The patch titled
Subject: mm: add is_huge_zero_folio()
has been added to the -mm mm-unstable branch. Its filename is
mm-add-is_huge_zero_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-is_huge_zero_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 is_huge_zero_folio()
Date: Tue, 26 Mar 2024 20:28:22 +0000
This is the folio equivalent of is_huge_zero_page(). It doesn't add any
efficiency, but it does prevent the caller from passing a tail page and
getting confused when the predicate returns false.
Link: https://lkml.kernel.org/r/20240326202833.523759-3-willy@xxxxxxxxxxxxx
Signed-off-by: Matthew Wilcox (Oracle) <willy@xxxxxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
fs/proc/page.c | 2 +-
include/linux/huge_mm.h | 10 ++++++++++
mm/huge_memory.c | 6 +++---
mm/mempolicy.c | 2 +-
mm/swap.c | 2 +-
mm/swap_state.c | 2 +-
mm/userfaultfd.c | 2 +-
7 files changed, 18 insertions(+), 8 deletions(-)
--- a/fs/proc/page.c~mm-add-is_huge_zero_folio
+++ a/fs/proc/page.c
@@ -155,7 +155,7 @@ u64 stable_page_flags(const struct page
else if (folio_test_large(folio)) {
if ((k & PG_lru) || is_anon)
u |= 1 << KPF_THP;
- else if (is_huge_zero_page(&folio->page)) {
+ else if (is_huge_zero_folio(folio)) {
u |= 1 << KPF_ZERO_PAGE;
u |= 1 << KPF_THP;
}
--- a/include/linux/huge_mm.h~mm-add-is_huge_zero_folio
+++ a/include/linux/huge_mm.h
@@ -356,6 +356,11 @@ static inline bool is_huge_zero_page(con
return READ_ONCE(huge_zero_page) == page;
}
+static inline bool is_huge_zero_folio(const struct folio *folio)
+{
+ return READ_ONCE(huge_zero_page) == &folio->page;
+}
+
static inline bool is_huge_zero_pmd(pmd_t pmd)
{
return pmd_present(pmd) && READ_ONCE(huge_zero_pfn) == pmd_pfn(pmd);
@@ -484,6 +489,11 @@ static inline bool is_huge_zero_page(con
{
return false;
}
+
+static inline bool is_huge_zero_folio(const struct folio *folio)
+{
+ return false;
+}
static inline bool is_huge_zero_pmd(pmd_t pmd)
{
--- a/mm/huge_memory.c~mm-add-is_huge_zero_folio
+++ a/mm/huge_memory.c
@@ -789,12 +789,12 @@ struct deferred_split *get_deferred_spli
}
#endif
-static inline bool is_transparent_hugepage(struct folio *folio)
+static inline bool is_transparent_hugepage(const struct folio *folio)
{
if (!folio_test_large(folio))
return false;
- return is_huge_zero_page(&folio->page) ||
+ return is_huge_zero_folio(folio) ||
folio_test_large_rmappable(folio);
}
@@ -3085,7 +3085,7 @@ int split_huge_page_to_list_to_order(str
}
- is_hzp = is_huge_zero_page(&folio->page);
+ is_hzp = is_huge_zero_folio(folio);
if (is_hzp) {
pr_warn_ratelimited("Called split_huge_page for huge zero page\n");
return -EBUSY;
--- a/mm/mempolicy.c~mm-add-is_huge_zero_folio
+++ a/mm/mempolicy.c
@@ -510,7 +510,7 @@ static void queue_folios_pmd(pmd_t *pmd,
return;
}
folio = pfn_folio(pmd_pfn(*pmd));
- if (is_huge_zero_page(&folio->page)) {
+ if (is_huge_zero_folio(folio)) {
walk->action = ACTION_CONTINUE;
return;
}
--- a/mm/swap.c~mm-add-is_huge_zero_folio
+++ a/mm/swap.c
@@ -985,7 +985,7 @@ void folios_put_refs(struct folio_batch
struct folio *folio = folios->folios[i];
unsigned int nr_refs = refs ? refs[i] : 1;
- if (is_huge_zero_page(&folio->page))
+ if (is_huge_zero_folio(folio))
continue;
if (folio_is_zone_device(folio)) {
--- a/mm/swap_state.c~mm-add-is_huge_zero_folio
+++ a/mm/swap_state.c
@@ -301,7 +301,7 @@ void free_page_and_swap_cache(struct pag
struct folio *folio = page_folio(page);
free_swap_cache(folio);
- if (!is_huge_zero_page(page))
+ if (!is_huge_zero_folio(folio))
folio_put(folio);
}
--- a/mm/userfaultfd.c~mm-add-is_huge_zero_folio
+++ a/mm/userfaultfd.c
@@ -1699,7 +1699,7 @@ ssize_t move_pages(struct userfaultfd_ct
!pmd_none(dst_pmdval)) {
struct folio *folio = pfn_folio(pmd_pfn(*src_pmd));
- if (!folio || (!is_huge_zero_page(&folio->page) &&
+ if (!folio || (!is_huge_zero_folio(folio) &&
!PageAnonExclusive(&folio->page))) {
spin_unlock(ptl);
err = -EBUSY;
_
Patches currently in -mm which might be from willy@xxxxxxxxxxxxx are
mm-always-initialise-folio-_deferred_list.patch
mm-create-folio_flag_false-and-folio_type_ops-macros.patch
mm-remove-folio_prep_large_rmappable.patch
mm-support-page_mapcount-on-page_has_type-pages.patch
mm-turn-folio_test_hugetlb-into-a-pagetype.patch
mm-turn-folio_test_hugetlb-into-a-pagetype-fix.patch
mm-remove-a-call-to-compound_head-from-is_page_hwpoison.patch
mm-free-up-pg_slab.patch
mm-free-up-pg_slab-fix.patch
mm-improve-dumping-of-mapcount-and-page_type.patch
hugetlb-remove-mention-of-destructors.patch
sh-remove-use-of-pg_arch_1-on-individual-pages.patch
xtensa-remove-uses-of-pg_arch_1-on-individual-pages.patch
mm-make-page_ext_get-take-a-const-argument.patch
mm-make-folio_test_idle-and-folio_test_young-take-a-const-argument.patch
mm-make-is_free_buddy_page-take-a-const-argument.patch
mm-make-page_mapped-take-a-const-argument.patch
mm-convert-arch_clear_hugepage_flags-to-take-a-folio.patch
slub-remove-use-of-page-flags.patch
remove-references-to-page-flags-in-documentation.patch
proc-rewrite-stable_page_flags.patch
sparc-use-is_huge_zero_pmd.patch
mm-add-is_huge_zero_folio.patch
mm-add-pmd_folio.patch
mm-convert-migrate_vma_collect_pmd-to-use-a-folio.patch
mm-convert-huge_zero_page-to-huge_zero_folio.patch
mm-convert-do_huge_pmd_anonymous_page-to-huge_zero_folio.patch
dax-use-huge_zero_folio.patch
mm-rename-mm_put_huge_zero_page-to-mm_put_huge_zero_folio.patch
