[Mesa-dev] [PATCH] i965: Fix GLX_MESA_query_renderer video memory on 32-bit.

[Chris Wilson]

On Thu, Mar 30, 2017 at 06:48:38PM -0700, Kenneth Graunke wrote:
> Looking again...libdrm_intel sets bufmgr_gem->gtt_size to
> drm_i915_gem_get_aperture::aper_available_size - and uses that field
> to -ENOSPC your execbuffers.  drm_intel_get_aperture_sizes, and this
> query, use drm_i915_gem_get_aperture::aper_size - which is not quite
> the same.  Reading the kernel sources, it looks like aper_available_size
> subtracts any pinned memory.  At least in a PPGTT world, that's probably
> not materially different given how early we're calling it.

get_aperture is *meaningless* with full-ppgtt. But if libdrm is limiting
your batchbuffers using its result, than that is the maximum usable
memory for GL (whilst it remains using libdrm_intel batchbuffers). :(
-Chris

-- 
Chris Wilson, Intel Open Source Technology Centre