARP >transports, there is no exchange of the IRD/ORD during connect request and >so the only way to ensure compatability is to use the >/proc/sys/sunrpc/svc_rdma/max_outbound_read_requests file to control >server ORD. Well, technically the iWARP connection manager *currently* does not exchange these values. I think the comment would be more accurate if it said "in the absence of"... >-static void handle_connect_req(struct rdma_cm_id *new_cma_id) >+static void handle_connect_req(struct rdma_cm_id *new_cma_id, u8 client_ird) While "u8" might be the limit of the implementations today, wouldn't "int" be easier to understand, and more portable? >+ /* Save client advertised inbound read limit for use later in accept. */ >+ newxprt->sc_ord = client_ird; >+ and... >+ /* >+ * Limit ORD based on client limit, local device limit, and >+ * configured svcrdma limit. >+ */ >+ newxprt->sc_ord = min((size_t)devattr.max_qp_rd_atom, newxprt->sc_ord); >+ newxprt->sc_ord = min((size_t)svcrdma_ord, newxprt->sc_ord); Looks good, but it's a little odd that the value goes into sc_ord in one routine, only to be changed before being used. I guess the device attrs aren't handy at the time the connection is notified though, so ok. Tom. -- To unsubscribe from this list: send the line "unsubscribe linux-nfs" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
