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| author | Davidlohr Bueso <dave@stgolabs.net> | 2017-09-08 16:15:08 -0700 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2017-09-08 18:26:49 -0700 |
| commit | f808c13fd3738948e10196496959871130612b61 (patch) | |
| tree | 0f9b1bf3ccc9c4d051bf4fed87b493dced56d032 /mm/mmap.c | |
| parent | 09663c86e24953556ff8696efa023557901f2b66 (diff) | |
| download | lwn-f808c13fd3738948e10196496959871130612b61.tar.gz lwn-f808c13fd3738948e10196496959871130612b61.zip | |
lib/interval_tree: fast overlap detection
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 <dbueso@suse.de>
Signed-off-by: Jérôme Glisse <jglisse@redhat.com>
Acked-by: Christian König <christian.koenig@amd.com>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Acked-by: Doug Ledford <dledford@redhat.com>
Acked-by: Michael S. Tsirkin <mst@redhat.com>
Cc: David Airlie <airlied@linux.ie>
Cc: Jason Wang <jasowang@redhat.com>
Cc: Christian Benvenuti <benve@cisco.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'mm/mmap.c')
| -rw-r--r-- | mm/mmap.c | 10 |
1 files changed, 5 insertions, 5 deletions
diff --git a/mm/mmap.c b/mm/mmap.c index 4c5981651407..680506faceae 100644 --- a/mm/mmap.c +++ b/mm/mmap.c @@ -685,7 +685,7 @@ int __vma_adjust(struct vm_area_struct *vma, unsigned long start, struct mm_struct *mm = vma->vm_mm; struct vm_area_struct *next = vma->vm_next, *orig_vma = vma; struct address_space *mapping = NULL; - struct rb_root *root = NULL; + struct rb_root_cached *root = NULL; struct anon_vma *anon_vma = NULL; struct file *file = vma->vm_file; bool start_changed = false, end_changed = false; @@ -3340,7 +3340,7 @@ static DEFINE_MUTEX(mm_all_locks_mutex); static void vm_lock_anon_vma(struct mm_struct *mm, struct anon_vma *anon_vma) { - if (!test_bit(0, (unsigned long *) &anon_vma->root->rb_root.rb_node)) { + if (!test_bit(0, (unsigned long *) &anon_vma->root->rb_root.rb_root.rb_node)) { /* * The LSB of head.next can't change from under us * because we hold the mm_all_locks_mutex. @@ -3356,7 +3356,7 @@ static void vm_lock_anon_vma(struct mm_struct *mm, struct anon_vma *anon_vma) * anon_vma->root->rwsem. */ if (__test_and_set_bit(0, (unsigned long *) - &anon_vma->root->rb_root.rb_node)) + &anon_vma->root->rb_root.rb_root.rb_node)) BUG(); } } @@ -3458,7 +3458,7 @@ out_unlock: static void vm_unlock_anon_vma(struct anon_vma *anon_vma) { - if (test_bit(0, (unsigned long *) &anon_vma->root->rb_root.rb_node)) { + if (test_bit(0, (unsigned long *) &anon_vma->root->rb_root.rb_root.rb_node)) { /* * The LSB of head.next can't change to 0 from under * us because we hold the mm_all_locks_mutex. @@ -3472,7 +3472,7 @@ static void vm_unlock_anon_vma(struct anon_vma *anon_vma) * anon_vma->root->rwsem. */ if (!__test_and_clear_bit(0, (unsigned long *) - &anon_vma->root->rb_root.rb_node)) + &anon_vma->root->rb_root.rb_root.rb_node)) BUG(); anon_vma_unlock_write(anon_vma); } |