Re: [PATCH] Properly account for freed pages in free_pages_bulk()and when allocating high-order pages in buffered_rmqueue()

[Hugh Dickins]

On Tue, 28 Apr 2009, Mel Gorman wrote:
> On Tue, Apr 28, 2009 at 12:37:22PM -0400, Christoph Lameter wrote:
> > On Tue, 28 Apr 2009, Mel Gorman wrote:
> > 
> > > @@ -1151,6 +1151,7 @@ again:
> > >  	} else {
> > >  		spin_lock_irqsave(&zone->lock, flags);
> > >  		page = __rmqueue(zone, order, migratetype);
> > > +		__mod_zone_page_state(zone, NR_FREE_PAGES, -(1UL << order));
> > >  		spin_unlock(&zone->lock);
> > >  		if (!page)
> > >  			goto failed;
> > 
> > __mod_zone_page_state takes an signed integer argument. Not sure what is
> > won by the UL suffix here.
> > 
> 
> Matches other call sites such as in __offline_isolated_pages(), habit when
> using shifts like this and matches other locations, paranoia, doesn't hurt.

Well, not a big deal, but I'd say that it does hurt: by wasting people's
time (mine!), wondering what that "UL" is for - I'd have had to ask, if
Christoph hadn't cleared this up first (thank you).  And elsewhere,
you're using an int << order to update NR_FREE_PAGES, so I don't see
the consistency argument.

Hugh
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