[PATCH v2 1/3] mm: remove activate_page() from unuse_pte()

[Yu Zhao]

We don't initially add anon pages to active lruvec after
commit b518154e59aa ("mm/vmscan: protect the workingset on anonymous LRU").
Remove activate_page() from unuse_pte(), which seems to be missed by
the commit. And make the function static while we are at it.

Before the commit, we called lru_cache_add_active_or_unevictable() to
add new ksm pages to active lruvec. Therefore, activate_page() wasn't
necessary for them in the first place.

Signed-off-by: Yu Zhao <yuzhao@xxxxxxxxxx>
---
 include/linux/swap.h | 1 -
 mm/swap.c            | 4 ++--
 mm/swapfile.c        | 5 -----
 3 files changed, 2 insertions(+), 8 deletions(-)

diff --git a/include/linux/swap.h b/include/linux/swap.h
index 661046994db4..df6207346078 100644
--- a/include/linux/swap.h
+++ b/include/linux/swap.h
@@ -340,7 +340,6 @@ extern void lru_note_cost_page(struct page *);
 extern void lru_cache_add(struct page *);
 extern void lru_add_page_tail(struct page *page, struct page *page_tail,
 			 struct lruvec *lruvec, struct list_head *head);
-extern void activate_page(struct page *);
 extern void mark_page_accessed(struct page *);
 extern void lru_add_drain(void);
 extern void lru_add_drain_cpu(int cpu);
diff --git a/mm/swap.c b/mm/swap.c
index d16d65d9b4e0..25c4043491b3 100644
--- a/mm/swap.c
+++ b/mm/swap.c
@@ -348,7 +348,7 @@ static bool need_activate_page_drain(int cpu)
 	return pagevec_count(&per_cpu(lru_pvecs.activate_page, cpu)) != 0;
 }
 
-void activate_page(struct page *page)
+static void activate_page(struct page *page)
 {
 	page = compound_head(page);
 	if (PageLRU(page) && !PageActive(page) && !PageUnevictable(page)) {
@@ -368,7 +368,7 @@ static inline void activate_page_drain(int cpu)
 {
 }
 
-void activate_page(struct page *page)
+static void activate_page(struct page *page)
 {
 	pg_data_t *pgdat = page_pgdat(page);
 
diff --git a/mm/swapfile.c b/mm/swapfile.c
index 12f59e641b5e..c287c560f96d 100644
--- a/mm/swapfile.c
+++ b/mm/swapfile.c
@@ -1925,11 +1925,6 @@ static int unuse_pte(struct vm_area_struct *vma, pmd_t *pmd,
 		lru_cache_add_inactive_or_unevictable(page, vma);
 	}
 	swap_free(entry);
-	/*
-	 * Move the page to the active list so it is not
-	 * immediately swapped out again after swapon.
-	 */
-	activate_page(page);
 out:
 	pte_unmap_unlock(pte, ptl);
 	if (page != swapcache) {
-- 
2.28.0.220.ged08abb693-goog