The patch titled
Subject: memory_hotplug: ensure every online node has NORMAL memory
has been added to the -mm tree. Its filename is
memory_hotplug-ensure-every-online-node-has-normal-memory.patch
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------------------------------------------------------
From: Lai Jiangshan <laijs@xxxxxxxxxxxxxx>
Subject: memory_hotplug: ensure every online node has NORMAL memory
Old memory hotplug code and new online/movable may cause a online node
don't have any normal memory, but memory-management acts bad when we have
nodes which is online but don't have any normal memory. Example: it may
cause a bound task fail on all kernel allocation and cause the task can't
create task or create other kernel object.
So we disable non-normal-memory-node here, we will enable it when we
prepared.
Signed-off-by: Lai Jiangshan <laijs@xxxxxxxxxxxxxx>
Signed-off-by: Wen Congyang <wency@xxxxxxxxxxxxxx>
Cc: Yasuaki Ishimatsu <isimatu.yasuaki@xxxxxxxxxxxxxx>
Cc: Lai Jiangshan <laijs@xxxxxxxxxxxxxx>
Cc: Jiang Liu <jiang.liu@xxxxxxxxxx>
Cc: KOSAKI Motohiro <kosaki.motohiro@xxxxxxxxxxxxxx>
Cc: Minchan Kim <minchan.kim@xxxxxxxxx>
Cc: Mel Gorman <mgorman@xxxxxxx>
Cc: David Rientjes <rientjes@xxxxxxxxxx>
Cc: Yinghai Lu <yinghai@xxxxxxxxxx>
Cc: Rusty Russell <rusty@xxxxxxxxxxxxxxx>
Cc: Greg KH <greg@xxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
mm/memory_hotplug.c | 40 ++++++++++++++++++++++++++++++++++++++++
1 file changed, 40 insertions(+)
diff -puN mm/memory_hotplug.c~memory_hotplug-ensure-every-online-node-has-normal-memory mm/memory_hotplug.c
--- a/mm/memory_hotplug.c~memory_hotplug-ensure-every-online-node-has-normal-memory
+++ a/mm/memory_hotplug.c
@@ -588,6 +588,12 @@ static int online_pages_range(unsigned l
return 0;
}
+/* ensure every online node has NORMAL memory */
+static bool can_online_high_movable(struct zone *zone)
+{
+ return node_state(zone_to_nid(zone), N_NORMAL_MEMORY);
+}
+
/* check which state of node_states will be changed when online memory */
static void node_states_check_changes_online(unsigned long nr_pages,
struct zone *zone, struct memory_notify *arg)
@@ -653,6 +659,12 @@ int __ref online_pages(unsigned long pfn
*/
zone = page_zone(pfn_to_page(pfn));
+ if ((zone_idx(zone) > ZONE_NORMAL || online_type == ONLINE_MOVABLE) &&
+ !can_online_high_movable(zone)) {
+ unlock_memory_hotplug();
+ return -1;
+ }
+
if (online_type == ONLINE_KERNEL && zone_idx(zone) == ZONE_MOVABLE) {
if (move_pfn_range_left(zone - 1, zone, pfn, pfn + nr_pages)) {
unlock_memory_hotplug();
@@ -1061,6 +1073,30 @@ check_pages_isolated(unsigned long start
return offlined;
}
+/* ensure the node has NORMAL memory if it is still online */
+static bool can_offline_normal(struct zone *zone, unsigned long nr_pages)
+{
+ struct pglist_data *pgdat = zone->zone_pgdat;
+ unsigned long present_pages = 0;
+ enum zone_type zt;
+
+ for (zt = 0; zt <= ZONE_NORMAL; zt++)
+ present_pages += pgdat->node_zones[zt].present_pages;
+
+ if (present_pages > nr_pages)
+ return true;
+
+ present_pages = 0;
+ for (; zt <= ZONE_MOVABLE; zt++)
+ present_pages += pgdat->node_zones[zt].present_pages;
+
+ /*
+ * we can't offline the last normal memory until all
+ * higher memory is offlined.
+ */
+ return present_pages == 0;
+}
+
/* check which state of node_states will be changed when offline memory */
static void node_states_check_changes_offline(unsigned long nr_pages,
struct zone *zone, struct memory_notify *arg)
@@ -1148,6 +1184,10 @@ static int __ref __offline_pages(unsigne
node = zone_to_nid(zone);
nr_pages = end_pfn - start_pfn;
+ ret = -EINVAL;
+ if (zone_idx(zone) <= ZONE_NORMAL && !can_offline_normal(zone, nr_pages))
+ goto out;
+
/* set above range as isolated */
ret = start_isolate_page_range(start_pfn, end_pfn,
MIGRATE_MOVABLE, true);
_
Patches currently in -mm which might be from laijs@xxxxxxxxxxxxxx are
linux-next.patch
memory_hotplug-fix-possible-incorrect-node_states.patch
slub-hotplug-ignore-unrelated-nodes-hot-adding-and-hot-removing.patch
drivers-base-nodec-cleanup-node_state_attr.patch
mm-memory-hotplug-dynamic-configure-movable-memory-and-portion-memory.patch
mm-memory-hotplug-dynamic-configure-movable-memory-and-portion-memory-fix.patch
memory_hotplug-handle-empty-zone-when-online_movable-online_kernel.patch
memory_hotplug-ensure-every-online-node-has-normal-memory.patch
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