[PATCH v3 2/7] mm/page_owner: add MR_NEVER to enum migrate_reason and use it for last_migrate

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* [PATCH v3 2/7] mm/page_owner: add MR_NEVER to enum migrate_reason and use it for last_migrate_reason
       [not found] <20260630015331.147174-1-ye.liu@linux.dev>
@ 2026-06-30  1:53 ` Ye Liu
  2026-06-30  1:58   ` Zi Yan
  2026-06-30  7:28   ` Vlastimil Babka (SUSE)
  2026-06-30  1:53 ` [PATCH v3 3/7] mm: use enum migrate_reason instead of int for migration reason parameters Ye Liu
  1 sibling, 2 replies; 6+ messages in thread
From: Ye Liu @ 2026-06-30  1:53 UTC (permalink / raw)
  To: Andrew Morton, David Hildenbrand, Steven Rostedt,
	Masami Hiramatsu, Vlastimil Babka
  Cc: Ye Liu, Zi Yan, Matthew Brost, Joshua Hahn, Rakie Kim,
	Byungchul Park, Gregory Price, Ying Huang, Alistair Popple,
	Mathieu Desnoyers, Suren Baghdasaryan, Michal Hocko,
	Brendan Jackman, Johannes Weiner, linux-mm, linux-kernel,
	linux-trace-kernel

The last_migrate_reason field uses -1 as a sentinel value to mean "no
migration has happened".  Replace the four bare -1 occurrences by
adding a proper MR_NEVER member to enum migrate_reason, defining a
corresponding "never_migrated" string in the MIGRATE_REASON trace
macro, and removing the local MIGRATE_REASON_NONE define.

No functional change.

Signed-off-by: Ye Liu <ye.liu@linux.dev>
---
 include/linux/migrate_mode.h   | 1 +
 include/trace/events/migrate.h | 3 ++-
 mm/page_owner.c                | 8 ++++----
 3 files changed, 7 insertions(+), 5 deletions(-)

diff --git a/include/linux/migrate_mode.h b/include/linux/migrate_mode.h
index 265c4328b36a..05102d4d2490 100644
--- a/include/linux/migrate_mode.h
+++ b/include/linux/migrate_mode.h
@@ -25,6 +25,7 @@ enum migrate_reason {
 	MR_LONGTERM_PIN,
 	MR_DEMOTION,
 	MR_DAMON,
+	MR_NEVER,		/* page has never been migrated */
 	MR_TYPES
 };
 
diff --git a/include/trace/events/migrate.h b/include/trace/events/migrate.h
index cd01dd7b3640..11bc0aa14c7e 100644
--- a/include/trace/events/migrate.h
+++ b/include/trace/events/migrate.h
@@ -23,7 +23,8 @@
 	EM( MR_CONTIG_RANGE,	"contig_range")			\
 	EM( MR_LONGTERM_PIN,	"longterm_pin")			\
 	EM( MR_DEMOTION,	"demotion")			\
-	EMe(MR_DAMON,		"damon")
+	EM( MR_DAMON,		"damon")			\
+	EMe(MR_NEVER,		"never_migrated")
 
 /*
  * First define the enums in the above macros to be exported to userspace
diff --git a/mm/page_owner.c b/mm/page_owner.c
index 342549891a8d..c2f43ab860eb 100644
--- a/mm/page_owner.c
+++ b/mm/page_owner.c
@@ -339,7 +339,7 @@ noinline void __set_page_owner(struct page *page, unsigned short order,
 	depot_stack_handle_t handle;
 
 	handle = save_stack(gfp_mask);
-	__update_page_owner_handle(page, handle, order, gfp_mask, -1,
+	__update_page_owner_handle(page, handle, order, gfp_mask, MR_NEVER,
 				   ts_nsec, current->pid, current->tgid,
 				   current->comm);
 	inc_stack_record_count(handle, gfp_mask, 1 << order);
@@ -596,7 +596,7 @@ print_page_owner(char __user *buf, size_t count, unsigned long pfn,
 	if (ret >= count)
 		goto err;
 
-	if (page_owner->last_migrate_reason != -1) {
+	if (page_owner->last_migrate_reason != MR_NEVER) {
 		ret += scnprintf(kbuf + ret, count - ret,
 			"Page has been migrated, last migrate reason: %s\n",
 			migrate_reason_names[page_owner->last_migrate_reason]);
@@ -667,7 +667,7 @@ void __dump_page_owner(const struct page *page)
 		stack_depot_print(handle);
 	}
 
-	if (page_owner->last_migrate_reason != -1)
+	if (page_owner->last_migrate_reason != MR_NEVER)
 		pr_alert("page has been migrated, last migrate reason: %s\n",
 			migrate_reason_names[page_owner->last_migrate_reason]);
 	page_ext_put(page_ext);
@@ -826,7 +826,7 @@ static void init_pages_in_zone(struct zone *zone)
 
 			/* Found early allocated page */
 			__update_page_owner_handle(page, early_handle, 0, 0,
-						   -1, local_clock(), current->pid,
+						   MR_NEVER, local_clock(), current->pid,
 						   current->tgid, current->comm);
 			count++;
 ext_put_continue:
-- 
2.43.0


^ permalink raw reply related	[flat|nested] 6+ messages in thread

* Re: [PATCH v3 2/7] mm/page_owner: add MR_NEVER to enum migrate_reason and use it for last_migrate_reason
  2026-06-30  1:53 ` [PATCH v3 2/7] mm/page_owner: add MR_NEVER to enum migrate_reason and use it for last_migrate_reason Ye Liu
@ 2026-06-30  1:58   ` Zi Yan
  2026-06-30  7:28   ` Vlastimil Babka (SUSE)
  1 sibling, 0 replies; 6+ messages in thread
From: Zi Yan @ 2026-06-30  1:58 UTC (permalink / raw)
  To: Ye Liu, Andrew Morton, David Hildenbrand, Steven Rostedt,
	Masami Hiramatsu, Vlastimil Babka
  Cc: Matthew Brost, Joshua Hahn, Rakie Kim, Byungchul Park,
	Gregory Price, Ying Huang, Alistair Popple, Mathieu Desnoyers,
	Suren Baghdasaryan, Michal Hocko, Brendan Jackman,
	Johannes Weiner, linux-mm, linux-kernel, linux-trace-kernel

On Mon Jun 29, 2026 at 9:53 PM EDT, Ye Liu wrote:
> The last_migrate_reason field uses -1 as a sentinel value to mean "no
> migration has happened".  Replace the four bare -1 occurrences by
> adding a proper MR_NEVER member to enum migrate_reason, defining a
> corresponding "never_migrated" string in the MIGRATE_REASON trace
> macro, and removing the local MIGRATE_REASON_NONE define.
>
> No functional change.
>
> Signed-off-by: Ye Liu <ye.liu@linux.dev>
> ---
>  include/linux/migrate_mode.h   | 1 +
>  include/trace/events/migrate.h | 3 ++-
>  mm/page_owner.c                | 8 ++++----
>  3 files changed, 7 insertions(+), 5 deletions(-)
>

LGTM. Thanks.

Reviewed-by: Zi Yan <ziy@nvidia.com>


-- 
Best Regards,
Yan, Zi


^ permalink raw reply	[flat|nested] 6+ messages in thread

* Re: [PATCH v3 2/7] mm/page_owner: add MR_NEVER to enum migrate_reason and use it for last_migrate_reason
  2026-06-30  1:53 ` [PATCH v3 2/7] mm/page_owner: add MR_NEVER to enum migrate_reason and use it for last_migrate_reason Ye Liu
  2026-06-30  1:58   ` Zi Yan
@ 2026-06-30  7:28   ` Vlastimil Babka (SUSE)
  1 sibling, 0 replies; 6+ messages in thread
From: Vlastimil Babka (SUSE) @ 2026-06-30  7:28 UTC (permalink / raw)
  To: Ye Liu, Andrew Morton, David Hildenbrand, Steven Rostedt,
	Masami Hiramatsu
  Cc: Zi Yan, Matthew Brost, Joshua Hahn, Rakie Kim, Byungchul Park,
	Gregory Price, Ying Huang, Alistair Popple, Mathieu Desnoyers,
	Suren Baghdasaryan, Michal Hocko, Brendan Jackman,
	Johannes Weiner, linux-mm, linux-kernel, linux-trace-kernel

On 6/30/26 03:53, Ye Liu wrote:
> The last_migrate_reason field uses -1 as a sentinel value to mean "no
> migration has happened".  Replace the four bare -1 occurrences by
> adding a proper MR_NEVER member to enum migrate_reason, defining a
> corresponding "never_migrated" string in the MIGRATE_REASON trace
> macro, and removing the local MIGRATE_REASON_NONE define.
> 
> No functional change.
> 
> Signed-off-by: Ye Liu <ye.liu@linux.dev>

Reviewed-by: Vlastimil Babka (SUSE) <vbabka@kernel.org>

> ---
>  include/linux/migrate_mode.h   | 1 +
>  include/trace/events/migrate.h | 3 ++-
>  mm/page_owner.c                | 8 ++++----
>  3 files changed, 7 insertions(+), 5 deletions(-)
> 
> diff --git a/include/linux/migrate_mode.h b/include/linux/migrate_mode.h
> index 265c4328b36a..05102d4d2490 100644
> --- a/include/linux/migrate_mode.h
> +++ b/include/linux/migrate_mode.h
> @@ -25,6 +25,7 @@ enum migrate_reason {
>  	MR_LONGTERM_PIN,
>  	MR_DEMOTION,
>  	MR_DAMON,
> +	MR_NEVER,		/* page has never been migrated */
>  	MR_TYPES
>  };
>  
> diff --git a/include/trace/events/migrate.h b/include/trace/events/migrate.h
> index cd01dd7b3640..11bc0aa14c7e 100644
> --- a/include/trace/events/migrate.h
> +++ b/include/trace/events/migrate.h
> @@ -23,7 +23,8 @@
>  	EM( MR_CONTIG_RANGE,	"contig_range")			\
>  	EM( MR_LONGTERM_PIN,	"longterm_pin")			\
>  	EM( MR_DEMOTION,	"demotion")			\
> -	EMe(MR_DAMON,		"damon")
> +	EM( MR_DAMON,		"damon")			\
> +	EMe(MR_NEVER,		"never_migrated")
>  
>  /*
>   * First define the enums in the above macros to be exported to userspace
> diff --git a/mm/page_owner.c b/mm/page_owner.c
> index 342549891a8d..c2f43ab860eb 100644
> --- a/mm/page_owner.c
> +++ b/mm/page_owner.c
> @@ -339,7 +339,7 @@ noinline void __set_page_owner(struct page *page, unsigned short order,
>  	depot_stack_handle_t handle;
>  
>  	handle = save_stack(gfp_mask);
> -	__update_page_owner_handle(page, handle, order, gfp_mask, -1,
> +	__update_page_owner_handle(page, handle, order, gfp_mask, MR_NEVER,
>  				   ts_nsec, current->pid, current->tgid,
>  				   current->comm);
>  	inc_stack_record_count(handle, gfp_mask, 1 << order);
> @@ -596,7 +596,7 @@ print_page_owner(char __user *buf, size_t count, unsigned long pfn,
>  	if (ret >= count)
>  		goto err;
>  
> -	if (page_owner->last_migrate_reason != -1) {
> +	if (page_owner->last_migrate_reason != MR_NEVER) {
>  		ret += scnprintf(kbuf + ret, count - ret,
>  			"Page has been migrated, last migrate reason: %s\n",
>  			migrate_reason_names[page_owner->last_migrate_reason]);
> @@ -667,7 +667,7 @@ void __dump_page_owner(const struct page *page)
>  		stack_depot_print(handle);
>  	}
>  
> -	if (page_owner->last_migrate_reason != -1)
> +	if (page_owner->last_migrate_reason != MR_NEVER)
>  		pr_alert("page has been migrated, last migrate reason: %s\n",
>  			migrate_reason_names[page_owner->last_migrate_reason]);
>  	page_ext_put(page_ext);
> @@ -826,7 +826,7 @@ static void init_pages_in_zone(struct zone *zone)
>  
>  			/* Found early allocated page */
>  			__update_page_owner_handle(page, early_handle, 0, 0,
> -						   -1, local_clock(), current->pid,
> +						   MR_NEVER, local_clock(), current->pid,
>  						   current->tgid, current->comm);
>  			count++;
>  ext_put_continue:


^ permalink raw reply	[flat|nested] 6+ messages in thread

* [PATCH v3 3/7] mm: use enum migrate_reason instead of int for migration reason parameters
       [not found] <20260630015331.147174-1-ye.liu@linux.dev>
  2026-06-30  1:53 ` [PATCH v3 2/7] mm/page_owner: add MR_NEVER to enum migrate_reason and use it for last_migrate_reason Ye Liu
@ 2026-06-30  1:53 ` Ye Liu
  2026-06-30  2:01   ` Zi Yan
  2026-06-30  7:30   ` Vlastimil Babka (SUSE)
  1 sibling, 2 replies; 6+ messages in thread
From: Ye Liu @ 2026-06-30  1:53 UTC (permalink / raw)
  To: Muchun Song, Oscar Salvador, Andrew Morton, David Hildenbrand,
	Steven Rostedt, Masami Hiramatsu, Vlastimil Babka
  Cc: Ye Liu, Zi Yan, Matthew Brost, Joshua Hahn, Rakie Kim,
	Byungchul Park, Gregory Price, Ying Huang, Alistair Popple,
	Lorenzo Stoakes, Liam R. Howlett, Mike Rapoport,
	Suren Baghdasaryan, Michal Hocko, Mathieu Desnoyers,
	Brendan Jackman, Johannes Weiner, linux-mm, linux-kernel,
	linux-trace-kernel

Replace all 'int reason' function parameters that carry migrate_reason
values with the proper 'enum migrate_reason' type.  This makes the
intent explicit and leverages compiler type checking.  The affected
subsystems are:

  - page_owner: __folio_set_owner_migrate_reason(),
                folio_set_owner_migrate_reason()
  - migrate: migrate_pages(), migrate_pages_sync(),
             migrate_pages_batch(), migrate_folios_move(),
             migrate_hugetlbs(), unmap_and_move_huge_page()
  - hugetlb: move_hugetlb_state(), htlb_allow_alloc_fallback()
  - trace: mm_migrate_pages and mm_migrate_pages_start events

The 'short last_migrate_reason' struct field and internal helper
parameter in page_owner are intentionally left as 'short' since they
store per-page metadata where size matters.

No functional change.

Signed-off-by: Ye Liu <ye.liu@linux.dev>
---
 include/linux/hugetlb.h        |  9 +++++----
 include/linux/migrate.h        |  6 ++++--
 include/linux/page_owner.h     |  7 ++++---
 include/trace/events/migrate.h |  8 ++++----
 mm/hugetlb.c                   |  3 ++-
 mm/migrate.c                   | 12 ++++++------
 mm/page_owner.c                |  2 +-
 7 files changed, 26 insertions(+), 21 deletions(-)

diff --git a/include/linux/hugetlb.h b/include/linux/hugetlb.h
index 2abaf99321e9..fa828232dfcc 100644
--- a/include/linux/hugetlb.h
+++ b/include/linux/hugetlb.h
@@ -154,7 +154,8 @@ long hugetlb_unreserve_pages(struct inode *inode, long start, long end,
 bool folio_isolate_hugetlb(struct folio *folio, struct list_head *list);
 int get_hwpoison_hugetlb_folio(struct folio *folio, bool *hugetlb, bool unpoison);
 void folio_putback_hugetlb(struct folio *folio);
-void move_hugetlb_state(struct folio *old_folio, struct folio *new_folio, int reason);
+void move_hugetlb_state(struct folio *old_folio, struct folio *new_folio,
+			enum migrate_reason reason);
 void hugetlb_fix_reserve_counts(struct inode *inode);
 extern struct mutex *hugetlb_fault_mutex_table;
 u32 hugetlb_fault_mutex_hash(struct address_space *mapping, pgoff_t idx);
@@ -424,7 +425,7 @@ static inline void folio_putback_hugetlb(struct folio *folio)
 }
 
 static inline void move_hugetlb_state(struct folio *old_folio,
-					struct folio *new_folio, int reason)
+					struct folio *new_folio, enum migrate_reason reason)
 {
 }
 
@@ -956,7 +957,7 @@ static inline gfp_t htlb_modify_alloc_mask(struct hstate *h, gfp_t gfp_mask)
 	return modified_mask;
 }
 
-static inline bool htlb_allow_alloc_fallback(int reason)
+static inline bool htlb_allow_alloc_fallback(enum migrate_reason reason)
 {
 	bool allowed_fallback = false;
 
@@ -1238,7 +1239,7 @@ static inline gfp_t htlb_modify_alloc_mask(struct hstate *h, gfp_t gfp_mask)
 	return 0;
 }
 
-static inline bool htlb_allow_alloc_fallback(int reason)
+static inline bool htlb_allow_alloc_fallback(enum migrate_reason reason)
 {
 	return false;
 }
diff --git a/include/linux/migrate.h b/include/linux/migrate.h
index d5af2b7f577b..1f83924615d6 100644
--- a/include/linux/migrate.h
+++ b/include/linux/migrate.h
@@ -57,7 +57,8 @@ void putback_movable_pages(struct list_head *l);
 int migrate_folio(struct address_space *mapping, struct folio *dst,
 		struct folio *src, enum migrate_mode mode);
 int migrate_pages(struct list_head *l, new_folio_t new, free_folio_t free,
-		  unsigned long private, enum migrate_mode mode, int reason,
+		  unsigned long private, enum migrate_mode mode,
+		  enum migrate_reason reason,
 		  unsigned int *ret_succeeded);
 struct folio *alloc_migration_target(struct folio *src, unsigned long private);
 bool isolate_movable_ops_page(struct page *page, isolate_mode_t mode);
@@ -77,7 +78,8 @@ int set_movable_ops(const struct movable_operations *ops, enum pagetype type);
 static inline void putback_movable_pages(struct list_head *l) {}
 static inline int migrate_pages(struct list_head *l, new_folio_t new,
 		free_folio_t free, unsigned long private,
-		enum migrate_mode mode, int reason, unsigned int *ret_succeeded)
+		enum migrate_mode mode, enum migrate_reason reason,
+		unsigned int *ret_succeeded)
 	{ return -ENOSYS; }
 static inline struct folio *alloc_migration_target(struct folio *src,
 		unsigned long private)
diff --git a/include/linux/page_owner.h b/include/linux/page_owner.h
index 3328357f6dba..9fe51dfccf26 100644
--- a/include/linux/page_owner.h
+++ b/include/linux/page_owner.h
@@ -3,6 +3,7 @@
 #define __LINUX_PAGE_OWNER_H
 
 #include <linux/jump_label.h>
+#include <linux/migrate_mode.h>
 
 #ifdef CONFIG_PAGE_OWNER
 extern struct static_key_false page_owner_inited;
@@ -14,7 +15,7 @@ extern void __set_page_owner(struct page *page,
 extern void __split_page_owner(struct page *page, int old_order,
 			int new_order);
 extern void __folio_copy_owner(struct folio *newfolio, struct folio *old);
-extern void __folio_set_owner_migrate_reason(struct folio *folio, int reason);
+extern void __folio_set_owner_migrate_reason(struct folio *folio, enum migrate_reason reason);
 extern void __dump_page_owner(const struct page *page);
 extern void pagetypeinfo_showmixedcount_print(struct seq_file *m,
 					pg_data_t *pgdat, struct zone *zone);
@@ -43,7 +44,7 @@ static inline void folio_copy_owner(struct folio *newfolio, struct folio *old)
 	if (static_branch_unlikely(&page_owner_inited))
 		__folio_copy_owner(newfolio, old);
 }
-static inline void folio_set_owner_migrate_reason(struct folio *folio, int reason)
+static inline void folio_set_owner_migrate_reason(struct folio *folio, enum migrate_reason reason)
 {
 	if (static_branch_unlikely(&page_owner_inited))
 		__folio_set_owner_migrate_reason(folio, reason);
@@ -68,7 +69,7 @@ static inline void split_page_owner(struct page *page, int old_order,
 static inline void folio_copy_owner(struct folio *newfolio, struct folio *folio)
 {
 }
-static inline void folio_set_owner_migrate_reason(struct folio *folio, int reason)
+static inline void folio_set_owner_migrate_reason(struct folio *folio, enum migrate_reason reason)
 {
 }
 static inline void dump_page_owner(const struct page *page)
diff --git a/include/trace/events/migrate.h b/include/trace/events/migrate.h
index 11bc0aa14c7e..15ee2ef201b5 100644
--- a/include/trace/events/migrate.h
+++ b/include/trace/events/migrate.h
@@ -52,7 +52,7 @@ TRACE_EVENT(mm_migrate_pages,
 	TP_PROTO(unsigned long succeeded, unsigned long failed,
 		 unsigned long thp_succeeded, unsigned long thp_failed,
 		 unsigned long thp_split, unsigned long large_folio_split,
-		 enum migrate_mode mode, int reason),
+		 enum migrate_mode mode, enum migrate_reason reason),
 
 	TP_ARGS(succeeded, failed, thp_succeeded, thp_failed,
 		thp_split, large_folio_split, mode, reason),
@@ -65,7 +65,7 @@ TRACE_EVENT(mm_migrate_pages,
 		__field(	unsigned long,		thp_split)
 		__field(	unsigned long,		large_folio_split)
 		__field(	enum migrate_mode,	mode)
-		__field(	int,			reason)
+		__field(	enum migrate_reason,	reason)
 	),
 
 	TP_fast_assign(
@@ -92,13 +92,13 @@ TRACE_EVENT(mm_migrate_pages,
 
 TRACE_EVENT(mm_migrate_pages_start,
 
-	TP_PROTO(enum migrate_mode mode, int reason),
+	TP_PROTO(enum migrate_mode mode, enum migrate_reason reason),
 
 	TP_ARGS(mode, reason),
 
 	TP_STRUCT__entry(
 		__field(enum migrate_mode, mode)
-		__field(int, reason)
+		__field(enum migrate_reason, reason)
 	),
 
 	TP_fast_assign(
diff --git a/mm/hugetlb.c b/mm/hugetlb.c
index 571212b80835..17732d1fdc5e 100644
--- a/mm/hugetlb.c
+++ b/mm/hugetlb.c
@@ -7182,7 +7182,8 @@ void folio_putback_hugetlb(struct folio *folio)
 	folio_put(folio);
 }
 
-void move_hugetlb_state(struct folio *old_folio, struct folio *new_folio, int reason)
+void move_hugetlb_state(struct folio *old_folio, struct folio *new_folio,
+			enum migrate_reason reason)
 {
 	struct hstate *h = folio_hstate(old_folio);
 
diff --git a/mm/migrate.c b/mm/migrate.c
index d9b23909d716..49e10feeb094 100644
--- a/mm/migrate.c
+++ b/mm/migrate.c
@@ -1469,7 +1469,7 @@ static int migrate_folio_move(free_folio_t put_new_folio, unsigned long private,
 static int unmap_and_move_huge_page(new_folio_t get_new_folio,
 		free_folio_t put_new_folio, unsigned long private,
 		struct folio *src, int force, enum migrate_mode mode,
-		int reason, struct list_head *ret)
+		enum migrate_reason reason, struct list_head *ret)
 {
 	struct folio *dst;
 	int rc = -EAGAIN;
@@ -1626,7 +1626,7 @@ struct migrate_pages_stats {
  */
 static int migrate_hugetlbs(struct list_head *from, new_folio_t get_new_folio,
 			    free_folio_t put_new_folio, unsigned long private,
-			    enum migrate_mode mode, int reason,
+			    enum migrate_mode mode, enum migrate_reason reason,
 			    struct migrate_pages_stats *stats,
 			    struct list_head *ret_folios)
 {
@@ -1716,7 +1716,7 @@ static int migrate_hugetlbs(struct list_head *from, new_folio_t get_new_folio,
 static void migrate_folios_move(struct list_head *src_folios,
 		struct list_head *dst_folios,
 		free_folio_t put_new_folio, unsigned long private,
-		enum migrate_mode mode, int reason,
+		enum migrate_mode mode, enum migrate_reason reason,
 		struct list_head *ret_folios,
 		struct migrate_pages_stats *stats,
 		int *retry, int *thp_retry, int *nr_failed,
@@ -1799,7 +1799,7 @@ static void migrate_folios_undo(struct list_head *src_folios,
  */
 static int migrate_pages_batch(struct list_head *from,
 		new_folio_t get_new_folio, free_folio_t put_new_folio,
-		unsigned long private, enum migrate_mode mode, int reason,
+		unsigned long private, enum migrate_mode mode, enum migrate_reason reason,
 		struct list_head *ret_folios, struct list_head *split_folios,
 		struct migrate_pages_stats *stats, int nr_pass)
 {
@@ -2011,7 +2011,7 @@ static int migrate_pages_batch(struct list_head *from,
 
 static int migrate_pages_sync(struct list_head *from, new_folio_t get_new_folio,
 		free_folio_t put_new_folio, unsigned long private,
-		enum migrate_mode mode, int reason,
+		enum migrate_mode mode, enum migrate_reason reason,
 		struct list_head *ret_folios, struct list_head *split_folios,
 		struct migrate_pages_stats *stats)
 {
@@ -2088,7 +2088,7 @@ static int migrate_pages_sync(struct list_head *from, new_folio_t get_new_folio,
  */
 int migrate_pages(struct list_head *from, new_folio_t get_new_folio,
 		free_folio_t put_new_folio, unsigned long private,
-		enum migrate_mode mode, int reason, unsigned int *ret_succeeded)
+		enum migrate_mode mode, enum migrate_reason reason, unsigned int *ret_succeeded)
 {
 	int rc, rc_gather;
 	int nr_pages;
diff --git a/mm/page_owner.c b/mm/page_owner.c
index c2f43ab860eb..4e352941a6e2 100644
--- a/mm/page_owner.c
+++ b/mm/page_owner.c
@@ -345,7 +345,7 @@ noinline void __set_page_owner(struct page *page, unsigned short order,
 	inc_stack_record_count(handle, gfp_mask, 1 << order);
 }
 
-void __folio_set_owner_migrate_reason(struct folio *folio, int reason)
+void __folio_set_owner_migrate_reason(struct folio *folio, enum migrate_reason reason)
 {
 	struct page_ext *page_ext = page_ext_get(&folio->page);
 	struct page_owner *page_owner;
-- 
2.43.0


^ permalink raw reply related	[flat|nested] 6+ messages in thread

* Re: [PATCH v3 3/7] mm: use enum migrate_reason instead of int for migration reason parameters
  2026-06-30  1:53 ` [PATCH v3 3/7] mm: use enum migrate_reason instead of int for migration reason parameters Ye Liu
@ 2026-06-30  2:01   ` Zi Yan
  2026-06-30  7:30   ` Vlastimil Babka (SUSE)
  1 sibling, 0 replies; 6+ messages in thread
From: Zi Yan @ 2026-06-30  2:01 UTC (permalink / raw)
  To: Ye Liu, Muchun Song, Oscar Salvador, Andrew Morton,
	David Hildenbrand, Steven Rostedt, Masami Hiramatsu,
	Vlastimil Babka
  Cc: Matthew Brost, Joshua Hahn, Rakie Kim, Byungchul Park,
	Gregory Price, Ying Huang, Alistair Popple, Lorenzo Stoakes,
	Liam R. Howlett, Mike Rapoport, Suren Baghdasaryan, Michal Hocko,
	Mathieu Desnoyers, Brendan Jackman, Johannes Weiner, linux-mm,
	linux-kernel, linux-trace-kernel

On Mon Jun 29, 2026 at 9:53 PM EDT, Ye Liu wrote:
> Replace all 'int reason' function parameters that carry migrate_reason
> values with the proper 'enum migrate_reason' type.  This makes the
> intent explicit and leverages compiler type checking.  The affected
> subsystems are:
>
>   - page_owner: __folio_set_owner_migrate_reason(),
>                 folio_set_owner_migrate_reason()
>   - migrate: migrate_pages(), migrate_pages_sync(),
>              migrate_pages_batch(), migrate_folios_move(),
>              migrate_hugetlbs(), unmap_and_move_huge_page()
>   - hugetlb: move_hugetlb_state(), htlb_allow_alloc_fallback()
>   - trace: mm_migrate_pages and mm_migrate_pages_start events
>
> The 'short last_migrate_reason' struct field and internal helper
> parameter in page_owner are intentionally left as 'short' since they
> store per-page metadata where size matters.
>
> No functional change.
>
> Signed-off-by: Ye Liu <ye.liu@linux.dev>
> ---
>  include/linux/hugetlb.h        |  9 +++++----
>  include/linux/migrate.h        |  6 ++++--
>  include/linux/page_owner.h     |  7 ++++---
>  include/trace/events/migrate.h |  8 ++++----
>  mm/hugetlb.c                   |  3 ++-
>  mm/migrate.c                   | 12 ++++++------
>  mm/page_owner.c                |  2 +-
>  7 files changed, 26 insertions(+), 21 deletions(-)
>

LGTM. Thanks.
Reviewed-by: Zi Yan <ziy@nvidia.com>

-- 
Best Regards,
Yan, Zi


^ permalink raw reply	[flat|nested] 6+ messages in thread

* Re: [PATCH v3 3/7] mm: use enum migrate_reason instead of int for migration reason parameters
  2026-06-30  1:53 ` [PATCH v3 3/7] mm: use enum migrate_reason instead of int for migration reason parameters Ye Liu
  2026-06-30  2:01   ` Zi Yan
@ 2026-06-30  7:30   ` Vlastimil Babka (SUSE)
  1 sibling, 0 replies; 6+ messages in thread
From: Vlastimil Babka (SUSE) @ 2026-06-30  7:30 UTC (permalink / raw)
  To: Ye Liu, Muchun Song, Oscar Salvador, Andrew Morton,
	David Hildenbrand, Steven Rostedt, Masami Hiramatsu
  Cc: Zi Yan, Matthew Brost, Joshua Hahn, Rakie Kim, Byungchul Park,
	Gregory Price, Ying Huang, Alistair Popple, Lorenzo Stoakes,
	Liam R. Howlett, Mike Rapoport, Suren Baghdasaryan, Michal Hocko,
	Mathieu Desnoyers, Brendan Jackman, Johannes Weiner, linux-mm,
	linux-kernel, linux-trace-kernel

On 6/30/26 03:53, Ye Liu wrote:
> Replace all 'int reason' function parameters that carry migrate_reason
> values with the proper 'enum migrate_reason' type.  This makes the
> intent explicit and leverages compiler type checking.  The affected
> subsystems are:
> 
>   - page_owner: __folio_set_owner_migrate_reason(),
>                 folio_set_owner_migrate_reason()
>   - migrate: migrate_pages(), migrate_pages_sync(),
>              migrate_pages_batch(), migrate_folios_move(),
>              migrate_hugetlbs(), unmap_and_move_huge_page()
>   - hugetlb: move_hugetlb_state(), htlb_allow_alloc_fallback()
>   - trace: mm_migrate_pages and mm_migrate_pages_start events
> 
> The 'short last_migrate_reason' struct field and internal helper
> parameter in page_owner are intentionally left as 'short' since they
> store per-page metadata where size matters.
> 
> No functional change.
> 
> Signed-off-by: Ye Liu <ye.liu@linux.dev>

Reviewed-by: Vlastimil Babka (SUSE) <vbabka@kernel.org>


^ permalink raw reply	[flat|nested] 6+ messages in thread

end of thread, other threads:[~2026-06-30  7:30 UTC | newest]

Thread overview: 6+ messages (download: mbox.gz follow: Atom feed
-- links below jump to the message on this page --
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2026-06-30  1:53 ` [PATCH v3 2/7] mm/page_owner: add MR_NEVER to enum migrate_reason and use it for last_migrate_reason Ye Liu
2026-06-30  1:58   ` Zi Yan
2026-06-30  7:28   ` Vlastimil Babka (SUSE)
2026-06-30  1:53 ` [PATCH v3 3/7] mm: use enum migrate_reason instead of int for migration reason parameters Ye Liu
2026-06-30  2:01   ` Zi Yan
2026-06-30  7:30   ` Vlastimil Babka (SUSE)

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