Re: [ANNOUNCE] 3.0-rt6 : BUG at kernel/trmutex.c:724!

From: Peter Zijlstra
Date: Thu Aug 04 2011 - 12:37:56 EST


On Thu, 2011-08-04 at 18:34 +0200, Tim Sander wrote:
> I was really happy to find 6 preempt rt releases for the 3.0 kernel after holliday :-).
>
> So i went for a testdrive and found an error: The error occurs in a non released non
> mainline kernel and is available from me upon request. It has been working on
> (2.6.39,3.0) but is not working on 3.0-rt6. It fails in an interrupt which calls:
>
> wake_up_interruptible(&hbm_device.wait);
>
> The waitque has been initialized with:
> init_waitqueue_head(&hbm_device.wait);
> before interrupts where enabled. So i don't think its a race.

looks like it tries to use waitqueues from hardirq context, that's a
no-no for -rt. That interrupt should be a threaded interrupt.
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