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/extents_status.h b/fs/ext4/extents_status.h
index efd5f97..0e6a33e 100644
--- a/fs/ext4/extents_status.h
+++ b/fs/ext4/extents_status.h
@@ -65,14 +65,13 @@
};
struct ext4_es_stats {
- unsigned long es_stats_last_sorted;
unsigned long es_stats_shrunk;
unsigned long es_stats_cache_hits;
unsigned long es_stats_cache_misses;
u64 es_stats_scan_time;
u64 es_stats_max_scan_time;
struct percpu_counter es_stats_all_cnt;
- struct percpu_counter es_stats_lru_cnt;
+ struct percpu_counter es_stats_shk_cnt;
};
extern int __init ext4_init_es(void);
@@ -151,7 +150,7 @@
extern int ext4_es_register_shrinker(struct ext4_sb_info *sbi);
extern void ext4_es_unregister_shrinker(struct ext4_sb_info *sbi);
-extern void ext4_es_lru_add(struct inode *inode);
-extern void ext4_es_lru_del(struct inode *inode);
+extern void ext4_es_list_add(struct inode *inode);
+extern void ext4_es_list_del(struct inode *inode);
#endif /* _EXT4_EXTENTS_STATUS_H */