From: Joonsoo Kim <iamjoonsoo.kim@xxxxxxx>
To calculate the correct node to migrate the page for hotplug, we need
to check node id of the page. Wrapper for alloc_migration_target() exists
for this purpose.
However, Vlastimil informs that all migration source pages come from
a single node. In this case, we don't need to check the node id for each
page and we don't need to re-set the target nodemask for each page by
using the wrapper. Set up the migration_target_control once and use it for
all pages.
Acked-by: Vlastimil Babka <vbabka@xxxxxxx>
Acked-by: Michal Hocko <mhocko@xxxxxxxx>
Signed-off-by: Joonsoo Kim <iamjoonsoo.kim@xxxxxxx>
---
mm/memory_hotplug.c | 46 ++++++++++++++++++++++------------------------
1 file changed, 22 insertions(+), 24 deletions(-)
diff --git a/mm/memory_hotplug.c b/mm/memory_hotplug.c
index 431b470f..7c216d6 100644
--- a/mm/memory_hotplug.c
+++ b/mm/memory_hotplug.c
@@ -1265,27 +1265,6 @@ static int scan_movable_pages(unsigned long start, unsigned long end,
return 0;
}
-static struct page *new_node_page(struct page *page, unsigned long private)
-{
- nodemask_t nmask = node_states[N_MEMORY];
- struct migration_target_control mtc = {
- .nid = page_to_nid(page),
- .nmask = &nmask,
- .gfp_mask = GFP_USER | __GFP_MOVABLE | __GFP_RETRY_MAYFAIL,
- };
-
- /*
- * try to allocate from a different node but reuse this node if there
- * are no other online nodes to be used (e.g. we are offlining a part
- * of the only existing node)
- */
- node_clear(mtc.nid, nmask);
- if (nodes_empty(nmask))
- node_set(mtc.nid, nmask);
-
- return alloc_migration_target(page, (unsigned long)&mtc);
-}
-
static int
do_migrate_range(unsigned long start_pfn, unsigned long end_pfn)
{
@@ -1345,9 +1324,28 @@ do_migrate_range(unsigned long start_pfn, unsigned long end_pfn)
put_page(page);
}
if (!list_empty(&source)) {
- /* Allocate a new page from the nearest neighbor node */
- ret = migrate_pages(&source, new_node_page, NULL, 0,
- MIGRATE_SYNC, MR_MEMORY_HOTPLUG);
+ nodemask_t nmask = node_states[N_MEMORY];
+ struct migration_target_control mtc = {
+ .nmask = &nmask,
+ .gfp_mask = GFP_USER | __GFP_MOVABLE | __GFP_RETRY_MAYFAIL,
+ };
+
+ /*
+ * We have checked that migration range is on a single zone so
+ * we can use the nid of the first page to all the others.
+ */
+ mtc.nid = page_to_nid(list_first_entry(&source, struct page, lru));
+
+ /*
+ * try to allocate from a different node but reuse this node
+ * if there are no other online nodes to be used (e.g. we are
+ * offlining a part of the only existing node)
+ */
+ node_clear(mtc.nid, nmask);
+ if (nodes_empty(nmask))
+ node_set(mtc.nid, nmask);
+ ret = migrate_pages(&source, alloc_migration_target, NULL,
+ (unsigned long)&mtc, MIGRATE_SYNC, MR_MEMORY_HOTPLUG);
if (ret) {
list_for_each_entry(page, &source, lru) {
pr_warn("migrating pfn %lx failed ret:%d ",
--
2.7.4
