[libvirt] [PATCH] Explicitly pin hotplugged vcpu to all cpus

Peter Krempa pkrempa at redhat.com
Fri May 23 12:53:19 UTC 2014


On 05/23/14 14:45, Peter Krempa wrote:
> On 05/23/14 14:37, Ján Tomko wrote:
>> QEMU does not join vcpu threads after vcpu hotunplug.
>> The thread might stay pinned when we hotplug the cpu again.
>>
>> We were already pinning the hotplugged vcpus when a per-domain
>> pinning was specified.
>>
>> Explicitly pin the hotplugged vcpu to all cpus if there is no
>> cpuset specified in domain XML, to make sure the vcpupin
>> stays accurate.
>>
>> https://bugzilla.redhat.com/show_bug.cgi?id=1099836
>> ---
>>  src/qemu/qemu_driver.c | 20 ++++++++++++++++++++
>>  1 file changed, 20 insertions(+)
>>
> 
> The statements about qemu are true only for the downstream version.
> Upstream qemu promises that it will clean up the threads once they
> implement vCPU hot unplug so we will not need to execute the code you've
> proposed in upstream.

Hmmm, re-reading the code ... pinning the currently hotplugged  vcpu
thread to all cpus isn't silly on the other hand. The stuff is that qemu
upstream doesn't do hot unplug and thus the statements about qemu
shouldn't be in libvirt's code.

I'll respond to the original mail again to clarify my intent.

> 
> NACK for merging this upstream.
> 
> Peter
> 

Peter

> 
> 
> 
> --
> libvir-list mailing list
> libvir-list at redhat.com
> https://www.redhat.com/mailman/listinfo/libvir-list
> 


-------------- next part --------------
A non-text attachment was scrubbed...
Name: signature.asc
Type: application/pgp-signature
Size: 901 bytes
Desc: OpenPGP digital signature
URL: <http://listman.redhat.com/archives/libvir-list/attachments/20140523/395437c1/attachment-0001.sig>


More information about the libvir-list mailing list