Commit d822b86a authored by Wen Congyang's avatar Wen Congyang Committed by Linus Torvalds
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memory-hotplug: free node_data when a node is offlined

We call hotadd_new_pgdat() to allocate memory to store node_data.  So we
should free it when removing a node.
Signed-off-by: default avatarWen Congyang <>
Signed-off-by: default avatarTang Chen <>
Reviewed-by: default avatarKamezawa Hiroyuki <>
Cc: KOSAKI Motohiro <>
Cc: Jiang Liu <>
Cc: Jianguo Wu <>
Cc: Lai Jiangshan <>
Cc: Wu Jianguo <>
Cc: Yasuaki Ishimatsu <>
Cc: Ingo Molnar <>
Cc: Thomas Gleixner <>
Cc: "H. Peter Anvin" <>
Signed-off-by: default avatarAndrew Morton <>
Signed-off-by: default avatarLinus Torvalds <>
parent 60a5a19e
......@@ -1700,9 +1700,12 @@ static int check_cpu_on_node(void *data)
/* offline the node if all memory sections of this node are removed */
static void try_offline_node(int nid)
unsigned long start_pfn = NODE_DATA(nid)->node_start_pfn;
unsigned long end_pfn = start_pfn + NODE_DATA(nid)->node_spanned_pages;
pg_data_t *pgdat = NODE_DATA(nid);
unsigned long start_pfn = pgdat->node_start_pfn;
unsigned long end_pfn = start_pfn + pgdat->node_spanned_pages;
unsigned long pfn;
struct page *pgdat_page = virt_to_page(pgdat);
int i;
for (pfn = start_pfn; pfn < end_pfn; pfn += PAGES_PER_SECTION) {
unsigned long section_nr = pfn_to_section_nr(pfn);
......@@ -1720,7 +1723,7 @@ static void try_offline_node(int nid)
if (stop_machine(check_cpu_on_node, NODE_DATA(nid), NULL))
if (stop_machine(check_cpu_on_node, pgdat, NULL))
......@@ -1729,6 +1732,27 @@ static void try_offline_node(int nid)
if (!PageSlab(pgdat_page) && !PageCompound(pgdat_page))
/* node data is allocated from boot memory */
/* free waittable in each zone */
for (i = 0; i < MAX_NR_ZONES; i++) {
struct zone *zone = pgdat->node_zones + i;
if (zone->wait_table)
* Since there is no way to guarentee the address of pgdat/zone is not
* on stack of any kernel threads or used by other kernel objects
* without reference counting or other symchronizing method, do not
* reset node_data and free pgdat here. Just reset it to 0 and reuse
* the memory when the node is online again.
memset(pgdat, 0, sizeof(*pgdat));
int __ref remove_memory(int nid, u64 start, u64 size)
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