Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754053Ab2FEQQI (ORCPT ); Tue, 5 Jun 2012 12:16:08 -0400 Received: from db3ehsobe004.messaging.microsoft.com ([213.199.154.142]:2719 "EHLO db3outboundpool.messaging.microsoft.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753449Ab2FEQQG (ORCPT ); Tue, 5 Jun 2012 12:16:06 -0400 X-Forefront-Antispam-Report: CIP:70.37.183.190;KIP:(null);UIP:(null);IPV:NLI;H:mail.freescale.net;RD:none;EFVD:NLI X-SpamScore: -11 X-BigFish: VS-11(zzbb2dI9371I1432N98dKzz1202hzzz2dh2a8h668h839hd25he5bhf0ah) Message-ID: <4FCE30B8.2070902@freescale.com> Date: Tue, 5 Jun 2012 11:15:52 -0500 From: Scott Wood User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:12.0) Gecko/20120430 Thunderbird/12.0.1 MIME-Version: 1.0 To: Zhao Chenhui CC: , , , Subject: Re: [PATCH v5 2/5] powerpc/85xx: add HOTPLUG_CPU support References: <1336737235-15370-1-git-send-email-chenhui.zhao@freescale.com> <1336737235-15370-2-git-send-email-chenhui.zhao@freescale.com> <4FC933BF.1020901@freescale.com> <20120604110444.GA20676@localhost.localdomain> <4FCCE32F.1060301@freescale.com> <20120605111823.GB22427@localhost.localdomain> In-Reply-To: <20120605111823.GB22427@localhost.localdomain> Content-Type: text/plain; charset="ISO-8859-1" Content-Transfer-Encoding: 7bit X-OriginatorOrg: freescale.com Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1515 Lines: 38 On 06/05/2012 06:18 AM, Zhao Chenhui wrote: > On Mon, Jun 04, 2012 at 11:32:47AM -0500, Scott Wood wrote: >> On 06/04/2012 06:04 AM, Zhao Chenhui wrote: >>> On Fri, Jun 01, 2012 at 04:27:27PM -0500, Scott Wood wrote: >>>> On 05/11/2012 06:53 AM, Zhao Chenhui wrote: >>>>> -#ifdef CONFIG_KEXEC >>>>> +#if defined(CONFIG_KEXEC) || defined(CONFIG_HOTPLUG_CPU) >>>> >>>> Let's not grow lists like this. Is there any harm in building it >>>> unconditionally? >>>> >>>> -Scott >>> >>> We need this ifdef. We only set give_timebase/take_timebase >>> when CONFIG_KEXEC or CONFIG_HOTPLUG_CPU is defined. >> >> If we really need this to be a compile-time decision, make a new symbol >> for it, but I really think this should be decided at runtime. Just >> because we have kexec or hotplug support enabled doesn't mean that's >> actually what we're doing at the moment. >> >> -Scott > > If user does not enable kexec or hotplug, these codes are redundant. > So use CONFIG_KEXEC and CONFIG_HOTPLUG_CPU to gard them. My point is that these lists tend to grow and be a maintenance pain. For small things it's often better to not worry about saving a few bytes. For larger things that need to be conditional, define a new symbol rather than growing ORed lists like this. -Scott -- 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/