[PATCH 1/2] drm/ttm: swap consecutive allocated cached pages

[Michel Dänzer]

On 2017-12-04 12:42 PM, Christian König wrote:
> When we detect consecutive allocation of pages swap them to avoid
> accidentally freeing them as huge page.
> 
> Signed-off-by: Christian König <christian.koenig at amd.com>
> ---
>  drivers/gpu/drm/ttm/ttm_page_alloc.c | 8 ++++++++
>  1 file changed, 8 insertions(+)
> 
> diff --git a/drivers/gpu/drm/ttm/ttm_page_alloc.c b/drivers/gpu/drm/ttm/ttm_page_alloc.c
> index c82d94cbbabc..60401350a01a 100644
> --- a/drivers/gpu/drm/ttm/ttm_page_alloc.c
> +++ b/drivers/gpu/drm/ttm/ttm_page_alloc.c
> @@ -921,6 +921,14 @@ static int ttm_get_pages(struct page **pages, unsigned npages, int flags,
>  				return -ENOMEM;
>  			}
>  
> +			/* Swap the pages if we detect consecutive order */
> +			if (i && pages[i - 1] == p - 1) {
> +				struct page *tmp = p;
> +
> +				p = pages[i - 1];
> +				pages[i - 1] = tmp;
> +			}
> +

Should be (something like):

		if (i && pages[i - 1] == p - 1)
			swap(pages[i - 1], p);


-- 
Earthling Michel Dänzer               |               http://www.amd.com
Libre software enthusiast             |             Mesa and X developer