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Date: Thu, 22 Apr 2010 02:06:22 +0900
Message-ID: <i2t28c262361004211006yc1301a84ncf9b3acbff37e212@mail.gmail.com>
Subject: Re: [PATCH 2/6] change alloc function in pcpu_alloc_pages
From: Minchan Kim <minchan.kim@gmail.com>
To: Christoph Lameter <cl@linux-foundation.org>
Cc: Mel Gorman <mel@csn.ul.ie>, Tejun Heo <tj@kernel.org>,
       Andrew Morton <akpm@linux-foundation.org>,
       KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>,
       Bob Liu <lliubbo@gmail.com>, linux-kernel@vger.kernel.org,
       linux-mm@kvack.org
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On Wed, Apr 21, 2010 at 11:15 PM, Christoph Lameter
<cl@linux-foundation.org> wrote:
> On Tue, 20 Apr 2010, Mel Gorman wrote:
>
>> alloc_pages_exact_node() avoids a branch in a hot path that is checking for
>> something the caller already knows. That's the reason it exists.
>
> We can avoid alloc_pages_exact_node() by making all callers of
> alloc_pages_node() never use -1. -1 is ambiguous and only rarely will a
> caller pass that to alloc_pages_node().

That's very reasonable to me.
Then, we can remove alloc_pages_exact_node and nid < 0 check in
alloc_pages_node at the same time.

Mel. Could you agree?

Firstly Tejun suggested this but I didn't got the point.
Sorry for bothering you.

Okay. I will dive into this approach.
Thanks for careful review, All.


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-- 
Kind regards,
Minchan Kim
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