[PATCH v13 111/137] mm/filemap: Convert filemap_get_read_batch to use folios

Matthew Wilcox (Oracle)
2021-07-12T04:08:06Z

The page cache only stores folios, never tail pages. Saves 29 bytes
due to removing calls to compound_head().

Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
---
mm/filemap.c | 23 +++++++++++------------
1 file changed, 11 insertions(+), 12 deletions(-)

diff --git a/mm/filemap.c b/mm/filemap.c
index 4920f52268a3..3d1a8d5f595b 100644
--- a/mm/filemap.c
+++ b/mm/filemap.c
@@ -2272,32 +2272,31 @@ static void filemap_get_read_batch(struct address_space *mapping,
pgoff_t index, pgoff_t max, struct pagevec *pvec)
{
XA_STATE(xas, &mapping->i_pages, index);
- struct page *head;
+ struct folio *folio;

rcu_read_lock();
- for (head = xas_load(&xas); head; head = xas_next(&xas)) {
- if (xas_retry(&xas, head))
+ for (folio = xas_load(&xas); folio; folio = xas_next(&xas)) {
+ if (xas_retry(&xas, folio))
continue;
- if (xas.xa_index > max || xa_is_value(head))
+ if (xas.xa_index > max || xa_is_value(folio))
break;
- if (!page_cache_get_speculative(head))
+ if (!folio_try_get_rcu(folio))
goto retry;

- /* Has the page moved or been split? */
- if (unlikely(head != xas_reload(&xas)))
+ if (unlikely(folio != xas_reload(&xas)))
goto put_page;

- if (!pagevec_add(pvec, head))
+ if (!pagevec_add(pvec, &folio->page))
break;
- if (!PageUptodate(head))
+ if (!folio_uptodate(folio))
break;
- if (PageReadahead(head))
+ if (folio_readahead(folio))
break;
- xas.xa_index = head->index + thp_nr_pages(head) - 1;
+ xas.xa_index = folio->index + folio_nr_pages(folio) - 1;
xas.xa_offset = (xas.xa_index >> xas.xa_shift) & XA_CHUNK_MASK;
continue;
put_page:
- put_page(head);
+ folio_put(folio);
retry:
xas_reset(&xas);
}
--
2.30.2