Re: [Xenomai-help] I/O privilege losted and killed message

[Jan Kiszka <jan.kiszka@domain.hid>]

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Nicolas BLANCHARD wrote:
> Hello,
> 
> Sometime i lose my i/o privilege put with the system call ioperm (in
> the main function of my program).
> 
> My application stop with a "killed" message in the console and  in
> /proc/xenomai/fault i've an "general fault".
> To ignore this problem, i use the call system iopl (with full
> privilege) or recall ioperm before each inb or outb.
> But there is a problem, why i/o privilege are losted ?
> 
> In attachment you can find an archive with an example (application and
> source) witch show the problem.
> This program has 2 task :
> - task_1 priority 23 period 100 ms, lock a mutex, access to /dev/rtc,
> unlock the mutex, outb on hardware.
> - task 2 priority 25 period 1 ms, do nothing !
> 
> I put a 1 ms period to task_2 because it's near the speedest period on
> my cpu (166 MHz).
> With this period it stop immediatly.
> If i put 10 ms it's need 1 or 2 minutes.
> 
> On my Pentium 4 (Ubuntu on VmWare worstation under WindowsXP), i put 30
> ms (the more speed before overrun).
> 
> If i use iopl (and not ioperm), no problem.
> If i just have task_1, no problem.
> If i don't use mutex (lock for Rtc access) on task_2, no problem.
> 
> I use Xenomai Xenomai 2.3-rc2 (adeos 1.5-02), same probleme with
> 2.2.3.
> 
> If you have an idea.

No idea yet and no time to dig out the reason. But I can confirm the
sporadic lost of ioperms of a Xenomai task that enters secondary mode
(QEMU UP with CONFIG_XENO_OPT_RPIDISABLE and CONFIG_PREEMPT_NONE).

Jan


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