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Date: Thu, 9 Apr 2015 21:24:41 -0700
From: Andrew Morton <akpm@linux-foundation.org>
To: ZhangNeil <neilzhang1123@hotmail.com>
Cc: "linux-mm@kvack.org" <linux-mm@kvack.org>,
        "linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>
Subject: Re: [PATCH v2] mm: show free pages per each migrate type
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On Fri, 10 Apr 2015 04:16:15 +0000 ZhangNeil <neilzhang1123@hotmail.com> wrote:

> > I think we can eliminate nr_free[][]:
> 
> what about make it as global__variable?

That isn't as good - it permanently consumes memory and really requires
new locking to protect the array from concurrent callers.