From mboxrd@z Thu Jan  1 00:00:00 1970
From: Christoph Hellwig <hch@infradead.org>
Subject: Re: [PATCH 04/19] fs: Implement lazy LRU updates for inodes.
Date: Sat, 16 Oct 2010 20:47:42 -0400
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Cc: Christoph Hellwig <hch@infradead.org>,
	Dave Chinner <david@fromorbit.com>,
	linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org
To: Nick Piggin <npiggin@kernel.dk>
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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.