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mm: swap: update get_swap_pages() to take folio order

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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 <ryan.roberts@arm.com>
Reviewed-by: "Huang, Ying" <ying.huang@intel.com>
Reviewed-by: David Hildenbrand <david@redhat.com>
Cc: Barry Song <21cnbao@gmail.com>
Cc: Barry Song <v-songbaohua@oppo.com>
Cc: Chris Li <chrisl@kernel.org>
Cc: Gao Xiang <xiang@kernel.org>
Cc: Kefeng Wang <wangkefeng.wang@huawei.com>
Cc: Lance Yang <ioworker0@gmail.com>
Cc: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Yang Shi <shy828301@gmail.com>
Cc: Yu Zhao <yuzhao@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
This commit is contained in:
Ryan Roberts 2024-04-08 19:39:43 +01:00 committed by Andrew Morton
parent 14c62da21b
commit 9faaa0f816
3 changed files with 11 additions and 10 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

2
include/linux/swap.h
View File

@ -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);

6
mm/swap_slots.c
View File

@ -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);

13
mm/swapfile.c
View File

@ -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)