From: Michael Ellerman <michael@ellerman.id.au>
To: Li Zhong <zhong@linux.vnet.ibm.com>
Cc: Paul Mackerras <paulus@samba.org>,
PowerPC email list <linuxppc-dev@lists.ozlabs.org>
Subject: Re: [RFC PATCH powerpc] try secondary hash before BUG in kernel_map_linear_page()
Date: Wed, 10 Apr 2013 12:21:08 +1000 [thread overview]
Message-ID: <20130410022107.GA15929@concordia> (raw)
In-Reply-To: <1361784575.3001.5.camel@ThinkPad-T5421.cn.ibm.com>
On Mon, Feb 25, 2013 at 05:29:35PM +0800, Li Zhong wrote:
> This patch tries to fix following issue when CONFIG_DEBUG_PAGEALLOC
> is enabled:
>
> [ 543.075675] ------------[ cut here ]------------
> [ 543.075701] kernel BUG at arch/powerpc/mm/hash_utils_64.c:1239!
> [ 543.075714] Oops: Exception in kernel mode, sig: 5 [#1]
So the issue is that kernel_map_linear_page() doesn't try the secondary
hash slot.
> The code is borrowed from that in __hash_page_huge().
It is, and in fact there is another copy in hash_low_64.S - in assembler.
So I think we should at least try and keep ourselves to two
implementations, one in asm and one in C. So can you split it out into a
helper routine called by both kernel_map_linear_page() and
__hash_page_huge() ?
cheers
next prev parent reply other threads:[~2013-04-10 2:21 UTC|newest]
Thread overview: 3+ messages / expand[flat|nested] mbox.gz Atom feed top
2013-02-25 9:29 [RFC PATCH powerpc] try secondary hash before BUG in kernel_map_linear_page() Li Zhong
2013-04-10 2:21 ` Michael Ellerman [this message]
2013-04-10 5:29 ` Li Zhong
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