[PATCH 4/7] xfs: Sort delayed write buffers before dispatch

[Dave Chinner]

On Mon, Jan 25, 2010 at 07:00:54AM -0500, Christoph Hellwig wrote:
> > @@ -1937,42 +1967,46 @@ xfs_flush_buftarg(
> >  	xfs_buftarg_t	*target,
> >  	int		wait)
> >  {
> > -	struct list_head tmp;
> > -	xfs_buf_t	*bp, *n;
> > +	xfs_buf_t	*bp;
> >  	int		pincount = 0;
> > +	LIST_HEAD(tmp_list);
> > +	LIST_HEAD(wait_list);
> >  
> >  	xfs_buf_runall_queues(xfsconvertd_workqueue);
> >  	xfs_buf_runall_queues(xfsdatad_workqueue);
> >  	xfs_buf_runall_queues(xfslogd_workqueue);
> >  
> >  	set_bit(XBT_FORCE_FLUSH, &target->bt_flags);
> > -	pincount = xfs_buf_delwri_split(target, &tmp, 0);
> > +	pincount = xfs_buf_delwri_split(target, &tmp_list, 0);
> >  
> >  	/*
> > -	 * Dropped the delayed write list lock, now walk the temporary list
> > +	 * Dropped the delayed write list lock, now walk the temporary list.
> > +	 * All I/O is issued async and then if we need to wait for completion
> > +	 * we do that after issuing all the IO.
> >  	 */
> > -	list_for_each_entry_safe(bp, n, &tmp, b_list) {
> > +	list_sort(NULL, &tmp_list, xfs_buf_cmp);
> > +	while (!list_empty(&tmp_list)) {
> > +		struct xfs_buf *bp;
> 
> This now has a bp variable both in functionp-wide scope and a local one
> here.  Might be worth to decide for either style.

I removed the second declaration.

Cheers,

Dave.
-- 
Dave Chinner
david at fromorbit.com