Commit 5cd2fe6d authored Apr 09, 2009 by Steve Wise Committed by David S. Miller Apr 09, 2009

RDS/IW+IB: Set recv ring low water mark to 1/2 full.



Currently the recv ring low water mark is 1/4 the depth.  Performance
measurements show that this limits iWARP throughput by flow controlling
the rds-stress senders.  Setting it to 1/2 seems to max the T3
performance.  I tried even higher levels but that didn't help and it
started to increase the rds thread cpu utilization.

Signed-off-by: Steve Wise <swise@opengridcomputing.com>
Signed-off-by: Andy Grover <andy.grover@oracle.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

parent a0c31fdf

net/rds/ib_ring.c

+1 −1

Original line number	Diff line number	Diff line
		@@ -137,7 +137,7 @@ int rds_ib_ring_empty(struct rds_ib_work_ring *ring)

		int rds_ib_ring_low(struct rds_ib_work_ring *ring)
		{
		return __rds_ib_ring_used(ring) <= (ring->w_nr >> 2);
		return __rds_ib_ring_used(ring) <= (ring->w_nr >> 1);
		}

		/*

net/rds/iw_ring.c

+1 −1

Original line number	Diff line number	Diff line
		@@ -137,7 +137,7 @@ int rds_iw_ring_empty(struct rds_iw_work_ring *ring)

		int rds_iw_ring_low(struct rds_iw_work_ring *ring)
		{
		return __rds_iw_ring_used(ring) <= (ring->w_nr >> 2);
		return __rds_iw_ring_used(ring) <= (ring->w_nr >> 1);
		}