Re: lockdep WARNING for run_timer_softirq()

From: Steven Rostedt
Date: Wed Sep 05 2012 - 13:14:54 EST


On Wed, 2012-09-05 at 19:09 +0200, Peter Zijlstra wrote:
> On Wed, 2012-09-05 at 10:20 -0400, Steven Rostedt wrote:
> > Well, the branch tracer was active. That means all 'if()'s were being
> > traced. It comes down to how you define 'if' ;-)
>
> Yeah, I tried making an argument for:
>
> we tell lockdep irqs are enabled hit an if() end up in lockdep code
> through the branch tracer and find borken state, or vice-versa.
>
> Just couldn't find it in the provided stack-trace. Might be I didn't
> look hard enough, might be there's something else entirely.
>
> All I know is I've never seen it on real hardware, then again, I hardly
> ever have CONFIG_PARAVIRT or CONFIG_TRACE_BRANCH_PROFILING, let alone
> both.
>

This looks very familiar to Fengguang's previous bug report. I can't
seem to find it on LKML.org. Probably because of the two attachments
(dmesg and config) caused lkml to nuke it.

I'll forward it to you.

-- Steve


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