[Intel-gfx] [PATCH 2/3] drm/mm: optimize find_hole() as well

[Nirmoy]

Acked-by: Nirmoy Das <nirmoy.das at amd.com>

On 6/15/20 4:54 PM, Christian König wrote:
> Abort early if there isn't enough space to allocate from a subtree.
>
> Signed-off-by: Christian König <christian.koenig at amd.com>
> ---
>   drivers/gpu/drm/drm_mm.c                | 11 +++++++----
>   drivers/gpu/drm/selftests/test-drm_mm.c | 11 -----------
>   2 files changed, 7 insertions(+), 15 deletions(-)
>
> diff --git a/drivers/gpu/drm/drm_mm.c b/drivers/gpu/drm/drm_mm.c
> index 425fcd3590e8..177a5df0fe95 100644
> --- a/drivers/gpu/drm/drm_mm.c
> +++ b/drivers/gpu/drm/drm_mm.c
> @@ -325,7 +325,7 @@ static struct drm_mm_node *best_hole(struct drm_mm *mm, u64 size)
>   	return best;
>   }
>   
> -static struct drm_mm_node *find_hole(struct drm_mm *mm, u64 addr)
> +static struct drm_mm_node *find_hole_addr(struct drm_mm *mm, u64 addr, u64 size)
>   {
>   	struct rb_node *rb = mm->holes_addr.rb_node;
>   	struct drm_mm_node *node = NULL;
> @@ -333,6 +333,9 @@ static struct drm_mm_node *find_hole(struct drm_mm *mm, u64 addr)
>   	while (rb) {
>   		u64 hole_start;
>   
> +		if (rb_hole_addr_to_node(rb)->subtree_max_hole < size)
> +			break;
> +
>   		node = rb_hole_addr_to_node(rb);
>   		hole_start = __drm_mm_hole_node_start(node);
>   
> @@ -358,10 +361,10 @@ first_hole(struct drm_mm *mm,
>   		return best_hole(mm, size);
>   
>   	case DRM_MM_INSERT_LOW:
> -		return find_hole(mm, start);
> +		return find_hole_addr(mm, start, size);
>   
>   	case DRM_MM_INSERT_HIGH:
> -		return find_hole(mm, end);
> +		return find_hole_addr(mm, end, size);
>   
>   	case DRM_MM_INSERT_EVICT:
>   		return list_first_entry_or_null(&mm->hole_stack,
> @@ -497,7 +500,7 @@ int drm_mm_reserve_node(struct drm_mm *mm, struct drm_mm_node *node)
>   		return -ENOSPC;
>   
>   	/* Find the relevant hole to add our node to */
> -	hole = find_hole(mm, node->start);
> +	hole = find_hole_addr(mm, node->start, 0);
>   	if (!hole)
>   		return -ENOSPC;
>   
> diff --git a/drivers/gpu/drm/selftests/test-drm_mm.c b/drivers/gpu/drm/selftests/test-drm_mm.c
> index ca5f35def905..b879aedfc00d 100644
> --- a/drivers/gpu/drm/selftests/test-drm_mm.c
> +++ b/drivers/gpu/drm/selftests/test-drm_mm.c
> @@ -1981,16 +1981,6 @@ static int __igt_once(unsigned int mode)
>   	}
>   
>   	memset(&node, 0, sizeof(node));
> -	err = drm_mm_insert_node_generic(&mm, &node,
> -					 2, 0, 0,
> -					 mode | DRM_MM_INSERT_ONCE);
> -	if (!err) {
> -		pr_err("Unexpectedly inserted the node into the wrong hole: node.start=%llx\n",
> -		       node.start);
> -		err = -EINVAL;
> -		goto err_node;
> -	}
> -
>   	err = drm_mm_insert_node_generic(&mm, &node, 2, 0, 0, mode);
>   	if (err) {
>   		pr_err("Could not insert the node into the available hole!\n");
> @@ -1998,7 +1988,6 @@ static int __igt_once(unsigned int mode)
>   		goto err_hi;
>   	}
>   
> -err_node:
>   	drm_mm_remove_node(&node);
>   err_hi:
>   	drm_mm_remove_node(&rsvd_hi);