From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from e33.co.us.ibm.com (e33.co.us.ibm.com [32.97.110.151]) (using TLSv1 with cipher DHE-RSA-AES256-SHA (256/256 bits)) (Client CN "e33.co.us.ibm.com", Issuer "GeoTrust SSL CA" (not verified)) by ozlabs.org (Postfix) with ESMTPS id 5A7532C0085 for ; Sat, 9 Feb 2013 11:37:04 +1100 (EST) Received: from /spool/local by e33.co.us.ibm.com with IBM ESMTP SMTP Gateway: Authorized Use Only! Violators will be prosecuted for from ; Fri, 8 Feb 2013 17:37:01 -0700 Received: from d03relay05.boulder.ibm.com (d03relay05.boulder.ibm.com [9.17.195.107]) by d03dlp01.boulder.ibm.com (Postfix) with ESMTP id 29B1E1FF0038 for ; Fri, 8 Feb 2013 17:14:42 -0700 (MST) Received: from d03av02.boulder.ibm.com (d03av02.boulder.ibm.com [9.17.195.168]) by d03relay05.boulder.ibm.com (8.13.8/8.13.8/NCO v10.0) with ESMTP id r190Eh9f170924 for ; Fri, 8 Feb 2013 17:14:43 -0700 Received: from d03av02.boulder.ibm.com (loopback [127.0.0.1]) by d03av02.boulder.ibm.com (8.14.4/8.13.1/NCO v10.0 AVout) with ESMTP id r190EeaN026573 for ; Fri, 8 Feb 2013 17:14:43 -0700 Date: Fri, 8 Feb 2013 16:14:39 -0800 From: "Paul E. McKenney" To: "Srivatsa S. Bhat" Subject: Re: [PATCH v5 14/45] rcu, CPU hotplug: Fix comment referring to stop_machine() Message-ID: <20130209001439.GQ2666@linux.vnet.ibm.com> References: <20130122073210.13822.50434.stgit@srivatsabhat.in.ibm.com> <20130122073630.13822.99359.stgit@srivatsabhat.in.ibm.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii In-Reply-To: <20130122073630.13822.99359.stgit@srivatsabhat.in.ibm.com> Cc: linux-doc@vger.kernel.org, peterz@infradead.org, fweisbec@gmail.com, linux-kernel@vger.kernel.org, mingo@kernel.org, linux-arch@vger.kernel.org, linux@arm.linux.org.uk, xiaoguangrong@linux.vnet.ibm.com, wangyun@linux.vnet.ibm.com, nikunj@linux.vnet.ibm.com, linux-pm@vger.kernel.org, rusty@rustcorp.com.au, rostedt@goodmis.org, rjw@sisk.pl, namhyung@kernel.org, tglx@linutronix.de, linux-arm-kernel@lists.infradead.org, netdev@vger.kernel.org, oleg@redhat.com, sbw@mit.edu, tj@kernel.org, akpm@linux-foundation.org, linuxppc-dev@lists.ozlabs.org Reply-To: paulmck@linux.vnet.ibm.com List-Id: Linux on PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , On Tue, Jan 22, 2013 at 01:06:34PM +0530, Srivatsa S. Bhat wrote: > Don't refer to stop_machine() in the CPU hotplug path, since we are going > to get rid of it. Also, move the comment referring to callback adoption > to the CPU_DEAD case, because that's where it happens now. > > Signed-off-by: Srivatsa S. Bhat Ouch! That comment is indeed obsolete and must die. I queued this to -rcu with your Signed-off-by. However, I omitted the added comment, as it is imcomplete -- it is easy to look at rcu_cleanup_dead_cpu() to see what it does. Thanx, Paul > --- > > kernel/rcutree.c | 9 ++++----- > 1 file changed, 4 insertions(+), 5 deletions(-) > > diff --git a/kernel/rcutree.c b/kernel/rcutree.c > index e441b77..ac94474 100644 > --- a/kernel/rcutree.c > +++ b/kernel/rcutree.c > @@ -2827,11 +2827,6 @@ static int __cpuinit rcu_cpu_notify(struct notifier_block *self, > break; > case CPU_DYING: > case CPU_DYING_FROZEN: > - /* > - * The whole machine is "stopped" except this CPU, so we can > - * touch any data without introducing corruption. We send the > - * dying CPU's callbacks to an arbitrarily chosen online CPU. > - */ > for_each_rcu_flavor(rsp) > rcu_cleanup_dying_cpu(rsp); > rcu_cleanup_after_idle(cpu); > @@ -2840,6 +2835,10 @@ static int __cpuinit rcu_cpu_notify(struct notifier_block *self, > case CPU_DEAD_FROZEN: > case CPU_UP_CANCELED: > case CPU_UP_CANCELED_FROZEN: > + /* > + * We send the dead CPU's callbacks to an arbitrarily chosen > + * online CPU. > + */ > for_each_rcu_flavor(rsp) > rcu_cleanup_dead_cpu(cpu, rsp); > break; >