Re: [RFC] - Mapping ACPI tables as CACHED

From: Len Brown
Date: Thu Jul 22 2010 - 11:52:34 EST


> The following experimental patch changes the kernel mapping for ACPI tables
> to CACHED. This eliminates the page attibute conflict & allows users to map
> the tables CACHEABLE. This significantly speeds up boot:
>
> 38 minutes without the patch
> 27 minutes with the patch
> ~30% improvement
>
> Time to run ACPIDUMP on a large system:
> 527 seconds without the patch
> 8 seconds with the patch

Interesting.

Can you detect a performance differene on a 1-node machine
that doesn't magnify the penalty of the remote uncached access?

thanks,
-Len Brown, Intel Open Source Technology Cetner

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