From: Frederic Weisbecker <fweisbec@gmail.com>
To: Li Zhong <zhong@linux.vnet.ibm.com>
Cc: linux-next list <linux-next@vger.kernel.org>,
LKML <linux-kernel@vger.kernel.org>,
paulmck@linux.vnet.ibm.com, sasha.levin@oracle.com,
gleb@redhat.com, avi@redhat.com
Subject: Re: [RFC PATCH] Fix abnormal rcu dynticks_nesting values related to async page fault
Date: Tue, 27 Nov 2012 16:39:59 +0100 [thread overview]
Message-ID: <CAFTL4hydk-FT_hqCbcSPFcNCKnqxtWGz0VjTu3nNnQYfbtTz6Q@mail.gmail.com> (raw)
In-Reply-To: <1353993325.14050.49.camel@ThinkPad-T5421.cn.ibm.com>
2012/11/27 Li Zhong <zhong@linux.vnet.ibm.com>:
> I noticed some warnings complaining about dynticks_nesting value, like
>
> [ 267.545032] ------------[ cut here ]------------
> [ 267.545032] WARNING: at kernel/rcutree.c:382 rcu_eqs_enter+0xab/0xc0()
> [ 267.545032] Hardware name: Bochs
> [ 267.545032] Modules linked in:
> [ 267.545032] Pid: 0, comm: swapper/2 Not tainted 3.7.0-rc5-next-20121115 #8
> [ 267.545032] Call Trace:
> [ 267.545032] [<ffffffff8104714f>] warn_slowpath_common+0x7f/0xc0
> [ 267.545032] [<ffffffff810471aa>] warn_slowpath_null+0x1a/0x20
> [ 267.545032] [<ffffffff810e607b>] rcu_eqs_enter+0xab/0xc0
> [ 267.545032] [<ffffffff810e60bb>] rcu_idle_enter+0x2b/0x70
> [ 267.545032] [<ffffffff8100d44f>] cpu_idle+0x6f/0x100
> [ 267.545032] [<ffffffff814bf055>] start_secondary+0x205/0x20c
> [ 267.545032] ---[ end trace 924ae80da035028d ]---
>
> After enabling rcu-dyntick tracing, I got following abnormal
> dynticks_nesting values (13fffffffffffff, ff00000000000001,etc):
> ...
> 1 <idle>-0 [002] dN.2 18739.518567: rcu_dyntick: End 0 140000000000000 rcu_idle_exit
> 2 sshd-696 [002] d..1 18739.518675: rcu_dyntick: ++= 140000000000000 140000000000001 rcu_irq_enter - apf (not present)
>
> 3 <idle>-0 [002] d..2 18739.518705: rcu_dyntick: Start 140000000000001 0 rcu_idle_enter
> 4 <idle>-0 [002] d..2 18739.521252: rcu_dyntick: End 0 1 rcu_irq_enter - apf (page ready)
> 5 <idle>-0 [002] dN.2 18739.521261: rcu_dyntick: Start 1 0 rcu_irq_exit - apf (page ready)
> 6 <idle>-0 [002] dN.2 18739.521263: rcu_dyntick: End 0 140000000000000 rcu_idle_exit
>
> 7 sshd-696 [002] d..1 18739.521299: rcu_dyntick: --= 140000000000000 13fffffffffffff rcu_irq_exit - apf (not present)
Calling rcu_irq_exit() without a matching rcu_irq_enter() after the
last rcu_idle_exit() is illegal, isn't it?
next prev parent reply other threads:[~2012-11-27 15:40 UTC|newest]
Thread overview: 50+ messages / expand[flat|nested] mbox.gz Atom feed top
2012-11-27 5:15 [RFC PATCH] Fix abnormal rcu dynticks_nesting values related to async page fault Li Zhong
2012-11-27 5:58 ` [PATCH rcu] use new nesting value for rcu_dyntick trace in rcu_eqs_enter_common Li Zhong
2012-11-27 15:18 ` Paul E. McKenney
2012-11-27 13:07 ` [RFC PATCH] Fix abnormal rcu dynticks_nesting values related to async page fault Gleb Natapov
2012-11-27 14:01 ` Sasha Levin
2012-11-27 15:25 ` Paul E. McKenney
2012-11-27 15:34 ` Frederic Weisbecker
2012-11-27 14:38 ` Frederic Weisbecker
2012-11-27 15:44 ` Gleb Natapov
2012-11-27 15:56 ` Frederic Weisbecker
2012-11-27 16:19 ` Paul E. McKenney
2012-11-27 16:48 ` Frederic Weisbecker
2012-11-27 16:59 ` Paul E. McKenney
2012-11-27 16:39 ` Gleb Natapov
2012-11-27 16:51 ` Frederic Weisbecker
2012-11-27 17:00 ` Gleb Natapov
2012-11-27 17:30 ` Frederic Weisbecker
2012-11-27 17:47 ` Gleb Natapov
2012-11-27 18:12 ` Frederic Weisbecker
2012-11-27 19:27 ` Gleb Natapov
2012-11-27 22:53 ` Frederic Weisbecker
2012-11-27 22:54 ` Frederic Weisbecker
2012-11-27 15:39 ` Frederic Weisbecker [this message]
2012-11-27 16:16 ` Paul E. McKenney
2012-11-27 16:31 ` Frederic Weisbecker
2012-11-27 16:29 ` Frederic Weisbecker
2012-11-28 8:18 ` [RFC PATCH v2] Add rcu user eqs exception hooks for " Li Zhong
2012-11-28 12:55 ` Frederic Weisbecker
2012-11-28 13:53 ` Gleb Natapov
2012-11-28 14:25 ` Frederic Weisbecker
2012-11-29 11:07 ` Gleb Natapov
2012-11-29 14:47 ` Frederic Weisbecker
2012-11-30 9:18 ` [RFC PATCH v3] " Li Zhong
2012-11-30 10:26 ` Gleb Natapov
2012-12-03 2:08 ` Li Zhong
2012-12-03 8:30 ` Gleb Natapov
2012-12-03 9:57 ` Gleb Natapov
2012-12-04 2:35 ` [ PATCH] " Li Zhong
2012-12-18 13:25 ` Gleb Natapov
2012-12-04 2:36 ` [RFC PATCH v3] " Li Zhong
2012-12-04 5:11 ` Gleb Natapov
2012-12-04 5:40 ` Li Zhong
2012-12-04 13:02 ` Gleb Natapov
2012-12-04 14:28 ` Paul E. McKenney
2012-11-29 1:49 ` [RFC PATCH v2] " Li Zhong
2012-11-29 14:40 ` Frederic Weisbecker
2012-11-29 17:25 ` Gleb Natapov
2012-11-30 8:36 ` Li Zhong
2012-11-30 10:08 ` Gleb Natapov
2012-11-27 16:43 ` [RFC PATCH] Fix abnormal rcu dynticks_nesting values related to " Frederic Weisbecker
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