+ mm-convert-set_compound_page_dtor-and-set_compound_order-to-folios.patch added to mm-unstable branch

+ mm-convert-set_compound_page_dtor-and-set_compound_order-to-folios.patch added to mm-unstable branch

[Andrew Morton]

The patch titled
     Subject: mm: convert set_compound_page_dtor() and set_compound_order() to folios
has been added to the -mm mm-unstable branch.  Its filename is
     mm-convert-set_compound_page_dtor-and-set_compound_order-to-folios.patch

This patch will shortly appear at
     https://git.kernel.org/pub/scm/linux/kernel/git/akpm/25-new.git/tree/patches/mm-convert-set_compound_page_dtor-and-set_compound_order-to-folios.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@infradead.org>
Subject: mm: convert set_compound_page_dtor() and set_compound_order() to folios
Date: Wed, 11 Jan 2023 14:29:04 +0000

Replace uses of compound_dtor, compound_order and compound_nr by their
folio equivalents.

Link: https://lkml.kernel.org/r/20230111142915.1001531-19-willy@infradead.org
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
---

 include/linux/mm.h |   11 ++++++++---
 1 file changed, 8 insertions(+), 3 deletions(-)

--- a/include/linux/mm.h~mm-convert-set_compound_page_dtor-and-set_compound_order-to-folios
+++ a/include/linux/mm.h
@@ -984,8 +984,11 @@ extern compound_page_dtor * const compou
 static inline void set_compound_page_dtor(struct page *page,
 		enum compound_dtor_id compound_dtor)
 {
+	struct folio *folio = (struct folio *)page;
+
 	VM_BUG_ON_PAGE(compound_dtor >= NR_COMPOUND_DTORS, page);
-	page[1].compound_dtor = compound_dtor;
+	VM_BUG_ON_PAGE(!PageHead(page), page);
+	folio->_folio_dtor = compound_dtor;
 }
 
 static inline void folio_set_compound_dtor(struct folio *folio,
@@ -999,9 +1002,11 @@ void destroy_large_folio(struct folio *f
 
 static inline void set_compound_order(struct page *page, unsigned int order)
 {
-	page[1].compound_order = order;
+	struct folio *folio = (struct folio *)page;
+
+	folio->_folio_order = order;
 #ifdef CONFIG_64BIT
-	page[1].compound_nr = 1U << order;
+	folio->_folio_nr_pages = 1U << order;
 #endif
 }
 
_

Patches currently in -mm which might be from willy@infradead.org are

buffer-add-b_folio-as-an-alias-of-b_page.patch
buffer-replace-obvious-uses-of-b_page-with-b_folio.patch
buffer-use-b_folio-in-touch_buffer.patch
buffer-use-b_folio-in-end_buffer_async_read.patch
buffer-use-b_folio-in-end_buffer_async_write.patch
page_io-remove-buffer_head-include.patch
buffer-use-b_folio-in-mark_buffer_dirty.patch
gfs2-replace-obvious-uses-of-b_page-with-b_folio.patch
jbd2-replace-obvious-uses-of-b_page-with-b_folio.patch
nilfs2-replace-obvious-uses-of-b_page-with-b_folio.patch
reiserfs-replace-obvious-uses-of-b_page-with-b_folio.patch
mpage-use-b_folio-in-do_mpage_readpage.patch
mm-memcg-add-folio_memcg_check.patch
mm-remove-folio_pincount_ptr-and-head_compound_pincount.patch
mm-convert-head_subpages_mapcount-into-folio_nr_pages_mapped.patch
doc-clarify-refcount-section-by-referring-to-folios-pages.patch
mm-convert-total_compound_mapcount-to-folio_total_mapcount.patch
mm-convert-page_remove_rmap-to-use-a-folio-internally.patch
mm-convert-page_add_anon_rmap-to-use-a-folio-internally.patch
mm-convert-page_add_file_rmap-to-use-a-folio-internally.patch
mm-add-folio_add_new_anon_rmap.patch
page_alloc-use-folio-fields-directly.patch
mm-use-a-folio-in-hugepage_add_anon_rmap-and-hugepage_add_new_anon_rmap.patch
mm-use-entire_mapcount-in-__page_dup_rmap.patch
mm-debug-remove-call-to-head_compound_mapcount.patch
hugetlb-remove-uses-of-folio_mapcount_ptr.patch
mm-convert-page_mapcount-to-use-folio_entire_mapcount.patch
mm-remove-head_compound_mapcount-and-_ptr-functions.patch
mm-reimplement-compound_order.patch
mm-reimplement-compound_nr.patch
mm-convert-set_compound_page_dtor-and-set_compound_order-to-folios.patch
mm-convert-is_transparent_hugepage-to-use-a-folio.patch
mm-convert-destroy_large_folio-to-use-folio_dtor.patch
hugetlb-remove-uses-of-compound_dtor-and-compound_nr.patch
mm-remove-first-tail-page-members-from-struct-page.patch
doc-correct-struct-folio-kernel-doc.patch
mm-move-page-deferred_list-to-folio-_deferred_list.patch
mm-huge_memory-remove-page_deferred_list.patch
mm-huge_memory-convert-get_deferred_split_queue-to-take-a-folio.patch
mm-convert-deferred_split_huge_page-to-deferred_split_folio.patch