linux-kernel - Re: PROBLEM: 3.0-rc kernels unbootable since -rc3

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: <20110712180151.GA18257@dumpdata.com>
Date:	Tue, 12 Jul 2011 14:01:51 -0400
From:	Konrad Rzeszutek Wilk <konrad.wilk@...cle.com>
To:	"Paul E. McKenney" <paulmck@...ux.vnet.ibm.com>,
	Jeremy Fitzhardinge <jeremy@...p.org>
Cc:	xen-devel@...ts.xensource.com,
	julie Sullivan <kernelmail.jms@...il.com>,
	linux-kernel@...r.kernel.org, chengxu@...ux.vnet.ibm.com
Subject: Re: PROBLEM: 3.0-rc kernels unbootable since -rc3

> > http://darnok.org/xen/loop_cnt.log
> > 
> > which seems to imply that we are indeed stuck in that loop
> > forever.
> 
> It does indeed, thank you!  Also it looks like interrupts are
> disabled, and that timekeeping is similarly out of action.

.. With the latest patch the time looks to be advancing.

> Disabling CONFIG_NO_HZ would be an interesting test case.

Hadn't done that yet. Compiling a kernel with "# CONFIG_NO_HZ is not set"
right now.
> 
> > > o	Problems due to portions of the code attempting to use
> > > 	RCU read-side critical sections while in dyntick-idle mode.
> > > 	Frederic Weisbecker has located some of these, (though not yet
> > > 	in Xen) and he has some diagnositics which may be found at:
> > > 
> > > 	git://git.kernel.org/pub/scm/linux/kernel/git/paulmck/linux-2.6-rcu.git
> > > 
> > > 	on branch eqscheck.2011.07.08a.
> > > 
> > > 	You need to enable CONFIG_PROVE_RCU for these diagnostics to
> > > 	be executed.
> > 
> > Ok, let me try those too.
> 
> Thank you!

Will shortly do this.
> 
> > > o	As always, there might be bugs in RCU.  ;-)
> > > 
> > > But the loop in task_waking_fair() looks like the most prominent smoking
> > > gun at the moment.
> 
> And could you also please try out the patch that I posted earlier?

With the previous patch and the .. this is getting confusing. With this patch:
http://darnok.org/xen/loop_cnt-extra.patch

I get this output: http://darnok.org/xen/log.loop_cnt-extra-patch (one guest
with 4 VCPUS) and http://darnok.org/xen/loop_cnt-extra-patch.log (the guest with 16 VCPUs)
--
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/