From: Ingo Molnar <mingo@elte.hu>
To: "Paul E. McKenney" <paulmck@linux.vnet.ibm.com>
Cc: Yinghai Lu <yinghai@kernel.org>, linux-kernel@vger.kernel.org
Subject: Re: [GIT PULL rcu/next] rcu commits for 2.6.40
Date: Mon, 16 May 2011 09:39:28 +0200 [thread overview]
Message-ID: <20110516073928.GA23252@elte.hu> (raw)
In-Reply-To: <20110516070849.GA20580@linux.vnet.ibm.com>
* Paul E. McKenney <paulmck@linux.vnet.ibm.com> wrote:
> > And the way you can prove that it is my code rather than the arch
> > code is to show that the warning happens on your system when the
> > irq_enter()/irq_exit() calls are perfectly nested.
>
> So I took another look at the RCU debugfs stats you provided earlier,
> and realized that your system gets a lot more NMIs than do the ones
> that I have access to. So as a diagnostic patch, I ifdefed out the
> body of rcu_nmi_enter() and rcu_nmi_exit().
Well, but the delays are occuring all the time (and it's bisectable) and NMIs
are generally not deterministic.
I'd really suggest the creation of a revert + finegrained series on top of
core/rcu which would IMHO help us narrow this down a lot more directly than
jumping between the 'need_resched bug', 'nmi bug' and 'barrier bug' hypoteses.
( Btw., the bug still has the feeling of a need_resched/scheduling/timing
artifact to me, not barriers or NMI. )
Thanks,
Ingo
next prev parent reply other threads:[~2011-05-16 7:39 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 ` [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 [this message]
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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