memory-hotplug: fix wrong edge when hot add a new node (f9126ab9) · Commits · 戴 / test

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>

mm/memory_hotplug.c

+3 −0

Original line number	Diff line number	Diff line
		@@ -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);

mm/page_alloc.c

+8 −0

Original line number	Diff line number	Diff line
		@@ -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);

Admin message