[Intel-gfx] [PATCH 5/6] drm,i915: Introduce drm_malloc_gfp()

[Chris Wilson]

On Tue, Apr 05, 2016 at 01:57:36PM +0100, Chris Wilson wrote:
> I have instances where I want to use drm_malloc_ab() but with a custom
> gfp mask. And with those, where I want a temporary allocation, I want to
> try a high-order kmalloc() before using a vmalloc().
> 
> So refactor my usage into drm_malloc_gfp().
> 
> Signed-off-by: Chris Wilson <chris at chris-wilson.co.uk>
> Cc: dri-devel at lists.freedesktop.org
> Cc: Ville Syrjälä <ville.syrjala at linux.intel.com>
> Reviewed-by: Ville Syrjälä <ville.syrjala at linux.intel.com>
> Acked-by: Dave Airlie <airlied at redhat.com>

> +static __inline__ void *drm_malloc_gfp(size_t nmemb, size_t size, gfp_t gfp)
> +{
> +	if (size != 0 && nmemb > SIZE_MAX / size)
> +		return NULL;

I know Dave G. has some fancy code to detect when the size parameter is
not constant, but one thing I noticed was that gcc would uninline this
function and we would lose the constant folding. Is there anything we
can do to convince gcc to avoid a div here (other than pure macro)?
-Chris

-- 
Chris Wilson, Intel Open Source Technology Centre