From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755341Ab1GJDZf (ORCPT ); Sat, 9 Jul 2011 23:25:35 -0400 Received: from e7.ny.us.ibm.com ([32.97.182.137]:58479 "EHLO e7.ny.us.ibm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755306Ab1GJDZe (ORCPT ); Sat, 9 Jul 2011 23:25:34 -0400 Date: Sat, 9 Jul 2011 20:25:10 -0700 From: "Paul E. McKenney" To: julie Sullivan Cc: linux-kernel@vger.kernel.org, mingo@elte.hu, laijs@cn.fujitsu.com, dipankar@in.ibm.com, akpm@linux-foundation.org, mathieu.desnoyers@polymtl.ca, josh@joshtriplett.org, niv@us.ibm.com, tglx@linutronix.de, peterz@infradead.org, rostedt@goodmis.org, Valdis.Kletnieks@vt.edu, dhowells@redhat.com, eric.dumazet@gmail.com, darren@dvhart.com, patches@linaro.org, torvalds@linux-foundation.org Subject: Re: PROBLEM: 3.0-rc kernels unbootable since -rc3 Message-ID: <20110710032510.GG6014@linux.vnet.ibm.com> Reply-To: paulmck@linux.vnet.ibm.com References: <201107072047.14429.kernelmail.jms@gmail.com> <20110707195845.GD6014@linux.vnet.ibm.com> <201107072147.12751.kernelmail.jms@gmail.com> <20110708002903.GI6014@linux.vnet.ibm.com> <20110709100900.GB6014@linux.vnet.ibm.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.5.20 (2009-06-14) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Sun, Jul 10, 2011 at 01:45:35AM +0100, julie Sullivan wrote: > >Very good. I have created a new jms.2011.07.07a branch in the -rcu > >git tree at: > > I get my own branch! :-) (thanks for all your trouble with this.) > > >Hello, Julie, > > >Any news? > > Sorry for the delay (again), I have to work very late Fridays and Saturdays. > Anyway, I have tested the six commits on my v3.0-rc4 branch (with > f8b7fc6b514f34a5 and a46e0899eec7a3069bc reverted) and can confirm > that they _all_ produce a bootable kernel at my end. I am not yet sure whether this is good news or bad news, but thank you very much for all the testing! > Btw, you may have noticed that my config has RCU_BOOST=n? > If I build a simple v3.0-rc4 kernel (ie one which includes the four > original commits (f8b7fc6b514, a46e0899eec, 09223371dea and > 9a432736904)) but with RCU_BOOST=y it _will_ boot. I didn't know if > this was helpful or not. OK, that certainly tells me what the next patch in the series needs to be. The reverse of the usual experience, but so it goes. > If it is helpful, you probably know this, but in order to get > RCU_BOOST=y I have to change a couple of other configs - PREEMPT_RCU=y > (previously n) and to get PREEMPT_RCU=y, my preemption model has to be > 'Preemptible Kernel (Low-Latency Desktop)' - PREEMPT=y (instead of > 'Voluntary Kernel Preemption (Desktop)' - PREEMPT=n which it was > originally). Agreed, to get RCU_BOOST, you need either TREE_PREEMPT_RCU or TINY_PREEMPT_RCU, which requires PREEMPT. > It's my day off tomorrow so I'll do some more testing (on -rc5 and > -rc6) (past 1.30am here in the UK now). I added another patch onto the jms.2011.07.07a in the -rcu git tree. If you get a chance to test it, please let me know how it goes. Thanx, Paul