ext4: change LRU to round-robin in extent status tree shrinker
In this commit we discard the lru algorithm for inodes with extent
status tree because it takes significant effort to maintain a lru list
in extent status tree shrinker and the shrinker can take a long time to
scan this lru list in order to reclaim some objects.
We replace the lru ordering with a simple round-robin. After that we
never need to keep a lru list. That means that the list needn't be
sorted if the shrinker can not reclaim any objects in the first round.
Cc: Andreas Dilger <adilger.kernel@dilger.ca>
Signed-off-by: Zheng Liu <wenqing.lz@taobao.com>
Signed-off-by: Jan Kara <jack@suse.cz>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
diff --git a/fs/ext4/super.c b/fs/ext4/super.c
index 4b79f39..32df08e 100644
--- a/fs/ext4/super.c
+++ b/fs/ext4/super.c
@@ -871,10 +871,9 @@
spin_lock_init(&ei->i_prealloc_lock);
ext4_es_init_tree(&ei->i_es_tree);
rwlock_init(&ei->i_es_lock);
- INIT_LIST_HEAD(&ei->i_es_lru);
+ INIT_LIST_HEAD(&ei->i_es_list);
ei->i_es_all_nr = 0;
- ei->i_es_lru_nr = 0;
- ei->i_touch_when = 0;
+ ei->i_es_shk_nr = 0;
ei->i_reserved_data_blocks = 0;
ei->i_reserved_meta_blocks = 0;
ei->i_allocated_meta_blocks = 0;
@@ -963,7 +962,7 @@
dquot_drop(inode);
ext4_discard_preallocations(inode);
ext4_es_remove_extent(inode, 0, EXT_MAX_BLOCKS);
- ext4_es_lru_del(inode);
+ ext4_es_list_del(inode);
if (EXT4_I(inode)->jinode) {
jbd2_journal_release_jbd_inode(EXT4_JOURNAL(inode),
EXT4_I(inode)->jinode);