Re: [PATCH 0/4] CPU online/offline support in Xen

[Gavin Maltby <Gavin.Maltby@Sun.COM>]

Hi,

Keir Fraser wrote:
 > You can hardly expect to do work in private and then 'surface the submarine'
 > when others post patches and expect them to do the work to merge with you.
 > If Intel's patches look acceptable then they will be checked in and Sun will
 > have to do the merge work to get any extra enhancements or features in their
 > patchset to work on top. That is unless you can see strong reason why Sun's
 > patches are technically better.
 >

Agreed.  Sun and Intel have exchanged a few loose emails on our intentions
in this area, but no close coordination.  We (Sun) aren't expecting
to try to contribute ours as patches to xen-unstable straight-away
as we have a broader project to float first, and we also have to
take our 3.1.4-based work up to the xen-unstable base.  So by
all means take in the Intel patch - we have no objections
(although we might feel differently when next our base is
updated to a later Xen release!).  I've asked the author of the
Sun work to have a look at this proposed patch to see how it
fits with our work.

Thanks

Gavin


>  -- Keir
> 
> On 9/9/08 10:06, "Christoph Egger" <Christoph.Egger@amd.com> wrote:
> 
>> SUN also has code for physical cpu hotplugging.
>> So this is duplicate work now.
>> Please get into contact with each other and merge your patches.
>>
>> Christoph
>>
>>
>> On Tuesday 09 September 2008 10:58:41 Shan, Haitao wrote:
>>> Hi, Keir,
>>>
>>> The following patches enable Xen to online/offline a physical CPU. This
>>> feature will be needed by possibly CPU hot-plug and RAS features.
>>> Some code of cpu online/offline is already in Xen, ever since S3 feature
>>> was added to Xen. This patch series only adds the missing part.
>>>
>>> Note: We only add the code to implement the function that actually
>>> online/offline a CPU. The patches for tests are only served as a test
>>> purpose. We do the tests by hooking online/offline decision to vcpu
>>> online/offline path in Dom0. Thus, writes to
>>> /sys/devices/system/cpu/cpuX/online will online/offline the vcpu, as
>>> well as physical cpu.
>>>
>>>
>>> Here is the description of the patches.
>>>
>>> cpu_offline.patch Implements cpu offline feature
>>> cpu_online.patch Implements cpu online feature
>>>
>>> cpu_online_offline_test.patch Used for tests -- Xen part
>>> cpu_online_offline_kernel.patch Used for tests -- Dom0 kernel part
>>>
>>>
>>> Best Regards
>>> Haitao Shan
>>
> 
>