This is an archived copy of the Xen.org mailing list, which we have preserved to ensure that existing links to archives are not broken. The live archive, which contains the latest emails, can be found at http://lists.xen.org/
Home Products Support Community News


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

To: Keir Fraser <keir.fraser@xxxxxxxxxxxxx>
Subject: Re: [Xen-devel] [PATCH 0/4] CPU online/offline support in Xen
From: Gavin Maltby <Gavin.Maltby@xxxxxxx>
Date: Tue, 09 Sep 2008 20:35:07 +1000
Cc: Frank Van Der Linden <Frank.Vanderlinden@xxxxxxx>, Christoph Egger <Christoph.Egger@xxxxxxx>, xen-devel@xxxxxxxxxxxxxxxxxxx, "Shan, Haitao" <haitao.shan@xxxxxxxxx>, "Jiang, Yunhong" <yunhong.jiang@xxxxxxxxx>
Delivery-date: Tue, 09 Sep 2008 03:35:37 -0700
Envelope-to: www-data@xxxxxxxxxxxxxxxxxxx
In-reply-to: <C4EC0C72.1CF76%keir.fraser@xxxxxxxxxxxxx>
List-help: <mailto:xen-devel-request@lists.xensource.com?subject=help>
List-id: Xen developer discussion <xen-devel.lists.xensource.com>
List-post: <mailto:xen-devel@lists.xensource.com>
List-subscribe: <http://lists.xensource.com/mailman/listinfo/xen-devel>, <mailto:xen-devel-request@lists.xensource.com?subject=subscribe>
List-unsubscribe: <http://lists.xensource.com/mailman/listinfo/xen-devel>, <mailto:xen-devel-request@lists.xensource.com?subject=unsubscribe>
References: <C4EC0C72.1CF76%keir.fraser@xxxxxxxxxxxxx>
Sender: xen-devel-bounces@xxxxxxxxxxxxxxxxxxx
User-agent: Thunderbird (X11/20080728)

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.



 -- Keir

On 9/9/08 10:06, "Christoph Egger" <Christoph.Egger@xxxxxxx> 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.


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

Xen-devel mailing list