[PATCH v4 1/2] mm/migration: make isolate_movable_page always defined

[ysxie]

From: Yisheng Xie <xieyisheng1@xxxxxxxxxx>

Define isolate_movable_page as a static inline function when
CONFIG_MIGRATION is not enable. It should return false
here which means failed to isolate movable pages.

This patch do not have any functional change but prepare for
later patch.

Signed-off-by: Yisheng Xie <xieyisheng1@xxxxxxxxxx>
Cc: Michal Hocko <mhocko@xxxxxxxxxx>
Cc: Minchan Kim <minchan@xxxxxxxxxx>
Cc: Naoya Horiguchi <n-horiguchi@xxxxxxxxxxxxx>
CC: Vlastimil Babka <vbabka@xxxxxxx>
---
 include/linux/migrate.h | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/include/linux/migrate.h b/include/linux/migrate.h
index ae8d475..631a8c8 100644
--- a/include/linux/migrate.h
+++ b/include/linux/migrate.h
@@ -56,6 +56,8 @@ static inline int migrate_pages(struct list_head *l, new_page_t new,
 		free_page_t free, unsigned long private, enum migrate_mode mode,
 		int reason)
 	{ return -ENOSYS; }
+static inline bool isolate_movable_page(struct page *page, isolate_mode_t mode)
+	{ return false; }
 
 static inline int migrate_prep(void) { return -ENOSYS; }
 static inline int migrate_prep_local(void) { return -ENOSYS; }
-- 
1.9.1


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