[PATCH 3/3] mm/swap: remove unneeded swap_active_head

[Baoquan He <bhe@redhat.com>]

There's no user of swap_active_head, remove it now.

Signed-off-by: Baoquan He <bhe@redhat.com>
---
 include/linux/swap.h |  1 -
 mm/swapfile.c        | 20 ++++----------------
 2 files changed, 4 insertions(+), 17 deletions(-)

diff --git a/include/linux/swap.h b/include/linux/swap.h
index 5b7a39b20f58..dfc0cc9fc166 100644
--- a/include/linux/swap.h
+++ b/include/linux/swap.h
@@ -296,7 +296,6 @@ struct swap_info_struct {
 	struct percpu_ref users;	/* indicate and keep swap device valid. */
 	unsigned long	flags;		/* SWP_USED etc: see above */
 	signed short	prio;		/* swap priority of this type */
-	struct plist_node list;		/* entry in swap_active_head */
 	signed char	type;		/* strange name for an index */
 	unsigned int	max;		/* extent of the swap_map */
 	unsigned char *swap_map;	/* vmalloc'ed array of usage counts */
diff --git a/mm/swapfile.c b/mm/swapfile.c
index 18b52cc20749..80b34dc86a95 100644
--- a/mm/swapfile.c
+++ b/mm/swapfile.c
@@ -85,17 +85,10 @@ static const char Bad_offset[] = "Bad swap offset entry ";
 static const char Unused_offset[] = "Unused swap offset entry ";
 
 /*
- * all active swap_info_structs
- * protected with swap_lock, and ordered by priority.
- */
-static PLIST_HEAD(swap_active_head);
-
-/*
- * all available (active, not full) swap_info_structs
- * protected with swap_avail_lock, ordered by priority.
- * This is used by folio_alloc_swap() instead of swap_active_head
- * because swap_active_head includes all swap_info_structs,
- * but folio_alloc_swap() doesn't need to look at full ones.
+ * All available (active, not full) swap_info_structs protected with
+ * swap_avail_lock, ordered by priority.
+ * This is used by folio_alloc_swap() because folio_alloc_swap()
+ * doesn't need to look at full ones.
  * This uses its own lock instead of swap_lock because when a
  * swap_info_struct changes between not-full/full, it needs to
  * add/remove itself to/from this list, but the swap_info_struct->lock
@@ -2539,7 +2532,6 @@ static void setup_swap_info(struct swap_info_struct *si, int prio,
 	 * the plist prio is negated because plist ordering is
 	 * low-to-high, while swap ordering is high-to-low
 	 */
-	si->list.prio = -si->prio;
 	si->avail_list.prio = -si->prio;
 	si->swap_map = swap_map;
 	si->cluster_info = cluster_info;
@@ -2553,8 +2545,6 @@ static void _enable_swap_info(struct swap_info_struct *si)
 
 	assert_spin_locked(&swap_lock);
 
-	plist_add(&si->list, &swap_active_head);
-
 	/* Add back to available list */
 	add_to_avail_list(si, true);
 }
@@ -2682,7 +2672,6 @@ SYSCALL_DEFINE1(swapoff, const char __user *, specialfile)
 	}
 	spin_lock(&p->lock);
 	del_from_avail_list(p, true);
-	plist_del(&p->list, &swap_active_head);
 	atomic_long_sub(p->pages, &nr_swap_pages);
 	total_swap_pages -= p->pages;
 	spin_unlock(&p->lock);
@@ -2958,7 +2947,6 @@ static struct swap_info_struct *alloc_swap_info(void)
 		 */
 	}
 	p->swap_extent_root = RB_ROOT;
-	plist_node_init(&p->list, 0);
 	plist_node_init(&p->avail_list, 0);
 	p->flags = SWP_USED;
 	spin_unlock(&swap_lock);
-- 
2.41.0