From: Steve Wise Date: Thu, 9 Apr 2009 14:09:36 +0000 (+0000) Subject: RDS/IW+IB: Set recv ring low water mark to 1/2 full. X-Git-Tag: v2.6.31-rc1~14^2~760 X-Git-Url: http://review.tizen.org/git/?a=commitdiff_plain;h=5cd2fe6d54c91aa76893b3034f5f3473063c0202;p=platform%2Fkernel%2Flinux-3.10.git 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 Signed-off-by: Andy Grover Signed-off-by: David S. Miller --- diff --git a/net/rds/ib_ring.c b/net/rds/ib_ring.c index 99a6cca..ff97e8e 100644 --- a/net/rds/ib_ring.c +++ b/net/rds/ib_ring.c @@ -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); } /* diff --git a/net/rds/iw_ring.c b/net/rds/iw_ring.c index d422d4b..da8e3b6 100644 --- a/net/rds/iw_ring.c +++ b/net/rds/iw_ring.c @@ -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); }