Move PG_writeback into bottom byte so that it can use PG_waiters in a
later patch. Move PG_head into bottom byte as well to match with where
'order' is moving next. PG_active and PG_workingset move into the second
byte to make room for them.
Signed-off-by: Matthew Wilcox (Oracle) <willy@xxxxxxxxxxxxx>
---
include/linux/page-flags.h | 24 +++++++++++-------------
1 file changed, 11 insertions(+), 13 deletions(-)
diff --git a/include/linux/page-flags.h b/include/linux/page-flags.h
index aabf50dc71a3..6a0dd94b2460 100644
--- a/include/linux/page-flags.h
+++ b/include/linux/page-flags.h
@@ -99,13 +99,15 @@
*/
enum pageflags {
PG_locked, /* Page is locked. Don't touch. */
+ PG_writeback, /* Page is under writeback */
PG_referenced,
PG_uptodate,
PG_dirty,
PG_lru,
+ PG_head, /* Must be in bit 6 */
+ PG_waiters, /* Page has waiters, check its waitqueue. Must be bit #7 and in the same byte as "PG_locked" */
PG_active,
PG_workingset,
- PG_waiters, /* Page has waiters, check its waitqueue. Must be bit #7 and in the same byte as "PG_locked" */
PG_error,
PG_slab,
PG_owner_priv_1, /* Owner use. If pagecache, fs may use*/
@@ -113,8 +115,6 @@ enum pageflags {
PG_reserved,
PG_private, /* If pagecache, has fs-private data */
PG_private_2, /* If pagecache, has fs aux data */
- PG_writeback, /* Page is under writeback */
- PG_head, /* A head page */
PG_mappedtodisk, /* Has blocks allocated on-disk */
PG_reclaim, /* To be reclaimed asap */
PG_swapbacked, /* Page is backed by RAM/swap */
@@ -171,21 +171,19 @@ enum pageflags {
/* Remapped by swiotlb-xen. */
PG_xen_remapped = PG_owner_priv_1,
-#ifdef CONFIG_MEMORY_FAILURE
/*
- * Compound pages. Stored in first tail page's flags.
- * Indicates that at least one subpage is hwpoisoned in the
- * THP.
+ * Flags only valid for compound pages. Stored in first tail page's
+ * flags word.
*/
- PG_has_hwpoisoned = PG_error,
-#endif
-
- /* Is a hugetlb page. Stored in first tail page. */
- PG_hugetlb = PG_writeback,
- /* Has a deferred list (may be empty). First tail page. */
+ /* At least one page is hwpoisoned in the folio. */
+ PG_has_hwpoisoned = PG_error,
+ /* Belongs to hugetlb */
+ PG_hugetlb = PG_active,
+ /* Has a deferred list (does not indicate whether it is active) */
PG_deferred_list = PG_reclaim,
+
/* non-lru isolated movable page */
PG_isolated = PG_reclaim,
--
2.40.1
