tree f414417ca79fe9678743ea5af75bd5afb70ad8cd
parent 2f8e0a7c6c89f850ebd5d6c0b9a08317030d1b89
author Zheng Liu <wenqing.lz@taobao.com> 1416933937 -0500
committer Theodore Ts'o <tytso@mit.edu> 1416933937 -0500

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>