From 9faaa0f8168bfcd81469b0724b25ba3093097a08 Mon Sep 17 00:00:00 2001 From: Ryan Roberts Date: Mon, 8 Apr 2024 19:39:43 +0100 Subject: [PATCH] mm: swap: update get_swap_pages() to take folio order We are about to allow swap storage of any mTHP size. To prepare for that, let's change get_swap_pages() to take a folio order parameter instead of nr_pages. This makes the interface self-documenting; a power-of-2 number of pages must be provided. We will also need the order internally so this simplifies accessing it. Link: https://lkml.kernel.org/r/20240408183946.2991168-5-ryan.roberts@arm.com Signed-off-by: Ryan Roberts Reviewed-by: "Huang, Ying" Reviewed-by: David Hildenbrand Cc: Barry Song <21cnbao@gmail.com> Cc: Barry Song Cc: Chris Li Cc: Gao Xiang Cc: Kefeng Wang Cc: Lance Yang Cc: Matthew Wilcox (Oracle) Cc: Michal Hocko Cc: Yang Shi Cc: Yu Zhao Signed-off-by: Andrew Morton --- include/linux/swap.h | 2 +- mm/swap_slots.c | 6 +++--- mm/swapfile.c | 13 +++++++------ 3 files changed, 11 insertions(+), 10 deletions(-) diff --git a/include/linux/swap.h b/include/linux/swap.h index ce35fd4abdf0..b69b06733247 100644 --- a/include/linux/swap.h +++ b/include/linux/swap.h @@ -468,7 +468,7 @@ swp_entry_t folio_alloc_swap(struct folio *folio); bool folio_free_swap(struct folio *folio); void put_swap_folio(struct folio *folio, swp_entry_t entry); extern swp_entry_t get_swap_page_of_type(int); -extern int get_swap_pages(int n, swp_entry_t swp_entries[], int entry_size); +extern int get_swap_pages(int n, swp_entry_t swp_entries[], int order); 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); diff --git a/mm/swap_slots.c b/mm/swap_slots.c index 53abeaf1371d..13ab3b771409 100644 --- a/mm/swap_slots.c +++ b/mm/swap_slots.c @@ -264,7 +264,7 @@ static int refill_swap_slots_cache(struct swap_slots_cache *cache) cache->cur = 0; if (swap_slot_cache_active) cache->nr = get_swap_pages(SWAP_SLOTS_CACHE_SIZE, - cache->slots, 1); + cache->slots, 0); return cache->nr; } @@ -311,7 +311,7 @@ swp_entry_t folio_alloc_swap(struct folio *folio) if (folio_test_large(folio)) { if (IS_ENABLED(CONFIG_THP_SWAP)) - get_swap_pages(1, &entry, folio_nr_pages(folio)); + get_swap_pages(1, &entry, folio_order(folio)); goto out; } @@ -343,7 +343,7 @@ repeat: goto out; } - get_swap_pages(1, &entry, 1); + get_swap_pages(1, &entry, 0); out: if (mem_cgroup_try_charge_swap(folio, entry)) { put_swap_folio(folio, entry); diff --git a/mm/swapfile.c b/mm/swapfile.c index e3f855475278..d2e3d3cd439f 100644 --- a/mm/swapfile.c +++ b/mm/swapfile.c @@ -278,15 +278,15 @@ static void discard_swap_cluster(struct swap_info_struct *si, #ifdef CONFIG_THP_SWAP #define SWAPFILE_CLUSTER HPAGE_PMD_NR -#define swap_entry_size(size) (size) +#define swap_entry_order(order) (order) #else #define SWAPFILE_CLUSTER 256 /* - * Define swap_entry_size() as constant to let compiler to optimize + * Define swap_entry_order() as constant to let compiler to optimize * out some code if !CONFIG_THP_SWAP */ -#define swap_entry_size(size) 1 +#define swap_entry_order(order) 0 #endif #define LATENCY_LIMIT 256 @@ -1042,9 +1042,10 @@ static void swap_free_cluster(struct swap_info_struct *si, unsigned long idx) swap_range_free(si, offset, SWAPFILE_CLUSTER); } -int get_swap_pages(int n_goal, swp_entry_t swp_entries[], int entry_size) +int get_swap_pages(int n_goal, swp_entry_t swp_entries[], int entry_order) { - unsigned long size = swap_entry_size(entry_size); + int order = swap_entry_order(entry_order); + unsigned long size = 1 << order; struct swap_info_struct *si, *next; long avail_pgs; int n_ret = 0; @@ -1349,7 +1350,7 @@ void put_swap_folio(struct folio *folio, swp_entry_t entry) unsigned char *map; unsigned int i, free_entries = 0; unsigned char val; - int size = swap_entry_size(folio_nr_pages(folio)); + int size = 1 << swap_entry_order(folio_order(folio)); si = _swap_info_get(entry); if (!si)