Re: [X86] PCI: Use generic cacheline sizing instead of per-vendortests.

From: Jesse Barnes
Date: Wed Oct 14 2009 - 17:32:35 EST


On Wed, 14 Oct 2009 16:31:39 -0400
Dave Jones <davej@xxxxxxxxxx> wrote:

> Instead of the PCI code needing to have code to determine the
> cacheline size of each processor, use the data the cpu identification
> code should have already determined during early boot.
>
> (The vendor checks are also incomplete, and don't take into account
> modern CPUs)
>
> I've been carrying a variant of this code in Fedora for a while,
> that prints debug information. There are a number of cases where we
> are currently setting the PCI cacheline size to 32 bytes, when the CPU
> cacheline size is 64 bytes. With this patch, we set them both the
> same.
>
> Signed-off-by: Dave Jones <davej@xxxxxxxxxx>
>

Does this improve performance enough to warrant putting it into the
current cycle? Or is queuing it for 2.6.33 sufficient?

Thanks,
--
Jesse Barnes, Intel Open Source Technology Center
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