Commit 361a2a22 authored by Minchan Kim's avatar Minchan Kim Committed by Linus Torvalds
Browse files

mm: replace migrate_[prep|finish] with lru_cache_[disable|enable] 

Currently, migrate_[prep|finish] is merely a wrapper of
lru_cache_[disable|enable].  There is not much to gain from having
additional abstraction.

Use lru_cache_[disable|enable] instead of migrate_[prep|finish], which
would be more descriptive.

note: migrate_prep_local in compaction.c changed into lru_add_drain to
avoid CPU schedule cost with involving many other CPUs to keep old
behavior.

Link: https://lkml.kernel.org/r/20210319175127.886124-2-minchan@kernel.org


Signed-off-by: default avatarMinchan Kim <minchan@kernel.org>
Acked-by: default avatarMichal Hocko <mhocko@suse.com>
Reviewed-by: default avatarDavid Hildenbrand <david@redhat.com>
Cc: Chris Goldsworthy <cgoldswo@codeaurora.org>
Cc: John Dias <joaodias@google.com>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Oliver Sang <oliver.sang@intel.com>
Cc: Suren Baghdasaryan <surenb@google.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
parent d479960e

include/linux/migrate.h

+0 −7
Original line number Diff line number Diff line
@@ -45,9 +45,6 @@ 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 void migrate_prep(void);

extern void migrate_finish(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,
@@ -67,10 +64,6 @@ static inline struct page *alloc_migration_target(struct page *page, 
static inline int isolate_movable_page(struct page *page, isolate_mode_t mode)

	{ return -EBUSY; }



static inline int migrate_prep(void) { return -ENOSYS; }

static inline int migrate_finish(void) { return -ENOSYS; }

static inline int migrate_prep_local(void) { return -ENOSYS; }



static inline void migrate_page_states(struct page *newpage, struct page *page)

{

}

mm/compaction.c

+2 −1
Original line number Diff line number Diff line
@@ -2354,7 +2354,8 @@ compact_zone(struct compact_control *cc, struct capture_control *capc) 
	trace_mm_compaction_begin(start_pfn, cc->migrate_pfn,

				cc->free_pfn, end_pfn, sync);



	migrate_prep_local();

	/* lru_add_drain_all could be expensive with involving other CPUs */

	lru_add_drain();



	while ((ret = compact_finished(cc)) == COMPACT_CONTINUE) {

		int err;

mm/mempolicy.c

+4 −4
Original line number Diff line number Diff line
@@ -1124,7 +1124,7 @@ int do_migrate_pages(struct mm_struct *mm, const nodemask_t *from, 
	int err = 0;

	nodemask_t tmp;



	migrate_prep();

	lru_cache_disable();



	mmap_read_lock(mm);
@@ -1209,7 +1209,7 @@ int do_migrate_pages(struct mm_struct *mm, const nodemask_t *from, 
	}

	mmap_read_unlock(mm);



	migrate_finish();

	lru_cache_enable();

	if (err < 0)

		return err;

	return busy;
@@ -1325,7 +1325,7 @@ static long do_mbind(unsigned long start, unsigned long len, 


	if (flags & (MPOL_MF_MOVE | MPOL_MF_MOVE_ALL)) {



		migrate_prep();

		lru_cache_disable();

	}

	{

		NODEMASK_SCRATCH(scratch);
@@ -1374,7 +1374,7 @@ static long do_mbind(unsigned long start, unsigned long len, 
mpol_out:

	mpol_put(new);

	if (flags & (MPOL_MF_MOVE | MPOL_MF_MOVE_ALL))

		migrate_finish();

		lru_cache_enable();

	return err;

}

mm/migrate.c

+2 −26
Original line number Diff line number Diff line
@@ -57,30 +57,6 @@ 


#include "internal.h"



/*

 * migrate_prep() needs to be called before we start compiling a list of pages

 * to be migrated using isolate_lru_page(). If scheduling work on other CPUs is

 * undesirable, use migrate_prep_local()

 */

void migrate_prep(void)

{

	/*

	 * Clear the LRU lists so pages can be isolated.

	 */

	lru_cache_disable();

}



void migrate_finish(void)

{

	lru_cache_enable();

}



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

void migrate_prep_local(void)

{

	lru_add_drain();

}



int isolate_movable_page(struct page *page, isolate_mode_t mode)

{

	struct address_space *mapping;
@@ -1771,7 +1747,7 @@ static int do_pages_move(struct mm_struct *mm, nodemask_t task_nodes, 
	int start, i;

	int err = 0, err1;



	migrate_prep();

	lru_cache_disable();



	for (i = start = 0; i < nr_pages; i++) {

		const void __user *p;
@@ -1840,7 +1816,7 @@ static int do_pages_move(struct mm_struct *mm, nodemask_t task_nodes, 
	if (err >= 0)

		err = err1;

out:

	migrate_finish();

	lru_cache_enable();

	return err;

}

mm/page_alloc.c

+2 −2
Original line number Diff line number Diff line
@@ -8681,7 +8681,7 @@ static int __alloc_contig_migrate_range(struct compact_control *cc, 
		.gfp_mask = GFP_USER | __GFP_MOVABLE | __GFP_RETRY_MAYFAIL,

	};



	migrate_prep();

	lru_cache_disable();



	while (pfn < end || !list_empty(&cc->migratepages)) {

		if (fatal_signal_pending(current)) {
@@ -8716,7 +8716,7 @@ static int __alloc_contig_migrate_range(struct compact_control *cc, 
			break;

	}



	migrate_finish();

	lru_cache_enable();

	if (ret < 0) {

		alloc_contig_dump_pages(&cc->migratepages);

		putback_movable_pages(&cc->migratepages);