On 11/23/18 4:17 PM, Jan Kiszka wrote:
> On 23.11.18 16:04, Philippe Gerum wrote:
>> On 11/23/18 12:41 PM, Jan Kiszka wrote:
>>> On 23.11.18 12:29, Philippe Gerum wrote:
>>>> On 11/23/18 12:26 PM, Philippe Gerum via Xenomai wrote:
>>>>> On 11/23/18 12:11 PM, Jan Kiszka wrote:
>>>>>> On 23.11.18 11:56, Philippe Gerum wrote:
>>>>>>> On 11/22/18 6:57 PM, Jan Kiszka via Xenomai wrote:
>>>>>>>> This allows to remove the user-triggerable XENO_BUG from
>>>>>>>> xnsched_quota_setparam().
>>>>>>>
>>>>>>> Could you elaborate on the user trigger point you detected in the
>>>>>>> code?
>>>>>>
>>>>>> pthread_setschedparam_ex(pthread_self(), SCHED_QUOTA, <invalid-tgid>)
>>>>>
>>>>> Ouch. That is where the bug is rooted, xnthread_set_schedparam() is a
>>>>> broken obsolete interface which must be dropped entirely. The right
>>>>> way
>>>>> to change the scheduling class and/or parameters of a thread is by
>>>>> calling xnsched_set_policy().
>>>>
>>>> Nope, that won't work either. This needs more thought.
>>>>
>>>
>>> I don't see why catching the invalid tgid down in the sched class this
>>> way is a problem, except that we need to enhance the involved callback
>>> API a bit. The benefit is that no caller needs to deal with this check
>>> and has to become sched-class-aware.
>>>
>>
>> The code says:
>>
>> /*
>> * This is the ONLY place where calling
>> * steely_set_schedparam() is legit, sane and safe.
>> */
>> effective = steely_set_schedparam(thread, p);
>
> steely?
>
Same on the xenomai side:
/*
* This is the ONLY place where calling xnsched_setparam() is
* legit, sane and safe.
*/
effective = xnsched_setparam(thread, p);
if (effective) {
thread->sched_class = sched_class;
thread->wprio = xnsched_calc_wprio(sched_class, thread->cprio);
} else if (XENO_DEBUG(COBALT))
thread->sched_class = orig_effective_class;
--
Philippe.
