Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932295Ab2F1GCF (ORCPT ); Thu, 28 Jun 2012 02:02:05 -0400 Received: from fgwmail5.fujitsu.co.jp ([192.51.44.35]:53882 "EHLO fgwmail5.fujitsu.co.jp" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750789Ab2F1GCD (ORCPT ); Thu, 28 Jun 2012 02:02:03 -0400 X-SecurityPolicyCheck: OK by SHieldMailChecker v1.7.4 Message-ID: <4FEBF342.9030303@jp.fujitsu.com> Date: Thu, 28 Jun 2012 15:01:38 +0900 From: Yasuaki Ishimatsu User-Agent: Mozilla/5.0 (Windows NT 5.1; rv:13.0) Gecko/20120614 Thunderbird/13.0.1 MIME-Version: 1.0 To: KOSAKI Motohiro CC: Wen Congyang , , , , , , , , , , Subject: Re: [RFC PATCH 2/12] memory-hogplug : check memory offline in offline_pages References: <4FEA9C88.1070800@jp.fujitsu.com> <4FEA9DB1.7010303@jp.fujitsu.com> <4FEAC916.7030506@cn.fujitsu.com> <4FEBE646.5090801@jp.fujitsu.com> In-Reply-To: Content-Type: text/plain; charset="ISO-8859-1"; format=flowed Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1467 Lines: 37 Hi Kosaki-san, 2012/06/28 14:27, KOSAKI Motohiro wrote: > On Thu, Jun 28, 2012 at 1:06 AM, Yasuaki Ishimatsu > wrote: >> Hi Wen, >> >> 2012/06/27 17:49, Wen Congyang wrote: >>> At 06/27/2012 01:44 PM, Yasuaki Ishimatsu Wrote: >>>> When offline_pages() is called to offlined memory, the function fails since >>>> all memory has been offlined. In this case, the function should succeed. >>>> The patch adds the check function into offline_pages(). >>> >>> You miss such case: some pages are online, while some pages are offline. >>> offline_pages() will fail too in such case. >> >> You are right. But current code fails, when the function is called to offline >> memory. In this case, the function should succeed. So the patch confirms >> whether the memory was offlined or not. And if memory has already been >> offlined, offline_pages return 0. > > Can you please explain why the caller can't check it? I hope to avoid > an ignorance > as far as we can. Of course, caller side can check it. But there is a possibility that offline_pages() is called by many functions. So I do not think that it is good that all functions which call offline_pages() check it. Thanks, Yasuaki Ishimatsu -- 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/