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[Xen-devel] Re: [PATCH] Don't assume the vcpu_id is continous in alloc_v

To: "Jiang, Yunhong" <yunhong.jiang@xxxxxxxxx>, "xen-devel@xxxxxxxxxxxxxxxxxxx" <xen-devel@xxxxxxxxxxxxxxxxxxx>
Subject: [Xen-devel] Re: [PATCH] Don't assume the vcpu_id is continous in alloc_vcpu
From: Keir Fraser <keir.fraser@xxxxxxxxxxxxx>
Date: Thu, 12 Nov 2009 13:18:19 +0000
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Thread-topic: [PATCH] Don't assume the vcpu_id is continous in alloc_vcpu
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On 12/11/2009 11:31, "Keir Fraser" <keir.fraser@xxxxxxxxxxxxx> wrote:

>> Currently in alloc_vcpu, it assumes the vcpu is allocated with vcpu_id is
>> continous.
>> When cpu hot-added, this assumption is broken because the hot-added CPU may
>> be
>> brougt online by dom0 in arbitrary order. This patch try to link the new vcpu
>> to the end of the link.
>> Signed-off-by: Jiang, Yunhong <yunhong.jiang@xxxxxxxxx>
> Is this something to do with allocating vcpus for the idle domain?
> If so, I suggest we just allocate vcpu_ids sequentially on-demand. I can
> work up a patch for you to test if you like.

I was wrong, that was a bad idea since idle_vcpu[] is also the idle domain's
vcpu pointer array. Actually I also have been able to revert c/s 20045 since
I was mistaken about that being needed. And I've applied your patch as c/s
20433, but I rewrote it to keep vcpus in ascending order of vcpuid (not sure
it's necessary really, but it's nice to do).

 -- Keir

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