[Qemu-devel] Re: [PATCH 1/2] block: Add wr_highest_sector blockstat

[Kevin Wolf <kwolf@redhat.com>]

Am 28.04.2010 18:01, schrieb Anthony Liguori:
> On 04/28/2010 10:56 AM, Kevin Wolf wrote:
>> This adds the wr_highest_sector blockstat which implements what is generally
>> known as the high watermark. It is the highest offset of a sector written to
>> the respective BlockDriverState since it has been opened.
>>
>> The query-blockstat QMP command is extended to add this value to the result,
>> and also to add the statistics of the underlying protocol in a new "parent"
>> field. Note that to get the "high watermark" of a qcow2 image, you need to look
>> into the wr_highest_sector field of the parent (which can be a file, a
>> host_device, ...). The wr_highest_sector of the qcow2 BlockDriverState itself
>> is the highest offset on the _virtual_ disk that the guest has written to.
>>
>> Signed-off-by: Kevin Wolf<kwolf@redhat.com>
>>    
> 
> I see, you did print out stats for each layer.
> 
> I don't think we should take 2/2.  I don't mind QMP having more features 
> than the user monitor.

I agree, just posted it because it felt incomplete without it and I
wanted to give you the choice.

The only use case in the user monitor I saw for it would have been qemu
development anyway. I can keep the patch in a local branch for this (or
just rewrite it when/if I need it - it's small enough).

Kevin