From f808c13fd3738948e10196496959871130612b61 Mon Sep 17 00:00:00 2001 From: Davidlohr Bueso Date: Fri, 8 Sep 2017 16:15:08 -0700 Subject: lib/interval_tree: fast overlap detection MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Allow interval trees to quickly check for overlaps to avoid unnecesary tree lookups in interval_tree_iter_first(). As of this patch, all interval tree flavors will require using a 'rb_root_cached' such that we can have the leftmost node easily available. While most users will make use of this feature, those with special functions (in addition to the generic insert, delete, search calls) will avoid using the cached option as they can do funky things with insertions -- for example, vma_interval_tree_insert_after(). [jglisse@redhat.com: fix deadlock from typo vm_lock_anon_vma()] Link: http://lkml.kernel.org/r/20170808225719.20723-1-jglisse@redhat.com Link: http://lkml.kernel.org/r/20170719014603.19029-12-dave@stgolabs.net Signed-off-by: Davidlohr Bueso Signed-off-by: Jérôme Glisse Acked-by: Christian König Acked-by: Peter Zijlstra (Intel) Acked-by: Doug Ledford Acked-by: Michael S. Tsirkin Cc: David Airlie Cc: Jason Wang Cc: Christian Benvenuti Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- mm/interval_tree.c | 10 +++++----- 1 file changed, 5 insertions(+), 5 deletions(-) (limited to 'mm/interval_tree.c') diff --git a/mm/interval_tree.c b/mm/interval_tree.c index f2c2492681bf..b47664358796 100644 --- a/mm/interval_tree.c +++ b/mm/interval_tree.c @@ -28,7 +28,7 @@ INTERVAL_TREE_DEFINE(struct vm_area_struct, shared.rb, /* Insert node immediately after prev in the interval tree */ void vma_interval_tree_insert_after(struct vm_area_struct *node, struct vm_area_struct *prev, - struct rb_root *root) + struct rb_root_cached *root) { struct rb_node **link; struct vm_area_struct *parent; @@ -55,7 +55,7 @@ void vma_interval_tree_insert_after(struct vm_area_struct *node, node->shared.rb_subtree_last = last; rb_link_node(&node->shared.rb, &parent->shared.rb, link); - rb_insert_augmented(&node->shared.rb, root, + rb_insert_augmented(&node->shared.rb, &root->rb_root, &vma_interval_tree_augment); } @@ -74,7 +74,7 @@ INTERVAL_TREE_DEFINE(struct anon_vma_chain, rb, unsigned long, rb_subtree_last, static inline, __anon_vma_interval_tree) void anon_vma_interval_tree_insert(struct anon_vma_chain *node, - struct rb_root *root) + struct rb_root_cached *root) { #ifdef CONFIG_DEBUG_VM_RB node->cached_vma_start = avc_start_pgoff(node); @@ -84,13 +84,13 @@ void anon_vma_interval_tree_insert(struct anon_vma_chain *node, } void anon_vma_interval_tree_remove(struct anon_vma_chain *node, - struct rb_root *root) + struct rb_root_cached *root) { __anon_vma_interval_tree_remove(node, root); } struct anon_vma_chain * -anon_vma_interval_tree_iter_first(struct rb_root *root, +anon_vma_interval_tree_iter_first(struct rb_root_cached *root, unsigned long first, unsigned long last) { return __anon_vma_interval_tree_iter_first(root, first, last); -- cgit v1.2.1