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Date: Mon, 28 Jan 2008 01:01:02 -0800
From: Andrew Morton <akpm@linux-foundation.org>
To: "minchan kim" <minchan.kim@gmail.com>
Cc: linux-mm@kvack.org, linux-kernel@vger.kernel.org,
       "Martin Bligh" <mbligh@mbligh.org>,
       "Nick Piggin" <nickpiggin@yahoo.com.au>
Subject: Re: [PATCH] remove duplicating priority setting in try_to_free_p
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On Mon, 28 Jan 2008 15:43:56 +0900 "minchan kim" <minchan.kim@gmail.com> wrote:

> > I think this is actually a bugfix.  The code you're removing doesn't do the
> >
> >         if (priority < zone->prev_priority)
> >
> > thing.
> >
> 
> shrink_zones() in try_to_free_pages() already called
> note_zone_scanning_priority().
> So, it have done it.

note_zone_scanning_priority() will only permit ->prev_priority to logically
increase, whereas the code which you've removed will also permit
->prev_priority to logically decrease.  So I don't see that they are
equivalent?