ext4: Use atomic_t's in struct flex_groups
Reduce pressure on the sb_bgl_lock family of locks by using atomic_t's
to track the number of free blocks and inodes in each flex_group.
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
diff --git a/fs/ext4/balloc.c b/fs/ext4/balloc.c
index b37b128..53c72ad 100644
--- a/fs/ext4/balloc.c
+++ b/fs/ext4/balloc.c
@@ -470,9 +470,8 @@
if (sbi->s_log_groups_per_flex) {
ext4_group_t flex_group = ext4_flex_group(sbi, block_group);
- spin_lock(sb_bgl_lock(sbi, flex_group));
- sbi->s_flex_groups[flex_group].free_blocks += blocks_freed;
- spin_unlock(sb_bgl_lock(sbi, flex_group));
+ atomic_add(blocks_freed,
+ &sbi->s_flex_groups[flex_group].free_blocks);
}
/*
* request to reload the buddy with the