memory_hotplug: handle empty zone when online_movable/online_kernel
Make online_movable/online_kernel can empty a zone or can move memory to a
empty zone.
Signed-off-by: Lai Jiangshan <laijs@cn.fujitsu.com>
Signed-off-by: Wen Congyang <wency@cn.fujitsu.com>
Cc: Yasuaki Ishimatsu <isimatu.yasuaki@jp.fujitsu.com>
Cc: Lai Jiangshan <laijs@cn.fujitsu.com>
Cc: Jiang Liu <jiang.liu@huawei.com>
Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Cc: Minchan Kim <minchan.kim@gmail.com>
Cc: Mel Gorman <mgorman@suse.de>
Cc: David Rientjes <rientjes@google.com>
Cc: Yinghai Lu <yinghai@kernel.org>
Cc: Rusty Russell <rusty@rustcorp.com.au>
Cc: Greg KH <greg@kroah.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
diff --git a/mm/memory_hotplug.c b/mm/memory_hotplug.c
index 5c1f495..c370491 100644
--- a/mm/memory_hotplug.c
+++ b/mm/memory_hotplug.c
@@ -219,8 +219,17 @@
{
zone_span_writelock(zone);
- zone->zone_start_pfn = start_pfn;
- zone->spanned_pages = end_pfn - start_pfn;
+ if (end_pfn - start_pfn) {
+ zone->zone_start_pfn = start_pfn;
+ zone->spanned_pages = end_pfn - start_pfn;
+ } else {
+ /*
+ * make it consist as free_area_init_core(),
+ * if spanned_pages = 0, then keep start_pfn = 0
+ */
+ zone->zone_start_pfn = 0;
+ zone->spanned_pages = 0;
+ }
zone_span_writeunlock(zone);
}
@@ -236,10 +245,19 @@
set_page_links(pfn_to_page(pfn), zid, nid, pfn);
}
-static int move_pfn_range_left(struct zone *z1, struct zone *z2,
+static int __meminit move_pfn_range_left(struct zone *z1, struct zone *z2,
unsigned long start_pfn, unsigned long end_pfn)
{
+ int ret;
unsigned long flags;
+ unsigned long z1_start_pfn;
+
+ if (!z1->wait_table) {
+ ret = init_currently_empty_zone(z1, start_pfn,
+ end_pfn - start_pfn, MEMMAP_HOTPLUG);
+ if (ret)
+ return ret;
+ }
pgdat_resize_lock(z1->zone_pgdat, &flags);
@@ -253,7 +271,13 @@
if (end_pfn <= z2->zone_start_pfn)
goto out_fail;
- resize_zone(z1, z1->zone_start_pfn, end_pfn);
+ /* use start_pfn for z1's start_pfn if z1 is empty */
+ if (z1->spanned_pages)
+ z1_start_pfn = z1->zone_start_pfn;
+ else
+ z1_start_pfn = start_pfn;
+
+ resize_zone(z1, z1_start_pfn, end_pfn);
resize_zone(z2, end_pfn, z2->zone_start_pfn + z2->spanned_pages);
pgdat_resize_unlock(z1->zone_pgdat, &flags);
@@ -266,10 +290,19 @@
return -1;
}
-static int move_pfn_range_right(struct zone *z1, struct zone *z2,
+static int __meminit move_pfn_range_right(struct zone *z1, struct zone *z2,
unsigned long start_pfn, unsigned long end_pfn)
{
+ int ret;
unsigned long flags;
+ unsigned long z2_end_pfn;
+
+ if (!z2->wait_table) {
+ ret = init_currently_empty_zone(z2, start_pfn,
+ end_pfn - start_pfn, MEMMAP_HOTPLUG);
+ if (ret)
+ return ret;
+ }
pgdat_resize_lock(z1->zone_pgdat, &flags);
@@ -283,8 +316,14 @@
if (start_pfn >= z1->zone_start_pfn + z1->spanned_pages)
goto out_fail;
+ /* use end_pfn for z2's end_pfn if z2 is empty */
+ if (z2->spanned_pages)
+ z2_end_pfn = z2->zone_start_pfn + z2->spanned_pages;
+ else
+ z2_end_pfn = end_pfn;
+
resize_zone(z1, z1->zone_start_pfn, start_pfn);
- resize_zone(z2, start_pfn, z2->zone_start_pfn + z2->spanned_pages);
+ resize_zone(z2, start_pfn, z2_end_pfn);
pgdat_resize_unlock(z1->zone_pgdat, &flags);