xprtrdma: Revert commit e7104a2a9606 ('xprtrdma: Cap req_cqinit').

The root of the problem was that sends (especially unsignalled
FASTREG and LOCAL_INV Work Requests) were not properly flow-
controlled, which allowed a send queue overrun.

Now that the RPC/RDMA reply handler waits for invalidation to
complete, the send queue is properly flow-controlled. Thus this
limit is no longer necessary.

Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Tested-by: Devesh Sharma <devesh.sharma@avagotech.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>

2 files changed, 2 insertions, 10 deletions

diff --git a/net/sunrpc/xprtrdma/verbs.c b/net/sunrpc/xprtrdma/verbs.c
index 003630733ef3..732c71ce5dca 100644
--- a/net/sunrpc/xprtrdma/verbs.c
+++ b/net/sunrpc/xprtrdma/verbs.c
@@ -616,10 +616,8 @@ rpcrdma_ep_create(struct rpcrdma_ep *ep, struct rpcrdma_ia *ia,
 
         /* set trigger for requesting send completion */
         ep->rep_cqinit = ep->rep_attr.cap.max_send_wr/2 - 1;
-        if (ep->rep_cqinit > RPCRDMA_MAX_UNSIGNALED_SENDS)
-                ep->rep_cqinit = RPCRDMA_MAX_UNSIGNALED_SENDS;
-        else if (ep->rep_cqinit <= 2)
-                ep->rep_cqinit = 0;
+        if (ep->rep_cqinit <= 2)
+                ep->rep_cqinit = 0;     /* always signal? */
         INIT_CQCOUNT(ep);
         init_waitqueue_head(&ep->rep_connect_wait);
         INIT_DELAYED_WORK(&ep->rep_connect_worker, rpcrdma_connect_worker);
diff --git a/net/sunrpc/xprtrdma/xprt_rdma.h b/net/sunrpc/xprtrdma/xprt_rdma.h
index ddae4909982b..728101ddc44b 100644
--- a/net/sunrpc/xprtrdma/xprt_rdma.h
+++ b/net/sunrpc/xprtrdma/xprt_rdma.h
@@ -88,12 +88,6 @@ struct rpcrdma_ep {
         struct delayed_work     rep_connect_worker;
 };
 
-/*
- * Force a signaled SEND Work Request every so often,
- * in case the provider needs to do some housekeeping.
- */
-#define RPCRDMA_MAX_UNSIGNALED_SENDS    (32)
-
 #define INIT_CQCOUNT(ep) atomic_set(&(ep)->rep_cqcount, (ep)->rep_cqinit)
 #define DECR_CQCOUNT(ep) atomic_sub_return(1, &(ep)->rep_cqcount)