All of lore.kernel.org
 help / color / mirror / Atom feed
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: Thu, 19 May 2011 23:15:00 +0200	[thread overview]
Message-ID: <20110519211458.GG1956@nowhere> (raw)
In-Reply-To: <4DD574BE.7050709@kernel.org>

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 ?

  reply	other threads:[~2011-05-19 21:15 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 [this message]
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                                                                             ` [GIT PULL rcu/next] rcu commits for 2.6.40 Frederic Weisbecker
2011-05-13 14:40                                             ` 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

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=20110519211458.GG1956@nowhere \
    --to=fweisbec@gmail.com \
    --cc=linux-kernel@vger.kernel.org \
    --cc=mingo@elte.hu \
    --cc=paulmck@linux.vnet.ibm.com \
    --cc=rostedt@goodmis.org \
    --cc=yinghai@kernel.org \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line before the message body.
This is an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.