Re: [RFC] page-writeback: move indoes from one superblock together

[Wu Fengguang <fengguang.wu@intel.com>]

On Thu, Sep 24, 2009 at 09:17:39PM +0800, Jens Axboe wrote:
> > > Could just reuse inode.
> > oops, forgot to remove it when moveing inode to global.
> 
> This is the one I merged. I added the below as wel, we don't need to
> reiterate the list if we only moved inodes from a single super block.

Looks good to me.

> diff --git a/fs/fs-writeback.c b/fs/fs-writeback.c
> index b27406d..225c731 100644
> --- a/fs/fs-writeback.c
> +++ b/fs/fs-writeback.c
> @@ -336,17 +336,27 @@ static void move_expired_inodes(struct list_head *delaying_queue,
>  {
>  	LIST_HEAD(tmp);
>  	struct list_head *pos, *node;
> -	struct super_block *sb;
> +	struct super_block *sb = NULL;
>  	struct inode *inode;
> +	int do_sb_sort = 0;
>  
>  	while (!list_empty(delaying_queue)) {
>  		inode = list_entry(delaying_queue->prev, struct inode, i_list);
>  		if (older_than_this &&
>  		    inode_dirtied_after(inode, *older_than_this))
>  			break;
> +		if (sb && sb != inode->i_sb)
> +			do_sb_sort = 1;
> +		sb = inode->i_sb;
>  		list_move(&inode->i_list, &tmp);
>  	}
>  
> +	/* just one sb in list, splice to dispatch_queue and we're done */
> +	if (!do_sb_sort) {
> +		list_splice(&tmp, dispatch_queue);
> +		return;
> +	}
> +
>  	/* Move inodes from one superblock together */
>  	while (!list_empty(&tmp)) {
>  		inode = list_entry(tmp.prev, struct inode, i_list);
> 
> -- 
> Jens Axboe