From: Michael wang <wangyun@linux.vnet.ibm.com>
To: Peter Zijlstra <peterz@infradead.org>
Cc: paulus@samba.org, Ingo Molnar <mingo@redhat.com>,
acme@ghostprotocols.net, Thomas Gleixner <tglx@linutronix.de>,
"H. Peter Anvin" <hpa@zytor.com>,
x86@kernel.org, LKML <linux-kernel@vger.kernel.org>
Subject: Re: [BUG] sched: tip/master show panic while booting/rebooting
Date: Wed, 19 Feb 2014 11:12:11 +0800 [thread overview]
Message-ID: <5304210B.9060604@linux.vnet.ibm.com> (raw)
In-Reply-To: <20140218112230.GA27965@twins.programming.kicks-ass.net>
On 02/18/2014 07:22 PM, Peter Zijlstra wrote:
> On Tue, Feb 18, 2014 at 01:12:03PM +0800, Michael wang wrote:
>> Hi, Folks
>>
>> Got below panic while testing tip/master on x86 box, it randomly
>> occur while booting or rebooting, any ideas?
>
> The obvious pick would be the relocation of the idle_balance call, but
> I'm not sure how that'll end up stalling.
I've review the code again, seems like it was caused by the same issue
we discussed (RT/DL enqueued issue), I found that idle_balance() will
return 1 in such cases:
/*
* While browsing the domains, we released the rq lock.
* A task could have be enqueued in the meantime
*/
if (this_rq->nr_running && !pulled_task)
return 1;
And if no more fair task to be pulled, we will do balance again and
again in pick_next_task_fair() until panic in NMI...
The solution we discussed could solve the problem I suppose, it was
already in progress, correct?
Please let me know if there are any thing I could help with ;-)
Regards,
Michael Wang
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next prev parent reply other threads:[~2014-02-19 3:12 UTC|newest]
Thread overview: 7+ messages / expand[flat|nested] mbox.gz Atom feed top
2014-02-18 5:12 [BUG] sched: tip/master show panic while booting/rebooting Michael wang
2014-02-18 11:22 ` Peter Zijlstra
2014-02-19 3:12 ` Michael wang [this message]
2014-02-19 11:57 ` Peter Zijlstra
2014-02-25 0:30 ` Paul E. McKenney
2014-02-25 2:45 ` Michael wang
2014-02-25 4:41 ` Paul E. McKenney
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