[RFC PATCH 0/3] mm/damon: use alloc_migration_target() for DAMOS_MIGRATE_{HOT,COLD}

[RFC PATCH 0/3] mm/damon: use alloc_migration_target() for DAMOS_MIGRATE_{HOT,COLD}

[SeongJae Park]

DAMOS_MIGRATE_{HOT,COLD} implementation resembles that for demotion, and
hence the behavior is also similar to that.  But, since those are not
only for demotion but general migrations, it would be better to match
with that for move_pages() system call.  Make the implementation and the
behavior more similar to move_pages() by not setting migration fallback
nodes, and using alloc_migration_target() instead of
alloc_migrate_folio().

alloc_migrate_folio() was renamed from alloc_demote_folio() and been
non-static function, to let DAMOS_MIGRATE_{HOT,COLD} call it.  As
alloc_migration_target() is called instead, the renaming and non-static
changes are no more required but could only make future code readers
be confused.  Revert the changes, too.

SeongJae Park (3):
  mm/damon/paddr: use alloc_migartion_target() with no migration
    fallback nodemask
  Revert "mm: rename alloc_demote_folio to alloc_migrate_folio"
  Revert "mm: make alloc_demote_folio externally invokable for
    migration"

 mm/damon/paddr.c | 4 +---
 mm/internal.h    | 1 -
 mm/vmscan.c      | 5 +++--
 3 files changed, 4 insertions(+), 6 deletions(-)


base-commit: 7af1516cc219fe5ecc2e2ba01e578a75e955d0b4
-- 
2.39.5

[RFC PATCH 1/3] mm/damon/paddr: use alloc_migartion_target() with no migration fallback nodemask

[SeongJae Park]

DAMOS_MIGRATE_{HOT,COLD} implementation resembles that for
demote_folio_list().  Because those are not only for demotion but
general folio migrations, it makes more sense to behave similarly to
move_pages() system call.  Make the behavior more similar to
move_pages(), by using alloc_migration_target() instead of
alloc_migrate_folio(), without fallback nodemask.

Signed-off-by: SeongJae Park <sj@kernel.org>
---
 mm/damon/paddr.c | 4 +---
 1 file changed, 1 insertion(+), 3 deletions(-)

diff --git a/mm/damon/paddr.c b/mm/damon/paddr.c
index 4102a8c5f992..fcab148e6865 100644
--- a/mm/damon/paddr.c
+++ b/mm/damon/paddr.c
@@ -386,7 +386,6 @@ static unsigned int __damon_pa_migrate_folio_list(
 		int target_nid)
 {
 	unsigned int nr_succeeded = 0;
-	nodemask_t allowed_mask = NODE_MASK_NONE;
 	struct migration_target_control mtc = {
 		/*
 		 * Allocate from 'node', or fail quickly and quietly.
@@ -396,7 +395,6 @@ static unsigned int __damon_pa_migrate_folio_list(
 		.gfp_mask = (GFP_HIGHUSER_MOVABLE & ~__GFP_RECLAIM) |
 			__GFP_NOWARN | __GFP_NOMEMALLOC | GFP_NOWAIT,
 		.nid = target_nid,
-		.nmask = &allowed_mask
 	};
 
 	if (pgdat->node_id == target_nid || target_nid == NUMA_NO_NODE)
@@ -406,7 +404,7 @@ static unsigned int __damon_pa_migrate_folio_list(
 		return 0;
 
 	/* Migration ignores all cpuset and mempolicy settings */
-	migrate_pages(migrate_folios, alloc_migrate_folio, NULL,
+	migrate_pages(migrate_folios, alloc_migration_target, NULL,
 		      (unsigned long)&mtc, MIGRATE_ASYNC, MR_DAMON,
 		      &nr_succeeded);
 
-- 
2.39.5

[RFC PATCH 2/3] Revert "mm: rename alloc_demote_folio to alloc_migrate_folio"

[SeongJae Park]

This reverts commit 8f75267d22bdf8e3baf70f2fa7092d8c2f58da71.

Commit 8f75267d22bd ("mm: rename alloc_demote_folio to
alloc_migrate_folio") was to reflect the fact the function is called for
not only demotion, but also general migrations from
DAMOS_MIGRATE_{HOT,COLD}.  The previous commit made the DAMOS actions to
not use alloc_migrate_folio(), though.  So, demote_folio_list() is the
only caller of alloc_migrate_folio(), and the name could now be rather
confusing.  Revert the renaming commit.

Signed-off-by: SeongJae Park <sj@kernel.org>
---
 mm/internal.h | 2 +-
 mm/vmscan.c   | 4 ++--
 2 files changed, 3 insertions(+), 3 deletions(-)

diff --git a/mm/internal.h b/mm/internal.h
index 71eaea2db9b0..b76b5162314a 100644
--- a/mm/internal.h
+++ b/mm/internal.h
@@ -1227,7 +1227,7 @@ extern unsigned long  __must_check vm_mmap_pgoff(struct file *, unsigned long,
         unsigned long, unsigned long);
 
 extern void set_pageblock_order(void);
-struct folio *alloc_migrate_folio(struct folio *src, unsigned long private);
+struct folio *alloc_demote_folio(struct folio *src, unsigned long private);
 unsigned long reclaim_pages(struct list_head *folio_list);
 unsigned int reclaim_clean_pages_from_list(struct zone *zone,
 					    struct list_head *folio_list);
diff --git a/mm/vmscan.c b/mm/vmscan.c
index a93a1ba9009e..6bebc91cbf2f 100644
--- a/mm/vmscan.c
+++ b/mm/vmscan.c
@@ -1006,7 +1006,7 @@ static void folio_check_dirty_writeback(struct folio *folio,
 		mapping->a_ops->is_dirty_writeback(folio, dirty, writeback);
 }
 
-struct folio *alloc_migrate_folio(struct folio *src, unsigned long private)
+struct folio *alloc_demote_folio(struct folio *src, unsigned long private)
 {
 	struct folio *dst;
 	nodemask_t *allowed_mask;
@@ -1069,7 +1069,7 @@ static unsigned int demote_folio_list(struct list_head *demote_folios,
 	node_get_allowed_targets(pgdat, &allowed_mask);
 
 	/* Demotion ignores all cpuset and mempolicy settings */
-	migrate_pages(demote_folios, alloc_migrate_folio, NULL,
+	migrate_pages(demote_folios, alloc_demote_folio, NULL,
 		      (unsigned long)&mtc, MIGRATE_ASYNC, MR_DEMOTION,
 		      &nr_succeeded);
 
-- 
2.39.5

[RFC PATCH 3/3] Revert "mm: make alloc_demote_folio externally invokable for migration"

[SeongJae Park]

This reverts commit a00ce85af2a1be494d3b0c9457e8e81cdcce2a89.

Commit a00ce85af2a1 ("mm: make alloc_demote_folio externally invokable
for migration") was made to let DAMOS_MIGRATE_{HOT,COLD} call the
function.  But a previous commit made DAMOS_MIGRATE_{HOT,COLD} call
alloc_migration_target() instead.  Hence there are no more callers of
the function outside of vmscan.c.  Revert the commit to make the
function static again.

Signed-off-by: SeongJae Park <sj@kernel.org>
---
 mm/internal.h | 1 -
 mm/vmscan.c   | 3 ++-
 2 files changed, 2 insertions(+), 2 deletions(-)

diff --git a/mm/internal.h b/mm/internal.h
index b76b5162314a..12470ee5f05b 100644
--- a/mm/internal.h
+++ b/mm/internal.h
@@ -1227,7 +1227,6 @@ extern unsigned long  __must_check vm_mmap_pgoff(struct file *, unsigned long,
         unsigned long, unsigned long);
 
 extern void set_pageblock_order(void);
-struct folio *alloc_demote_folio(struct folio *src, unsigned long private);
 unsigned long reclaim_pages(struct list_head *folio_list);
 unsigned int reclaim_clean_pages_from_list(struct zone *zone,
 					    struct list_head *folio_list);
diff --git a/mm/vmscan.c b/mm/vmscan.c
index 6bebc91cbf2f..620dce753b64 100644
--- a/mm/vmscan.c
+++ b/mm/vmscan.c
@@ -1006,7 +1006,8 @@ static void folio_check_dirty_writeback(struct folio *folio,
 		mapping->a_ops->is_dirty_writeback(folio, dirty, writeback);
 }
 
-struct folio *alloc_demote_folio(struct folio *src, unsigned long private)
+static struct folio *alloc_demote_folio(struct folio *src,
+		unsigned long private)
 {
 	struct folio *dst;
 	nodemask_t *allowed_mask;
-- 
2.39.5