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RE: [Xen-ia64-devel] [PATCH][RFC]discontig memory support

To: "Tian, Kevin" <kevin.tian@xxxxxxxxx>, "Kouya SHIMURA" <kouya@xxxxxxxxxxxxxx>, <xen-ia64-devel@xxxxxxxxxxxxxxxxxxx>
Subject: RE: [Xen-ia64-devel] [PATCH][RFC]discontig memory support
From: "Tian, Kevin" <kevin.tian@xxxxxxxxx>
Date: Mon, 3 Apr 2006 23:29:10 +0800
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Thread-topic: [Xen-ia64-devel] [PATCH][RFC]discontig memory support
>From:Tian, Kevin
>Sent: 2006年4月3日 23:01
>
>It's OK to start from easy way first, and then evaluate which one is better.
>>From what I recalled, there's no obvious preference on ia64/linux
>community upon these two approaches(simplicity Vs complex, TLB Vs
>cache) and that's why two approaches still co-exist waiting for more data
>to distinguish. However things may become a bit different for xen/ia64,
>since currently there's no VHPT table used for Xen hypervisor. A rough
>thought based on that background is, people may have to face many
>TLB
>misses caused by access to vmem_map table and thus the benefit of
>VIRTUAL_MEM_MAP is pulled down...

Oops, I should say TLB behavior of VIRTUAL_MEM_MAP is made worse 
instead of benefit pulled down. BTW, maybe you can try allocating frame 
tables contiguous instead of page by page which can give better cache 
behavior. Yes, there's always balance against resource. :-)

Thanks,
Kevin

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