The patch titled
Subject: mm/mm_init: initialize page->_mapcount directly in __init_single_page()
has been added to the -mm mm-unstable branch. Its filename is
mm-mm_init-initialize-page-_mapcount-directly-in-__init_single_page.patch
This patch will shortly appear at
https://git.kernel.org/pub/scm/linux/kernel/git/akpm/25-new.git/tree/patches/mm-mm_init-initialize-page-_mapcount-directly-in-__init_single_page.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: David Hildenbrand <david@xxxxxxxxxx>
Subject: mm/mm_init: initialize page->_mapcount directly in __init_single_page()
Date: Wed, 29 May 2024 13:19:04 +0200
Let's simply reinitialize the page->_mapcount directly. We can now get
rid of page_mapcount_reset().
Link: https://lkml.kernel.org/r/20240529111904.2069608-7-david@xxxxxxxxxx
Signed-off-by: David Hildenbrand <david@xxxxxxxxxx>
Cc: Hyeonggon Yoo <42.hyeyoo@xxxxxxxxx>
Cc: Matthew Wilcox (Oracle) <willy@xxxxxxxxxxxxx>
Cc: Mike Rapoport (IBM) <rppt@xxxxxxxxxx>
Cc: Minchan Kim <minchan@xxxxxxxxxx>
Cc: Sergey Senozhatsky <senozhatsky@xxxxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
include/linux/mm.h | 5 -----
mm/mm_init.c | 2 +-
2 files changed, 1 insertion(+), 6 deletions(-)
--- a/include/linux/mm.h~mm-mm_init-initialize-page-_mapcount-directly-in-__init_single_page
+++ a/include/linux/mm.h
@@ -1206,11 +1206,6 @@ static inline int folio_entire_mapcount(
return atomic_read(&folio->_entire_mapcount) + 1;
}
-static inline void page_mapcount_reset(struct page *page)
-{
- atomic_set(&(page)->_mapcount, -1);
-}
-
/**
* page_mapcount() - Number of times this precise page is mapped.
* @page: The page.
--- a/mm/mm_init.c~mm-mm_init-initialize-page-_mapcount-directly-in-__init_single_page
+++ a/mm/mm_init.c
@@ -568,7 +568,7 @@ void __meminit __init_single_page(struct
mm_zero_struct_page(page);
set_page_links(page, zone, nid, pfn);
init_page_count(page);
- page_mapcount_reset(page);
+ atomic_set(&page->_mapcount, -1);
page_cpupid_reset_last(page);
page_kasan_tag_reset(page);
_
Patches currently in -mm which might be from david@xxxxxxxxxx are
mm-memory-move-page_count-check-into-validate_page_before_insert.patch
mm-memory-cleanly-support-zeropage-in-vm_insert_page-vm_map_pages-and-vmf_insert_mixed.patch
mm-rmap-sanity-check-that-zeropages-are-not-passed-to-rmap.patch
mm-update-_mapcount-and-page_type-documentation.patch
mm-allow-reuse-of-the-lower-16-bit-of-the-page-type-with-an-actual-type.patch
mm-zsmalloc-use-a-proper-page-type.patch
mm-page_alloc-clear-pagebuddy-using-__clearpagebuddy-for-bad-pages.patch
mm-filemap-reinitialize-folio-_mapcount-directly.patch
mm-mm_init-initialize-page-_mapcount-directly-in-__init_single_page.patch
