rds: Reintroduce statistics counting

In commit 7e3f2952 ("rds: don't let RDS shutdown a connection
while senders are present"), refilling the receive queue was removed
from rds_ib_recv(), along with the increment of
s_ib_rx_refill_from_thread.

Commit 73ce4317 ("RDS: make sure we post recv buffers")
re-introduces filling the receive queue from rds_ib_recv(), but does
not add the statistics counter. rds_ib_recv() was later renamed to
rds_ib_recv_path().

This commit reintroduces the statistics counting of
s_ib_rx_refill_from_thread and s_ib_rx_refill_from_cq.
Signed-off-by: NHåkon Bugge <haakon.bugge@oracle.com>
Reviewed-by: NKnut Omang <knut.omang@oracle.com>
Reviewed-by: NWei Lin Guay <wei.lin.guay@oracle.com>
Reviewed-by: NShamir Rabinovitch <shamir.rabinovitch@oracle.com>
Acked-by: NSantosh Shilimkar <santosh.shilimkar@oracle.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

net/rds/ib_recv.c

@@ -1015,8 +1015,10 @@ void rds_ib_recv_cqe_handler(struct rds_ib_connection *ic,
 	if (rds_ib_ring_empty(&ic->i_recv_ring))
 		rds_ib_stats_inc(s_ib_rx_ring_empty);
 
-	if (rds_ib_ring_low(&ic->i_recv_ring))
+	if (rds_ib_ring_low(&ic->i_recv_ring)) {
 		rds_ib_recv_refill(conn, 0, GFP_NOWAIT);
+		rds_ib_stats_inc(s_ib_rx_refill_from_cq);
+	}
 }
 
 int rds_ib_recv_path(struct rds_conn_path *cp)
@@ -1029,6 +1031,7 @@ int rds_ib_recv_path(struct rds_conn_path *cp)
 	if (rds_conn_up(conn)) {
 		rds_ib_attempt_ack(ic);
 		rds_ib_recv_refill(conn, 0, GFP_KERNEL);
+		rds_ib_stats_inc(s_ib_rx_refill_from_thread);
 	}
 
 	return ret;