mm: fix PSWPIN counter for large folios swap-in

Similar to PSWPOUT, we should count the number of base pages instead of
large folios.

Link: https://lkml.kernel.org/r/20241023210201.2798-1-21cnbao@gmail.com
Fixes: 242d12c ("mm: support large folios swap-in for sync io devices")
Signed-off-by: Barry Song <v-songbaohua@oppo.com>
Acked-by: David Hildenbrand <david@redhat.com>
Reviewed-by: Baolin Wang <baolin.wang@linux.alibaba.com>
Cc: Chris Li <chrisl@kernel.org>
Cc: Yosry Ahmed <yosryahmed@google.com>
Cc: "Huang, Ying" <ying.huang@intel.com>
Cc: Kairui Song <kasong@tencent.com>
Cc: Ryan Roberts <ryan.roberts@arm.com>
Cc: Kanchana P Sridhar <kanchana.p.sridhar@intel.com>
Cc: Usama Arif <usamaarif642@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

mm/page_io.c

@@ -570,7 +570,7 @@ static void swap_read_folio_bdev_sync(struct folio *folio,
 	 * attempt to access it in the page fault retry time check.
 	 */
 	get_task_struct(current);
-	count_vm_event(PSWPIN);
+	count_vm_events(PSWPIN, folio_nr_pages(folio));
 	submit_bio_wait(&bio);
 	__end_swap_bio_read(&bio);
 	put_task_struct(current);
@@ -585,7 +585,7 @@ static void swap_read_folio_bdev_async(struct folio *folio,
 	bio->bi_iter.bi_sector = swap_folio_sector(folio);
 	bio->bi_end_io = end_swap_bio_read;
 	bio_add_folio_nofail(bio, folio, folio_size(folio), 0);
-	count_vm_event(PSWPIN);
+	count_vm_events(PSWPIN, folio_nr_pages(folio));
 	submit_bio(bio);
 }