[PATCH] drm: micro optimise cache flushing

[Chris Wilson]

On Wed, 19 Sep 2012 11:12:41 +1000, Dave Airlie <airlied at gmail.com> wrote:
> From: Dave Airlie <airlied at redhat.com>
> 
> We hit this a lot with i915 and although we'd like to engineer things to hit
> it a lot less, this commit at least makes it consume a few less cycles.
> 
> from something containing
> movzwl 0x0(%rip),%r10d
> to
> add    %r8,%rdx
> 
> I only noticed it while using perf to profile something else.
> 
> Signed-off-by: Dave Airlie <airlied at redhat.com>
Reviewed-by: Chris Wilson <chris at chris-wilson.co.uk>

I would have thought this is something the compiler should, with the
appropriate hints, be smart enough to decide for itself as boot_cpu_data
should be constant once defined. *shrug*
-Chris

-- 
Chris Wilson, Intel Open Source Technology Centre