Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752881Ab2H1KAF (ORCPT ); Tue, 28 Aug 2012 06:00:05 -0400 Received: from cn.fujitsu.com ([222.73.24.84]:56205 "EHLO song.cn.fujitsu.com" rhost-flags-OK-FAIL-OK-OK) by vger.kernel.org with ESMTP id S1752714Ab2H1KAA (ORCPT ); Tue, 28 Aug 2012 06:00:00 -0400 X-IronPort-AV: E=Sophos;i="4.77,841,1336320000"; d="scan'208";a="5739726" From: wency@cn.fujitsu.com To: x86@kernel.org, linux-mm@kvack.org, linux-kernel@vger.kernel.org, linuxppc-dev@lists.ozlabs.org, linux-acpi@vger.kernel.org, linux-s390@vger.kernel.org, linux-sh@vger.kernel.org, linux-ia64@vger.kernel.org, cmetcalf@tilera.com, sparclinux@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, isimatu.yasuaki@jp.fujitsu.com, Wen Congyang Subject: [RFC v8 PATCH 05/20] memory-hotplug: check whether memory is present or not Date: Tue, 28 Aug 2012 18:00:12 +0800 Message-Id: <1346148027-24468-6-git-send-email-wency@cn.fujitsu.com> X-Mailer: git-send-email 1.7.1 In-Reply-To: <1346148027-24468-1-git-send-email-wency@cn.fujitsu.com> References: <1346148027-24468-1-git-send-email-wency@cn.fujitsu.com> X-MIMETrack: Itemize by SMTP Server on mailserver/fnst(Release 8.5.3|September 15, 2011) at 2012/08/28 17:55:07, Serialize by Router on mailserver/fnst(Release 8.5.3|September 15, 2011) at 2012/08/28 17:55:17, Serialize complete at 2012/08/28 17:55:17 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2635 Lines: 83 From: Yasuaki Ishimatsu 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 | 19 +++++++++++++++++++ mm/memory_hotplug.c | 13 +++++++++++++ 2 files changed, 32 insertions(+), 0 deletions(-) diff --git a/include/linux/mmzone.h b/include/linux/mmzone.h index 2daa54f..ac3ae30 100644 --- a/include/linux/mmzone.h +++ b/include/linux/mmzone.h @@ -1180,6 +1180,25 @@ 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 + i)) + continue; + else + 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 diff --git a/mm/memory_hotplug.c b/mm/memory_hotplug.c index 80cded7..3f1d7c5 100644 --- a/mm/memory_hotplug.c +++ b/mm/memory_hotplug.c @@ -467,6 +467,19 @@ int __ref online_pages(unsigned long pfn, unsigned long nr_pages) 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; -- 1.7.1 -- 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/