memory-hotplug: more general validation of zone during online
When memory is onlined, we are only able to rezone from ZONE_MOVABLE to
ZONE_KERNEL, or from (ZONE_MOVABLE - 1) to ZONE_MOVABLE.
To be more flexible, use the following criteria instead; to online
memory from zone X into zone Y,
* Any zones between X and Y must be unused.
* If X is lower than Y, the onlined memory must lie at the end of X.
* If X is higher than Y, the onlined memory must lie at the start of X.
Add zone_can_shift() to make this determination.
Link: http://lkml.kernel.org/r/1462816419-4479-3-git-send-email-arbab@linux.vnet.ibm.com
Signed-off-by: Reza Arbab <arbab@linux.vnet.ibm.com>
Reviewd-by: Yasuaki Ishimatsu <isimatu.yasuaki@jp.fujitsu.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Daniel Kiper <daniel.kiper@oracle.com>
Cc: Dan Williams <dan.j.williams@intel.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: Tang Chen <tangchen@cn.fujitsu.com>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: David Vrabel <david.vrabel@citrix.com>
Cc: Vitaly Kuznetsov <vkuznets@redhat.com>
Cc: David Rientjes <rientjes@google.com>
Cc: Andrew Banman <abanman@sgi.com>
Cc: Chen Yucong <slaoub@gmail.com>
Cc: Yasunori Goto <y-goto@jp.fujitsu.com>
Cc: Zhang Zhen <zhenzhang.zhang@huawei.com>
Cc: Shaohua Li <shaohua.li@intel.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 a86a66c..82d0b98 100644
--- a/mm/memory_hotplug.c
+++ b/mm/memory_hotplug.c
@@ -1047,6 +1047,37 @@
node_set_state(node, N_MEMORY);
}
+int zone_can_shift(unsigned long pfn, unsigned long nr_pages,
+ enum zone_type target)
+{
+ struct zone *zone = page_zone(pfn_to_page(pfn));
+ enum zone_type idx = zone_idx(zone);
+ int i;
+
+ if (idx < target) {
+ /* pages must be at end of current zone */
+ if (pfn + nr_pages != zone_end_pfn(zone))
+ return 0;
+
+ /* no zones in use between current zone and target */
+ for (i = idx + 1; i < target; i++)
+ if (zone_is_initialized(zone - idx + i))
+ return 0;
+ }
+
+ if (target < idx) {
+ /* pages must be at beginning of current zone */
+ if (pfn != zone->zone_start_pfn)
+ return 0;
+
+ /* no zones in use between current zone and target */
+ for (i = target + 1; i < idx; i++)
+ if (zone_is_initialized(zone - idx + i))
+ return 0;
+ }
+
+ return target - idx;
+}
/* Must be protected by mem_hotplug_begin() */
int __ref online_pages(unsigned long pfn, unsigned long nr_pages, int online_type)
@@ -1072,13 +1103,10 @@
!can_online_high_movable(zone))
return -EINVAL;
- if (online_type == MMOP_ONLINE_KERNEL &&
- zone_idx(zone) == ZONE_MOVABLE)
- zone_shift = -1;
-
- if (online_type == MMOP_ONLINE_MOVABLE &&
- zone_idx(zone) == ZONE_MOVABLE - 1)
- zone_shift = 1;
+ if (online_type == MMOP_ONLINE_KERNEL)
+ zone_shift = zone_can_shift(pfn, nr_pages, ZONE_NORMAL);
+ else if (online_type == MMOP_ONLINE_MOVABLE)
+ zone_shift = zone_can_shift(pfn, nr_pages, ZONE_MOVABLE);
zone = move_pfn_range(zone_shift, pfn, pfn + nr_pages);
if (!zone)