When offline a node in try_offline_node, pgdat is not released. So that
pgdat could be reused in hotadd_new_pgdat. While we re-allocate
pgdat->per_cpu_nodestats if this pgdat is reused.
This patch prevents the memory leak by just allocate per_cpu_nodestats
when it is a new pgdat.
NOTE: This is not tested since I didn't manage to create a case to
offline a whole node. If my analysis is not correct, please let me know.
Signed-off-by: Wei Yang <richardw.yang@xxxxxxxxxxxxxxx>
---
mm/memory_hotplug.c | 10 +++++++++-
1 file changed, 9 insertions(+), 1 deletion(-)
diff --git a/mm/memory_hotplug.c b/mm/memory_hotplug.c
index c73f09913165..efaf9e6f580a 100644
--- a/mm/memory_hotplug.c
+++ b/mm/memory_hotplug.c
@@ -933,8 +933,11 @@ static pg_data_t __ref *hotadd_new_pgdat(int nid, u64 start)
if (!pgdat)
return NULL;
+ pgdat->per_cpu_nodestats =
+ alloc_percpu(struct per_cpu_nodestat);
arch_refresh_nodedata(nid, pgdat);
} else {
+ int cpu;
/*
* Reset the nr_zones, order and classzone_idx before reuse.
* Note that kswapd will init kswapd_classzone_idx properly
@@ -943,6 +946,12 @@ static pg_data_t __ref *hotadd_new_pgdat(int nid, u64 start)
pgdat->nr_zones = 0;
pgdat->kswapd_order = 0;
pgdat->kswapd_classzone_idx = 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));
+ }
}
/* we can use NODE_DATA(nid) from here */
@@ -952,7 +961,6 @@ static pg_data_t __ref *hotadd_new_pgdat(int nid, u64 start)
/* init node's zones as empty zones, we don't have any present pages.*/
free_area_init_core_hotplug(nid);
- pgdat->per_cpu_nodestats = alloc_percpu(struct per_cpu_nodestat);
/*
* The node we allocated has no zone fallback lists. For avoiding
--
2.17.1
