From b0d40c92adafde7c2d81203ce7c1c69275f41140 Mon Sep 17 00:00:00 2001 From: Dave Chinner Date: Fri, 8 Jul 2011 14:14:42 +1000 Subject: superblock: introduce per-sb cache shrinker infrastructure With context based shrinkers, we can implement a per-superblock shrinker that shrinks the caches attached to the superblock. We currently have global shrinkers for the inode and dentry caches that split up into per-superblock operations via a coarse proportioning method that does not batch very well. The global shrinkers also have a dependency - dentries pin inodes - so we have to be very careful about how we register the global shrinkers so that the implicit call order is always correct. With a per-sb shrinker callout, we can encode this dependency directly into the per-sb shrinker, hence avoiding the need for strictly ordering shrinker registrations. We also have no need for any proportioning code for the shrinker subsystem already provides this functionality across all shrinkers. Allowing the shrinker to operate on a single superblock at a time means that we do less superblock list traversals and locking and reclaim should batch more effectively. This should result in less CPU overhead for reclaim and potentially faster reclaim of items from each filesystem. Signed-off-by: Dave Chinner Signed-off-by: Al Viro --- include/linux/fs.h | 7 +++++++ 1 file changed, 7 insertions(+) (limited to 'include/linux/fs.h') diff --git a/include/linux/fs.h b/include/linux/fs.h index 460d2cc21ec6..d7f35e90b84a 100644 --- a/include/linux/fs.h +++ b/include/linux/fs.h @@ -393,6 +393,7 @@ struct inodes_stat_t { #include #include #include +#include #include #include @@ -1444,8 +1445,14 @@ struct super_block { * Saved pool identifier for cleancache (-1 means none) */ int cleancache_poolid; + + struct shrinker s_shrink; /* per-sb shrinker handle */ }; +/* superblock cache pruning functions */ +extern void prune_icache_sb(struct super_block *sb, int nr_to_scan); +extern void prune_dcache_sb(struct super_block *sb, int nr_to_scan); + extern struct timespec current_fs_time(struct super_block *sb); /* -- cgit v1.2.3