Re: [Xenomai-core] RFC: 2.5 todo list.

[Philippe Gerum <rpm@xenomai.org>]

On Tue, 2009-10-06 at 14:26 -0400, Andreas Glatz wrote:
> On Fri, 2009-10-02 at 21:00 +0200, Philippe Gerum wrote:
> > On Fri, 2009-10-02 at 14:01 -0400, Andreas Glatz wrote:
> > > > 
> > > > - powerpc32 updates for 2.6.30. Mainly to merge the once experimental
> > > > bits that prevent most alignment faults from triggering a secondary mode
> > > > switch. Andreas told me this works like a charm on 83xx, and I did not
> > > > see any issue on 52xx, 85xx or 86xx either.
> > > > 
> > > 
> > > Can I get a version of that patch for testing? Is it in your git
> > > repository?
> > 
> > I just pushed this commit to my remote tree (ipipe-2.6.30-powerpc
> > branch); it should appear in a few hours once mirrored (cron job).
> > 
> 
> I finally had a chance to test the ipipe-2.6.30-powerpc version
> from the git repository. Unfortunately, I noticed that our application
> dies after some time and that this behaviour is related to that 
> alignment patch (if I take it out everything runs fine for > 2 days).
> 
> Currently I'm investigating the reasons for that crash. It has
> something to do with floating point registers not being restored
> properly. Our alignment exceptions are mainly triggered by accesses 
> to unaligned floating point data.
> 

This patch fixes an issue I have just discovered when running two
switchtest programs concurrently on 52xx; that issue was introduced by
the no-switch-upon-alignment patch. The bug you saw may be related.

http://download.gna.org/adeos/patches/v2.6/powerpc/adeos-ipipe-2.6.30.3-powerpc-DENX-2.7-01.patch

> Andreas
-- 
Philippe.