From: "Michael R. Hines" <mrhines@linux.vnet.ibm.com>
To: zhanghailiang <zhang.zhanghailiang@huawei.com>,
Alexandre DERUMIER <aderumier@odiso.com>
Cc: hinesmr@cn.ibm.com, qemu-devel <qemu-devel@nongnu.org>
Subject: Re: [Qemu-devel] ballooning not working on hotplugged pc-dimm
Date: Thu, 11 Sep 2014 09:57:27 +0800 [thread overview]
Message-ID: <54110187.7060107@linux.vnet.ibm.com> (raw)
In-Reply-To: <54101328.4070802@huawei.com>
On 09/10/2014 05:00 PM, zhanghailiang wrote:
> On 2014/9/9 11:05, Alexandre DERUMIER wrote:
>> Hello,
>>
>> I was playing with pc-dimm hotplug, and I notice that balloning is
>> not working on
>> memory space of pc-dimm devices.
>>
>> example:
>>
>> qemu -m size=1024,slots=255,maxmem=15000M
>>
>> #free -m : 1024M
>> -> qmp balloon 512M
>> #free -m : 512M
>>
>> -> hotplug pc-dimm 1G:
>>
>> #free -m : 1512M
>>
>>
>> (This is the same behavior if qemu is started with pc-dimm devices)
>>
>>
>> qemu 2.1
>> Guest kernel : 3.12.
>>
>>
>>
>> Does it need a guest balloon module update ?
>>
>> Regards,
>>
>> Alexandre Derumier
>>
>>
>>
> Hi,
>
> I noticed this fault also;-), this is a bug in qemu, And some work in
> process...
>
> Actually in QEMU the hotplugged memory(named hotplug-memory) is
> distinguished
> from the common memory(named pc.ram). When do balloon action, QEMU
> wrongly
> stats the ram_size.
>
> I will send a patch series which also include other bug fix for the
> memory hotplug.
>
> Thanks,
> zhanghailiang
>
>
>
Why does hotplugging use a different name?
This also affects RDMA live migration - we are explicitly looking up
"pc.ram" ram blocks and pinning them for memory registration with Linux.
- Michael
next prev parent reply other threads:[~2014-09-11 1:57 UTC|newest]
Thread overview: 6+ messages / expand[flat|nested] mbox.gz Atom feed top
[not found] <0a98da72-f316-4e2b-8327-201f85a6e879@mailpro>
2014-09-09 3:05 ` [Qemu-devel] ballooning not working on hotplugged pc-dimm Alexandre DERUMIER
2014-09-10 9:00 ` zhanghailiang
2014-09-11 1:57 ` Michael R. Hines [this message]
2014-09-11 6:22 ` Paolo Bonzini
2014-09-11 6:27 ` Michael R. Hines
2014-09-11 6:33 ` zhanghailiang
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