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authorTang Chen <tangchen@cn.fujitsu.com>2015-09-04 15:42:32 -0700
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2015-09-21 10:10:59 -0700
commit42c7443496288aab3504a2e9dc61930cc96f92a5 (patch)
parent95125d513b1a434c00f68276b7484acd59022606 (diff)
memory-hotplug: add hot-added memory ranges to memblock before allocate node_data for a node.
commit 7f36e3e56db1ae75d1e157011b3cb2e0957f0a7e upstream. Commit f9126ab9241f ("memory-hotplug: fix wrong edge when hot add a new node") hot-added memory range to memblock, after creating pgdat for 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. Initmem setup node 5 [mem 0x0000000000000000-0xffffffffffffffff] On node 5 totalpages: 0 Built 5 zonelists in Node order, mobility grouping on. Total pages: 32588823 Policy zone: Normal init_memory_mapping: [mem 0x60000000000-0x607ffffffff] The solution is simple, just add the memory range to memblock a little earlier, before hotadd_new_pgdat(). [akpm@linux-foundation.org: coding-style fixes] Signed-off-by: Tang Chen <tangchen@cn.fujitsu.com> Cc: Xishi Qiu <qiuxishi@huawei.com> Cc: Yasuaki Ishimatsu <isimatu.yasuaki@jp.fujitsu.com> Cc: Kamezawa Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Cc: Taku Izumi <izumi.taku@jp.fujitsu.com> Cc: Gu Zheng <guz.fnst@cn.fujitsu.com> Cc: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com> Cc: Vlastimil Babka <vbabka@suse.cz> Cc: Mel Gorman <mgorman@techsingularity.net> Cc: David Rientjes <rientjes@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
1 files changed, 9 insertions, 1 deletions
diff --git a/mm/memory_hotplug.c b/mm/memory_hotplug.c
index 6da82bcb0a8b..8fd97dac538a 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)
+ /*
+ * 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 removed 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);
+ memblock_remove(start, size);