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memory-hotplug: fix wrong edge when hot add a new node

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When we add a new node, the edge of memory may be wrong.

e.g. system has 4 nodes, and node3 is movable, node3 mem:[24G-32G],

1. hotremove the node3,
2. then hotadd node3 with a part of memory, mem:[26G-30G],
3. call hotadd_new_pgdat()
        free_area_init_node()
                get_pfn_range_for_nid()
4. it will return wrong start_pfn and end_pfn, because we have not
update the memblock.

This patch also fixes a BUG_ON during hot-addition, please see
http://marc.info/?l=linux-kernel&m=142961156129456&w=2

Signed-off-by: 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: Tang Chen <tangchen@cn.fujitsu.com>
Cc: Gu Zheng <guz.fnst@cn.fujitsu.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This commit is contained in:
Xishi Qiu 2015-08-14 15:35:16 -07:00 committed by Linus Torvalds
parent 2baf9e8948
commit f9126ab924
2 changed files with 11 additions and 0 deletions
repo.diff.show_diff_stats Download patch file Download diff file Expand all files Collapse all files

3
mm/memory_hotplug.c
View file

@ -1277,6 +1277,7 @@ 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;
@ -2013,6 +2014,8 @@ void __ref remove_memory(int nid, u64 start, u64 size)
/* remove memmap entry */
firmware_map_remove(start, start + size, "System RAM");
memblock_free(start, size);
memblock_remove(start, size);
arch_remove_memory(start, size);

8
mm/page_alloc.c
View file

@ -5060,6 +5060,10 @@ static unsigned long __meminit zone_spanned_pages_in_node(int nid,
{
unsigned long zone_start_pfn, zone_end_pfn;
/* When hotadd a new node, the node should be empty */
if (!node_start_pfn && !node_end_pfn)
return 0;
/* Get the start and end of the zone */
zone_start_pfn = arch_zone_lowest_possible_pfn[zone_type];
zone_end_pfn = arch_zone_highest_possible_pfn[zone_type];
@ -5123,6 +5127,10 @@ static unsigned long __meminit zone_absent_pages_in_node(int nid,
unsigned long zone_high = arch_zone_highest_possible_pfn[zone_type];
unsigned long zone_start_pfn, zone_end_pfn;
/* When hotadd a new node, the node should be empty */
if (!node_start_pfn && !node_end_pfn)
return 0;
zone_start_pfn = clamp(node_start_pfn, zone_low, zone_high);
zone_end_pfn = clamp(node_end_pfn, zone_low, zone_high);