Re: [PATCH 04/19] fs: Implement lazy LRU updates for inodes.

Christoph Hellwig
2010-10-17T00:47:46Z

On Sun, Oct 17, 2010 at 04:34:22AM +1100, Nick Piggin wrote:
> > This might actually be the better approach anyway (even for upstream)
> > -- it means we don't have to worry about the "check head element"
> > heuristic of the LRU check which could get false negatives if there is
> > a lot of concurrency on the LRU.
>
> Oh hmm, but then you do have the double lock of the LRU lock.
>
> if (can_unuse_after_iput(inode)) {
> spin_lock(&inode_lock);
> list_move(inode, list tail)
> spin_unlock(&inode_lock);
> }
> iput(inode);
> spin_lock(&inode_lock);
>
> Is that worth it?

Probably not.