The patch titled
Subject: mm,hugetlb: use folio fields in second tail page: fix
has been added to the -mm mm-unstable branch. Its filename is
mmhugetlb-use-folio-fields-in-second-tail-page-fix.patch
This patch will shortly appear at
https://git.kernel.org/pub/scm/linux/kernel/git/akpm/25-new.git/tree/patches/mmhugetlb-use-folio-fields-in-second-tail-page-fix.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: Hugh Dickins <hughd@xxxxxxxxxx>
Subject: mm,hugetlb: use folio fields in second tail page: fix
Date: Wed, 9 Nov 2022 18:13:50 -0800 (PST)
Per review comment from Sidhartha: prefix folio's page_1 and page_2 with
double underscore, to underscore that they are fillers for alignment
rather than directly usable members of the union (whereas the first
"struct page page" is important for folio<->page conversions).
Per review comment from Kirill: give folio's _flags_2 and _head_2 a line
of documentation each, though both of them "Do not use" (I think _flags_1
should be enough for now, and shouldn't recommend spilling to _flags_2).
Link: https://lkml.kernel.org/r/9e2cb6b-5b58-d3f2-b5ee-5f8a14e8f10@xxxxxxxxxx
Signed-off-by: Hugh Dickins <hughd@xxxxxxxxxx>
Cc: David Hildenbrand <david@xxxxxxxxxx>
Cc: James Houghton <jthoughton@xxxxxxxxxx>
Cc: John Hubbard <jhubbard@xxxxxxxxxx>
Cc: Kirill A. Shutemov <kirill.shutemov@xxxxxxxxxxxxxxx>
Cc: Matthew Wilcox (Oracle) <willy@xxxxxxxxxxxxx>
Cc: Miaohe Lin <linmiaohe@xxxxxxxxxx>
Cc: Mike Kravetz <mike.kravetz@xxxxxxxxxx>
Cc: Mina Almasry <almasrymina@xxxxxxxxxx>
Cc: Muchun Song <songmuchun@xxxxxxxxxxxxx>
Cc: Naoya Horiguchi <naoya.horiguchi@xxxxxxxxx>
Cc: Peter Xu <peterx@xxxxxxxxxx>
Cc: Sidhartha Kumar <sidhartha.kumar@xxxxxxxxxx>
Cc: Vlastimil Babka <vbabka@xxxxxxx>
Cc: Yang Shi <shy828301@xxxxxxxxx>
Cc: Zach O'Keefe <zokeefe@xxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
include/linux/mm_types.h | 6 ++++--
1 file changed, 4 insertions(+), 2 deletions(-)
--- a/include/linux/mm_types.h~mmhugetlb-use-folio-fields-in-second-tail-page-fix
+++ a/include/linux/mm_types.h
@@ -273,6 +273,8 @@ struct page {
* @_total_mapcount: Do not use directly, call folio_entire_mapcount().
* @_pincount: Do not use directly, call folio_maybe_dma_pinned().
* @_folio_nr_pages: Do not use directly, call folio_nr_pages().
+ * @_flags_2: For alignment. Do not use.
+ * @_head_2: Points to the folio. Do not use.
* @_hugetlb_subpool: Do not use directly, use accessor in hugetlb.h.
* @_hugetlb_cgroup: Do not use directly, use accessor in hugetlb_cgroup.h.
* @_hugetlb_cgroup_rsvd: Do not use directly, use accessor in hugetlb_cgroup.h.
@@ -327,7 +329,7 @@ struct folio {
unsigned int _folio_nr_pages;
#endif
};
- struct page page_1;
+ struct page __page_1;
};
union {
struct {
@@ -338,7 +340,7 @@ struct folio {
void *_hugetlb_cgroup_rsvd;
void *_hugetlb_hwpoison;
};
- struct page page_2;
+ struct page __page_2;
};
};
_
Patches currently in -mm which might be from hughd@xxxxxxxxxx are
mmhugetlb-use-folio-fields-in-second-tail-page.patch
mmhugetlb-use-folio-fields-in-second-tail-page-fix.patch
mmthprmap-simplify-compound-page-mapcount-handling.patch
mmthprmap-lock_compound_mapcounts-on-thp-mapcounts.patch
