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? I expect we'd end up taking both inode_lock and the new sb->lru_lock in several places, which wouldn't be of any help, at least in the interim. Long-term, the locking for fs-writeback.c should move to the per-superblock one also, at which time this problem largely goes away I think. Unfortunately the writeback inode lists got moved into the backing_dev_info, whcih messes things up a bit. > inodes_stat.nr_unused--; > + inode->i_sb->s_nr_inodes_unused--; It's regrettable to be counting the same thing twice. Did you look into removing (or no longer using) inodes_stat.nr_unused? > + /* Now, we reclaim unused dentrins with fairness. May as well fix the typo while we're there. Please review all these comments to ensure that they are still accurate and complete. -- To unsubscribe from this list: send the line "unsubscribe linux-fsdevel" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
