Re: Question about a freeze under Xenomai 3.2.1

[Julien Aube <julien.aube@smile.fr>]

Hello,

Le 03/05/2023 à 16:57, Jan Kiszka a écrit :
> Well, 3.2.3 would also work with 5.15.y.


Thanks. Following this comment I tried the kernel 
5.15.109-dovetail1-rebased on all the following tests.
I just had to update a few unrelated things like the DTS.

The behaviour with 5.15 is exactly the same.


> First of all, can you reproduce the issue when disabling Xenomai? And
> when also disabling dovetail? And when using the corresponding LTS
> kernel as is?


Here is what I have tested:

* LTS kernel (5.10.177 & 5.15.109) : works
* Dovetail kernel (5.10.177-dovetail1 & 5.15.109-dovetail1-rebase)  / 
xenomai 3.2.1
     * with CONFIG_DOVETAIL=n + CONFIG_SMP=y : works
     * with CONFIG_DOVETAIL=y + CONFIG_XENOMAI=n + CONFIG_SMP=y : works
     * with CONFIG_DOVETAIL=y + CONFIG_XENOMAI=y + CONFIG_SMP=n : works
     * with CONFIG_DOVETAIL=y + CONFIG_XENOMAI=y + CONFIG_SMP=y : fails

As an additional test, I tried with CONFIG_SMP=y but nr_cpus=1 on the 
cmdline.
In this configuration the failure still happens.


=> For me there is a problem specific to the SMP behaviour, since the 
tests are working fine in the non SMP case.
It might be that I do not understand the full extend of the SMP vs 
xenomai setting though.

As a sidenote I've added all I the debug flags I could think of.
Unfortunaly I can't use KDB since my serial console (usb-based on 
motherboard) does not translate a break correctly and I cannot fall into 
kdb.


Julien