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

julie Sullivan
2011-07-07T19:47:21Z

On Wednesday 06 July 2011 22:23:48 Paul E. McKenney wrote:
> On Wed, Jul 06, 2011 at 10:10:16PM +0100, julie Sullivan wrote:
> > None of my kernels after 3.0-rc3 will boot on my Dell XPS-M1730
> > (x86-64 2-core) test box running
> > Ubuntu (Kubuntu) 11.04 (i.e. the first unbootable one was -rc4).
> > The machine freezes immediately after selecting the kernel from the
> > bootloader menu, leaving
> > me with a blank blue screen so I can't give you any log messages.
> >
> > It bisects to the following commit:
> >
> > commit a46e0899eec7a3069bcadd45dfba7bf67c6ed016
> > Author: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
> > Date: Wed Jun 15 15:47:09 2011 -0700
> >
> > rcu: use softirq instead of kthreads except when RCU_BOOST=y
> >
> > This patch #ifdefs RCU kthreads out of the kernel unless RCU_BOOST=y,
> > thus eliminating context-switch overhead if RCU priority boosting has
> > not been configured.
> >
> > Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>

>
> Hello, Julie,
>
> One approach would be to cherry-pick the following commits:
>
> f8b7fc6b514f34a51875dd48dff70d4d17a54f38 rcu: Move RCU_BOOST #ifdefs to header f
> a46e0899eec7a3069bcadd45dfba7bf67c6ed016 rcu: use softirq instead of kthreads ex
> 09223371deac67d08ca0b70bd18787920284c967 rcu: Use softirq to address performance
> 9a432736904d386cda28b987b38ba14dae960ecc rcu: Simplify curing of load woes

>
> Another approach would be to move ahead to v3.0-rc4 or later.
>
> Thanx, Paul

Hi Paul
Thanks for your prompt reply, sorry for the delay in mine (real life intervened :-)
I tried reverting those 4 commits on v3.0-rc4 and can confirm that it _does_ give me a bootable 3.0-rc4 kernel.
I'll do some more testing. If you would like me to try anything specific just let me know :-)

Cheers
Julie