[Intel-gfx] [PATCH v3] drm/i915/gtt: Avoid calling kcalloc in a loop when allocating temp bitmaps

Chris Wilson chris at chris-wilson.co.uk
Wed Sep 2 06:46:41 PDT 2015


On Wed, Sep 02, 2015 at 02:40:03PM +0100, Michel Thierry wrote:
> On 9/1/2015 10:06 AM, Michał Winiarski wrote:
> >On each call to gen8_alloc_va_range_3lvl we're allocating temporary
> >bitmaps needed for error handling. Unfortunately, when we increase
> >address space size (48b ppgtt) we do additional (512 - 4) calls to
> >kcalloc, increasing latency between exec and actual start of execution
> >on the GPU. Let's just do a single kcalloc, we can also drop the size
> >from free_gen8_temp_bitmaps since it's no longer used.
> >
> >v2: Use GFP_TEMPORARY to make the allocations reclaimable.
> >v3: Drop the 2D array, just allocate a single block.
> >
> >Cc: Chris Wilson <chris at chris-wilson.co.uk>
> >Cc: Mika Kuoppala <mika.kuoppala at linux.intel.com>
> >Cc: Michel Thierry <michel.thierry at intel.com>
> >Signed-off-by: Michał Winiarski <michal.winiarski at intel.com>
> 
> Unless Chris thinks otherwise, I see Michał already addressed his comments.

I think I spotted a misaligned bracket... ;)
Reviewed-by: Chris Wilson <chris at chris-wilson.co.uk>
-Chri

-- 
Chris Wilson, Intel Open Source Technology Centre


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