From: Frederic Weisbecker <fweisbec@gmail.com>
To: Yinghai Lu <yinghai@kernel.org>
Cc: "Paul E. McKenney" <paulmck@linux.vnet.ibm.com>,
Ingo Molnar <mingo@elte.hu>,
linux-kernel@vger.kernel.org,
Steven Rostedt <rostedt@goodmis.org>
Subject: Re: [GIT PULL rcu/next] rcu commits for 2.6.40
Date: Fri, 20 May 2011 02:14:23 +0200 [thread overview]
Message-ID: <20110520001421.GH1956@nowhere> (raw)
In-Reply-To: <4DD58F90.4090506@kernel.org>
On Thu, May 19, 2011 at 02:45:52PM -0700, Yinghai Lu wrote:
> On 05/19/2011 02:15 PM, Frederic Weisbecker wrote:
> > On Thu, May 19, 2011 at 12:51:26PM -0700, Yinghai Lu wrote:
> >> [ 85.194797] <idle>-0 0d... 85152953us : rcu_irq_enter: 1 49
> >> [ 85.194808] <idle>-0 0dN.. 85153081us : <stack trace>
> >> [ 85.194809] => rcu_irq_exit
> >> [ 85.194810] => irq_exit
> >> [ 85.194811] => smp_apic_timer_interrupt
> >> [ 85.194812] => apic_timer_interrupt
> >> [ 85.194813] => cpu_idle
> >> [ 85.194813] => rest_init
> >> [ 85.194814] => start_kernel
> >> [ 85.194815] => x86_64_start_reservations
> >
> > So it's the dynticks_nesting going crazy. As if we had rcu_irq_enter()
> > without rcu_irq_exit().
> >
> > I see you have CONFIG_DEBUG_LOCKING_API_SELFTESTS=y
> > and the locking api selftest is doing a strange thing: if we look
> > at HARDIRQ_ENTER(), it calls irq_enter(), but HARDIRQ_EXIT() only
> > calls __irq_exit(). Which means it lacks the rcu_irq_exit().
> >
> > So, if I understood correctly the thing there, some selftests simulating
> > the hardirq context are unbalancing the rcu state.
> >
> > Does that help if you unset CONFIG_DEBUG_LOCKING_API_SELFTESTS ?
>
>
> yes, after unset that, no warning and delay...
Thanks a lot for all your testing! I've just proposed a fix, let's see
how that goes.
next prev parent reply other threads:[~2011-05-20 0:14 UTC|newest]
Thread overview: 76+ messages / expand[flat|nested] mbox.gz Atom feed top
2011-05-08 15:18 [GIT PULL rcu/next] rcu commits for 2.6.40 Paul E. McKenney
2011-05-09 7:36 ` Ingo Molnar
2011-05-09 21:09 ` Yinghai Lu
2011-05-10 8:56 ` Paul E. McKenney
2011-05-10 9:37 ` Ingo Molnar
2011-05-10 18:04 ` Yinghai Lu
2011-05-10 19:32 ` Paul E. McKenney
2011-05-10 20:52 ` Yinghai Lu
2011-05-11 4:54 ` Paul E. McKenney
2011-05-11 6:03 ` Yinghai Lu
2011-05-11 6:42 ` Yinghai Lu
2011-05-11 20:13 ` Paul E. McKenney
2011-05-11 16:54 ` Yinghai Lu
2011-05-11 16:56 ` Yinghai Lu
2011-05-11 20:18 ` Paul E. McKenney
2011-05-11 20:59 ` Yinghai Lu
2011-05-11 21:30 ` Yinghai Lu
2011-05-11 23:02 ` Yinghai Lu
2011-05-12 6:03 ` Ingo Molnar
2011-05-12 7:27 ` Yinghai Lu
2011-05-12 7:42 ` Yinghai Lu
2011-05-12 9:20 ` Paul E. McKenney
2011-05-12 17:31 ` Yinghai Lu
2011-05-12 21:36 ` Yinghai Lu
2011-05-13 1:28 ` Yinghai Lu
2011-05-13 8:42 ` Ingo Molnar
2011-05-13 12:19 ` Ingo Molnar
2011-05-13 13:04 ` Ingo Molnar
2011-05-13 13:12 ` Ingo Molnar
2011-05-13 14:14 ` Paul E. McKenney
2011-05-13 15:07 ` Ingo Molnar
2011-05-13 16:26 ` Paul E. McKenney
2011-05-16 7:08 ` Ingo Molnar
2011-05-16 7:48 ` Paul E. McKenney
2011-05-16 11:51 ` Ingo Molnar
2011-05-16 12:23 ` Ingo Molnar
2011-05-16 14:30 ` Ingo Molnar
2011-05-16 21:33 ` Paul E. McKenney
2011-05-16 22:07 ` Paul E. McKenney
2011-05-16 21:24 ` Paul E. McKenney
2011-05-16 23:52 ` Frederic Weisbecker
2011-05-17 2:40 ` Frederic Weisbecker
2011-05-17 7:53 ` Paul E. McKenney
2011-05-17 12:43 ` Frederic Weisbecker
2011-05-17 22:21 ` Paul E. McKenney
2011-05-18 21:10 ` Yinghai Lu
2011-05-18 23:13 ` Frederic Weisbecker
2011-05-19 4:33 ` Yinghai Lu
2011-05-19 14:47 ` Frederic Weisbecker
2011-05-19 19:51 ` Yinghai Lu
2011-05-19 21:15 ` Frederic Weisbecker
2011-05-19 21:45 ` Yinghai Lu
2011-05-20 0:09 ` [PATCH] rcu: Fix unpaired rcu_irq_enter() from locking selftests Frederic Weisbecker
2011-05-20 8:36 ` Ingo Molnar
2011-05-20 15:12 ` Paul E. McKenney
2011-05-20 15:11 ` Paul E. McKenney
2011-05-20 0:14 ` Frederic Weisbecker [this message]
2011-05-13 14:40 ` [GIT PULL rcu/next] rcu commits for 2.6.40 Ingo Molnar
2011-05-13 16:38 ` Paul E. McKenney
2011-05-16 7:10 ` Ingo Molnar
2011-05-13 21:08 ` Yinghai Lu
2011-05-14 14:26 ` Paul E. McKenney
2011-05-14 15:31 ` Paul E. McKenney
2011-05-14 18:34 ` Paul E. McKenney
2011-05-15 3:59 ` Yinghai Lu
2011-05-15 4:14 ` Yinghai Lu
2011-05-15 5:41 ` Yinghai Lu
2011-05-15 5:49 ` Yinghai Lu
2011-05-15 6:04 ` Paul E. McKenney
2011-05-15 6:59 ` Paul E. McKenney
2011-05-16 7:08 ` Paul E. McKenney
2011-05-16 7:39 ` Ingo Molnar
2011-05-15 6:01 ` Paul E. McKenney
2011-05-15 22:01 ` Frederic Weisbecker
2011-05-16 5:56 ` Paul E. McKenney
2011-05-16 22:40 ` Frederic Weisbecker
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