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From: Paul Mackerras <paulus@samba.org>
To: "Aneesh Kumar K.V" <aneesh.kumar@linux.vnet.ibm.com>
Cc: phileas-fogg@mail.ru, linuxppc-dev@lists.ozlabs.org, geoff@infradead.org
Subject: Re: [PATCH 4/4] powerpc: Add vm debug code to catch errors
Date: Fri, 15 Feb 2013 15:46:41 +1100	[thread overview]
Message-ID: <20130215044641.GA25703@drongo> (raw)
In-Reply-To: <1360830983-1812-4-git-send-email-aneesh.kumar@linux.vnet.ibm.com>

On Thu, Feb 14, 2013 at 02:06:23PM +0530, Aneesh Kumar K.V wrote:
> From: "Aneesh Kumar K.V" <aneesh.kumar@linux.vnet.ibm.com>
> 
> We need to make sure that we don't have higher bits of kernel effective
> address set. That would result in multiple kernel segments having same
> proto vsid. Add debug code to make sure we capture this.

I'm not sure that WARN_ON is the best way to handle this, since this
code is called from low levels of the MMU management code, and a
WARN_ON will cause a trap that could possibly come at a time when we
can't handle a trap very well.  I think instead these functions should
return a vsid of 0 for bad addresses, and the callers should detect
that case and handle it appropriately, e.g. hash_page() should return
an error.

Paul.

      reply	other threads:[~2013-02-15  4:46 UTC|newest]

Thread overview: 7+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
     [not found] <a>
2013-02-14  8:36 ` [PATCH 1/4] powerpc: Make VSID_BITS* dependency explicit Aneesh Kumar K.V
2013-02-14  8:36   ` [PATCH 2/4] powerpc: Update kernel VSID range Aneesh Kumar K.V
2013-02-14 17:21     ` Aneesh Kumar K.V
2013-02-15  4:42     ` Paul Mackerras
2013-02-14  8:36   ` [PATCH 3/4] powerpc: Don't update r10 early in the call Aneesh Kumar K.V
2013-02-14  8:36   ` [PATCH 4/4] powerpc: Add vm debug code to catch errors Aneesh Kumar K.V
2013-02-15  4:46     ` Paul Mackerras [this message]

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