From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753279Ab2GRKIB (ORCPT ); Wed, 18 Jul 2012 06:08:01 -0400 Received: from fgwmail6.fujitsu.co.jp ([192.51.44.36]:54084 "EHLO fgwmail6.fujitsu.co.jp" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752778Ab2GRKH6 (ORCPT ); Wed, 18 Jul 2012 06:07:58 -0400 X-SecurityPolicyCheck: OK by SHieldMailChecker v1.7.4 Message-ID: <50068AE9.3050804@jp.fujitsu.com> Date: Wed, 18 Jul 2012 19:07:37 +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: , , , CC: , , , , , , , , , Subject: [PATCH v4 3/13] memory-hotplug : check whether memory is present or not References: <50068974.1070409@jp.fujitsu.com> In-Reply-To: <50068974.1070409@jp.fujitsu.com> Content-Type: text/plain; charset="ISO-2022-JP" Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org If system supports memory hot-remove, online_pages() may online removed pages. So online_pages() need to check whether onlining pages are present or not. CC: David Rientjes CC: Jiang Liu CC: Len Brown CC: Benjamin Herrenschmidt CC: Paul Mackerras CC: Christoph Lameter Cc: Minchan Kim CC: Andrew Morton CC: KOSAKI Motohiro CC: Wen Congyang Signed-off-by: Yasuaki Ishimatsu --- include/linux/mmzone.h | 21 +++++++++++++++++++++ mm/memory_hotplug.c | 13 +++++++++++++ 2 files changed, 34 insertions(+) Index: linux-3.5-rc6/include/linux/mmzone.h =================================================================== --- linux-3.5-rc6.orig/include/linux/mmzone.h 2012-07-08 09:23:56.000000000 +0900 +++ linux-3.5-rc6/include/linux/mmzone.h 2012-07-17 16:10:21.588186145 +0900 @@ -1168,6 +1168,27 @@ void sparse_init(void); #define sparse_index_init(_sec, _nid) do {} while (0) #endif /* CONFIG_SPARSEMEM */ +#ifdef CONFIG_SPARSEMEM +static inline int pfns_present(unsigned long pfn, unsigned long nr_pages) +{ + int i; + for (i = 0; i < nr_pages; i++) { + if (pfn_present(pfn + 1)) + continue; + else { + unlock_memory_hotplug(); + return -EINVAL; + } + } + return 0; +} +#else +static inline int pfns_present(unsigned long pfn, unsigned long nr_pages) +{ + return 0; +} +#endif /* CONFIG_SPARSEMEM*/ + #ifdef CONFIG_NODES_SPAN_OTHER_NODES bool early_pfn_in_nid(unsigned long pfn, int nid); #else Index: linux-3.5-rc6/mm/memory_hotplug.c =================================================================== --- linux-3.5-rc6.orig/mm/memory_hotplug.c 2012-07-17 14:26:40.000000000 +0900 +++ linux-3.5-rc6/mm/memory_hotplug.c 2012-07-17 16:09:50.070580170 +0900 @@ -467,6 +467,19 @@ int __ref online_pages(unsigned long pfn struct memory_notify arg; lock_memory_hotplug(); + /* + * If system supports memory hot-remove, the memory may have been + * removed. So we check whether the memory has been removed or not. + * + * Note: When CONFIG_SPARSEMEM is defined, pfns_present() become + * effective. If CONFIG_SPARSEMEM is not defined, pfns_present() + * always returns 0. + */ + ret = pfns_present(pfn, nr_pages); + if (ret) { + unlock_memory_hotplug(); + return ret; + } arg.start_pfn = pfn; arg.nr_pages = nr_pages; arg.status_change_nid = -1;