Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S933757Ab2JaNgJ (ORCPT ); Wed, 31 Oct 2012 09:36:09 -0400 Received: from e7.ny.us.ibm.com ([32.97.182.137]:59020 "EHLO e7.ny.us.ibm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753386Ab2JaNgG (ORCPT ); Wed, 31 Oct 2012 09:36:06 -0400 Date: Wed, 31 Oct 2012 06:35:39 -0700 From: "Paul E. McKenney" To: Shan Wei Cc: dipankar@in.ibm.com, Kernel-Maillist , cl@linux-foundation.org Subject: Re: [PATCH 7/9] rcu: use this_cpu_ptr per-cpu helper instead of per_cpu_ptr(p, raw_smp_processor_id()) Message-ID: <20121031133539.GY3027@linux.vnet.ibm.com> Reply-To: paulmck@linux.vnet.ibm.com References: <50910A17.1090600@gmail.com> <20121031115140.GX3027@linux.vnet.ibm.com> <50912593.8050305@gmail.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <50912593.8050305@gmail.com> User-Agent: Mutt/1.5.21 (2010-09-15) X-Content-Scanned: Fidelis XPS MAILER x-cbid: 12103113-5806-0000-0000-00001B3C24AA Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 762 Lines: 23 On Wed, Oct 31, 2012 at 09:20:19PM +0800, Shan Wei wrote: > Paul E. McKenney said, at 2012/10/31 19:51: > > > > The first uses smp_processor_id(), which will complain if > > force_quiescent_state() is called with preemption disabled, which it > > sometimes is. > > > > So what am I missing here? > > Hi Paul > > this patch is not right for CONFIG_DEBUG_PREEMPT case. > __this_cpu_ptr is ok which do not check for preemption context. Ah, got it. Please feel free to submit an updated patch. Thanx, Paul -- 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/