From: Wen Congyang <wency@xxxxxxxxxxxxxx>
We call hotadd_new_pgdat() to allocate memory to store node_data. So we
should free it when removing a node.
Signed-off-by: Wen Congyang <wency@xxxxxxxxxxxxxx>
Reviewed-by: Kamezawa Hiroyuki <kamezawa.hiroyu@xxxxxxxxxxxxxx>
---
mm/memory_hotplug.c | 30 +++++++++++++++++++++++++++---
1 files changed, 27 insertions(+), 3 deletions(-)
diff --git a/mm/memory_hotplug.c b/mm/memory_hotplug.c
index a8703f7..8b67752 100644
--- a/mm/memory_hotplug.c
+++ b/mm/memory_hotplug.c
@@ -1699,9 +1699,12 @@ 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);
@@ -1719,7 +1722,7 @@ static void try_offline_node(int nid)
return;
}
- if (stop_machine(check_cpu_on_node, NODE_DATA(nid), NULL))
+ if (stop_machine(check_cpu_on_node, pgdat, NULL))
return;
/*
@@ -1728,6 +1731,27 @@ static void try_offline_node(int nid)
*/
node_set_offline(nid);
unregister_one_node(nid);
+
+ if (!PageSlab(pgdat_page) && !PageCompound(pgdat_page))
+ /* node data is allocated from boot memory */
+ return;
+
+ /* free waittable in each zone */
+ for (i = 0; i < MAX_NR_ZONES; i++) {
+ struct zone *zone = pgdat->node_zones + i;
+
+ if (zone->wait_table)
+ vfree(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)
--
1.7.1
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