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From: "Paul E. McKenney" <paulmck@linux.vnet.ibm.com>
To: Fengguang Wu <wfg@linux.intel.com>
Cc: Josh Triplett <josh@joshtriplett.org>,
	Lai Jiangshan <laijs@cn.fujitsu.com>,
	LKML <linux-kernel@vger.kernel.org>,
	Steven Rostedt <rostedt@goodmis.org>
Subject: Re: rcu_dyntick and suspicious RCU usage
Date: Thu, 12 Jul 2012 10:02:42 -0700	[thread overview]
Message-ID: <20120712170242.GB31396@linux.vnet.ibm.com> (raw)
In-Reply-To: <20120712165738.GA21630@localhost>

On Fri, Jul 13, 2012 at 12:57:38AM +0800, Fengguang Wu wrote:
> On Thu, Jul 12, 2012 at 09:43:08AM -0700, Paul E. McKenney wrote:
> > On Wed, Jul 11, 2012 at 12:49:24AM -0700, Paul E. McKenney wrote:
> > > On Tue, Jul 10, 2012 at 12:47:00PM +0800, Fengguang Wu wrote:
> > > > Hi Paul,
> > > > 
> > > > Fortunately this bug is bisectable and the first bad commit is:
> > > > 
> > > >         commit 9b2e4f1880b789be1f24f9684f7a54b90310b5c0
> > > >         Author: Paul E. McKenney <paul.mckenney@linaro.org>
> > > >         Date:   Fri Sep 30 12:10:22 2011 -0700
> > > > 
> > > >             rcu: Track idleness independent of idle tasks
> > > 
> > > OK, there is a problem in TINY_RCU's handling of dyntick-idle: it
> > > traces while in idle.  The confusion on my part was that in TREE_RCU,
> > > the nesting and dyntick-idle indication are different, while in
> > > TINY_RCU they are one and the same.
> > > 
> > > Does the following patch help?
> > 
> > This one failed in my testing.  Please see the end for the fixed
> > version, with on small but important change.
> 
> It worked, thanks!
> 
> Tested-by: Fengguang Wu <wfg@linux.intel.com>

Very good!  (And please ignore my resend of the same patch.)

I will queue this.

							Thanx, Paul


  reply	other threads:[~2012-07-12 17:13 UTC|newest]

Thread overview: 13+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2012-07-09 13:56 rcu_dyntick and suspicious RCU usage wfg
2012-07-09 14:57 ` Fengguang Wu
2012-07-10  4:47   ` Fengguang Wu
2012-07-11  7:49     ` Paul E. McKenney
2012-07-11 12:36       ` Fengguang Wu
2012-07-11 12:55         ` Fengguang Wu
2012-07-12 14:11           ` Fengguang Wu
2012-07-12 17:01             ` Paul E. McKenney
2012-07-12 16:43       ` Paul E. McKenney
2012-07-12 16:57         ` Fengguang Wu
2012-07-12 17:02           ` Paul E. McKenney [this message]
2012-07-13  9:12             ` Fengguang Wu
2012-07-17 20:58               ` Paul E. McKenney

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