[PATCH RFC 3/6] mm: swap: make should_try_to_free_swap() support large-folio

Barry Song
2024-01-18T11:11:48Z

From: Chuanhua Han <hanchuanhua@oppo.com>

should_try_to_free_swap() works with an assumption that swap-in is always done
at normal page granularity, aka, folio_nr_pages = 1. To support large folio
swap-in, this patch removes the assumption.

Signed-off-by: Chuanhua Han <hanchuanhua@oppo.com>
Co-developed-by: Barry Song <v-songbaohua@oppo.com>
Signed-off-by: Barry Song <v-songbaohua@oppo.com>
---
mm/memory.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/mm/memory.c b/mm/memory.c
index 7e1f4849463a..f61a48929ba7 100644
--- a/mm/memory.c
+++ b/mm/memory.c
@@ -3714,7 +3714,7 @@ static inline bool should_try_to_free_swap(struct folio *folio,
* reference only in case it's likely that we'll be the exlusive user.
*/
return (fault_flags & FAULT_FLAG_WRITE) && !folio_test_ksm(folio) &&
- folio_ref_count(folio) == 2;
+ folio_ref_count(folio) == (1 + folio_nr_pages(folio));
}

static vm_fault_t pte_marker_clear(struct vm_fault *vmf)
--
2.34.1