From: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
To: Allen Pais <allen.pais@oracle.com>
Cc: linux-rt-users <linux-rt-users@vger.kernel.org>,
Thomas Gleixner <tglx@linutronix.de>,
davem@davemloft.net,
SebastianAndrzejSiewiorbigeasy@linutronix.de
Subject: Re: Cyclictest results on Sparc64 with PREEMPT_RT
Date: Fri, 7 Feb 2014 13:35:29 +0100 [thread overview]
Message-ID: <20140207123529.GA2382@linutronix.de> (raw)
In-Reply-To: <52E616DB.2040202@oracle.com>
* Allen Pais | 2014-01-27 13:50:43 [+0530]:
>Hi,
Hi,
>[ 1143.894099] INFO: rcu_preempt self-detected stall on CPU { 36} (t=2100 jiffies g=373 c=372 q=61)
>[ 1143.894130] CPU[ 0]: TSTATE[0000009980001602] TPC[000000000048d1ac] TNPC[000000000048d1b0] TASK[ksoftirqd/0:3]
>[ 1143.894151] TPC[idle_cpu+0x2c/0x80] O7[cpumask_next_and+0x18/0x80] I7[find_busiest_group+0x21c/0xa40] RPC[load_balance+0xe8/0x880]
so you have CPU stall on cpu36
>
>[ 1150.135499] BUG: soft lockup - CPU#36 stuck for 23s! [swapper/36:0]
>[ 1150.135564] TPC: <rtrap_no_irq_enable+0x0/0xc>
>[ 1150.135572] RPC: <tl0_irq15+0x14/0x20>
>[ 1150.135581] I7: <tl0_irq15+0x14/0x20>
This is your NMI handler where you are right now…
>[ 1150.135582] Call Trace:
>[ 1150.135584] [0000000000404b54] rtrap_no_irq_enable+0x0/0xc
>[ 1150.135586] [0000000000404b54] rtrap_no_irq_enable+0x0/0xc
>[ 1150.135588] [0000000000404b54] rtrap_no_irq_enable+0x0/0xc
>[ 1150.135590] [0000000000404b54] rtrap_no_irq_enable+0x0/0xc
>[ 1150.135592] [0000000000404b54] rtrap_no_irq_enable+0x0/0xc
>[ 1150.135594] [0000000000404b54] rtrap_no_irq_enable+0x0/0xc
>[ 1150.135595] [0000000000404b54] rtrap_no_irq_enable+0x0/0xc
>[ 1150.135597] [0000000000404b54] rtrap_no_irq_enable+0x0/0xc
>[ 1150.135599] [0000000000404b54] rtrap_no_irq_enable+0x0/0xc
>[ 1150.135600] [0000000000404b54] rtrap_no_irq_enable+0x0/0xc
This is the stack where the NMI got injected. Not sure why this is more
than once here but then this the sparc64 trace I see :)
>[ 1150.135604] [00000000004acc00] in_lock_functions+0x0/0x40
>[ 1150.135608] [000000000080a038] add_preempt_count+0xd8/0x140
>[ 1150.135610] [000000000080617c] __schedule+0x1c/0x500
>[ 1150.135613] [0000000000806b7c] schedule+0x1c/0xc0
>[ 1150.135615] [0000000000806f8c] schedule_preempt_disabled+0xc/0x40
>[ 1150.135617] [000000000049dd10] cpu_startup_entry+0x150/0x300
And this where the CPU was before the NMI. Doesn't look blocking.
in_lock_functions() compares a few values no locking involved so the CPU
probably was here while the NMI hit and an usec later it might be an
instruction later. What I thnig is odd, is that it is exactly at the
begin of the function, not an instruction later.
>Am yet to debug what went wrong.
>
>- Allen
Sebastian
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next prev parent reply other threads:[~2014-02-07 12:35 UTC|newest]
Thread overview: 6+ messages / expand[flat|nested] mbox.gz Atom feed top
2014-01-27 8:20 Cyclictest results on Sparc64 with PREEMPT_RT Allen Pais
2014-02-07 12:35 ` Sebastian Andrzej Siewior [this message]
2014-02-07 12:41 ` Allen Pais
2014-02-07 13:25 ` Sebastian Andrzej Siewior
2014-02-07 13:30 ` Allen Pais
2014-02-11 21:44 ` Kirill Tkhai
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