The patch titled
Subject: mm: add tail private fields to struct folio
has been added to the -mm mm-unstable branch. Its filename is
mm-add-tail-private-fields-to-struct-folio.patch
This patch will shortly appear at
https://git.kernel.org/pub/scm/linux/kernel/git/akpm/25-new.git/tree/patches/mm-add-tail-private-fields-to-struct-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: mm: add tail private fields to struct folio
Date: Wed, 16 Aug 2023 16:12:00 +0100
Because THP_SWAP uses page->private for each page, we must not use the
space which overlaps that field for anything which would conflict with
that. We avoid the conflict on 32-bit systems by disallowing THP_SWAP on
32-bit.
Link: https://lkml.kernel.org/r/20230816151201.3655946-13-willy@xxxxxxxxxxxxx
Signed-off-by: Matthew Wilcox (Oracle) <willy@xxxxxxxxxxxxx>
Cc: David Hildenbrand <david@xxxxxxxxxx>
Cc: Jens Axboe <axboe@xxxxxxxxx>
Cc: Sidhartha Kumar <sidhartha.kumar@xxxxxxxxxx>
Cc: Yanteng Si <siyanteng@xxxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
include/linux/mm_types.h | 14 +++++++++++++-
1 file changed, 13 insertions(+), 1 deletion(-)
--- a/include/linux/mm_types.h~mm-add-tail-private-fields-to-struct-folio
+++ a/include/linux/mm_types.h
@@ -322,8 +322,11 @@ struct folio {
atomic_t _pincount;
#ifdef CONFIG_64BIT
unsigned int _folio_nr_pages;
-#endif
+ /* 4 byte gap here */
/* private: the union with struct page is transitional */
+ /* Fix THP_SWAP to not use tail->private */
+ unsigned long _private_1;
+#endif
};
struct page __page_1;
};
@@ -344,6 +347,9 @@ struct folio {
/* public: */
struct list_head _deferred_list;
/* private: the union with struct page is transitional */
+ unsigned long _avail_2a;
+ /* Fix THP_SWAP to not use tail->private */
+ unsigned long _private_2a;
};
struct page __page_2;
};
@@ -368,12 +374,18 @@ FOLIO_MATCH(memcg_data, memcg_data);
offsetof(struct page, pg) + sizeof(struct page))
FOLIO_MATCH(flags, _flags_1);
FOLIO_MATCH(compound_head, _head_1);
+#ifdef CONFIG_64BIT
+FOLIO_MATCH(private, _private_1);
+#endif
#undef FOLIO_MATCH
#define FOLIO_MATCH(pg, fl) \
static_assert(offsetof(struct folio, fl) == \
offsetof(struct page, pg) + 2 * sizeof(struct page))
FOLIO_MATCH(flags, _flags_2);
FOLIO_MATCH(compound_head, _head_2);
+FOLIO_MATCH(flags, _flags_2a);
+FOLIO_MATCH(compound_head, _head_2a);
+FOLIO_MATCH(private, _private_2a);
#undef FOLIO_MATCH
/**
_
Patches currently in -mm which might be from willy@xxxxxxxxxxxxx are
mm-memoryc-fix-mismerge.patch
mm-drop-per-vma-lock-when-returning-vm_fault_retry-or-vm_fault_completed-fix.patch
zswap-make-zswap_store-take-a-folio.patch
memcg-convert-get_obj_cgroup_from_page-to-get_obj_cgroup_from_folio.patch
swap-remove-some-calls-to-compound_head-in-swap_readpage.patch
zswap-make-zswap_load-take-a-folio.patch
mm-improve-the-comment-in-isolate_migratepages_block.patch
minmax-add-in_range-macro.patch
mm-convert-page_table_check_pte_set-to-page_table_check_ptes_set.patch
mm-add-generic-flush_icache_pages-and-documentation.patch
mm-add-folio_flush_mapping.patch
mm-remove-arch_implements_flush_dcache_folio.patch
mm-add-default-definition-of-set_ptes.patch
alpha-implement-the-new-page-table-range-api.patch
arc-implement-the-new-page-table-range-api.patch
arm-implement-the-new-page-table-range-api.patch
arm64-implement-the-new-page-table-range-api.patch
csky-implement-the-new-page-table-range-api.patch
hexagon-implement-the-new-page-table-range-api.patch
ia64-implement-the-new-page-table-range-api.patch
ia64-implement-the-new-page-table-range-api-fix.patch
loongarch-implement-the-new-page-table-range-api.patch
m68k-implement-the-new-page-table-range-api.patch
microblaze-implement-the-new-page-table-range-api.patch
mips-implement-the-new-page-table-range-api.patch
nios2-implement-the-new-page-table-range-api.patch
openrisc-implement-the-new-page-table-range-api.patch
parisc-implement-the-new-page-table-range-api.patch
powerpc-implement-the-new-page-table-range-api.patch
powerpc-implement-the-new-page-table-range-api-fix.patch
riscv-implement-the-new-page-table-range-api.patch
s390-implement-the-new-page-table-range-api.patch
sh-implement-the-new-page-table-range-api.patch
sparc32-implement-the-new-page-table-range-api.patch
sparc64-implement-the-new-page-table-range-api.patch
um-implement-the-new-page-table-range-api.patch
x86-implement-the-new-page-table-range-api.patch
xtensa-implement-the-new-page-table-range-api.patch
mm-remove-page_mapping_file.patch
mm-rationalise-flush_icache_pages-and-flush_icache_page.patch
mm-tidy-up-set_ptes-definition.patch
mm-use-flush_icache_pages-in-do_set_pmd.patch
mm-call-update_mmu_cache_range-in-more-page-fault-handling-paths.patch
mm-allow-fault_dirty_shared_page-to-be-called-under-the-vma-lock.patch
io_uring-stop-calling-free_compound_page.patch
mm-call-free_huge_page-directly.patch
mm-convert-free_huge_page-to-free_huge_folio.patch
mm-convert-free_transhuge_folio-to-folio_undo_large_rmappable.patch
mm-convert-prep_transhuge_page-to-folio_prep_large_rmappable.patch
mm-remove-free_compound_page-and-the-compound_page_dtors-array.patch
mm-remove-hugetlb_page_dtor.patch
mm-add-large_rmappable-page-flag.patch
mm-rearrange-page-flags.patch
mm-free-up-a-word-in-the-first-tail-page.patch
mm-remove-folio_test_transhuge.patch
mm-add-tail-private-fields-to-struct-folio.patch
mm-convert-split_huge_pages_pid-to-use-a-folio.patch
