The patch titled
Subject: mm: constify testing page/folio flags
has been added to the -mm mm-unstable branch. Its filename is
mm-constify-testing-page-folio-flags.patch
This patch will shortly appear at
https://git.kernel.org/pub/scm/linux/kernel/git/akpm/25-new.git/tree/patches/mm-constify-testing-page-folio-flags.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: constify testing page/folio flags
Date: Tue, 27 Feb 2024 19:23:33 +0000
Now that dump_page() takes a const argument, we can constify all the page
flag tests.
Link: https://lkml.kernel.org/r/20240227192337.757313-7-willy@xxxxxxxxxxxxx
Signed-off-by: Matthew Wilcox (Oracle) <willy@xxxxxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
include/linux/page-flags.h | 24 +++++++++++++++++-------
1 file changed, 17 insertions(+), 7 deletions(-)
--- a/include/linux/page-flags.h~mm-constify-testing-page-folio-flags
+++ a/include/linux/page-flags.h
@@ -237,7 +237,7 @@ static inline const struct page *page_fi
}
#endif
-static __always_inline int page_is_fake_head(struct page *page)
+static __always_inline int page_is_fake_head(const struct page *page)
{
return page_fixed_fake_head(page) != page;
}
@@ -281,12 +281,12 @@ static inline unsigned long _compound_he
*/
#define folio_page(folio, n) nth_page(&(folio)->page, n)
-static __always_inline int PageTail(struct page *page)
+static __always_inline int PageTail(const struct page *page)
{
return READ_ONCE(page->compound_head) & 1 || page_is_fake_head(page);
}
-static __always_inline int PageCompound(struct page *page)
+static __always_inline int PageCompound(const struct page *page)
{
return test_bit(PG_head, &page->flags) ||
READ_ONCE(page->compound_head) & 1;
@@ -306,6 +306,16 @@ static inline void page_init_poison(stru
}
#endif
+static const unsigned long *const_folio_flags(const struct folio *folio,
+ unsigned n)
+{
+ const struct page *page = &folio->page;
+
+ VM_BUG_ON_PGFLAGS(PageTail(page), page);
+ VM_BUG_ON_PGFLAGS(n > 0 && !test_bit(PG_head, &page->flags), page);
+ return &page[n].flags;
+}
+
static unsigned long *folio_flags(struct folio *folio, unsigned n)
{
struct page *page = &folio->page;
@@ -367,8 +377,8 @@ static unsigned long *folio_flags(struct
* Macros to create function definitions for page flags
*/
#define FOLIO_TEST_FLAG(name, page) \
-static __always_inline bool folio_test_##name(struct folio *folio) \
-{ return test_bit(PG_##name, folio_flags(folio, page)); }
+static __always_inline bool folio_test_##name(const struct folio *folio) \
+{ return test_bit(PG_##name, const_folio_flags(folio, page)); }
#define FOLIO_SET_FLAG(name, page) \
static __always_inline void folio_set_##name(struct folio *folio) \
@@ -401,7 +411,7 @@ FOLIO_CLEAR_FLAG(name, page)
#define TESTPAGEFLAG(uname, lname, policy) \
FOLIO_TEST_FLAG(lname, FOLIO_##policy) \
-static __always_inline int Page##uname(struct page *page) \
+static __always_inline int Page##uname(const struct page *page) \
{ return test_bit(PG_##lname, &policy(page, 0)->flags); }
#define SETPAGEFLAG(uname, lname, policy) \
@@ -801,7 +811,7 @@ static __always_inline bool folio_test_h
return test_bit(PG_head, folio_flags(folio, FOLIO_PF_ANY));
}
-static __always_inline int PageHead(struct page *page)
+static __always_inline int PageHead(const struct page *page)
{
PF_POISONED_CHECK(page);
return test_bit(PG_head, &page->flags) && !page_is_fake_head(page);
_
Patches currently in -mm which might be from willy@xxxxxxxxxxxxx are
mm-support-order-1-folios-in-the-page-cache.patch
mm-make-folios_put-the-basis-of-release_pages.patch
mm-convert-free_unref_page_list-to-use-folios.patch
mm-add-free_unref_folios.patch
mm-use-folios_put-in-__folio_batch_release.patch
memcg-add-mem_cgroup_uncharge_folios.patch
mm-remove-use-of-folio-list-from-folios_put.patch
mm-use-free_unref_folios-in-put_pages_list.patch
mm-use-__page_cache_release-in-folios_put.patch
mm-handle-large-folios-in-free_unref_folios.patch
mm-allow-non-hugetlb-large-folios-to-be-batch-processed.patch
mm-free-folios-in-a-batch-in-shrink_folio_list.patch
mm-free-folios-directly-in-move_folios_to_lru.patch
memcg-remove-mem_cgroup_uncharge_list.patch
mm-remove-free_unref_page_list.patch
mm-remove-lru_to_page.patch
mm-convert-free_pages_and_swap_cache-to-use-folios_put.patch
mm-use-a-folio-in-__collapse_huge_page_copy_succeeded.patch
mm-convert-free_swap_cache-to-take-a-folio.patch
mm-use-folio-more-widely-in-__split_huge_page.patch
mm-separate-out-folio_flags-from-pageflags.patch
mm-remove-pagewaiters-pagesetwaiters-and-pageclearwaiters.patch
mm-remove-pageyoung-and-pageidle-definitions.patch
mm-add-__dump_folio.patch
mm-make-dump_page-take-a-const-argument.patch
mm-constify-testing-page-folio-flags.patch
mm-constify-more-page-folio-tests.patch
mm-remove-cast-from-page_to_nid.patch
