From: "Paul E. McKenney" <paulmck@linux.vnet.ibm.com>
To: Catalin Marinas <catalin.marinas@arm.com>
Cc: Eric Sesterhenn <eric.sesterhenn@lsexperts.de>,
linux-kernel <linux-kernel@vger.kernel.org>
Subject: Re: RCU callbacks and TREE_PREEMPT_RCU
Date: Wed, 16 Sep 2009 08:47:16 -0700 [thread overview]
Message-ID: <20090916154716.GC6737@linux.vnet.ibm.com> (raw)
In-Reply-To: <1253115255.31751.96.camel@pc1117.cambridge.arm.com>
On Wed, Sep 16, 2009 at 04:34:15PM +0100, Catalin Marinas wrote:
> On Wed, 2009-09-16 at 08:29 -0700, Paul E. McKenney wrote:
> > On Wed, Sep 16, 2009 at 03:17:21PM +0100, Catalin Marinas wrote:
> > > When TREE_PREEMPT_RCU is enabled, the rcu list traversing above fails
> > > with access to 0x6b6b6b6b but it is fine with TREE_PREEMPT_RCU=n and
> > > TREE_RCU=y. During clean-up, kmemleak objects should no longer be freed
> > > by other means since kmemleak was disabled and all callbacks are
> > > ignored. The system is a 900Mhz P3, 256MB RAM, CONFIG_SMP=n.
> > >
> > > Is there something I'm doing wrong in kmemleak or a bug with RCU
> > > preemption? The kernel oops looks like this:
> >
> > From your description and the code above, I must suspect a bug with
> > RCU preemption. A new one, as the only bugs I am currently chasing
> > involve NR_CPUS>32 (>64 on 64-bit systems).
> >
> > CONFIG_SMP=n implies NR_CPUS==1 in your build, correct?
>
> CONFIG_NR_CPUS=1.
I was afraid of that. ;-)
Thanx, Paul
next prev parent reply other threads:[~2009-09-16 15:47 UTC|newest]
Thread overview: 12+ messages / expand[flat|nested] mbox.gz Atom feed top
2009-09-16 14:17 RCU callbacks and TREE_PREEMPT_RCU Catalin Marinas
2009-09-16 15:29 ` Paul E. McKenney
2009-09-16 15:34 ` Catalin Marinas
2009-09-16 15:47 ` Paul E. McKenney [this message]
2009-09-16 15:57 ` Paul E. McKenney
2009-09-16 16:00 ` Eric Sesterhenn
2009-09-16 23:19 ` Eric Sesterhenn
2009-09-16 23:26 ` Paul E. McKenney
2009-09-17 8:29 ` Eric Sesterhenn
2009-09-17 22:21 ` Paul E. McKenney
2009-09-18 12:12 ` Eric Sesterhenn
2009-09-18 12:41 ` Paul E. McKenney
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