On 11/21/19 4:52 PM, Jan Kiszka wrote:
> On 21.11.19 16:31, Philippe Gerum wrote:
>> On 11/19/19 6:39 PM, Philippe Gerum wrote:
>>> On 11/19/19 5:46 PM, Philippe Gerum via Xenomai wrote:
>>>> On 11/18/19 4:13 PM, Lange Norbert via Xenomai wrote:
>>>>> Hello,
>>>>>
>>>>> Here's one of my deadlocks, the output seems interleaved from 2 
>>>>> concurrent dumps,
>>>>> I ran the crashlog through decode_stacktrace.sh.
>>>>>
>>>>
>>>> Ok, I can reproduce this one, including in a vm. The symptom can be either 
>>>> a lockup, or recursive faults. I'm on it.
>>>>
>>>
>>> #0b9e81807 seems to have introduced a regression. Something there may be 
>>> subtly at odds with the core scheduler logic. More later.
>>
>> Eh, no. #0b9e81807 only exposed a very serious and longstanding issue into 
>> the scheduler core, which may cause a CPU to pick threads from a remote 
>> runqueue in rare circumstances. And that bug is definitely mine. I need to 
>> review more code to make sure no more horror shows alike are waiting for 
>> prime time. This bug affects all Xenomai series, 3.1, 3.0, 2.x.
>>
> 
> Uh... good that we surfaced this now. Curious to see the result!
> 

Good news is that unlike initially suspected, Xenomai 2.x is _not_ affected by 
the thread-suspend bug. The synchronous bp feature increased the likeliness of 
triggering it, as XNDBGSTOP needs to be sent to multiple threads while 
single-stepping.

-- 
Philippe.

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