linux-kernel - Re: [RFC patch 2/5] smpboot: Provide infrastructure for percpu hotplug threads

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID: <20120614164825.GH2458@linux.vnet.ibm.com>
Date:	Thu, 14 Jun 2012 09:48:25 -0700
From:	"Paul E. McKenney" <paulmck@...ux.vnet.ibm.com>
To:	Thomas Gleixner <tglx@...utronix.de>
Cc:	LKML <linux-kernel@...r.kernel.org>,
	Peter Zijlstra <peterz@...radead.org>,
	Ingo Molnar <mingo@...nel.org>,
	"Srivatsa S. Bhat" <srivatsa.bhat@...ux.vnet.ibm.com>,
	Rusty Russell <rusty@...tcorp.com.au>,
	Tejun Heo <tj@...nel.org>
Subject: Re: [RFC patch 2/5] smpboot: Provide infrastructure for percpu
 hotplug threads

On Thu, Jun 14, 2012 at 06:19:50PM +0200, Thomas Gleixner wrote:
> On Thu, 14 Jun 2012, Paul E. McKenney wrote:
> 
> > On Thu, Jun 14, 2012 at 07:50:38AM -0700, Paul E. McKenney wrote:
> > > On Thu, Jun 14, 2012 at 03:32:19PM +0200, Thomas Gleixner wrote:
> > > > On Thu, 14 Jun 2012, Paul E. McKenney wrote:
> > > > > On Thu, Jun 14, 2012 at 01:20:39PM +0200, Thomas Gleixner wrote:
> > > > > > I gave it a quick shot, but I was not able to reproduce the hang yet.
> > > > > 
> > > > > Really?  I have a strictly Western-Hemisphere bug?  ;-)
> > > > 
> > > > I guess I need to fire up rcu torture to make it surface.
> > > 
> > > A simple offline was triggering it for me.  Perhaps some of my debug
> > > code was inappropriate, will retry.
> > 
> > And removing my debug code did the trick.  I guess some of it was really
> > just bug code.  In any case, it now passes short rcutorture testing for
> > me as well.
> > 
> > However, I do see the splat shown below.  The splat confuses me greatly,
> > as I thought that this kthread should be affinitied to a single CPU and
> > thus smp_processor_id() should refrain from splatting.  I don't see any
> > sort of "I broke affinity" message from the scheduler.
> 
> Hmm. Is that reproducible ?

Twice so far, will retry.

							Thanx, Paul

--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/