[Intel-gfx] [PATCH] drm/915: Pad GTT views of exec objects up to user specified size

Tvrtko Ursulin tvrtko.ursulin at linux.intel.com
Thu Oct 22 02:00:54 PDT 2015

On 21/10/15 16:24, Chris Wilson wrote:
> Our GPUs impose certain requirements upon buffers that depend upon how
> exactly they are used. Typically this is expressed as that they require
> a larger surface than would be naively computed by pitch * height.
> Normally such requirements are hidden away in the userspace driver, but
> when we accept pointers from strangers and later impose extra conditions
> on them, the original client allocator has no idea about the
> monstrosities in the GPU and we require the userspace driver to inform
> the kernel how many padding pages are required beyond the client
> allocation.
> v2: Long time, no see
> Signed-off-by: Chris Wilson <chris at chris-wilson.co.uk>
> Cc: Tvrtko Ursulin <tvrtko.ursulin at intel.com>

Reviewed-by: Tvrtko Ursulin <tvrtko.ursulin at intel.com>

As mentioned by Chris, IGT can be found as "tests/gem_exec_pad_to_size: 
Test object padding at execbuf", might need a respin for top-down 
allocation policy change.

And libdrm support is "libdrm_intel: Add API for execbuf pad to size 

Both patches from April this year.



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