scsi: storvsc: Reduce default ring buffer size to 128 Kbytes

ed2e63aa · Michael Kelley <[email protected]> · 2019-04-01 21:42:06 +00:00

Reduce the default VMbus channel ring buffer size for storvsc SCSI devices
from 1 Mbyte to 128 Kbytes. Measurements show that ring buffer sizes above
128 Kbytes do not increase performance even at very high IOPS rates, so
don't waste the memory. Also remove the dependence on PAGE_SIZE, since the
ring buffer size should not change on architectures where PAGE_SIZE is not
4 Kbytes.

Signed-off-by: Michael Kelley <[email protected]>
Reviewed-by: Haiyang Zhang <[email protected]>
Signed-off-by: Martin K. Petersen <[email protected]>

Commit: ed2e63aaec4fbf248275d2d83c4cfd65e069594f
Parents: 382e06d1

Changes

1 files changed · +1 −1

File	Status	Add	Del	Content
drivers/scsi/storvsc_drv.c	modified	+1	−1	View file

drivers/scsi/storvsc_drv.c

View file

diff --git a/drivers/scsi/storvsc_drv.c b/drivers/scsi/storvsc_drv.c
index e186743..8472de1 100644
--- a/drivers/scsi/storvsc_drv.c
+++ b/drivers/scsi/storvsc_drv.c
@@ -385,7 +385,7 @@ enum storvsc_request_type {
  * This is the end of Protocol specific defines.
  */
 
-static int storvsc_ringbuffer_size = (256 * PAGE_SIZE);
+static int storvsc_ringbuffer_size = (128 * 1024);
 static u32 max_outstanding_req_per_channel;
 
 static int storvsc_vcpus_per_sub_channel = 4;