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Subject: Re: 2.6.32.21 - uptime related crashes?
From: john stultz <johnstul@us.ibm.com>
To: MINOURA Makoto / =?UTF-8?Q?=E7=AE=95=E6=B5=A6_=E7=9C=9F?= 
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Date: Mon, 11 Jul 2011 18:40:19 -0700
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On Tue, 2011-07-12 at 10:18 +0900, MINOURA Makoto / 箕浦 真 wrote:
> We're experiencing similar but slightly different
> problems.  Some KVM hosts crash after 210-220 uptime.
> Some of them hits divide-by-zero, but one of them shows:
> 
> [671528.8780080] BUG: soft lockup - CPU#4 stuck for 61s! [kvm:11131]
> 
> (sorry we have no full crash message including the backtrace)
> 
> The host kernel is 2.6.32.11-based (ubuntu 2.6.32-22-server,
> 2.6.32-22.36).
> 
> I'm not sure but probably the task scheduler is confusing by
> the sched_clock overflow?

I'm working on a debug patch that will hopefully trip sched_clock
overflows very early to see if we can't shake these issues out.

thanks
-john