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| author | Liu Bo <bo.liu@linux.alibaba.com> | 2018-08-23 03:51:52 +0800 |
|---|---|---|
| committer | David Sterba <dsterba@suse.com> | 2018-10-15 17:23:33 +0200 |
| commit | 07e1ce096db3605f3e0c98695df66a51e2be9f05 (patch) | |
| tree | 3e4a910cd136c1b6666d3be7e33b826dbd016db6 /fs/btrfs/tests | |
| parent | 03a1d4c891634dd5b98da865fb783e8b22d4d027 (diff) | |
| download | linux-07e1ce096db3605f3e0c98695df66a51e2be9f05.tar.bz2 | |
Btrfs: extent_map: use rb_first_cached
rb_first_cached() trades an extra pointer "leftmost" for doing the
same job as rb_first() but in O(1).
As evict_inode_truncate_pages() removes all extent mapping by always
looking for the first rb entry, it's helpful to use rb_first_cached
instead.
For more details about the optimization see patch "Btrfs: delayed-refs:
use rb_first_cached for href_root".
Tested-by: Holger Hoffstätte <holger@applied-asynchrony.com>
Signed-off-by: Liu Bo <bo.liu@linux.alibaba.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Diffstat (limited to 'fs/btrfs/tests')
| -rw-r--r-- | fs/btrfs/tests/extent-map-tests.c | 4 |
1 files changed, 2 insertions, 2 deletions
diff --git a/fs/btrfs/tests/extent-map-tests.c b/fs/btrfs/tests/extent-map-tests.c index 385a5316e4bf..bf15d3a7f20e 100644 --- a/fs/btrfs/tests/extent-map-tests.c +++ b/fs/btrfs/tests/extent-map-tests.c @@ -12,8 +12,8 @@ static void free_extent_map_tree(struct extent_map_tree *em_tree) struct extent_map *em; struct rb_node *node; - while (!RB_EMPTY_ROOT(&em_tree->map)) { - node = rb_first(&em_tree->map); + while (!RB_EMPTY_ROOT(&em_tree->map.rb_root)) { + node = rb_first_cached(&em_tree->map); em = rb_entry(node, struct extent_map, rb_node); remove_extent_mapping(em_tree, em); |