From: Atsushi Nemoto <anemo@mba.ocn.ne.jp>
To: mroberto@cpti.cetuc.puc-rio.br
Cc: akpm@linux-foundation.org, kosaki.motohiro@jp.fujitsu.com,
cl@linux-foundation.org, mel@csn.ul.ie, minchan.kim@gmail.com,
linux@arm.linux.org.uk, sfr@canb.auug.org.au, hpa@zytor.com,
yinghai@kernel.org, sshtylyov@mvista.com,
linux-kernel@vger.kernel.org, linux-mm@kvack.org
Subject: Re: [PATCH] MM: Fix NR_SECTION_ROOTS == 0 when using using sparsemem extreme.
Date: Thu, 20 May 2010 01:14:47 +0900 (JST) [thread overview]
Message-ID: <20100520.011447.193688848.anemo@mba.ocn.ne.jp> (raw)
In-Reply-To: <n2pcecb6d8f1005051519ze48b22a0t8548311839f510b0@mail.gmail.com> <1273093366-3388-1-git-send-email-mroberto@cpti.cetuc.puc-rio.br>
On Wed, 5 May 2010 18:02:46 -0300, Marcelo Roberto Jimenez <mroberto@cpti.cetuc.puc-rio.br> wrote:
> Got this while compiling for ARM/SA1100:
>
> mm/sparse.c: In function '__section_nr':
> mm/sparse.c:135: warning: 'root' is used uninitialized in this function
>
> This patch follows Russell King's suggestion for a new calculation for
> NR_SECTION_ROOTS. Thanks also to Sergei Shtylyov for pointing out the
> existence of the macro DIV_ROUND_UP.
JFYI, This fix is not just silence the warning, fix a real problem.
Without this fix, mem_section[] might have 0 size so mem_section[0]
will share other variable area. For example, I got:
c030c700 b __warned.16478
c030c700 B mem_section
c030c701 b __warned.16483
This might cause very strange behavior. Your patch actually fixes it.
Thank you.
---
Atsushi Nemoto
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prev parent reply other threads:[~2010-05-19 16:14 UTC|newest]
Thread overview: 3+ messages / expand[flat|nested] mbox.gz Atom feed top
2010-05-05 21:02 Marcelo Roberto Jimenez
2010-05-05 22:19 ` Marcelo Jimenez
2010-05-19 16:14 ` Atsushi Nemoto [this message]
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