Re: [linuxsh-dev] [PATCH] Preemptible kernel for SH

[Jeremy Siegel]

Just FYI... the preemptible kernel depends on non-preemptible critical regions
denoted by spinlock calls (see Robert Love's excellent summary in
Documentation/preempt-locking.txt).  Many common drivers are assumed to have
correct locking for SMP operation, but non-SMP drivers may not. I've only run
the PreK SH kernel on the Solution Engine w/Ethernet and serial, but I did not
yet check to see if additional locks might be required in drivers/char/sh-sci.c
or drivers/net/stnic.c, which are specific to SH platforms and thus not SMP-safe
otherwise.

--Jeremy

Robert Love wrote:

> The attached is the fully preemptible linux kernel patch, for the SH
> arch.  This work is thanks to Jeremy Siegel of MontaVista.
>
> You will need an SH-patched kernel tree, available from
> http://sf.net/projects/linuxsh -- the CVS module "linux" has a drop-in
> replacement for 2.4.16.
>
> You will need the base preempt-kernel patch, available from
> ftp://ftp.kernel.org/pub/linux/kernel/people/rml/preempt-kernel
>
> Feedback is desired.
>
>         Robert Love