The patch titled
Subject: swap: convert swapon() to use a folio
has been added to the -mm mm-unstable branch. Its filename is
swap-convert-swapon-to-use-a-folio.patch
This patch will shortly appear at
https://git.kernel.org/pub/scm/linux/kernel/git/akpm/25-new.git/tree/patches/swap-convert-swapon-to-use-a-folio.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: "Matthew Wilcox (Oracle)" <willy@xxxxxxxxxxxxx>
Subject: swap: convert swapon() to use a folio
Date: Mon, 26 Aug 2024 21:21:35 +0100
Retrieve a folio from the page cache rather than a page. Saves a couple
of conversions between page & folio.
Link: https://lkml.kernel.org/r/20240826202138.3804238-1-willy@xxxxxxxxxxxxx
Signed-off-by: Matthew Wilcox (Oracle) <willy@xxxxxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
mm/swapfile.c | 16 +++++++---------
1 file changed, 7 insertions(+), 9 deletions(-)
--- a/mm/swapfile.c~swap-convert-swapon-to-use-a-folio
+++ a/mm/swapfile.c
@@ -3355,7 +3355,7 @@ SYSCALL_DEFINE2(swapon, const char __use
unsigned char *swap_map = NULL;
unsigned long *zeromap = NULL;
struct swap_cluster_info *cluster_info = NULL;
- struct page *page = NULL;
+ struct folio *folio = NULL;
struct inode *inode = NULL;
bool inced_nr_rotate_swap = false;
@@ -3413,12 +3413,12 @@ SYSCALL_DEFINE2(swapon, const char __use
error = -EINVAL;
goto bad_swap_unlock_inode;
}
- page = read_mapping_page(mapping, 0, swap_file);
- if (IS_ERR(page)) {
- error = PTR_ERR(page);
+ folio = read_mapping_folio(mapping, 0, swap_file);
+ if (IS_ERR(folio)) {
+ error = PTR_ERR(folio);
goto bad_swap_unlock_inode;
}
- swap_header = kmap(page);
+ swap_header = kmap_local_folio(folio, 0);
maxpages = read_swap_header(si, swap_header, inode);
if (unlikely(!maxpages)) {
@@ -3572,10 +3572,8 @@ bad_swap:
if (swap_file)
filp_close(swap_file, NULL);
out:
- if (page && !IS_ERR(page)) {
- kunmap(page);
- put_page(page);
- }
+ if (!IS_ERR_OR_NULL(folio))
+ folio_release_kmap(folio, swap_header);
if (name)
putname(name);
if (inode)
_
Patches currently in -mm which might be from willy@xxxxxxxxxxxxx are
fs-remove-calls-to-set-and-clear-the-folio-error-flag.patch
mm-remove-pg_error.patch
mm-return-the-folio-from-swapin_readahead.patch
printf-remove-%pgt-support.patch
mm-introduce-page_mapcount_is_type.patch
mm-support-only-one-page_type-per-page.patch
zsmalloc-use-all-available-24-bits-of-page_type.patch
mm-remove-pageactive.patch
mm-remove-pageswapbacked.patch
mm-remove-pagereadahead.patch
mm-remove-pageswapcache.patch
mm-remove-pageunevictable.patch
mm-remove-pagemlocked.patch
mm-remove-pageownerpriv1.patch
mm-remove-page_has_private.patch
mm-rename-pg_mappedtodisk-to-pg_owner_2.patch
x86-remove-pg_uncached.patch
swap-convert-swapon-to-use-a-folio.patch
