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
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=20090916154716.GC6737@linux.vnet.ibm.com \
--to=paulmck@linux.vnet.ibm.com \
--cc=catalin.marinas@arm.com \
--cc=eric.sesterhenn@lsexperts.de \
--cc=linux-kernel@vger.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.