The patch titled
Subject: mm: swap: update get_swap_pages() to take folio order
has been added to the -mm mm-unstable branch. Its filename is
mm-swap-update-get_swap_pages-to-take-folio-order.patch
This patch will shortly appear at
https://git.kernel.org/pub/scm/linux/kernel/git/akpm/25-new.git/tree/patches/mm-swap-update-get_swap_pages-to-take-folio-order.patch
This patch will later appear in the mm-unstable branch at
git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm
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------------------------------------------------------
From: Ryan Roberts <ryan.roberts@xxxxxxx>
Subject: mm: swap: update get_swap_pages() to take folio order
Date: Mon, 8 Apr 2024 19:39:43 +0100
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@xxxxxxx
Signed-off-by: Ryan Roberts <ryan.roberts@xxxxxxx>
Reviewed-by: "Huang, Ying" <ying.huang@xxxxxxxxx>
Cc: Barry Song <21cnbao@xxxxxxxxx>
Cc: Barry Song <v-songbaohua@xxxxxxxx>
Cc: Chris Li <chrisl@xxxxxxxxxx>
Cc: David Hildenbrand <david@xxxxxxxxxx>
Cc: Gao Xiang <xiang@xxxxxxxxxx>
Cc: Kefeng Wang <wangkefeng.wang@xxxxxxxxxx>
Cc: Lance Yang <ioworker0@xxxxxxxxx>
Cc: Matthew Wilcox (Oracle) <willy@xxxxxxxxxxxxx>
Cc: Michal Hocko <mhocko@xxxxxxxx>
Cc: Yang Shi <shy828301@xxxxxxxxx>
Cc: Yu Zhao <yuzhao@xxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
include/linux/swap.h | 2 +-
mm/swap_slots.c | 6 +++---
mm/swapfile.c | 13 +++++++------
3 files changed, 11 insertions(+), 10 deletions(-)
--- a/include/linux/swap.h~mm-swap-update-get_swap_pages-to-take-folio-order
+++ a/include/linux/swap.h
@@ -468,7 +468,7 @@ swp_entry_t folio_alloc_swap(struct foli
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);
--- a/mm/swapfile.c~mm-swap-update-get_swap_pages-to-take-folio-order
+++ a/mm/swapfile.c
@@ -278,15 +278,15 @@ static void discard_swap_cluster(struct
#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 swa
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,
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)
--- a/mm/swap_slots.c~mm-swap-update-get_swap_pages-to-take-folio-order
+++ a/mm/swap_slots.c
@@ -264,7 +264,7 @@ static int refill_swap_slots_cache(struc
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 foli
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);
_
Patches currently in -mm which might be from ryan.roberts@xxxxxxx are
mm-swap-remove-cluster_flag_huge-from-swap_cluster_info-flags.patch
mm-swap-free_swap_and_cache_nr-as-batched-free_swap_and_cache.patch
mm-swap-simplify-struct-percpu_cluster.patch
mm-swap-update-get_swap_pages-to-take-folio-order.patch
mm-swap-allow-storage-of-all-mthp-orders.patch
mm-vmscan-avoid-split-during-shrink_folio_list.patch
mm-madvise-avoid-split-during-madv_pageout-and-madv_cold.patch
