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Re: [Xen-devel] [PATCH 0/6] grantable and address conversion patches

To: Keir Fraser <Keir.Fraser@xxxxxxxxxxxx>
Subject: Re: [Xen-devel] [PATCH 0/6] grantable and address conversion patches
From: Isaku Yamahata <yamahata@xxxxxxxxxxxxx>
Date: Wed, 12 Apr 2006 22:22:39 +0900
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I attached the patch which restrict netfront to 256 requests.

On Mon, Apr 10, 2006 at 10:00:38AM +0100, Keir Fraser wrote:
> On 10 Apr 2006, at 09:54, Keir Fraser wrote:
> >2/6: This is a poor fix. Either we should make the ring size fixed 
> >(e.g., 4kB) rather than architectural page-sized, or grants should be 
> >dynamically allocated in netfront rather than statically allocated. 
> >This was done quite some time ago for blkfront, and would be the 
> >preferred (although more difficult) fix here.
> Actually, another option that might be easier that dynamic grant 
> allocation, but less restrictive that reducing the size of the rings on 
> ia64, would be to modify netfront to queue only up to 256 requests 
> simultaneously on any ring, regardless of the actual ring size. Then 
> you'd only need to allocate 256 grants per ring, as x86, and the bigger 
> issue (dynamic allocation of grants) can be fixed later. At that point 
> we can lift the restriction of 256 requests per ring without having to 
> change the public interface at all (unlike if we'd reduced the 
> advertised ring size for ia64).
>  -- Keir
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Attachment: 9623:c98a65daa7bd_restrict_netfront_to_256_grant_reference.patch
Description: Text document

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