Re: [Xenomai-core] [PATCH] fix hw-timer setup/cleanup for i386

[Jan Kiszka <jan.kiszka@domain.hid>]

Stelian Pop wrote:
> Le vendredi 12 octobre 2007 à 23:58 +0200, Philippe Gerum a écrit :
>> On Fri, 2007-10-12 at 23:51 +0200, Stelian Pop wrote:
>>> On Fri, Oct 12, 2007 at 10:22:45PM +0200, Stelian Pop wrote:
>>>
>>>> Or even go crazy and activate SMP again ?
>>> Would have been too easy:
>>>
>>> # modprobe xeno_native
>>> Xenomai: native skin init failed, code -19.
>>>
>> The I-pipe likely told Xenomai that the LAPIC was unusable, because it
>> has been put in dummy state by the clock event layer. Must be something
>> silly going on at I-pipe level. Please switch HPET off just for kicks.
> 
> No, it doesn't change a thing.
> 
> What does change something however is CONFIG_X86_UP_IOAPIC. Without it
> (UP or UP+APIC), latency works (albeit with higher latencies - up to 30
> us - than with 2.6.20+xeno-2.3.4 - where I saw latencies up to 20-25

Those 5 us are likely due to the programming overhead of the PIT (in
contrast to the fast IO-APIC in LAPIC/SMP setups).

> _in_SMP_mode_). With IOAPIC I get code 19.
> 

Where do you get ENODEV? On nucleus startup? Please provide
/proc/timer_list output of the working and non-working setups.

Jan

PS: For unknown reasons your mails don't make it to my web.de address,
only to the list. Do you get any error messages?