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Date: Thu, 07 Jan 2010 10:56:19 -0600
From: Anthony Liguori <anthony@codemonkey.ws>
MIME-Version: 1.0
Subject: Re: [Qemu-devel] Re: [RFD] virtio: Add memory statistics reporting
	to the balloon driver
References: <1262711318.10698.104.camel@aglitke>	
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To: Avi Kivity <avi@redhat.com>
Cc: Luiz Capitulino <lcapitulino@redhat.com>, qemu-devel <qemu-devel@nongnu.org>, Adam Litke <agl@us.ibm.com>

On 01/07/2010 10:39 AM, Avi Kivity wrote:
> On 01/07/2010 06:27 PM, Adam Litke wrote:
>>
>>> I think 'info-balloon' should be synchronous and without side-effects.
>>> ie return the current stats that QEMU has. We could then add a separate
>>> 'refresh-balloon' command + async event notification when that 
>>> completes.
>>> The tool that is requiring the stats could thus refresh as often as it
>>> likes.
>> This would work well for the QMP case, but what about for a traditional
>> monitor?  We could include a sequence number or timestamp in the memory
>> stats results so the user could tell that they were updated.  This
>> doesn't seem very user friendly though
>
> A user would have an easier time logging into the guest and using its 
> native tools.

Yeah, without objections, I like having info-balloon attempt to refresh 
stats, timeout after 10s, and return the last reported stats.  I think 
it also satisfies danpb's criteria of not wasting cpu cycles polling.

Regards,

Anthony Liguori