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From: Dave Hansen <dave.hansen@intel.com>
To: Andrey Ryabinin <ryabinin.a.a@gmail.com>,
	kernel test robot <ying.huang@linux.intel.com>
Cc: LKP <lkp@01.org>, LKML <linux-kernel@vger.kernel.org>,
	Andrew Morton <akpm@linux-foundation.org>,
	David Rientjes <rientjes@google.com>,
	Pekka Enberg <penberg@kernel.org>,
	"H. Peter Anvin" <hpa@zytor.com>,
	Thomas Gleixner <tglx@linutronix.de>, Ingo Molnar <mingo@elte.hu>,
	Andi Kleen <andi@firstfloor.org>,
	Joonsoo Kim <iamjoonsoo.kim@lge.com>,
	Christoph Lameter <cl@linux.com>,
	Sasha Levin <sasha.levin@oracle.com>,
	Konstantin Khlebnikov <koct9i@gmail.com>,
	Yuri Gribov <tetra2005@gmail.com>,
	Andrey Konovalov <adech.fo@gmail.com>,
	Dmitry Chernenkov <dmitryc@google.com>,
	Konstantin Serebryany <kcc@google.com>,
	Dmitry Vyukov <dvyukov@google.com>,
	Linus Torvalds <torvalds@linux-foundation.org>
Subject: Re: [lkp] [fs] df4c0e36f1: NMI watchdog: BUG: soft lockup - CPU#0 stuck for 22s! [swapper/0:1]
Date: Mon, 2 Nov 2015 09:39:42 -0800	[thread overview]
Message-ID: <56379FDE.6010603@intel.com> (raw)
In-Reply-To: <CAPAsAGwVYSgXm0Rgbtim-5iFxhWaakc1emXQALKwYLm36OoVsw@mail.gmail.com>

On 11/02/2015 01:32 AM, Andrey Ryabinin wrote:
> And the major factor here is number 2.
> 
> In your dmesg:
> [   67.891156] rbtree testing -> 570841 cycles
> [   88.609636] augmented rbtree testing
> [  116.546697] NMI watchdog: BUG: soft lockup - CPU#0 stuck for 22s!
> [swapper/0:1]
> 
> 
> I've tried to reproduce this, and got this:
> [    0.693574] rbtree testing -> 15513 cycles
> 570841/15513 = 36x times faster.
> 
> [    1.159450] augmented rbtree testing -> 23675 cycles
> [    1.864996]
> It took less than a second, meanwhile in your case it didn't finish in
> 22 seconds.
> 
> This makes me think that your host is overloaded and the problem is on
> your side.

It's probably just a matter of putting some cond_resched()s in the test
code.

  reply	other threads:[~2015-11-02 17:39 UTC|newest]

Thread overview: 7+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2015-11-02  8:06 [lkp] [fs] df4c0e36f1: NMI watchdog: BUG: soft lockup - CPU#0 stuck for 22s! [swapper/0:1] kernel test robot
2015-11-02  9:17 ` Dmitry Vyukov
2015-11-02  9:32 ` Andrey Ryabinin
2015-11-02 17:39   ` Dave Hansen [this message]
2015-11-02 19:34     ` Andrey Ryabinin
2015-11-02 20:07       ` Dave Hansen
2015-11-02 21:29         ` Andrey Ryabinin

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