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Date: Fri, 8 Oct 2010 11:18:19 +0100
From: Al Viro <viro@ZenIV.linux.org.uk>
To: Dave Chinner <david@fromorbit.com>
Cc: linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org
Subject: Re: [PATCH 18/18] fs: Reduce inode I_FREEING and factor inode
 disposal
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On Fri, Oct 08, 2010 at 04:21:32PM +1100, Dave Chinner wrote:

> +			spin_unlock(&sb->s_inodes_lock);
>  
> -			spin_lock(&inode_lru_lock);
> -			list_move(&inode->i_lru, dispose);
> -			spin_unlock(&inode_lru_lock);
> +			dispose_one_inode(inode);
>  
> -			percpu_counter_dec(&nr_inodes_unused);
> +			spin_lock(&sb->s_inodes_lock);

And now you've unlocked the list and even blocked.  What's going to
keep next valid through that fun?

> +		spin_unlock(&inode_lru_lock);
> +
> +		dispose_one_inode(inode);
> +		cond_resched();
> +
> +		spin_lock(&inode_lru_lock);

Same, only worse - in the previous you might hope for lack of activity
on fs, in this one you really can't.