Re: [Xenomai-core] rare brokenness in latency output - FPU bug!

[Jeff Webb <jeff.webb@domain.hid>]

Philippe Gerum wrote:
> On Tue, 2006-09-19 at 09:48 -0500, Jeff Webb wrote:
>> Jeff Webb wrote:
>>> I don't have a plain xenomai-2.2.2 kernel handy, but I do have a patched 
>>> version.  I do not have any problems with switchtest for xenomai-2.2.2 
>>> with the following patches:
>>>
>>>  https://mail.gna.org/public/xenomai-help/2006-09/msg00084.html
>>>  https://mail.gna.org/public/xenomai-help/2006-09/msg00096.html
>>>
>>> These patches are to nucleus pipe.c and pipe.h / rtai fifo.c and fifo.h.
>>>
>>> I am running an Athlon64 X2 in with 32-bit Fedora Core 5.
>> I have done a couple more tests using xenomai from subversion.  Here is a summary of all the results I have so far:
>>
>> xenomai-2.2.2 (patched as described above): switchtest runs
>> svn/xenomai/trunk (r1586): switchtest runs
>> svn/xenomai/trunk (r1589): switchtest runs
>> xenomai-2.2.3 : switchtest fails
>>
>> This is on my Fedora Core 5 (32-bit x86), linux-2.6.17.13 SMP, ipipe-1.3 (except 1.4 for 2.2.3), gcc-4.1.1, Athlon64 X2.
>>
>> Hopefully this will help,
> 
> It does, thanks. This confirms Jan's findings that something went wrong
> from #1595. The issue is spotted now, somewhere in the FPU save/restore
> code in the x86 support layer.

I just rebuilt 2.2.3 with the latest FPU fix patch posted by Philippe:

  https://mail.gna.org/public/xenomai-help/2006-09/msg00157.html

This appears to fix the FPU switchtest bug on my Athlon64 X2 (2.6 kernel) machine.  Great job!

Thanks for the hard work,

Jeff