Re: i915.ko WC writes are slow after ea8596bb2d8d379

From: Chuck Ebbert
Date: Thu Oct 09 2014 - 08:52:54 EST

On Thu, 9 Oct 2014 07:53:31 +0100
Chris Wilson <chris@xxxxxxxxxxxxxxxxxx> wrote:

> # cat /proc/mtrr
> reg00: base=0x000000000 ( 0MB), size= 2048MB, count=1: write-back
> reg01: base=0x080000000 ( 2048MB), size= 256MB, count=1: write-back
> reg02: base=0x08e000000 ( 2272MB), size= 32MB, count=1: uncachable
> reg03: base=0x08d000000 ( 2256MB), size= 16MB, count=1: uncachable
> reg04: base=0x100000000 ( 4096MB), size= 2048MB, count=1: write-back
> reg05: base=0x170000000 ( 5888MB), size= 256MB, count=1: uncachable
> reg06: base=0x16f000000 ( 5872MB), size= 16MB, count=1: uncachable
> reg07: base=0x16e800000 ( 5864MB), size= 8MB, count=1: uncachable
> reg08: base=0x16e600000 ( 5862MB), size= 2MB, count=1: uncachable

Well that's what the kernel thinks is in every CPU.
Could you try installing x86info and running "x86info --mtrr
--all-cpus" while running the broken kernel?
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