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/[email protected]
Link: https://patchwork.freedesktop.org/patch/msgid/[email protected]
Fixes: f808c13fd3 ("lib/interval_tree: fast overlap detection")
Signed-off-by: Chris Wilson <[email protected]>
Reviewed-by: Joonas Lahtinen <[email protected]>
Acked-by: Davidlohr Bueso <[email protected]>
Cc: Jérôme Glisse <[email protected]>
Cc: Joonas Lahtinen <[email protected]>
Cc: Daniel Vetter <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>
This commit is contained in:
Chris Wilson 2017-12-14 15:32:28 -08:00 • committed by Linus Torvalds
commit 338f1d9d1b
3 changed files with 17 additions and 3 deletions

View file

@ -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)
{