Re: NOHZ: local_softirq_pending 20

["Uwe Kleine-König" <Uwe.Kleine-Koenig@digi.com>]

Hello,

Thomas Gleixner wrote:
> On Fri, 23 Nov 2007, Uwe Kleine-König wrote:
> > my kernel reported:
> > 
> > 	NOHZ: local_softirq_pending 20
> 
> Thats TASKLET_SOFTIRQ
I suppose you're right, and it's only me that fails to see that.  Just
from looking on the code, I'd say TASKLET_SOFTIRQ is 5.  Ah, OK, I see,
0x20 == 1 << TASKLET_SOFTIRQ.

> > I cannot interpret it, but probably this is bad, because before
> > bc5393a6c9c0e70b4b43fb2fb63e3315e9a15c8f this used to BUG().
> 
> We removed the BUG, because it's a situation where the kernel can
> easily recover. It should never happen that the kernel goes to sleep
> with a pending softirq, but it's not a fatal error.
> 
> > This happend while having a high load.  Up to now it only happend once
> > and I cannot reproduce it.
> 
> That's hard to tell then. Without a reproducible test case I can not
> do much to help debugging this.
Is there something I can do to be able to report more if it reoccurs?

Can you isolate the problem?  Has it to do with the arch-specific timing
code?  With the hardware?

Best regards and thanks
Uwe

-- 
Uwe Kleine-König, Software Engineer
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