Re: Real-Time Preemption, -RT-2.6.12-final-V0.7.51-12

William Weston
2005-07-07T20:06:19Z

On Thu, 7 Jul 2005, Ingo Molnar wrote:

> is this inheritance perpetual? It is normal for some tasks to be boosted
> momentarily, but if the condition remains even after jackd has exited,
> it's clearly an anomaly. (lets call it "RT priority leakage".) Priority
> leakage on SMP was fixed recently, but there could be other bugs
> remaining.
>
> There's priority-leakage debugging code in the -RT kernel, which is
> activated if you enable CONFIG_DEBUG_PREEMPT. This debugging code, if
> triggered, should produce 'BUG: comm/123 leaked RT prio 123 (123)?" type
> of messages. But ... due to a bug it would not print out anything but
> would lock up hard if it detects the condition (and if
> RT_DEADLOCK_DETECT is enabled). I have fixed this reporting bug in the
> -51-08 kernel.

-51-12 is still exhibhiting the RT priority leakage, but isn't producing
any BUG messages.

--ww