RDS/IB: Make all flow control code conditional on i_flowctl
Andy Grover [Fri, 15 Jan 2010 23:55:26 +0000 (15:55 -0800)]
Maybe things worked fine with the flow control code running
even in the non-flow-control case, but making it explicitly
conditional helps the non-fc case be easier to read.

Signed-off-by: Andy Grover <andy.grover@oracle.com>

net/rds/ib_send.c

index 48724b7..d839b40 100644 (file)
@@ -489,7 +489,7 @@ int rds_ib_xmit(struct rds_connection *conn, struct rds_message *rm,
                if (credit_alloc < work_alloc) {
                        rds_ib_ring_unalloc(&ic->i_send_ring, work_alloc - credit_alloc);
                        work_alloc = credit_alloc;
-                       flow_controlled++;
+                       flow_controlled = 1;
                }
                if (work_alloc == 0) {
                        set_bit(RDS_LL_SEND_FULL, &conn->c_flags);
@@ -552,9 +552,11 @@ int rds_ib_xmit(struct rds_connection *conn, struct rds_message *rm,
                /*
                 * Update adv_credits since we reset the ACK_REQUIRED bit.
                 */
-               rds_ib_send_grab_credits(ic, 0, &posted, 1, RDS_MAX_ADV_CREDIT - adv_credits);
-               adv_credits += posted;
-               BUG_ON(adv_credits > 255);
+               if (ic->i_flowctl) {
+                       rds_ib_send_grab_credits(ic, 0, &posted, 1, RDS_MAX_ADV_CREDIT - adv_credits);
+                       adv_credits += posted;
+                       BUG_ON(adv_credits > 255);
+               }
        }
 
        /* Sometimes you want to put a fence between an RDMA
@@ -619,13 +621,13 @@ int rds_ib_xmit(struct rds_connection *conn, struct rds_message *rm,
                /*
                 * Always signal the last one if we're stopping due to flow control.
                 */
-               if (flow_controlled && i == (work_alloc-1))
+               if (ic->i_flowctl && flow_controlled && i == (work_alloc-1))
                        send->s_wr.send_flags |= IB_SEND_SIGNALED | IB_SEND_SOLICITED;
 
                rdsdebug("send %p wr %p num_sge %u next %p\n", send,
                         &send->s_wr, send->s_wr.num_sge, send->s_wr.next);
 
-               if (adv_credits) {
+               if (ic->i_flowctl && adv_credits) {
                        struct rds_header *hdr = &ic->i_send_hdrs[pos];
 
                        /* add credit and redo the header checksum */