[PATCH 5/6] staging: hv: Increased storvsc ringbuffer and max_io_requests

[PATCH 5/6] staging: hv: Increased storvsc ringbuffer and max_io_requests

[Hank Janssen]

From: Hank Janssen <hjanssen@microsoft.com>

Increased storvsc ringbuffer and max_io_requests. This now more closely mimics 
the numbers on Hyper-V. And will allow more IO requests to take place for the SCSI driver.

Signed-off-by:Hank Janssen <hjanssen@microsoft.com>
Signed-off-by:Haiyang Zhang <haiyangz@microsoft.com> 

---
 drivers/staging/hv/storvsc_api.h |    4 ++--
 1 files changed, 2 insertions(+), 2 deletions(-)

diff --git a/drivers/staging/hv/storvsc_api.h b/drivers/staging/hv/storvsc_api.h
index 0063bde..8505a1c 100644
--- a/drivers/staging/hv/storvsc_api.h
+++ b/drivers/staging/hv/storvsc_api.h
@@ -28,10 +28,10 @@
 #include "vmbus_api.h"
 
 /* Defines */
-#define STORVSC_RING_BUFFER_SIZE			(10*PAGE_SIZE)
+#define STORVSC_RING_BUFFER_SIZE			(20*PAGE_SIZE)
 #define BLKVSC_RING_BUFFER_SIZE				(20*PAGE_SIZE)
 
-#define STORVSC_MAX_IO_REQUESTS				64
+#define STORVSC_MAX_IO_REQUESTS				128
 
 /*
  * In Hyper-V, each port/path/target maps to 1 scsi host adapter.  In
--
1.6.0.2

Re: [PATCH 5/6] staging: hv: Increased storvsc ringbuffer and max_io_requests

[Greg KH]

On Tue, Aug 03, 2010 at 05:31:55PM +0000, Hank Janssen wrote:
> From: Hank Janssen <hjanssen@microsoft.com>
> 
> Increased storvsc ringbuffer and max_io_requests. This now more closely mimics 
> the numbers on Hyper-V.

What do you mean by this?  The max provided by the hypervisor?

> And will allow more IO requests to take place for the SCSI driver.

Which means what, better throughput?  Or just more outstanding requests
and the same speed overall?

thanks,

greg k-h

Re: [PATCH 5/6] staging: hv: Increased storvsc ringbuffer and max_io_requests

[Greg KH]

On Tue, Aug 03, 2010 at 05:31:55PM +0000, Hank Janssen wrote:
> From: Hank Janssen <hjanssen@microsoft.com>
> 
> Increased storvsc ringbuffer and max_io_requests. This now more closely mimics 
> the numbers on Hyper-V. And will allow more IO requests to take place for the SCSI driver.
> 
> Signed-off-by:Hank Janssen <hjanssen@microsoft.com>
> Signed-off-by:Haiyang Zhang <haiyangz@microsoft.com> 

Again with the trailing spaces :(

RE: [PATCH 5/6] staging: hv: Increased storvsc ringbuffer and max_io_requests

[Hank Janssen]

>>And than Greg KH spoke these words:
>>On Tue, Aug 03, 2010 at 05:31:55PM +0000, Hank Janssen wrote:
> >From: Hank Janssen <hjanssen@microsoft.com>
> >
> >Increased storvsc ringbuffer and max_io_requests. This now more 
> >closely mimics the numbers on Hyper-V.
>
>What do you mean by this?  The max provided by the hypervisor?

Max_IO is set to double from what it was before, Hyper-V allows it and
We have had appliance builder requests to see if it was a problem to increase
The number.

Ringbuffer size for storvsc is now increased because I have seen 
A few buffer problems on extremely busy systems. They where 
Set pretty low before. And since max_io_requests is increased I
Really needed to increase the buffer as well.

>> And will allow more IO requests to take place for the SCSI driver.
>
>Which means what, better throughput?  Or just more outstanding requests and the same speed overall?

It means better throughput of high load systems, else you get buffer
Contention. 

Thanks,

Hank.

Re: [PATCH 5/6] staging: hv: Increased storvsc ringbuffer and max_io_requests

[Greg KH]

On Wed, Aug 04, 2010 at 03:23:09AM +0000, Hank Janssen wrote:
> 
> >>And than Greg KH spoke these words:
> >>On Tue, Aug 03, 2010 at 05:31:55PM +0000, Hank Janssen wrote:
> > >From: Hank Janssen <hjanssen@microsoft.com>
> > >
> > >Increased storvsc ringbuffer and max_io_requests. This now more 
> > >closely mimics the numbers on Hyper-V.
> >
> >What do you mean by this?  The max provided by the hypervisor?
> 
> Max_IO is set to double from what it was before, Hyper-V allows it and
> We have had appliance builder requests to see if it was a problem to increase
> The number.
> 
> Ringbuffer size for storvsc is now increased because I have seen 
> A few buffer problems on extremely busy systems. They where 
> Set pretty low before. And since max_io_requests is increased I
> Really needed to increase the buffer as well.
> 
> >> And will allow more IO requests to take place for the SCSI driver.
> >
> >Which means what, better throughput?  Or just more outstanding requests and the same speed overall?
> 
> It means better throughput of high load systems, else you get buffer
> Contention. 

All good, care to included this in the changelog comment when you resend
this whole series?

thanks,

greg k-h