Commit 338f1d9d authored by Chris Wilson's avatar Chris Wilson Committed by Linus Torvalds
Browse files

lib/rbtree,drm/mm: add rbtree_replace_node_cached() 

Add a variant of rbtree_replace_node() that maintains the leftmost cache
of struct rbtree_root_cached when replacing nodes within the rbtree.

As drm_mm is the only rb_replace_node() being used on an interval tree,
the mistake looks fairly self-contained.  Furthermore the only user of
drm_mm_replace_node() is its testsuite...

Testcase: igt/drm_mm/replace

Link: http://lkml.kernel.org/r/20171122100729.3742-1-chris@chris-wilson.co.uk
Link: https://patchwork.freedesktop.org/patch/msgid/20171109212435.9265-1-chris@chris-wilson.co.uk


Fixes: f808c13f ("lib/interval_tree: fast overlap detection")
Signed-off-by: default avatarChris Wilson <chris@chris-wilson.co.uk>
Reviewed-by: default avatarJoonas Lahtinen <joonas.lahtinen@linux.intel.com>
Acked-by: default avatarDavidlohr Bueso <dbueso@suse.de>
Cc: Jérôme Glisse <jglisse@redhat.com>
Cc: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>
Cc: Daniel Vetter <daniel.vetter@ffwll.ch>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
parent c47d7f56

drivers/gpu/drm/drm_mm.c

+5 −3
Original line number Diff line number Diff line
@@ -575,21 +575,23 @@ EXPORT_SYMBOL(drm_mm_remove_node); 
 */

void drm_mm_replace_node(struct drm_mm_node *old, struct drm_mm_node *new)

{

	struct drm_mm *mm = old->mm;



	DRM_MM_BUG_ON(!old->allocated);



	*new = *old;



	list_replace(&old->node_list, &new->node_list);

	rb_replace_node(&old->rb, &new->rb, &old->mm->interval_tree.rb_root);

	rb_replace_node_cached(&old->rb, &new->rb, &mm->interval_tree);



	if (drm_mm_hole_follows(old)) {

		list_replace(&old->hole_stack, &new->hole_stack);

		rb_replace_node(&old->rb_hole_size,

				&new->rb_hole_size,

				&old->mm->holes_size);

				&mm->holes_size);

		rb_replace_node(&old->rb_hole_addr,

				&new->rb_hole_addr,

				&old->mm->holes_addr);

				&mm->holes_addr);

	}



	old->allocated = false;

include/linux/rbtree.h

+2 −0
Original line number Diff line number Diff line
@@ -99,6 +99,8 @@ extern void rb_replace_node(struct rb_node *victim, struct rb_node *new, 
			    struct rb_root *root);

extern void rb_replace_node_rcu(struct rb_node *victim, struct rb_node *new,

				struct rb_root *root);

extern void rb_replace_node_cached(struct rb_node *victim, struct rb_node *new,

				   struct rb_root_cached *root);



static inline void rb_link_node(struct rb_node *node, struct rb_node *parent,

				struct rb_node **rb_link)

lib/rbtree.c

+10 −0
Original line number Diff line number Diff line
@@ -603,6 +603,16 @@ void rb_replace_node(struct rb_node *victim, struct rb_node *new, 
}

EXPORT_SYMBOL(rb_replace_node);



void rb_replace_node_cached(struct rb_node *victim, struct rb_node *new,

			    struct rb_root_cached *root)

{

	rb_replace_node(victim, new, &root->rb_root);



	if (root->rb_leftmost == victim)

		root->rb_leftmost = new;

}

EXPORT_SYMBOL(rb_replace_node_cached);



void rb_replace_node_rcu(struct rb_node *victim, struct rb_node *new,

			 struct rb_root *root)

{

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