From: Michal Hocko <mhocko@xxxxxxxx>
When a !node_online node is brought up it needs a hotplug specific
initialization because the node could be either uninitialized yet or it
could have been recycled after previous hotremove. hotadd_init_pgdat is
responsible for that.
Internal pgdat state is initialized at two places currently
- hotadd_init_pgdat
- free_area_init_core_hotplug
There is no real clear cut what should go where but this patch's chosen to
move the whole internal state initialization into free_area_init_core_hotplug.
hotadd_init_pgdat is still responsible to pull all the parts together -
most notably to initialize zonelists because those depend on the
overall topology.
This patch doesn't introduce any functional change.
Acked-by: Rafael Aquini <raquini@xxxxxxxxxx>
Signed-off-by: Michal Hocko <mhocko@xxxxxxxx>
/*
* The node we allocated has no zone fallback lists. For avoiding
@@ -1210,6 +1187,7 @@ static pg_data_t __ref *hotadd_init_pgdat(int nid)
* When memory is hot-added, all the memory is in offline state. So
* clear all zones' present_pages because they will be updated in
* online_pages() and offline_pages().
+ * TODO: should be in free_area_init_core_hotplug?
*/
reset_node_managed_pages(pgdat);
reset_node_present_pages(pgdat);
diff --git a/mm/page_alloc.c b/mm/page_alloc.c
index 1a05669044d3..32d0189de4c5 100644
--- a/mm/page_alloc.c
+++ b/mm/page_alloc.c
@@ -7506,12 +7506,33 @@ static void __meminit
zone_init_internals(struct zone *zone, enum zone_type idx,
* NOTE: this function is only called during memory hotplug
*/
#ifdef CONFIG_MEMORY_HOTPLUG
-void __ref free_area_init_core_hotplug(int nid)
+void __ref free_area_init_core_hotplug(struct pglist_data *pgdat)
{
+ int nid = pgdat->node_id;
enum zone_type z;
- pg_data_t *pgdat = NODE_DATA(nid);
+ int cpu;
pgdat_init_internals(pgdat);
+
+ if (pgdat->per_cpu_nodestats == &boot_nodestats)
+ pgdat->per_cpu_nodestats = alloc_percpu(struct per_cpu_nodestat);
+
+ /*
+ * Reset the nr_zones, order and highest_zoneidx before reuse.
+ * Note that kswapd will init kswapd_highest_zoneidx properly
+ * when it starts in the near future.
+ */
+ pgdat->nr_zones = 0;
+ pgdat->kswapd_order = 0;
+ pgdat->kswapd_highest_zoneidx = 0;
+ pgdat->node_start_pfn = 0;
+ for_each_online_cpu(cpu) {
+ struct per_cpu_nodestat *p;
+
+ p = per_cpu_ptr(pgdat->per_cpu_nodestats, cpu);
+ memset(p, 0, sizeof(*p));
+ }
+