xprtrdma: Pre-allocate Work Requests for backchannel
Pre-allocate extra send and receive Work Requests needed to handle
backchannel receives and sends.
The transport doesn't know how many extra WRs to pre-allocate until
the xprt_setup_backchannel() call, but that's long after the WRs are
allocated during forechannel setup.
So, use a fixed value for now.
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Reviewed-by: Sagi Grimberg <sagig@mellanox.com>
Tested-By: Devesh Sharma <devesh.sharma@avagotech.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
diff --git a/net/sunrpc/xprtrdma/verbs.c b/net/sunrpc/xprtrdma/verbs.c
index 7f0ed30..93883ff 100644
--- a/net/sunrpc/xprtrdma/verbs.c
+++ b/net/sunrpc/xprtrdma/verbs.c
@@ -568,6 +568,7 @@
struct ib_device_attr *devattr = &ia->ri_devattr;
struct ib_cq *sendcq, *recvcq;
struct ib_cq_init_attr cq_attr = {};
+ unsigned int max_qp_wr;
int rc, err;
if (devattr->max_sge < RPCRDMA_MAX_IOVS) {
@@ -576,18 +577,27 @@
return -ENOMEM;
}
+ if (devattr->max_qp_wr <= RPCRDMA_BACKWARD_WRS) {
+ dprintk("RPC: %s: insufficient wqe's available\n",
+ __func__);
+ return -ENOMEM;
+ }
+ max_qp_wr = devattr->max_qp_wr - RPCRDMA_BACKWARD_WRS;
+
/* check provider's send/recv wr limits */
- if (cdata->max_requests > devattr->max_qp_wr)
- cdata->max_requests = devattr->max_qp_wr;
+ if (cdata->max_requests > max_qp_wr)
+ cdata->max_requests = max_qp_wr;
ep->rep_attr.event_handler = rpcrdma_qp_async_error_upcall;
ep->rep_attr.qp_context = ep;
ep->rep_attr.srq = NULL;
ep->rep_attr.cap.max_send_wr = cdata->max_requests;
+ ep->rep_attr.cap.max_send_wr += RPCRDMA_BACKWARD_WRS;
rc = ia->ri_ops->ro_open(ia, ep, cdata);
if (rc)
return rc;
ep->rep_attr.cap.max_recv_wr = cdata->max_requests;
+ ep->rep_attr.cap.max_recv_wr += RPCRDMA_BACKWARD_WRS;
ep->rep_attr.cap.max_send_sge = RPCRDMA_MAX_IOVS;
ep->rep_attr.cap.max_recv_sge = 1;
ep->rep_attr.cap.max_inline_data = 0;