Commit 236c32eb authored by Yang Shi's avatar Yang Shi Committed by Linus Torvalds
Browse files

mm: migrate: clean up migrate_prep{_local} 

The migrate_prep{_local} never fails, so it is pointless to have return
value and check the return value.

Link: https://lkml.kernel.org/r/20201113205359.556831-5-shy828301@gmail.com


Signed-off-by: default avatarYang Shi <shy828301@gmail.com>
Reviewed-by: default avatarZi Yan <ziy@nvidia.com>
Cc: Jan Kara <jack@suse.cz>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Mel Gorman <mgorman@suse.de>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Song Liu <songliubraving@fb.com>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
parent c77c5cba

include/linux/migrate.h

+2 −2
Original line number Diff line number Diff line
@@ -45,8 +45,8 @@ extern struct page *alloc_migration_target(struct page *page, unsigned long priv 
extern int isolate_movable_page(struct page *page, isolate_mode_t mode);

extern void putback_movable_page(struct page *page);



extern int migrate_prep(void);

extern int migrate_prep_local(void);

extern void migrate_prep(void);

extern void migrate_prep_local(void);

extern void migrate_page_states(struct page *newpage, struct page *page);

extern void migrate_page_copy(struct page *newpage, struct page *page);

extern int migrate_huge_page_move_mapping(struct address_space *mapping,

mm/mempolicy.c

+2 −6
Original line number Diff line number Diff line
@@ -1114,9 +1114,7 @@ int do_migrate_pages(struct mm_struct *mm, const nodemask_t *from, 
	int err;

	nodemask_t tmp;



	err = migrate_prep();

	if (err)

		return err;

	migrate_prep();



	mmap_read_lock(mm);
@@ -1315,9 +1313,7 @@ static long do_mbind(unsigned long start, unsigned long len, 


	if (flags & (MPOL_MF_MOVE | MPOL_MF_MOVE_ALL)) {



		err = migrate_prep();

		if (err)

			goto mpol_out;

		migrate_prep();

	}

	{

		NODEMASK_SCRATCH(scratch);

mm/migrate.c

+2 −6
Original line number Diff line number Diff line
@@ -62,7 +62,7 @@ 
 * to be migrated using isolate_lru_page(). If scheduling work on other CPUs is

 * undesirable, use migrate_prep_local()

 */

int migrate_prep(void)

void migrate_prep(void)

{

	/*

	 * Clear the LRU lists so pages can be isolated.
@@ -71,16 +71,12 @@ int migrate_prep(void) 
	 * pages that may be busy.

	 */

	lru_add_drain_all();



	return 0;

}



/* Do the necessary work of migrate_prep but not if it involves other CPUs */

int migrate_prep_local(void)

void migrate_prep_local(void)

{

	lru_add_drain();



	return 0;

}



int isolate_movable_page(struct page *page, isolate_mode_t mode)