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Date: Tue, 18 Nov 2014 23:59:17 -0500
From: Dave Jones <davej@redhat.com>
To: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Don Zickus <dzickus@redhat.com>, Thomas Gleixner <tglx@linutronix.de>,
        Linux Kernel <linux-kernel@vger.kernel.org>,
        the arch/x86 maintainers <x86@kernel.org>
Subject: Re: frequent lockups in 3.18rc4
Message-ID: <20141119045917.GA17741@redhat.com>
Mail-Followup-To: Dave Jones <davej@redhat.com>,
	Linus Torvalds <torvalds@linux-foundation.org>,
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 <20141118145234.GA7487@redhat.com>
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On Tue, Nov 18, 2014 at 08:40:55PM -0800, Linus Torvalds wrote:
 > On Tue, Nov 18, 2014 at 6:19 PM, Dave Jones <davej@redhat.com> wrote:
 > >
 > > NMI watchdog: BUG: soft lockup - CPU#2 stuck for 21s! [trinity-c42:31480]
 > > CPU: 2 PID: 31480 Comm: trinity-c42 Not tainted 3.18.0-rc5+ #91 [loadavg: 174.61 150.35 148.64 9/411 32140]
 > > RIP: 0010:[<ffffffff8a1798b4>]  [<ffffffff8a1798b4>] context_tracking_user_enter+0xa4/0x190
 > > Call Trace:
 > >  [<ffffffff8a012fc5>] syscall_trace_leave+0xa5/0x160
 > >  [<ffffffff8a7d8624>] int_check_syscall_exit_work+0x34/0x3d
 > 
 > Hmm, if we are getting soft-lockups here, maybe it suggest too much exit-work.
 > 
 > Some TIF_NOHZ loop, perhaps? You have nohz on, don't you?

I do.

 > That makes me wonder: does the problem go away if you disable NOHZ?

I'll give it a try, and see what falls out overnight.

	Dave
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