[PATCH v5 04/10] mm/ksm: use folio in remove_stable_node

From: alexs
Date: Thu Apr 11 2024 - 02:15:23 EST


From: "Alex Shi (tencent)" <alexs@xxxxxxxxxx>

pages in stable tree are all single normal page, so uses ksm_get_folio()
and folio_set_stable_node(), also saves 3 calls to compound_head().

Cc: Izik Eidus <izik.eidus@xxxxxxxxxxxxxxxxxx>
Cc: Matthew Wilcox <willy@xxxxxxxxxxxxx>
Cc: Andrea Arcangeli <aarcange@xxxxxxxxxx>
Cc: Hugh Dickins <hughd@xxxxxxxxxx>
Cc: Chris Wright <chrisw@xxxxxxxxxxxx>
Signed-off-by: Alex Shi (tencent) <alexs@xxxxxxxxxx>
Reviewed-by: David Hildenbrand <david@xxxxxxxxxx>
---
mm/ksm.c | 24 ++++++++++++------------
1 file changed, 12 insertions(+), 12 deletions(-)

diff --git a/mm/ksm.c b/mm/ksm.c
index 3c52bf9df84c..1a7b13004589 100644
--- a/mm/ksm.c
+++ b/mm/ksm.c
@@ -1121,13 +1121,13 @@ static inline void folio_set_stable_node(struct folio *folio,
*/
static int remove_stable_node(struct ksm_stable_node *stable_node)
{
- struct page *page;
+ struct folio *folio;
int err;

- page = get_ksm_page(stable_node, GET_KSM_PAGE_LOCK);
- if (!page) {
+ folio = ksm_get_folio(stable_node, GET_KSM_PAGE_LOCK);
+ if (!folio) {
/*
- * get_ksm_page did remove_node_from_stable_tree itself.
+ * ksm_get_folio did remove_node_from_stable_tree itself.
*/
return 0;
}
@@ -1138,22 +1138,22 @@ static int remove_stable_node(struct ksm_stable_node *stable_node)
* merge_across_nodes/max_page_sharing be switched.
*/
err = -EBUSY;
- if (!page_mapped(page)) {
+ if (!folio_mapped(folio)) {
/*
- * The stable node did not yet appear stale to get_ksm_page(),
- * since that allows for an unmapped ksm page to be recognized
+ * The stable node did not yet appear stale to ksm_get_folio(),
+ * since that allows for an unmapped ksm folio to be recognized
* right up until it is freed; but the node is safe to remove.
- * This page might be in an LRU cache waiting to be freed,
- * or it might be PageSwapCache (perhaps under writeback),
+ * This folio might be in an LRU cache waiting to be freed,
+ * or it might be in the swapcache (perhaps under writeback),
* or it might have been removed from swapcache a moment ago.
*/
- set_page_stable_node(page, NULL);
+ folio_set_stable_node(folio, NULL);
remove_node_from_stable_tree(stable_node);
err = 0;
}

- unlock_page(page);
- put_page(page);
+ folio_unlock(folio);
+ folio_put(folio);
return err;
}

--
2.43.0