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Re: [Xen-devel] page ref/type count overflows

To: Jan Beulich <jbeulich@xxxxxxxxxx>
Subject: Re: [Xen-devel] page ref/type count overflows
From: Keir Fraser <keir.fraser@xxxxxxxxxxxxx>
Date: Tue, 27 Jan 2009 11:22:19 +0000
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On 27/01/2009 10:24, "Keir Fraser" <keir.fraser@xxxxxxxxxxxxx> wrote:

> On 27/01/2009 10:16, "Jan Beulich" <jbeulich@xxxxxxxxxx> wrote:
> 
>> Yes, I too realized that on my way home yesterday. The only thing I see as
>> viable for consideration would be to remove the embedded spinlock again, and
>> use the same bit-lock as x86-32 does.
> 
> Makes page_unlock() more expensive on x64. Don't know how much that matters.

I think we could perhaps merge it into type_info and take/release it at the
same time as get_page_type/put_page_type, to avoid extra atomic ops. I'll
look into that.

For the cpumask, I have some ideas there too...

 -- Keir



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