[PATCH v2 2/7] mm, swap: drop the flag TTRS_DIRECT

Kairui Song
2025-02-24T18:02:58Z

This flag exists temporarily to allow the allocator to bypass the slot
cache during freeing, so reclaiming one slot will free the slot
immediately.

But now we have already removed slot cache usage on freeing, so this
flag has no effect now.

Signed-off-by: Kairui Song <kasong@tencent.com>
Reviewed-by: Baoquan He <bhe@redhat.com>
---
mm/swapfile.c | 23 +++--------------------
1 file changed, 3 insertions(+), 20 deletions(-)

diff --git a/mm/swapfile.c b/mm/swapfile.c
index 5618cd1c4b03..6f2de59c6355 100644
--- a/mm/swapfile.c
+++ b/mm/swapfile.c
@@ -158,8 +158,6 @@ static long swap_usage_in_pages(struct swap_info_struct *si)
#define TTRS_UNMAPPED 0x2
/* Reclaim the swap entry if swap is getting full */
#define TTRS_FULL 0x4
-/* Reclaim directly, bypass the slot cache and don't touch device lock */
-#define TTRS_DIRECT 0x8

static bool swap_only_has_cache(struct swap_info_struct *si,
unsigned long offset, int nr_pages)
@@ -257,23 +255,8 @@ static int __try_to_reclaim_swap(struct swap_info_struct *si,
if (!need_reclaim)
goto out_unlock;

- if (!(flags & TTRS_DIRECT)) {
- /* Free through slot cache */
- delete_from_swap_cache(folio);
- folio_set_dirty(folio);
- ret = nr_pages;
- goto out_unlock;
- }
-
- xa_lock_irq(&address_space->i_pages);
- __delete_from_swap_cache(folio, entry, NULL);
- xa_unlock_irq(&address_space->i_pages);
- folio_ref_sub(folio, nr_pages);
+ delete_from_swap_cache(folio);
folio_set_dirty(folio);
-
- ci = lock_cluster(si, offset);
- swap_entry_range_free(si, ci, entry, nr_pages);
- unlock_cluster(ci);
ret = nr_pages;
out_unlock:
folio_unlock(folio);
@@ -697,7 +680,7 @@ static bool cluster_reclaim_range(struct swap_info_struct *si,
offset++;
break;
case SWAP_HAS_CACHE:
- nr_reclaim = __try_to_reclaim_swap(si, offset, TTRS_ANYWAY | TTRS_DIRECT);
+ nr_reclaim = __try_to_reclaim_swap(si, offset, TTRS_ANYWAY);
if (nr_reclaim > 0)
offset += nr_reclaim;
else
@@ -849,7 +832,7 @@ static void swap_reclaim_full_clusters(struct swap_info_struct *si, bool force)
if (READ_ONCE(map[offset]) == SWAP_HAS_CACHE) {
spin_unlock(&ci->lock);
nr_reclaim = __try_to_reclaim_swap(si, offset,
- TTRS_ANYWAY | TTRS_DIRECT);
+ TTRS_ANYWAY);
spin_lock(&ci->lock);
if (nr_reclaim) {
offset += abs(nr_reclaim);
--
2.48.1