From 54f7a49c20ebb5189980c53e6e66709d22bee572 Mon Sep 17 00:00:00 2001
From: Barry Song <v-songbaohua@oppo.com>
Date: Wed, 29 May 2024 20:28:20 +1200
Subject: mm: remove the implementation of swap_free() and always use
 swap_free_nr()

To streamline maintenance efforts, we propose removing the implementation
of swap_free().  Instead, we can simply invoke swap_free_nr() with nr set
to 1.  swap_free_nr() is designed with a bitmap consisting of only one
long, resulting in overhead that can be ignored for cases where nr equals
1.

A prime candidate for leveraging swap_free_nr() lies within
kernel/power/swap.c.  Implementing this change facilitates the adoption of
batch processing for hibernation.

Link: https://lkml.kernel.org/r/20240529082824.150954-3-21cnbao@gmail.com
Signed-off-by: Barry Song <v-songbaohua@oppo.com>
Suggested-by: "Huang, Ying" <ying.huang@intel.com>
Reviewed-by: "Huang, Ying" <ying.huang@intel.com>
Acked-by: Chris Li <chrisl@kernel.org>
Reviewed-by: Ryan Roberts <ryan.roberts@arm.com>
Cc: "Rafael J. Wysocki" <rafael@kernel.org>
Cc: Pavel Machek <pavel@ucw.cz>
Cc: Len Brown <len.brown@intel.com>
Cc: Hugh Dickins <hughd@google.com>
Cc: Christoph Hellwig <hch@infradead.org>
Cc: Andreas Larsson <andreas@gaisler.com>
Cc: Baolin Wang <baolin.wang@linux.alibaba.com>
Cc: Chuanhua Han <hanchuanhua@oppo.com>
Cc: David Hildenbrand <david@redhat.com>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Gao Xiang <xiang@kernel.org>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Kairui Song <kasong@tencent.com>
Cc: Khalid Aziz <khalid.aziz@oracle.com>
Cc: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: Suren Baghdasaryan <surenb@google.com>
Cc: Yosry Ahmed <yosryahmed@google.com>
Cc: Yu Zhao <yuzhao@google.com>
Cc: Zi Yan <ziy@nvidia.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
---
 include/linux/swap.h | 10 +++++-----
 1 file changed, 5 insertions(+), 5 deletions(-)

(limited to 'include/linux')

diff --git a/include/linux/swap.h b/include/linux/swap.h
index 0f41fe49c9dc..d33ce740b695 100644
--- a/include/linux/swap.h
+++ b/include/linux/swap.h
@@ -477,7 +477,6 @@ extern int add_swap_count_continuation(swp_entry_t, gfp_t);
 extern void swap_shmem_alloc(swp_entry_t);
 extern int swap_duplicate(swp_entry_t);
 extern int swapcache_prepare(swp_entry_t);
-extern void swap_free(swp_entry_t);
 extern void swap_free_nr(swp_entry_t entry, int nr_pages);
 extern void swapcache_free_entries(swp_entry_t *entries, int n);
 extern void free_swap_and_cache_nr(swp_entry_t entry, int nr);
@@ -556,10 +555,6 @@ static inline int swapcache_prepare(swp_entry_t swp)
 	return 0;
 }
 
-static inline void swap_free(swp_entry_t swp)
-{
-}
-
 static inline void swap_free_nr(swp_entry_t entry, int nr_pages)
 {
 }
@@ -608,6 +603,11 @@ static inline void free_swap_and_cache(swp_entry_t entry)
 	free_swap_and_cache_nr(entry, 1);
 }
 
+static inline void swap_free(swp_entry_t entry)
+{
+	swap_free_nr(entry, 1);
+}
+
 #ifdef CONFIG_MEMCG
 static inline int mem_cgroup_swappiness(struct mem_cgroup *memcg)
 {
-- 
cgit v1.2.3