From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752636AbbHWRIH (ORCPT ); Sun, 23 Aug 2015 13:08:07 -0400 Received: from cn.fujitsu.com ([59.151.112.132]:49385 "EHLO heian.cn.fujitsu.com" rhost-flags-OK-FAIL-OK-FAIL) by vger.kernel.org with ESMTP id S1752123AbbHWRHt (ORCPT ); Sun, 23 Aug 2015 13:07:49 -0400 X-IronPort-AV: E=Sophos;i="5.15,520,1432569600"; d="scan'208";a="99927678" From: Tang Chen To: , , , , , , , , , , CC: , Subject: [PATCH 1/1] memhp: Add hot-added memory ranges to memblock before allocate node_data for a node. Date: Mon, 24 Aug 2015 01:06:13 +0800 Message-ID: <1440349573-24260-1-git-send-email-tangchen@cn.fujitsu.com> X-Mailer: git-send-email 1.9.3 MIME-Version: 1.0 Content-Type: text/plain X-Originating-IP: [10.167.226.71] Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org The commit below adds hot-added memory range to memblock, after creating pgdat for new node. commit f9126ab9241f66562debf69c2c9d8fee32ddcc53 Author: Xishi Qiu Date: Fri Aug 14 15:35:16 2015 -0700 memory-hotplug: fix wrong edge when hot add a new node But there is a problem: add_memory() |--> hotadd_new_pgdat() |--> free_area_init_node() |--> get_pfn_range_for_nid() |--> find start_pfn and end_pfn in memblock |--> ...... |--> memblock_add_node(start, size, nid) -------- Here, just too late. get_pfn_range_for_nid() will find that start_pfn and end_pfn are both 0. As a result, when adding memory, dmesg will give the following wrong message. [ 2007.577000] Initmem setup node 5 [mem 0x0000000000000000-0xffffffffffffffff] [ 2007.584000] On node 5 totalpages: 0 [ 2007.585000] Built 5 zonelists in Node order, mobility grouping on. Total pages: 32588823 [ 2007.594000] Policy zone: Normal [ 2007.598000] init_memory_mapping: [mem 0x60000000000-0x607ffffffff] The solution is simple, just add the memory range to memblock a little earlier, before hotadd_new_pgdat(). Signed-off-by: Tang Chen --- mm/memory_hotplug.c | 10 +++++++++- 1 file changed, 9 insertions(+), 1 deletion(-) diff --git a/mm/memory_hotplug.c b/mm/memory_hotplug.c index 6da82bc..9b78aff 100644 --- a/mm/memory_hotplug.c +++ b/mm/memory_hotplug.c @@ -1248,6 +1248,14 @@ int __ref add_memory(int nid, u64 start, u64 size) mem_hotplug_begin(); + /* + * Add new range to memblock so that when hotadd_new_pgdat() is called to + * allocate new pgdat, get_pfn_range_for_nid() will be able to find this + * new range and calculate total pages correctly. The range will be remove + * at hot-remove time. + */ + memblock_add_node(start, size, nid); + new_node = !node_online(nid); if (new_node) { pgdat = hotadd_new_pgdat(nid, start); @@ -1277,7 +1285,6 @@ int __ref add_memory(int nid, u64 start, u64 size) /* create new memmap entry */ firmware_map_add_hotplug(start, start + size, "System RAM"); - memblock_add_node(start, size, nid); goto out; @@ -1286,6 +1293,7 @@ error: if (new_pgdat) rollback_node_hotadd(nid, pgdat); release_memory_resource(res); + memblock_remove(start, size); out: mem_hotplug_done(); -- 1.8.3.1