From mboxrd@z Thu Jan 1 00:00:00 1970 From: "Paul E. McKenney" Subject: Re: [PATCH RFC tip/core/rcu 1/2] rcu: Rationalize kthread spawning Date: Wed, 16 Jul 2014 22:33:34 -0700 Message-ID: <20140717053334.GL8690@linux.vnet.ibm.com> References: <20140714100604.GA9905@linux.vnet.ibm.com> <1405332404-10094-1-git-send-email-paulmck@linux.vnet.ibm.com> <53C73BA3.1070303@oracle.com> Reply-To: paulmck@linux.vnet.ibm.com Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Cc: linux-kernel@vger.kernel.org, mingo@kernel.org, laijs@cn.fujitsu.com, dipankar@in.ibm.com, akpm@linux-foundation.org, mathieu.desnoyers@efficios.com, josh@joshtriplett.org, niv@us.ibm.com, tglx@linutronix.de, peterz@infradead.org, rostedt@goodmis.org, dhowells@redhat.com, edumazet@google.com, dvhart@linux.intel.com, fweisbec@gmail.com, oleg@redhat.com, sbw@mit.edu, linux-rt-users@vger.kernel.org To: Sasha Levin Return-path: Received: from e39.co.us.ibm.com ([32.97.110.160]:52452 "EHLO e39.co.us.ibm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752816AbaGQFdp (ORCPT ); Thu, 17 Jul 2014 01:33:45 -0400 Received: from /spool/local by e39.co.us.ibm.com with IBM ESMTP SMTP Gateway: Authorized Use Only! Violators will be prosecuted for from ; Wed, 16 Jul 2014 23:33:44 -0600 Content-Disposition: inline In-Reply-To: <53C73BA3.1070303@oracle.com> Sender: linux-rt-users-owner@vger.kernel.org List-ID: On Wed, Jul 16, 2014 at 10:57:39PM -0400, Sasha Levin wrote: > On 07/14/2014 06:06 AM, Paul E. McKenney wrote: > > From: "Paul E. McKenney" > > > > Currently, RCU spawns kthreads from several different early_initcall() > > functions. Although this has served RCU well for quite some time, > > as more kthreads are added a more deterministic approach is required. > > This commit therefore causes all of RCU's early-boot kthreads to be > > spawned from a single early_initcall() function. > > > > Signed-off-by: Paul E. McKenney > > Hey Paul, > > I've updated to today's -next and my VM started hanging on boot. Bisect > pointed out this patch. > > I don't have any further info right now, but can provide whatever you'll > find useful. Could you please add initcall_debug to qemu's -append list? If sysrq-T works that early, its output would be helpful as well. Your .config would also be helpful. Thanx, Paul