On 13.08.25 07:05, Lance Yang wrote:
On Mon, Aug 11, 2025 at 10:47 PM David Hildenbrand <da...@redhat.com> wrote:
[...]
+++ b/mm/migrate.c
@@ -1176,16 +1176,6 @@ static int migrate_folio_unmap(new_folio_t get_new_folio,
bool locked = false;
bool dst_locked = false;
- if (folio_ref_count(src) == 1) {
- /* Folio was freed from under us. So we are done. */
- folio_clear_active(src);
- folio_clear_unevictable(src);
- /* free_pages_prepare() will clear PG_isolated. */
- list_del(&src->lru);
- migrate_folio_done(src, reason);
- return MIGRATEPAGE_SUCCESS;
- }
-
dst = get_new_folio(src, private);
if (!dst)
return -ENOMEM;
@@ -1275,7 +1265,7 @@ static int migrate_folio_unmap(new_folio_t get_new_folio,
if (unlikely(page_has_movable_ops(&src->page))) {
__migrate_folio_record(dst, old_page_state, anon_vma);
- return MIGRATEPAGE_UNMAP;
+ return 0;
}
/*
@@ -1305,7 +1295,7 @@ static int migrate_folio_unmap(new_folio_t get_new_folio,
if (!folio_mapped(src)) {
__migrate_folio_record(dst, old_page_state, anon_vma);
- return MIGRATEPAGE_UNMAP;
+ return 0;
}
out:
@@ -1848,14 +1838,28 @@ static int migrate_pages_batch(struct list_head *from,
continue;
}
+ /*
+ * If we are holding the last folio reference, the folio
+ * was freed from under us, so just drop our reference.
+ */
+ if (likely(!page_has_movable_ops(&folio->page)) &&
+ folio_ref_count(folio) == 1) {
+ folio_clear_active(folio);
+ folio_clear_unevictable(folio);
+ list_del(&folio->lru);
+ migrate_folio_done(folio, reason);
+ stats->nr_succeeded += nr_pages;
+ stats->nr_thp_succeeded += is_thp;
+ continue;
+ }
+
It seems the reason parameter is no longer used within migrate_folio_unmap()
after this patch.
Perhaps it could be removed from the function's signature ;)
Thanks, well spotted, @Andrew can you squash the following?
From 40938bb0de20e03250c813d5abc7286aea69d835 Mon Sep 17 00:00:00 2001
From: David Hildenbrand <da...@redhat.com>
Date: Mon, 18 Aug 2025 13:26:05 +0200
Subject: [PATCH] fixup: mm/migrate: remove MIGRATEPAGE_UNMAP
No need to pass "reason" to migrate_folio_unmap().
Signed-off-by: David Hildenbrand <da...@redhat.com>
---
mm/migrate.c | 5 ++---
1 file changed, 2 insertions(+), 3 deletions(-)
diff --git a/mm/migrate.c b/mm/migrate.c
index 2db4974178e6a..aabc736eec022 100644
--- a/mm/migrate.c
+++ b/mm/migrate.c
@@ -1166,7 +1166,7 @@ static void migrate_folio_done(struct folio *src,
static int migrate_folio_unmap(new_folio_t get_new_folio,
free_folio_t put_new_folio, unsigned long private,
struct folio *src, struct folio **dstp, enum migrate_mode mode,
- enum migrate_reason reason, struct list_head *ret)
+ struct list_head *ret)
{
struct folio *dst;
int rc = -EAGAIN;
@@ -1852,8 +1852,7 @@ static int migrate_pages_batch(struct list_head *from,
}
rc = migrate_folio_unmap(get_new_folio, put_new_folio,
- private, folio, &dst, mode, reason,
- ret_folios);
+ private, folio, &dst, mode, ret_folios);
/*
* The rules are:
* 0: folio will be put on unmap_folios list,
--
2.50.1
--
Cheers
David / dhildenb
