Re: [Xenomai-core] Kernel crash with Xenomai (caused by fork?)

[Tomas Kalibera <kalibera@domain.hid>]

Gilles Chanteperdrix wrote:
> Of course, we are looking for all bugs. But please tell me: do you get
> the lock-up even before fork is called ? If not, could you verify that
> at least some Xenomai programs run correctly, for instance latency ?
>   
The lock up with patch 5 happens before fork is called, but after a 
real-time task is started by the program. I don't know better now - I'd 
have to add more logging.  If I run in strace, the lock-up does not happen.

Thinking about that, it can be a bug in my program. If I understand the 
concept of Xenomai correctly, I can just write a real-time task that 
would starve the Linux kernel indefinitely, correct ? My program 
definitely does have bugs. So I'll do more debugging.

The lock-up does NOT happen with latency. But, the bug in the kernel 
without patch 5 (the one that lead to a stack trac, after call to fork), 
did not appear in latency, either.
> Looking at the code, I think I found a bug, but I doubt it could cause a
> lockup. The definition of VM_PINNED in include/linux/mm.h collides with
> another bit used by Linux, so this defintion should be changed from:
> #define VM_PINNED 0x08000000
> to:
> #define VM_PINNED 0x10000000
>
> I will now try, if possible, to reproduce the bug on a x86 box of mine
> and will keep you informed.
>   
Thanks ! I'll indeed build kernel with patch 6, test again, and test my 
application.

Tomas