Re: [Xenomai] XNARCH_TIMER_IRQ

[Philippe Gerum <rpm@xenomai.org>]

On 01/03/2013 06:25 PM, Jan Kiszka wrote:
> On 2013-01-03 17:27, Philippe Gerum wrote:
>> On 01/03/2013 04:44 PM, Jan Kiszka wrote:
>>> On 2013-01-03 16:16, Gilles Chanteperdrix wrote:
>>>> On 01/02/2013 06:43 PM, Jan Kiszka wrote:
>>>>> Hi,
>>>>>
>>>>> this may involve some refactoring of the HAL and a bit of I-pipe, so I
>>>>> better ask first:
>>>>>
>>>>> Not sure when it changed, but XNARCH_TIMER_IRQ may no longer return the
>>>>> same values when called on different CPUs. Therefore, It should rather
>>>>> be called XNARCH_THIS_CPU_TIMER_IRQ now.
>>>>>
>>>>> Looking at its users (an I-pipe debug warning pointed it out), there are
>>>>> two that don't expect this: xnintr_query_next() and format_irq_proc().
>>>>> The former actually wants XNARCH_TIMER_IRQ(cpu), the latter needs
>>>>> something like is_timer_irq_on_any_cpus(irq).
>>>>>
>>>>> So I would propose to refactor XNARCH_TIMER_IRQ and RTHAL_TIMER_IRQ
>>>>> accordingly. But this unfortunately requires extensions of I-pipe to
>>>>> provide something like __ipipe_hrtimer_irq(cpu) and
>>>>> __ipipe_this_cpu_hrtimer_irq. And some ugly workaround in Xenomai for
>>>>> older I-pipe versions.
>>>>>
>>>>> Does this make sense?
>>>>
>>>> Made something similar for forge:
>>>> http://git.xenomai.org/?p=xenomai-gch.git;a=commitdiff;h=37ca257af466e7e5fbfb402b39f088487d048fd5;hp=a9971c363fd361b428f12200536bc5a01dff9c05
>>>
>>
>> Caution, this code is WIP. nktimer will have to move to the percpu
>> scheduler descriptor to complete this.
>
> That's nkclock in 2.6. Mostly a cosmetic issue, the interrupt name will
> not be properly printed, statistics are already per-cpu. Could be
> improved nevertheless.
>

My point is to tell you that what you look to in -forge regarding this 
area is in a state of flux. I'm not referring to 2.6, I'm focusing 
almost exclusively on 3.x these days.

> Is there an easy way to find out if we have per-CPU timers on some arch?
>

Why should we assume differently?

> Jan
>


-- 
Philippe.