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 fix another bug, please see http://marc.info/?l=linux-kernel&m=142961156129456&w=2 Signed-off-by: Xishi Qiu <qiuxishi@xxxxxxxxxx> --- mm/memory_hotplug.c | 3 +++ mm/page_alloc.c | 8 ++++++++ 2 files changed, 11 insertions(+) diff --git a/mm/memory_hotplug.c b/mm/memory_hotplug.c index 26fbba7..11f26cc 100644 --- a/mm/memory_hotplug.c +++ b/mm/memory_hotplug.c @@ -1269,6 +1269,7 @@ 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; @@ -2005,6 +2006,8 @@ 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); diff --git a/mm/page_alloc.c b/mm/page_alloc.c index 1b91d37..7ca12b9 100644 --- a/mm/page_alloc.c +++ b/mm/page_alloc.c @@ -5050,6 +5050,10 @@ 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]; @@ -5113,6 +5117,10 @@ 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); -- 2.0.0 -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@xxxxxxxxx. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: <a href=mailto:"dont@xxxxxxxxx";> email@xxxxxxxxx </a>