[PATCH] drm/ttm: stop using GFP_TRANSHUGE_LIGHT

[Daniel Vetter]

On Wed, Jan 13, 2021 at 02:13:25PM +0100, Christian König wrote:
> The only flag we really need is __GFP_NOMEMALLOC, highmem depends on
> dma32 and moveable/compound should never be set in the first place.
> 
> Signed-off-by: Christian König <christian.koenig at amd.com>

Needs Fixes: line and References to the GFP_TRANSHUGE_LIGHT report from
Hans and for the chromium report for the mmap fail. With those:

Reviewed-by: Daniel Vetter <daniel.vetter at ffwll.ch>

Also I guess really time for me to stitch together that hack to catch
dma-buf sglist struct page abusers ...
-Daniel

> ---
>  drivers/gpu/drm/ttm/ttm_pool.c | 11 ++++++-----
>  1 file changed, 6 insertions(+), 5 deletions(-)
> 
> diff --git a/drivers/gpu/drm/ttm/ttm_pool.c b/drivers/gpu/drm/ttm/ttm_pool.c
> index 8cd776adc592..11e0313db0ea 100644
> --- a/drivers/gpu/drm/ttm/ttm_pool.c
> +++ b/drivers/gpu/drm/ttm/ttm_pool.c
> @@ -79,12 +79,13 @@ static struct page *ttm_pool_alloc_page(struct ttm_pool *pool, gfp_t gfp_flags,
>  	struct page *p;
>  	void *vaddr;
>  
> -	if (order) {
> -		gfp_flags |= GFP_TRANSHUGE_LIGHT | __GFP_NORETRY |
> +	/* Don't set the __GFP_COMP flag for higher order allocations.
> +	 * Mapping pages directly into an userspace process and calling
> +	 * put_page() on a TTM allocated page is illegal.
> +	 */
> +	if (order)
> +		gfp_flags |= __GFP_NOMEMALLOC | __GFP_NORETRY |
>  			__GFP_KSWAPD_RECLAIM;
> -		gfp_flags &= ~__GFP_MOVABLE;
> -		gfp_flags &= ~__GFP_COMP;
> -	}
>  
>  	if (!pool->use_dma_alloc) {
>  		p = alloc_pages(gfp_flags, order);
> -- 
> 2.25.1
> 

-- 
Daniel Vetter
Software Engineer, Intel Corporation
http://blog.ffwll.ch