On Fri, May 28, 2010 at 08:54:18AM +1000, Dave Chinner wrote: > On Thu, May 27, 2010 at 01:32:30PM -0700, Andrew Morton wrote: > > On Tue, 25 May 2010 18:53:04 +1000 > > Dave Chinner <david@xxxxxxxxxxxxx> wrote: > > > > > From: Dave Chinner <dchinner@xxxxxxxxxx> > > > > > > The inode unused list is currently a global LRU. This does not match > > > the other global filesystem cache - the dentry cache - which uses > > > per-superblock LRU lists. Hence we have related filesystem object > > > types using different LRU reclaimatin schemes. > > > > > > To enable a per-superblock filesystem cache shrinker, both of these > > > caches need to have per-sb unused object LRU lists. Hence this patch > > > converts the global inode LRU to per-sb LRUs. > > > > > > The patch only does rudimentary per-sb propotioning in the shrinker > > > infrastructure, as this gets removed when the per-sb shrinker > > > callouts are introduced later on. > > > > > > ... > > > > > > + list_move(&inode->i_list, &inode->i_sb->s_inode_lru); > > > > It's a shape that s_inode_lru is still protected by inode_lock. One > > day we're going to get in trouble over that lock. Migrating to a > > per-sb lock would be logical and might help. > > > > Did you look into this? > > Yes, I have. Yes, it's possible. It's solving a different problem, > so I figured it can be done in a different patch set. It almost all goes away in my inode lock splitup patches. Inode lru and dirty lists were the last things protected by the global lock there. I am actually going to do per-zone lrus for these guys and per-zone locks (which is actually better than per-sb because it gives NUMA scalability within a single sb). The dirty/writeback lists should probably be per-bdi locked. -- 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>