Xen devel - Apr 2008 - [Patch][RFC] Super Page Patch

The attached file is the super page patch which supports both 2MB and
4MB (depending on the paging modes of hypervisor) under hardware
assisted paging. The idea is to allocate super pages when guests are
being created. Whenever such requests cannot be satisfied, it falls back
to normal 4KB allocation. Also it splits large pages into normal 4KB
pages whenever necessary. This patch is applicable on the latest
xen-unstable tree. 
 
Any comment/suggestion is welcomed! Since it also touches a small
portion of IA64 and PowerPC code, I would appreciate the information of
whether this patch breaks IA64 or PowerPC compilation.
 
Thanks,
 
-Wei



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> The attached file is the super page patch which supports both 2MB and
> 4MB (depending on the paging modes of hypervisor) under hardware
> assisted paging. The idea is to allocate super pages when guests are
> being created. Whenever such requests cannot be satisfied, it falls
> back to normal 4KB allocation. Also it splits large pages into normal
> 4KB pages whenever necessary. This patch is applicable on the latest
> xen-unstable tree.
> 
> Any comment/suggestion is welcomed! Since it also touches a small
> portion of IA64 and PowerPC code, I would appreciate the information
of
> whether this patch breaks IA64 or PowerPC compilation.
It''s great to see this patch, thanks.

Could you give a summary of what testing its been subjected to? Also, do
you have any performance results? I''m particularly interested in
results
with a 64b hypervisor.

We''ll have to update the balloon driver to try and hand back 2MB
aligned
slabs to avoid fragmentation.

Thanks,
Ian




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Ian,

Super page has many advantages by reducing TLB misses and the nested
page table walk. I am currently collecting the performance results of
commonly used benchmarks. The results will be posted next time along
with a formal patch (probably this week).

Thanks,

-Wei

-----Original Message-----
From: Ian Pratt [mailto:Ian.Pratt@eu.citrix.com] 
Sent: Monday, April 21, 2008 6:52 PM
To: Huang2, Wei; xen-devel@lists.xensource.com
Cc: Ian Pratt
Subject: RE: [Xen-devel] [Patch][RFC] Super Page Patch
> The attached file is the super page patch which supports both 2MB and
> 4MB (depending on the paging modes of hypervisor) under hardware
> assisted paging. The idea is to allocate super pages when guests are
> being created. Whenever such requests cannot be satisfied, it falls
> back to normal 4KB allocation. Also it splits large pages into normal
> 4KB pages whenever necessary. This patch is applicable on the latest
> xen-unstable tree.
> 
> Any comment/suggestion is welcomed! Since it also touches a small
> portion of IA64 and PowerPC code, I would appreciate the information
of
> whether this patch breaks IA64 or PowerPC compilation.
It''s great to see this patch, thanks.

Could you give a summary of what testing its been subjected to? Also, do
you have any performance results? I''m particularly interested in
results
with a 64b hypervisor.

We''ll have to update the balloon driver to try and hand back 2MB
aligned
slabs to avoid fragmentation.

Thanks,
Ian






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Xen-devel mailing list
Xen-devel@lists.xensource.com
http://lists.xensource.com/xen-devel