Re: Possible regression due to "hrtimer: Get rid of hrtimer softirq"

From: Kevin Hilman
Date: Fri May 08 2015 - 13:15:14 EST

Simon Horman <horms@xxxxxxxxxxxx> writes:

> Hi Thomas,
> On Thu, May 07, 2015 at 02:35:59PM +0200, Thomas Gleixner wrote:
>> On Thu, 7 May 2015, Simon Horman wrote:
>> > ------------[ cut here ]------------
>> > kernel BUG at kernel/irq_work.c:135!
>> BUG_ON(!irqs_disabled());
>> So something enables interrupts in the periodic tick handling
>> machinery. Seems you have high resolution timers disabled, but nohz
>> enabled. And that code path has a local_irq_disable/enable pair which
>> causes havoc. Patch below.
> Thanks for your quick response. I have been able to confirm that
> when applied on top of next-20150507 the problem I observed no longer
> manifests. I have successfully tested it on all the boards
> where I previously observed a problem.
> If you are planning to formally submit the patch below feel free to add:
> Tested-by: Simon Horman <horms+renesas@xxxxxxxxxxxx>

FWIW, I confirmed this fixed a boot hang on my kzm9d in next-20150507

Tested-by: Kevin Hilman <khilman@xxxxxxxxxx>
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