Date: Wed, 10 Apr 2002 12:49:56 +0200
From: Erik Mouw <J.A.K.Mouw@its.tudelft.nl>
To: Emmanuel Michon <emmanuel_michon@realmagic.fr>
Cc: linux-kernel@vger.kernel.org
Subject: Re: module programming smp-safety howto?
Message-ID: <20020410104956.GD1465@arthur.ubicom.tudelft.nl>
In-Reply-To: <7w7knf98gk.fsf@avalon.france.sdesigns.com>
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On Wed, Apr 10, 2002 at 12:03:23PM +0200, Emmanuel Michon wrote:
> I'm responsible for the development of a kernel module for Sigma
> Designs EM84xx PCI chips (MPEG2 and MPEG4 hardware decoder
> boards). It's working properly now, irq sharing and multiple board
> support is ok.
> 
> I would like to make it smp-safe.
> 
> For instance, I use at a place cli()/restore to implement something that
> looks like a critical section (first code path is in a ioctl, second
> in a irq top half). I guess this approach is wrong with smp.
> 
> Is there some documentation or howto about what changes compared
> to non-smp computers?

Run "make psdocs" in your kernel tree, and you'll find Rusty's
kernel-locking guide in Documentation/DocBook/ . If you don't have the
proper tools, you can also download it from
http://www.kernelnewbies.org/documents/ .

> Maybe a specific kernel module can be considered as a good model?

I found the 8139too driver a nice source for good programming practice
(thanks, Jeff!).


Erik

-- 
J.A.K. (Erik) Mouw, Information and Communication Theory Group, Faculty
of Information Technology and Systems, Delft University of Technology,
PO BOX 5031, 2600 GA Delft, The Netherlands  Phone: +31-15-2783635
Fax: +31-15-2781843  Email: J.A.K.Mouw@its.tudelft.nl
WWW: http://www-ict.its.tudelft.nl/~erik/
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