Re: module programming smp-safety howto?

[Erik Mouw <J.A.K.Mouw@its.tudelft.nl>]

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,
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