RE: [PATCH 1/1] scsi: storvsc: Reduce default ring buffer size to 128 Kbytes

[Haiyang Zhang]

> -----Original Message-----
> From: linux-hyperv-owner@xxxxxxxxxxxxxxx <linux-hyperv-
> owner@xxxxxxxxxxxxxxx> On Behalf Of Michael Kelley
> Sent: Monday, April 1, 2019 5:42 PM
> To: KY Srinivasan <kys@xxxxxxxxxxxxx>; martin.petersen@xxxxxxxxxx; Long Li
> <longli@xxxxxxxxxxxxx>; James.Bottomley@xxxxxxxxxxxxxxxxxxxxx;
> emilne@xxxxxxxxxx; linux-hyperv@xxxxxxxxxxxxxxx; linux-
> kernel@xxxxxxxxxxxxxxx; linux-scsi@xxxxxxxxxxxxxxx
> Cc: Michael Kelley <mikelley@xxxxxxxxxxxxx>
> Subject: [PATCH 1/1] scsi: storvsc: Reduce default ring buffer size to 128 Kbytes
> 
> 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 <mikelley@xxxxxxxxxxxxx>

Reviewed-by: Haiyang Zhang <haiyangz@xxxxxxxxxxxxx>
Thank you.