From: Michal Hocko <mhocko@suse.cz>
To: Wang Sheng-Hui <shhuiw@gmail.com>
Cc: linux-mm@kvack.org, linux-kernel@vger.kernel.org,
Mel Gorman <mgorman@suse.de>,
Andrew Morton <akpm@linux-foundation.org>
Subject: Re: Question about __zone_watermark_ok: why there is a "+ 1" in computing free_pages?
Date: Mon, 5 Dec 2011 17:14:43 +0100 [thread overview]
Message-ID: <20111205161443.GA20663@tiehlicka.suse.cz> (raw)
In-Reply-To: <CAKXJSOHu+sQ1NeMsRvFyp2GYoB6g+50boUu=-QvbxxjcqgOAVA@mail.gmail.com>
On Fri 25-11-11 09:21:35, Wang Sheng-Hui wrote:
> In line 1459, we have "free_pages -= (1 << order) + 1;".
> Suppose allocating one 0-order page, here we'll get
> free_pages -= 1 + 1
> I wonder why there is a "+ 1"?
Good spot. Check the patch bellow.
---
next prev parent reply other threads:[~2011-12-05 16:14 UTC|newest]
Thread overview: 6+ messages / expand[flat|nested] mbox.gz Atom feed top
2011-11-25 1:21 Question about __zone_watermark_ok: why there is a "+ 1" in computing free_pages? Wang Sheng-Hui
2011-12-05 16:14 ` Michal Hocko [this message]
2011-12-05 17:06 ` Mel Gorman
2011-12-08 2:38 ` Wang Sheng-Hui
2011-12-08 8:05 ` Michal Hocko
2011-12-08 16:24 ` KOSAKI Motohiro
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