Since we no longer attempt to write back filesystem folios in pageout()
(they will be filtered out by the following check in pageout()), and only
tmpfs/shmem folios and anonymous swapcache folios can be written back,
we can remove the redundant folio_test_private() when checking the folio's
refcount, as tmpfs/shmem and swapcache folios do not use the PG_private flag.
While we're at it, we can open-code the folio refcount check instead of
adding a simple helper that has only one user.
Acked-by: David Hildenbrand <david@redhat.com>
Acked-by: Shakeel Butt <shakeel.butt@linux.dev>
Signed-off-by: Baolin Wang <baolin.wang@linux.alibaba.com>
---
mm/vmscan.c | 16 ++++------------
1 file changed, 4 insertions(+), 12 deletions(-)
diff --git a/mm/vmscan.c b/mm/vmscan.c
index 930add6d90ab..b3a57db6a445 100644
--- a/mm/vmscan.c
+++ b/mm/vmscan.c
@@ -477,17 +477,6 @@ static int reclaimer_offset(struct scan_control *sc)
return PGSTEAL_DIRECT - PGSTEAL_KSWAPD;
}
-static inline int is_page_cache_freeable(struct folio *folio)
-{
- /*
- * A freeable page cache folio is referenced only by the caller
- * that isolated the folio, the page cache and optional filesystem
- * private data at folio->private.
- */
- return folio_ref_count(folio) - folio_test_private(folio) ==
- 1 + folio_nr_pages(folio);
-}
-
/*
* We detected a synchronous write error writing a folio out. Probably
* -ENOSPC. We need to propagate that into the address_space for a subsequent
@@ -696,8 +685,11 @@ static pageout_t pageout(struct folio *folio, struct address_space *mapping,
* block, for some throttling. This happens by accident, because
* swap_backing_dev_info is bust: it doesn't reflect the
* congestion state of the swapdevs. Easy to fix, if needed.
+ *
+ * A freeable shmem or swapcache folio is referenced only by the
+ * caller that isolated the folio and the page cache.
*/
- if (!is_page_cache_freeable(folio))
+ if (folio_ref_count(folio) != 1 + folio_nr_pages(folio))
return PAGE_KEEP;
if (!mapping) {
/*
--
2.43.7