struct amd_iommu padding on 64 bit

Joerg Roedel joerg.roedel at amd.com
Mon Nov 24 03:38:07 PST 2008


On Mon, Nov 24, 2008 at 11:18:20AM +0000, Richard Kennedy wrote:
> Hi Joerg,
> 
> I run a report on my kernel builds to spot structures that are padded to
> maintain alignment on 64bit builds.
> 
> If amd_iommu was reordered it could shrink by up to 24 bytes from its
> current 136bytes. Just removing 8 bytes would let it use one fewer cache
> lines :) Swapping the order of dev & cap_ptr will do. 
> 
> I could send you a patch if your interested, but I've got no way to test
> it. And I don't really understand what this code does anyway ;)

Hey Richard,

yeah I am interested. Just send the patch, I can test and apply it.

Joerg

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