* [Qemu-devel] ballooning not working on hotplugged pc-dimm
[not found] <0a98da72-f316-4e2b-8327-201f85a6e879@mailpro>
@ 2014-09-09 3:05 ` Alexandre DERUMIER
2014-09-10 9:00 ` zhanghailiang
0 siblings, 1 reply; 6+ messages in thread
From: Alexandre DERUMIER @ 2014-09-09 3:05 UTC (permalink / raw)
To: qemu-devel
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
^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: [Qemu-devel] ballooning not working on hotplugged pc-dimm
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
0 siblings, 1 reply; 6+ messages in thread
From: zhanghailiang @ 2014-09-10 9:00 UTC (permalink / raw)
To: Alexandre DERUMIER; +Cc: qemu-devel
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
^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: [Qemu-devel] ballooning not working on hotplugged pc-dimm
2014-09-10 9:00 ` zhanghailiang
@ 2014-09-11 1:57 ` Michael R. Hines
2014-09-11 6:22 ` Paolo Bonzini
0 siblings, 1 reply; 6+ messages in thread
From: Michael R. Hines @ 2014-09-11 1:57 UTC (permalink / raw)
To: zhanghailiang, Alexandre DERUMIER; +Cc: hinesmr, qemu-devel
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
^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: [Qemu-devel] ballooning not working on hotplugged pc-dimm
2014-09-11 1:57 ` Michael R. Hines
@ 2014-09-11 6:22 ` Paolo Bonzini
2014-09-11 6:27 ` Michael R. Hines
0 siblings, 1 reply; 6+ messages in thread
From: Paolo Bonzini @ 2014-09-11 6:22 UTC (permalink / raw)
To: Michael R. Hines, zhanghailiang, Alexandre DERUMIER; +Cc: hinesmr, qemu-devel
Il 11/09/2014 03:57, Michael R. Hines ha scritto:
>>
>
> 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.
Are we? I cannot see any code that special cases pc.ram (it only
appears in a couple of comments). It'd also be surprising to see that
escaping review. :)
Paolo
^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: [Qemu-devel] ballooning not working on hotplugged pc-dimm
2014-09-11 6:22 ` Paolo Bonzini
@ 2014-09-11 6:27 ` Michael R. Hines
2014-09-11 6:33 ` zhanghailiang
0 siblings, 1 reply; 6+ messages in thread
From: Michael R. Hines @ 2014-09-11 6:27 UTC (permalink / raw)
To: Paolo Bonzini, zhanghailiang, Alexandre DERUMIER; +Cc: hinesmr, qemu-devel
On 09/11/2014 02:22 PM, Paolo Bonzini wrote:
> Il 11/09/2014 03:57, Michael R. Hines ha scritto:
>> 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.
> Are we? I cannot see any code that special cases pc.ram (it only
> appears in a couple of comments). It'd also be surprising to see that
> escaping review. :)
>
> Paolo
>
You're absolutely right =) I was thinking about old code. We loop
through all the ram blocks.
Good sanity check, though =)
- Michael
^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: [Qemu-devel] ballooning not working on hotplugged pc-dimm
2014-09-11 6:27 ` Michael R. Hines
@ 2014-09-11 6:33 ` zhanghailiang
0 siblings, 0 replies; 6+ messages in thread
From: zhanghailiang @ 2014-09-11 6:33 UTC (permalink / raw)
To: Michael R. Hines; +Cc: Paolo Bonzini, hinesmr, qemu-devel, Alexandre DERUMIER
On 2014/9/11 14:27, Michael R. Hines wrote:
> On 09/11/2014 02:22 PM, Paolo Bonzini wrote:
>> Il 11/09/2014 03:57, Michael R. Hines ha scritto:
>>> 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.
>> Are we? I cannot see any code that special cases pc.ram (it only
>> appears in a couple of comments). It'd also be surprising to see that
>> escaping review. :)
>>
>> Paolo
>>
>
>
> You're absolutely right =) I was thinking about old code. We loop through all the ram blocks.
>
> Good sanity check, though =)
>
> - Michael
>
>
>
Hmm, in this case, it is better to remove this confused comments;-)
^ permalink raw reply [flat|nested] 6+ messages in thread
end of thread, other threads:[~2014-09-11 6:34 UTC | newest]
Thread overview: 6+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
[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
2014-09-11 6:22 ` Paolo Bonzini
2014-09-11 6:27 ` Michael R. Hines
2014-09-11 6:33 ` zhanghailiang
This is an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.