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authorMatthew Wilcox (Oracle) <willy@infradead.org>2020-12-10 18:55:05 +0300
committerMatthew Wilcox (Oracle) <willy@infradead.org>2021-09-27 16:27:30 +0300
commit2f52578f9c64d7d9a96ab81c243cc20804fabf2b (patch)
tree9c1bf5583fb98d2e0027f972bd0a254114278db0 /mm/swapfile.c
parent352b47a6984470954e1e262126b1da5312c40b09 (diff)
downloadlinux-2f52578f9c64d7d9a96ab81c243cc20804fabf2b.tar.xz
mm/util: Add folio_mapping() and folio_file_mapping()
These are the folio equivalent of page_mapping() and page_file_mapping(). Add an out-of-line page_mapping() wrapper around folio_mapping() in order to prevent the page_folio() call from bloating every caller of page_mapping(). Adjust page_file_mapping() and page_mapping_file() to use folios internally. Rename __page_file_mapping() to swapcache_mapping() and change it to take a folio. This ends up saving 122 bytes of text overall. folio_mapping() is 45 bytes shorter than page_mapping() was, but the new page_mapping() wrapper is 30 bytes. The major reduction is a few bytes less in dozens of nfs functions (which call page_file_mapping()). Most of these appear to be a slight change in gcc's register allocation decisions, which allow: 48 8b 56 08 mov 0x8(%rsi),%rdx 48 8d 42 ff lea -0x1(%rdx),%rax 83 e2 01 and $0x1,%edx 48 0f 44 c6 cmove %rsi,%rax to become: 48 8b 46 08 mov 0x8(%rsi),%rax 48 8d 78 ff lea -0x1(%rax),%rdi a8 01 test $0x1,%al 48 0f 44 fe cmove %rsi,%rdi for a reduction of a single byte. Once the NFS client is converted to use folios, this entire sequence will disappear. Also add folio_mapping() documentation. Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org> Reviewed-by: Christoph Hellwig <hch@lst.de> Acked-by: Jeff Layton <jlayton@kernel.org> Acked-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Acked-by: Vlastimil Babka <vbabka@suse.cz> Reviewed-by: William Kucharski <william.kucharski@oracle.com> Reviewed-by: David Howells <dhowells@redhat.com>
Diffstat (limited to 'mm/swapfile.c')
-rw-r--r--mm/swapfile.c8
1 files changed, 4 insertions, 4 deletions
diff --git a/mm/swapfile.c b/mm/swapfile.c
index 22d10f713848..e3dcaeecc50f 100644
--- a/mm/swapfile.c
+++ b/mm/swapfile.c
@@ -3534,13 +3534,13 @@ struct swap_info_struct *page_swap_info(struct page *page)
}
/*
- * out-of-line __page_file_ methods to avoid include hell.
+ * out-of-line methods to avoid include hell.
*/
-struct address_space *__page_file_mapping(struct page *page)
+struct address_space *swapcache_mapping(struct folio *folio)
{
- return page_swap_info(page)->swap_file->f_mapping;
+ return page_swap_info(&folio->page)->swap_file->f_mapping;
}
-EXPORT_SYMBOL_GPL(__page_file_mapping);
+EXPORT_SYMBOL_GPL(swapcache_mapping);
pgoff_t __page_file_index(struct page *page)
{