[Intel-gfx] [PATCH 2/2] drm/i915: Disable page-faults around the fast pwrite/pread paths

[Keith Packard]

On Sat,  9 Jul 2011 09:38:51 +0100, Chris Wilson <chris at chris-wilson.co.uk> wrote:

> +		/* We have to disable faulting here in case the user address
> +		 * is really a GTT mapping and so we can not enter
> +		 * i915_gem_fault() whilst already holding struct_mutex.
> +		 */

I would (far, far) rather disallow pread through the GTT
mapping. There's no credible reason to allow it. Is there some
reasonably fast way to detect that these addresses are within the GTT
and just bail?

Any performance penalty that serves solely to enable abuse of the
interface is not reasonable.

-- 
keith.packard at intel.com
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