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Re: [PATCH] Add support for profiling Loongson 2E

To: "John Levon" <levon@movementarian.org>
Subject: Re: [PATCH] Add support for profiling Loongson 2E
From: "Dajie Tan" <jiankemeng@gmail.com>
Date: Thu, 26 Jul 2007 05:14:14 +0400
Cc: "Ralf Baechle" <ralf@linux-mips.org>, linux-mips <linux-mips@linux-mips.org>, phil.el@wanadoo.fr, oprofile-list@lists.sourceforge.net
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2007/7/25, John Levon <levon@movementarian.org>:
On Wed, Jul 25, 2007 at 07:41:21AM +0400, Dajie Tan wrote:

> >Why do you need this change?  It almost looks as if you're papering over
> >a bug where add_sample should not be called at all.
>
> Yeah,this change is to enhance the robust of oprofile. When using
> performace counter manually(writting control register in a module, no
> need to use the oprofile),I usually make kernel panic if I do not
> initialize the oprofile and enable the overflow interrupt carelessly.
> So, this change can avoid this panic. :D

This panic is good and should stay. It shows that you've made a mistake.

john


This panic is caused by accessing a null pointer.Do you think that
accessing a null
pointer is allowed in a robust system ?

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