Re: [PATCH 04/10] drm/i915: Fix MAX_ORDER usage in i915_gem_object_get_pages_internal()

[Vlastimil Babka]

On 3/15/23 12:31, Kirill A. Shutemov wrote:
> MAX_ORDER is not inclusive: the maximum allocation order buddy allocator
> can deliver is MAX_ORDER-1.
> 
> Fix MAX_ORDER usage in i915_gem_object_get_pages_internal().
> 
> Signed-off-by: Kirill A. Shutemov <kirill.shutemov@xxxxxxxxxxxxxxx>

Acked-by: Vlastimil Babka <vbabka@xxxxxxx>

> Cc: Jani Nikula <jani.nikula@xxxxxxxxxxxxxxx>
> Cc: Joonas Lahtinen <joonas.lahtinen@xxxxxxxxxxxxxxx>
> Cc: Rodrigo Vivi <rodrigo.vivi@xxxxxxxxx>
> Cc: Tvrtko Ursulin <tvrtko.ursulin@xxxxxxxxxxxxxxx>
> ---
>  drivers/gpu/drm/i915/gem/i915_gem_internal.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/drivers/gpu/drm/i915/gem/i915_gem_internal.c b/drivers/gpu/drm/i915/gem/i915_gem_internal.c
> index 6bc26b4b06b8..eae9e9f6d3bf 100644
> --- a/drivers/gpu/drm/i915/gem/i915_gem_internal.c
> +++ b/drivers/gpu/drm/i915/gem/i915_gem_internal.c
> @@ -36,7 +36,7 @@ static int i915_gem_object_get_pages_internal(struct drm_i915_gem_object *obj)
>  	struct sg_table *st;
>  	struct scatterlist *sg;
>  	unsigned int npages; /* restricted by sg_alloc_table */
> -	int max_order = MAX_ORDER;
> +	int max_order = MAX_ORDER - 1;
>  	unsigned int max_segment;
>  	gfp_t gfp;
>