[Intel-wired-lan] [next-queue 15/17] fm10k: change default Tx ITR to 25usec

Jacob Keller jacob.e.keller at intel.com
Tue Oct 13 23:39:12 UTC 2015


The current default ITR for Tx is overly restrictive. Using a simple
netperf TCP_STREAM test, we top out at about 10Gb/s for a single thread
when running using 1500 byte frames. By reducing the ITR value to 25usec
(up to 40K interrupts a second from 10K), we are able to achieve 36Gb/s
for a single thread TCP stream test.

Signed-off-by: Jacob Keller <jacob.e.keller at intel.com>
---
 drivers/net/ethernet/intel/fm10k/fm10k.h | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/drivers/net/ethernet/intel/fm10k/fm10k.h b/drivers/net/ethernet/intel/fm10k/fm10k.h
index bf2cc6f78418..5eb42fd21d3f 100644
--- a/drivers/net/ethernet/intel/fm10k/fm10k.h
+++ b/drivers/net/ethernet/intel/fm10k/fm10k.h
@@ -171,11 +171,12 @@ struct fm10k_ring_container {
 #define FM10K_ITR_MAX		0x0FFF	/* maximum value for ITR */
 #define FM10K_ITR_10K		100	/* 100us */
 #define FM10K_ITR_20K		50	/* 50us */
+#define FM10K_ITR_40K		25	/* 25us */
 #define FM10K_ITR_ADAPTIVE	0x8000	/* adaptive interrupt moderation flag */
 
 #define ITR_IS_ADAPTIVE(itr) (!!(itr & FM10K_ITR_ADAPTIVE))
 
-#define FM10K_TX_ITR_DEFAULT	FM10K_ITR_10K
+#define FM10K_TX_ITR_DEFAULT	FM10K_ITR_40K
 #define FM10K_RX_ITR_DEFAULT	FM10K_ITR_20K
 #define FM10K_ITR_ENABLE	(FM10K_ITR_AUTOMASK | FM10K_ITR_MASK_CLEAR)
 
-- 
2.6.1.264.gbab76a9



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