From mboxrd@z Thu Jan  1 00:00:00 1970
From: Carsten Emde <C.Emde@osadl.org>
Subject: Re: cpu stall and hyperthread
Date: Fri, 06 Jul 2012 01:02:25 +0200
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References: <4FEBCDDE.60503@gmail.com> <4FF351C6.3000100@gmail.com> <4FF4C94A.6040105@osadl.org> <4FF5DFDC.9010501@gmail.com>
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Cc: linux-rt-users@vger.kernel.org
To: Dong Liu <dliu.cn@gmail.com>
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Hi Dong,

> I tried to disable CONFIG_RT_GROUP_SCHED, but I still got cpu stalls!
Just had another look at your dmesg files. Didn't you get
   BUG: soft lockup - CPU#0 stuck for 279s! [swapper/0:0]
before? Now - with CONFIG_RT_GROUP_SCHED disabled - you get:
   rcu_preempt detected stalls on CPUs/tasks: { 3} [..]

Is it reproducible? Maybe, there are two different problems. One leads 
to soft lockups and is related to CONFIG_RT_GROUP_SCHED, and another one 
that leads to rcu_preempt stalls.

	-Carsten.