From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755459AbYIGLER (ORCPT ); Sun, 7 Sep 2008 07:04:17 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1753162AbYIGLEF (ORCPT ); Sun, 7 Sep 2008 07:04:05 -0400 Received: from one.firstfloor.org ([213.235.205.2]:34743 "EHLO one.firstfloor.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753080AbYIGLEE (ORCPT ); Sun, 7 Sep 2008 07:04:04 -0400 Date: Sun, 7 Sep 2008 13:07:29 +0200 From: Andi Kleen To: Manfred Spraul Cc: paulmck@linux.vnet.ibm.com, linux-kernel@vger.kernel.org, cl@linux-foundation.org, mingo@elte.hu, akpm@linux-foundation.org, dipankar@in.ibm.com, josht@linux.vnet.ibm.com, schamp@sgi.com, niv@us.ibm.com, dvhltc@us.ibm.com, ego@in.ibm.com, laijs@cn.fujitsu.com, rostedt@goodmis.org, peterz@infradead.org, penberg@cs.helsinki.fi, andi@firstfloor.org Subject: Re: [RFC, PATCH] Add a CPU_STARTING notifier (was: Re: [PATCH, RFC] v4 scalable classic RCU implementation) Message-ID: <20080907110729.GA26079@one.firstfloor.org> References: <20080821234318.GA1754@linux.vnet.ibm.com> <20080825000738.GA24339@linux.vnet.ibm.com> <20080830004935.GA28548@linux.vnet.ibm.com> <20080905152930.GA8124@linux.vnet.ibm.com> <48C3AA6A.3060402@colorfullife.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <48C3AA6A.3060402@colorfullife.com> User-Agent: Mutt/1.4.2.1i Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org > What about introducing a CPU_STARTING notifier call, similar to CPU_DYING: > - called with disabled interrupts > - called before interrupts are enabled > - must not sleep > - called on the new cpu. > > This might also be useful for something like kvm. I'm not sure if it's > guaranteed that hardware_enable() runs early enough. I would find that useful too. I had several cases where i had to add smp_call_function_single() with a second callback to the CPU_UP notifier, which always seemed ugly. -Andi -- ak@linux.intel.com