From mboxrd@z Thu Jan  1 00:00:00 1970
Return-Path: <linux-kernel-owner@vger.kernel.org>
Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand
	id S1752481Ab0LWKDV (ORCPT <rfc822;w@1wt.eu>);
	Thu, 23 Dec 2010 05:03:21 -0500
Received: from mx1.redhat.com ([209.132.183.28]:32606 "EHLO mx1.redhat.com"
	rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP
	id S1752277Ab0LWKDU (ORCPT <rfc822;linux-kernel@vger.kernel.org>);
	Thu, 23 Dec 2010 05:03:20 -0500
Message-ID: <4D131E42.1000201@redhat.com>
Date: Thu, 23 Dec 2010 18:02:42 +0800
From: Cong Wang <amwang@redhat.com>
User-Agent: Mozilla/5.0 (X11; U; Linux x86_64; en-US; rv:1.9.2.13) Gecko/20101209 Fedora/3.1.7-0.35.b3pre.fc14 Thunderbird/3.1.7
MIME-Version: 1.0
To: Peter Zijlstra <a.p.zijlstra@chello.nl>
CC: linux-kernel@vger.kernel.org, David Howells <dhowells@redhat.com>,
        Koichi Yasutake <yasutake.koichi@jp.panasonic.com>,
        Thomas Gleixner <tglx@linutronix.de>, Ingo Molnar <mingo@redhat.com>,
        "H. Peter Anvin" <hpa@zytor.com>, x86@kernel.org,
        Yinghai Lu <yinghai@kernel.org>, Tejun Heo <tj@kernel.org>,
        Andrew Morton <akpm@linux-foundation.org>,
        Jens Axboe <jaxboe@fusionio.com>,
        Heiko Carstens <heiko.carstens@de.ibm.com>,
        Venkatesh Pallipadi <venki@google.com>, linux-am33-list@redhat.com
Subject: Re: [PATCH] kernel: clean up USE_GENERIC_SMP_HELPERS
References: <1291010778-5669-1-git-send-email-amwang@redhat.com> <1293023333.2170.120.camel@laptop>
In-Reply-To: <1293023333.2170.120.camel@laptop>
Content-Type: text/plain; charset=UTF-8; format=flowed
Content-Transfer-Encoding: 8bit
Sender: linux-kernel-owner@vger.kernel.org
List-ID: <linux-kernel.vger.kernel.org>
X-Mailing-List: linux-kernel@vger.kernel.org

于 2010年12月22日 21:08, Peter Zijlstra 写道:
> On Mon, 2010-11-29 at 14:06 +0800, Amerigo Wang wrote:
>> For arch which needs USE_GENERIC_SMP_HELPERS, it has to
>> select USE_GENERIC_SMP_HELPERS, rather than leaving a choice
>> to user, since they don't provide their own implementions.
>>
>
>>   config MN10300_CURRENT_IN_E2
>> diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig
>> index e330da2..736beea 100644
>> --- a/arch/x86/Kconfig
>> +++ b/arch/x86/Kconfig
>> @@ -65,6 +65,7 @@ config X86
>>   	select HAVE_SPARSE_IRQ
>>   	select GENERIC_IRQ_PROBE
>>   	select GENERIC_PENDING_IRQ if SMP
>> +	select USE_GENERIC_SMP_HELPERS if SMP
>>
>>   config INSTRUCTION_DECODER
>>   	def_bool (KPROBES || PERF_EVENTS)
>> @@ -203,10 +204,6 @@ config HAVE_INTEL_TXT
>>   	def_bool y
>>   	depends on EXPERIMENTAL&&  DMAR&&  ACPI
>>
>> -config USE_GENERIC_SMP_HELPERS
>> -	def_bool y
>> -	depends on SMP
>> -
>>   config X86_32_SMP
>>   	def_bool y
>>   	depends on X86_32&&  SMP
>
> That changelog and the patch don't match, the patch is a total NOP,
> users never see that config option.

Ok, but isn't 'select' is supposed to be better to express this here? :)
This patch also moves on_each_cpu() to kernel/smp.c, btw.

Thanks.