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>
This commit is contained in:
Steve Wise 2009-04-09 14:09:36 +00:00 committed by David S. Miller
parent a0c31fdfb7
commit 5cd2fe6d54
2 changed files with 2 additions and 2 deletions

View file

@ -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);
}
/*

View file

@ -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);
}