[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]
Re: [Qemu-devel] [PATCH v2 1/3] pc-dimm: add a function to calculate VM'
From: |
Eric Blake |
Subject: |
Re: [Qemu-devel] [PATCH v2 1/3] pc-dimm: add a function to calculate VM's current RAM size |
Date: |
Wed, 19 Nov 2014 09:31:35 -0700 |
User-agent: |
Mozilla/5.0 (X11; Linux x86_64; rv:31.0) Gecko/20100101 Thunderbird/31.2.0 |
On 11/19/2014 09:06 AM, Michael S. Tsirkin wrote:
>>>> This affects QMP right?
>>>
>>> I think later patches will tell how. CC'ing Eric.
>>
>> As far as I can tell, this is just correcting a reporting issue; the
>> existing QMP commands/events for tracking balloon size will now properly
>> account for hotplugged memory.
>>
>> What I don't know is if this change in semantics will affect any users.
>> Libvirt is not yet supporting memory hotplug, so ideally, fixing this
>> bug before libvirt uses memory hotplug means libvirt will never have to
>> worry about qemu versions that do incorrect reporting.
>>
>> The alternative is to declare that the existing QMP commands cannot
>> change in semantics for the existing members that it reports, and must
>> instead report additional dictionary members describing the amount of
>> hot-plugged memory, and then require that the client add the numbers
>> together itself. That sounds mean to the client, so I'm hoping we don't
>> have to go there.
>
>
> IOW you ack this patch for 2.2?
>
Is memory hotplug one of the new features in 2.2? If so, then yes, we
should get its semantics right from the start (this is a bug fix to
avoid a release with broken semantics). On the other hand, if hotplug
existed in 2.1, then we already have a release with odd semantics, so
delaying this fix until 2.3 and leaving 2.2 with the same odd semantics
would not hurt, and it then becomes a judgment call of whether we are
rushing in a possibly incomplete solution by trying to get this into
2.2. (Sorry I haven't been following the history of memory hotplug closer)
--
Eric Blake eblake redhat com +1-919-301-3266
Libvirt virtualization library http://libvirt.org
signature.asc
Description: OpenPGP digital signature
- [Qemu-devel] [PATCH v2 0/3] fix bug about balloon working incorrectly when hotplug memeory, zhanghailiang, 2014/11/17
- [Qemu-devel] [PATCH v2 2/3] virtio-balloon: Fix balloon not working correctly when hotplug memory, zhanghailiang, 2014/11/17
- [Qemu-devel] [PATCH v2 3/3] virtio-balloon: Add some trace events, zhanghailiang, 2014/11/17
- [Qemu-devel] [PATCH v2 1/3] pc-dimm: add a function to calculate VM's current RAM size, zhanghailiang, 2014/11/17
- Re: [Qemu-devel] [PATCH v2 1/3] pc-dimm: add a function to calculate VM's current RAM size, Igor Mammedov, 2014/11/19
- Re: [Qemu-devel] [PATCH v2 1/3] pc-dimm: add a function to calculate VM's current RAM size, Michael S. Tsirkin, 2014/11/19
- Re: [Qemu-devel] [PATCH v2 1/3] pc-dimm: add a function to calculate VM's current RAM size, Luiz Capitulino, 2014/11/19
- Re: [Qemu-devel] [PATCH v2 1/3] pc-dimm: add a function to calculate VM's current RAM size, Eric Blake, 2014/11/19
- Re: [Qemu-devel] [PATCH v2 1/3] pc-dimm: add a function to calculate VM's current RAM size, Michael S. Tsirkin, 2014/11/19
- Re: [Qemu-devel] [PATCH v2 1/3] pc-dimm: add a function to calculate VM's current RAM size,
Eric Blake <=
- Re: [Qemu-devel] [PATCH v2 1/3] pc-dimm: add a function to calculate VM's current RAM size, zhanghailiang, 2014/11/19
- Re: [Qemu-devel] [PATCH v2 1/3] pc-dimm: add a function to calculate VM's current RAM size, Michael S. Tsirkin, 2014/11/20
- Re: [Qemu-devel] [PATCH v2 1/3] pc-dimm: add a function to calculate VM's current RAM size, zhanghailiang, 2014/11/19
Re: [Qemu-devel] [PATCH v2 0/3] fix bug about balloon working incorrectly when hotplug memeory, Michael S. Tsirkin, 2014/11/17
Re: [Qemu-devel] [PATCH v2 0/3] fix bug about balloon working incorrectly when hotplug memeory, Michael S. Tsirkin, 2014/11/17
Re: [Qemu-devel] [PATCH v2 0/3] fix bug about balloon working incorrectly when hotplug memeory, zhanghailiang, 2014/11/19