From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from psmtp.com (na3sys010amx196.postini.com [74.125.245.196]) by kanga.kvack.org (Postfix) with SMTP id D964A6B0070 for ; Wed, 18 Jul 2012 06:07:59 -0400 (EDT) Received: from m3.gw.fujitsu.co.jp (unknown [10.0.50.73]) by fgwmail6.fujitsu.co.jp (Postfix) with ESMTP id E30093EE0C0 for ; Wed, 18 Jul 2012 19:07:57 +0900 (JST) Received: from smail (m3 [127.0.0.1]) by outgoing.m3.gw.fujitsu.co.jp (Postfix) with ESMTP id CABF445DE7E for ; Wed, 18 Jul 2012 19:07:57 +0900 (JST) Received: from s3.gw.fujitsu.co.jp (s3.gw.fujitsu.co.jp [10.0.50.93]) by m3.gw.fujitsu.co.jp (Postfix) with ESMTP id 741DC45DEB4 for ; Wed, 18 Jul 2012 19:07:57 +0900 (JST) Received: from s3.gw.fujitsu.co.jp (localhost.localdomain [127.0.0.1]) by s3.gw.fujitsu.co.jp (Postfix) with ESMTP id 5F5CD1DB8049 for ; Wed, 18 Jul 2012 19:07:57 +0900 (JST) Received: from g01jpexchyt07.g01.fujitsu.local (g01jpexchyt07.g01.fujitsu.local [10.128.194.46]) by s3.gw.fujitsu.co.jp (Postfix) with ESMTP id 04C7F1DB8042 for ; Wed, 18 Jul 2012 19:07:57 +0900 (JST) Message-ID: <50068AE9.3050804@jp.fujitsu.com> Date: Wed, 18 Jul 2012 19:07:37 +0900 From: Yasuaki Ishimatsu MIME-Version: 1.0 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: owner-linux-mm@kvack.org List-ID: To: linux-mm@kvack.org, linux-kernel@vger.kernel.org, linuxppc-dev@lists.ozlabs.org, linux-acpi@vger.kernel.org Cc: rientjes@google.com, liuj97@gmail.com, len.brown@intel.com, benh@kernel.crashing.org, paulus@samba.org, cl@linux.com, minchan.kim@gmail.com, akpm@linux-foundation.org, kosaki.motohiro@jp.fujitsu.com, wency@cn.fujitsu.com 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; -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: email@kvack.org