[PATCH 1/2] drm/ttm: Don't add swapped BOs to swap-LRU list

[Christian König]

Am 18.01.2018 um 17:56 schrieb Felix Kuehling:
> A BO that's already swapped would be added back to the swap-LRU list
> for example if its validation failed under high memory pressure. This
> could later lead to swapping it out again and leaking previous swap
> storage.
>
> This commit adds a condition to prevent that from happening.
>
> v2: Check page_flags instead of swap_storage
>
> Signed-off-by: Felix Kuehling <Felix.Kuehling at amd.com>

Reviewed-by: Christian König <christian.koenig at amd.com> for both.

> ---
>   drivers/gpu/drm/ttm/ttm_bo.c | 3 ++-
>   1 file changed, 2 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/gpu/drm/ttm/ttm_bo.c b/drivers/gpu/drm/ttm/ttm_bo.c
> index 2eb71ff..62518b6 100644
> --- a/drivers/gpu/drm/ttm/ttm_bo.c
> +++ b/drivers/gpu/drm/ttm/ttm_bo.c
> @@ -170,7 +170,8 @@ void ttm_bo_add_to_lru(struct ttm_buffer_object *bo)
>   		list_add_tail(&bo->lru, &man->lru[bo->priority]);
>   		kref_get(&bo->list_kref);
>   
> -		if (bo->ttm && !(bo->ttm->page_flags & TTM_PAGE_FLAG_SG)) {
> +		if (bo->ttm && !(bo->ttm->page_flags &
> +				 (TTM_PAGE_FLAG_SG | TTM_PAGE_FLAG_SWAPPED))) {
>   			list_add_tail(&bo->swap,
>   				      &bo->glob->swap_lru[bo->priority]);
>   			kref_get(&bo->list_kref);