[PATCH v8 10/10] mm: memory_hotplug: memory hotremove supports thp migration

From: Zi Yan
Date: Sat Jul 01 2017 - 09:41:40 EST


From: Naoya Horiguchi <n-horiguchi@xxxxxxxxxxxxx>

This patch enables thp migration for memory hotremove.

---
ChangeLog v1->v2:
- base code switched from alloc_migrate_target to new_node_page()

Signed-off-by: Naoya Horiguchi <n-horiguchi@xxxxxxxxxxxxx>

ChangeLog v2->v7:
- base code switched from new_node_page() new_page_nodemask()

Signed-off-by: Zi Yan <zi.yan@xxxxxxxxxxxxxx>
---
include/linux/migrate.h | 15 ++++++++++++++-
mm/memory_hotplug.c | 4 +++-
2 files changed, 17 insertions(+), 2 deletions(-)

diff --git a/include/linux/migrate.h b/include/linux/migrate.h
index 67ca33665e83..ff1f76683ee6 100644
--- a/include/linux/migrate.h
+++ b/include/linux/migrate.h
@@ -35,16 +35,29 @@ static inline struct page *new_page_nodemask(struct page *page, int preferred_ni
nodemask_t *nodemask)
{
gfp_t gfp_mask = GFP_USER | __GFP_MOVABLE | __GFP_RETRY_MAYFAIL;
+ unsigned int order = 0;
+ struct page *new_page = NULL;

if (PageHuge(page))
return alloc_huge_page_nodemask(page_hstate(compound_head(page)),
preferred_nid, nodemask);

+ if (thp_migration_supported() && PageTransHuge(page)) {
+ order = HPAGE_PMD_ORDER;
+ gfp_mask |= GFP_TRANSHUGE;
+ }
+
if (PageHighMem(page)
|| (zone_idx(page_zone(page)) == ZONE_MOVABLE))
gfp_mask |= __GFP_HIGHMEM;

- return __alloc_pages_nodemask(gfp_mask, 0, preferred_nid, nodemask);
+ new_page = __alloc_pages_nodemask(gfp_mask, order,
+ preferred_nid, nodemask);
+
+ if (new_page && PageTransHuge(page))
+ prep_transhuge_page(new_page);
+
+ return new_page;
}

#ifdef CONFIG_MIGRATION
diff --git a/mm/memory_hotplug.c b/mm/memory_hotplug.c
index 57b03be3a8da..72110ea2ee1b 100644
--- a/mm/memory_hotplug.c
+++ b/mm/memory_hotplug.c
@@ -1416,7 +1416,9 @@ do_migrate_range(unsigned long start_pfn, unsigned long end_pfn)
if (isolate_huge_page(page, &source))
move_pages -= 1 << compound_order(head);
continue;
- }
+ } else if (thp_migration_supported() && PageTransHuge(page))
+ pfn = page_to_pfn(compound_head(page))
+ + hpage_nr_pages(page) - 1;

if (!get_page_unless_zero(page))
continue;
--
2.11.0