Gilles Chanteperdrix wrote:
> Gilles Chanteperdrix wrote:
>> Jan Kiszka wrote:
>>> Am 05.11.2010 00:25, Gilles Chanteperdrix wrote:
>>>> Jan Kiszka wrote:
>>>>> Am 04.11.2010 23:08, Gilles Chanteperdrix wrote:
>>>>>> Jan Kiszka wrote:
>>>>>>> rework. Safer for now is likely to revert 56ff4329ff, keeping nucleus
>>>>>>> debugging off.
>>>>>> That is not enough.
>>>>> It is, I've reviewed the code today.
>>>> The fallouts I am talking about are:
>>>> 47dac49c71e89b684203e854d1b0172ecacbc555
>>> Not related.
>>>
>>>> 38f2ca83a8e63cc94eaa911ff1c0940c884b5078
>>> An optimization.
>>>
>>>> 5e7cfa5c25672e4478a721eadbd6f6c5b4f88a2f
>>> That fall out of that commit is fixed in my series.
>>>
>>>>>> This commit was followed by several others to "fix
>>>>>> the fix". You know how things are, someone proposes a fix, which fixes
>>>>>> things for him, but it breaks in the other people configurations (one of
>>>>>> the fallouts was a complete revamp of include/asm-arm/atomic.h for
>>>>>> instance).
>>>>>>
>>>>> I've pushed a series that reverts that commit, then fixes and cleans up
>>>>> on top of it. Just pushed if you want to take a look. We can find some
>>>>> alternative debugging mechanism independently (though I'm curious to see
>>>>> it - it still makes no sense to me).
>>>> Since the fix is simply a modification to what we have currently. I
>>>> would prefer if we did not remove it. In fact, I think it would be
>>>> simpler if we started from what we currently have than reverting past
>>>> patches.
>>> Look at the series, it goes step by step to an IMHO clean state. We can
>>> pull out the debugging check removal, though, if you prefer to work on
>>> top of the existing code.
>> From my point of view, Anders looks for something that works, so 
>> following the rules that the minimal set of changes minimize the chances
>> of introducing new bugs while cleaning, I would go for the minimal set 
>> of changes, such as:
> 
> The tested one (on SMP, and UP with and without unlocked ctx switch):
> 
> diff --git a/include/nucleus/sched.h b/include/nucleus/sched.h
> index df56417..8888cf4 100644
> --- a/include/nucleus/sched.h
> +++ b/include/nucleus/sched.h
> @@ -165,28 +165,27 @@ struct xnsched_class {
>  #endif /* CONFIG_SMP */
>  
>  /* Test all resched flags from the given scheduler mask. */
> -static inline int xnsched_resched_p(struct xnsched *sched)
> +static inline int xnsched_remote_resched_p(struct xnsched *sched)
>  {
> -	return testbits(sched->status, XNRESCHED);
> +	return !xnarch_cpus_empty(sched->resched);
>  }
>  
> -static inline int xnsched_self_resched_p(struct xnsched *sched)
> +static inline int xnsched_resched_p(struct xnsched *sched)
>  {
>  	return testbits(sched->status, XNRESCHED);
>  }
>  
>  /* Set self resched flag for the given scheduler. */
>  #define xnsched_set_self_resched(__sched__) do {		\
> -  setbits((__sched__)->status, XNRESCHED);			\
> +  __setbits((__sched__)->status, XNRESCHED);			\
>  } while (0)
>  
>  /* Set specific resched flag into the local scheduler mask. */
>  #define xnsched_set_resched(__sched__) do {				\
>    xnsched_t *current_sched = xnpod_current_sched();			\
> -  setbits(current_sched->status, XNRESCHED);				\
> +  __setbits(current_sched->status, XNRESCHED);				\
>    if (current_sched != (__sched__))	{				\
>        xnarch_cpu_set(xnsched_cpu(__sched__), current_sched->resched);	\
> -      setbits((__sched__)->status, XNRESCHED);				\
>    }									\
>  } while (0)
>  
> diff --git a/ksrc/nucleus/pod.c b/ksrc/nucleus/pod.c
> index 862838c..4cb707a 100644
> --- a/ksrc/nucleus/pod.c
> +++ b/ksrc/nucleus/pod.c
> @@ -276,18 +276,16 @@ EXPORT_SYMBOL_GPL(xnpod_fatal_helper);
>  
>  void xnpod_schedule_handler(void) /* Called with hw interrupts off. */
>  {
> -	xnsched_t *sched;
> +	xnsched_t *sched = xnpod_current_sched();
>  
>  	trace_mark(xn_nucleus, sched_remote, MARK_NOARGS);
>  #if defined(CONFIG_SMP) && defined(CONFIG_XENO_OPT_PRIOCPL)
> -	sched = xnpod_current_sched();
>  	if (testbits(sched->status, XNRPICK)) {
>  		clrbits(sched->status, XNRPICK);
>  		xnshadow_rpi_check();
>  	}
> -#else
> -	(void)sched;
>  #endif /* CONFIG_SMP && CONFIG_XENO_OPT_PRIOCPL */
> +	xnsched_set_self_resched(sched);
>  	xnpod_schedule();
>  }
>  
> @@ -2174,7 +2172,7 @@ static inline int __xnpod_test_resched(struct xnsched *sched)
>  	int resched = testbits(sched->status, XNRESCHED);
>  #ifdef CONFIG_SMP
>  	/* Send resched IPI to remote CPU(s). */
> -	if (unlikely(xnsched_resched_p(sched))) {
> +	if (unlikely(xnsched_remote_resched_p(sched))) {
>  		xnarch_send_ipi(sched->resched);
>  		xnarch_cpus_clear(sched->resched);
>  	}
> diff --git a/ksrc/nucleus/timer.c b/ksrc/nucleus/timer.c
> index 1fe3331..a0ac627 100644
> --- a/ksrc/nucleus/timer.c
> +++ b/ksrc/nucleus/timer.c
> @@ -97,7 +97,7 @@ void xntimer_next_local_shot(xnsched_t *sched)
>  	__clrbits(sched->status, XNHDEFER);
>  	timer = aplink2timer(h);
>  	if (unlikely(timer == &sched->htimer)) {
> -		if (xnsched_self_resched_p(sched) ||
> +		if (xnsched_resched_p(sched) ||
>  		    !xnthread_test_state(sched->curr, XNROOT)) {
>  			h = xntimerq_it_next(&sched->timerqueue, &it, h);
>  			if (h) {
> 
> 
Looks very similar to what I have succesfully been running on top of 
2.5.5.2 (aka 2.5.5.3 beta :-) ), except that I didn't change any names 
(changes makes perfect sense).

/Anders