Re: [Xen-devel] [PATCH 2/2] drivers: xen/block: add multi-page ring support

[Bob Liu <bob.liu@xxxxxxxxxx>]

On 02/02/2015 06:43 PM, Roger Pau Monné wrote:
> El 23/01/15 a les 10.14, Bob Liu ha escrit:
>> Extend xen/block to support multi-page ring.
>>  * xen-blkback notify blkfront with feature-multi-ring-pages
>>  * xen-blkfront write to xenstore about how many pages are used as the ring
>>
>> If using 4 pages as the ring, inflight requests inscreased from 32 to 128 and
>> IOPS improved nearly 400% on our system.
>>
>> Signed-off-by: Bob Liu <bob.liu@xxxxxxxxxx>
>> ---
>>  drivers/block/xen-blkback/xenbus.c |   86 +++++++++++++++++++++++++--------
>>  drivers/block/xen-blkfront.c       |   94 
>> ++++++++++++++++++++++++++----------
> 
> This requires a patch to xen/include/public/io/blkif.h in the Xen
> repository describing how this protocol extension is going to work
> before reviewing the Linux implementation.
> 

But there is no protocol change, just add an parameter "max_ring_pages"
to control how many pages can be used as the ring. Now with one page we
can only have 32 requests.

-- 
Regards,
-Bob

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