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Re: [Xen-devel] 3.0.4 (and earlier): skbuff_ctor() use of xen_create_con

To: Jan Beulich <jbeulich@xxxxxxxxxx>
Subject: Re: [Xen-devel] 3.0.4 (and earlier): skbuff_ctor() use of xen_create_contiguous_region()
From: David Edmondson <dme@xxxxxxx>
Date: Fri, 9 Mar 2007 12:37:24 +0000
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On Fri, Mar 09, 2007 at 12:17:39PM +0000, Jan Beulich wrote:
> While I realize that this is gone from -unstable, I'd still like to
> understand what the purpose of using xen_create_contiguous_region()
> in skbuff_ctor() was, and specifically what consequences I am to
> expect when this call fails.

So that a multi-page packet is physically contiguous when passed to
the NIC for transmit?

If it's not physically contiguous and the NIC hardware can't do
scatter gather then the driver has to re-allocate and copy.


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