Re: [Xen-ia64-devel] [PATCH] per vcpu vhpt

[Isaku Yamahata <yamahata@xxxxxxxxxxxxx>]

Hi Anothy.
Thanks for your comments.

On Mon, Oct 09, 2006 at 03:46:26PM +0800, Xu, Anthony wrote:

> A very small comment,
> I noticed DomU still use VHPT_ADDR to map VHPT. While in function, for 
> instance, __vhpt_flush, it uses __va(vhpt_maddr) to access VHPT,  because 
> vhpt is allocated from dom heap, this may cause unnecessary tlb miss.
> There are two natural options here.
> 1. If DomU use __va(vhpt_maddr) to map VHPT, the unnecessary tlb miss can be 
> eliminated.
> 2. in function like __vhpt_flush, use VHPT_ADDR to access VHPT.

That makes sense. 
The option 1 is difficult because the vhpt size(currently 64KB and this
might be increased in future) is smaller than xen granule size (16MB) and
non-current vcpu's case must be handled.
The option 2 seems preferable.

-- 
yamahata

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