Re: [PATCH 2/3] drm/mm: optimize find_hole() as well

Acked-by: Nirmoy Das nirmoy.das@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@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);