Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751801AbZFHET7 (ORCPT ); Mon, 8 Jun 2009 00:19:59 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1750719AbZFHETu (ORCPT ); Mon, 8 Jun 2009 00:19:50 -0400 Received: from e23smtp02.au.ibm.com ([202.81.31.144]:60611 "EHLO e23smtp02.au.ibm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750699AbZFHETu (ORCPT ); Mon, 8 Jun 2009 00:19:50 -0400 Date: Mon, 8 Jun 2009 09:49:34 +0530 From: Gautham R Shenoy To: "Paul E. McKenney" Cc: Lai Jiangshan , Andrew Morton , Rusty Russell , Ingo Molnar , LKML , Peter Zijlstra , Oleg Nesterov , dipankar@in.ibm.com Subject: Re: [PATCH] cpuhotplug: introduce try_get_online_cpus() take 2 Message-ID: <20090608041934.GB17979@in.ibm.com> Reply-To: ego@in.ibm.com References: <4A1F9CEA.1070705@cn.fujitsu.com> <20090530015342.GA21502@linux.vnet.ibm.com> <20090530043739.GA12157@in.ibm.com> <4A27708C.6030703@cn.fujitsu.com> <20090605153714.GB6778@linux.vnet.ibm.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20090605153714.GB6778@linux.vnet.ibm.com> User-Agent: Mutt/1.5.17 (2007-11-01) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1087 Lines: 31 Hi Paul, On Fri, Jun 05, 2009 at 08:37:14AM -0700, Paul E. McKenney wrote: > > One question for Gautham Shenoy -- are non-atomic CPU-hotplug notifiers > always invoked from the task that did the cpu_hotplug_begin()? Except for the notifiers handling two events, rest of the notifiers are always invoked from the task that did the cpu_hotplug_begin(). The two events are CPU_DYING which is called from the context of the stop_machine_thread and CPU_STARTING which is called from the context of the idle thread on the CPU that has just come up. The notifiers handling these two events are expected to be atomic. > If so, well and good. If not, then it would not be possible to > expedite RCU grace periods from within CPU-hotplug notifiers. I hope this would be good enough :-) > > Thanx, Paul > -- Thanks and Regards gautham -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/