From 54f7a49c20ebb5189980c53e6e66709d22bee572 Mon Sep 17 00:00:00 2001 From: Barry Song Date: Wed, 29 May 2024 20:28:20 +1200 Subject: [PATCH] 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 Suggested-by: "Huang, Ying" Reviewed-by: "Huang, Ying" Acked-by: Chris Li Reviewed-by: Ryan Roberts Cc: "Rafael J. Wysocki" Cc: Pavel Machek Cc: Len Brown Cc: Hugh Dickins Cc: Christoph Hellwig Cc: Andreas Larsson Cc: Baolin Wang Cc: Chuanhua Han Cc: David Hildenbrand Cc: "David S. Miller" Cc: Gao Xiang Cc: Johannes Weiner Cc: Kairui Song Cc: Khalid Aziz Cc: Matthew Wilcox (Oracle) Cc: Suren Baghdasaryan Cc: Yosry Ahmed Cc: Yu Zhao Cc: Zi Yan Signed-off-by: Andrew Morton --- 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 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) { diff --git a/kernel/power/swap.c b/kernel/power/swap.c index 753b8dd42a59..82b884b67152 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; -- 2.25.1