From: Barry Song <v-songbaohua@xxxxxxxx>
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.
Suggested-by: "Huang, Ying" <ying.huang@xxxxxxxxx>
Signed-off-by: Barry Song <v-songbaohua@xxxxxxxx>
Reviewed-by: "Huang, Ying" <ying.huang@xxxxxxxxx>
Acked-by: Chris Li <chrisl@xxxxxxxxxx>
Reviewed-by: Ryan Roberts <ryan.roberts@xxxxxxx>
Cc: "Rafael J. Wysocki" <rafael@xxxxxxxxxx>
Cc: Pavel Machek <pavel@xxxxxx>
Cc: Len Brown <len.brown@xxxxxxxxx>
Cc: Hugh Dickins <hughd@xxxxxxxxxx>
Cc: Christoph Hellwig <hch@xxxxxxxxxxxxx>
---
include/linux/swap.h | 10 +++++-----
kernel/power/swap.c | 5 ++---
mm/swapfile.c | 17 ++++-------------
3 files changed, 11 insertions(+), 21 deletions(-)
diff --git a/include/linux/swap.h b/include/linux/swap.h
index 45f76dfe29b1..3df75d62a835 100644
--- a/include/linux/swap.h
+++ b/include/linux/swap.h
@@ -480,7 +480,6 @@ 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);
@@ -559,10 +558,6 @@ 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)
{
}
@@ -611,6 +606,11 @@ 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)
{
diff --git a/kernel/power/swap.c b/kernel/power/swap.c
index d9abb7ab031d..85a8b5f4a081 100644
--- a/kernel/power/swap.c
+++ b/kernel/power/swap.c
@@ -200,12 +200,11 @@ void free_all_swap_pages(int swap)
while ((node = swsusp_extents.rb_node)) {
struct swsusp_extent *ext;
- unsigned long offset;
ext = rb_entry(node, struct swsusp_extent, node);
rb_erase(node, &swsusp_extents);
- for (offset = ext->start; offset <= ext->end; offset++)
- swap_free(swp_entry(swap, offset));
+ swap_free_nr(swp_entry(swap, ext->start),
+ ext->end - ext->start + 1);
kfree(ext);
}
diff --git a/mm/swapfile.c b/mm/swapfile.c
index 92a045d34a97..9c6d8e557c0f 100644
--- a/mm/swapfile.c
+++ b/mm/swapfile.c
@@ -1343,19 +1343,6 @@ static void swap_entry_free(struct swap_info_struct *p, swp_entry_t entry)
swap_range_free(p, offset, 1);
}
-/*
- * Caller has made sure that the swap device corresponding to entry
- * is still around or has not been recycled.
- */
-void swap_free(swp_entry_t entry)
-{
- struct swap_info_struct *p;
-
- p = _swap_info_get(entry);
- if (p)
- __swap_entry_free(p, entry);
-}
-
static void cluster_swap_free_nr(struct swap_info_struct *sis,
unsigned long offset, int nr_pages)
{
@@ -1385,6 +1372,10 @@ static void cluster_swap_free_nr(struct swap_info_struct *sis,
unlock_cluster_or_swap_info(sis, ci);
}
+/*
+ * Caller has made sure that the swap device corresponding to entry
+ * is still around or has not been recycled.
+ */
void swap_free_nr(swp_entry_t entry, int nr_pages)
{
int nr;
--
2.34.1
