On Tue, 25 May 2010 18:53:06 +1000 Dave Chinner <david@xxxxxxxxxxxxx> wrote: > From: Dave Chinner <dchinner@xxxxxxxxxx> > > 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. > I go all tingly when a changelog contains the word "should". OK, it _should_ do X. But _does_ it actually do X? > fs/super.c | 53 +++++++++++++++++++++ > include/linux/fs.h | 7 +++ > 4 files changed, 88 insertions(+), 214 deletions(-) > > diff --git a/fs/dcache.c b/fs/dcache.c > index dba6b6d..d7bd781 100644 > --- a/fs/dcache.c > +++ b/fs/dcache.c > @@ -456,21 +456,16 @@ static void prune_one_dentry(struct dentry * dentry) > * which flags are set. This means we don't need to maintain multiple > * similar copies of this loop. > */ > -static void __shrink_dcache_sb(struct super_block *sb, int *count, int flags) > +static void __shrink_dcache_sb(struct super_block *sb, int count, int flags) Forgot to update the kerneldoc description of `count'. -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@xxxxxxxxxx For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: <a href=mailto:"dont@xxxxxxxxx";> email@xxxxxxxxx </a>