[PATCH v9 09/10] mm: migrate: move_pages() supports thp migration

From: Zi Yan
Date: Mon Jul 17 2017 - 15:40:48 EST


From: Naoya Horiguchi <n-horiguchi@xxxxxxxxxxxxx>

This patch enables thp migration for move_pages(2).

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

ChangeLog: v1 -> v5:
- fix page counting

ChangeLog: v5 -> v6:
- drop changes on soft-offline in unmap_and_move()

Signed-off-by: Zi Yan <zi.yan@xxxxxxxxxxxxxx>
---
mm/migrate.c | 45 ++++++++++++++++++++++++++++++++-------------
1 file changed, 32 insertions(+), 13 deletions(-)

diff --git a/mm/migrate.c b/mm/migrate.c
index 0e2916f0c201..fd33aa444f47 100644
--- a/mm/migrate.c
+++ b/mm/migrate.c
@@ -184,8 +184,8 @@ void putback_movable_pages(struct list_head *l)
unlock_page(page);
put_page(page);
} else {
- dec_node_page_state(page, NR_ISOLATED_ANON +
- page_is_file_cache(page));
+ mod_node_page_state(page_pgdat(page), NR_ISOLATED_ANON +
+ page_is_file_cache(page), -hpage_nr_pages(page));
putback_lru_page(page);
}
}
@@ -1145,8 +1145,8 @@ static ICE_noinline int unmap_and_move(new_page_t get_new_page,
* as __PageMovable
*/
if (likely(!__PageMovable(page)))
- dec_node_page_state(page, NR_ISOLATED_ANON +
- page_is_file_cache(page));
+ mod_node_page_state(page_pgdat(page), NR_ISOLATED_ANON +
+ page_is_file_cache(page), -hpage_nr_pages(page));
}

/*
@@ -1420,7 +1420,17 @@ static struct page *new_page_node(struct page *p, unsigned long private,
if (PageHuge(p))
return alloc_huge_page_node(page_hstate(compound_head(p)),
pm->node);
- else
+ else if (thp_migration_supported() && PageTransHuge(p)) {
+ struct page *thp;
+
+ thp = alloc_pages_node(pm->node,
+ (GFP_TRANSHUGE | __GFP_THISNODE) & ~__GFP_RECLAIM,
+ HPAGE_PMD_ORDER);
+ if (!thp)
+ return NULL;
+ prep_transhuge_page(thp);
+ return thp;
+ } else
return __alloc_pages_node(pm->node,
GFP_HIGHUSER_MOVABLE | __GFP_THISNODE, 0);
}
@@ -1447,6 +1457,8 @@ static int do_move_page_to_node_array(struct mm_struct *mm,
for (pp = pm; pp->node != MAX_NUMNODES; pp++) {
struct vm_area_struct *vma;
struct page *page;
+ struct page *head;
+ unsigned int follflags;

err = -EFAULT;
vma = find_vma(mm, pp->addr);
@@ -1454,8 +1466,10 @@ static int do_move_page_to_node_array(struct mm_struct *mm,
goto set_status;

/* FOLL_DUMP to ignore special (like zero) pages */
- page = follow_page(vma, pp->addr,
- FOLL_GET | FOLL_SPLIT | FOLL_DUMP);
+ follflags = FOLL_GET | FOLL_DUMP;
+ if (!thp_migration_supported())
+ follflags |= FOLL_SPLIT;
+ page = follow_page(vma, pp->addr, follflags);

err = PTR_ERR(page);
if (IS_ERR(page))
@@ -1465,7 +1479,6 @@ static int do_move_page_to_node_array(struct mm_struct *mm,
if (!page)
goto set_status;

- pp->page = page;
err = page_to_nid(page);

if (err == pp->node)
@@ -1480,16 +1493,22 @@ static int do_move_page_to_node_array(struct mm_struct *mm,
goto put_and_set;

if (PageHuge(page)) {
- if (PageHead(page))
+ if (PageHead(page)) {
isolate_huge_page(page, &pagelist);
+ err = 0;
+ pp->page = page;
+ }
goto put_and_set;
}

- err = isolate_lru_page(page);
+ pp->page = compound_head(page);
+ head = compound_head(page);
+ err = isolate_lru_page(head);
if (!err) {
- list_add_tail(&page->lru, &pagelist);
- inc_node_page_state(page, NR_ISOLATED_ANON +
- page_is_file_cache(page));
+ list_add_tail(&head->lru, &pagelist);
+ mod_node_page_state(page_pgdat(head),
+ NR_ISOLATED_ANON + page_is_file_cache(head),
+ hpage_nr_pages(head));
}
put_and_set:
/*
--
2.11.0