The patch titled Subject: mm: make is_free_buddy_page() take a const argument has been added to the -mm mm-unstable branch. Its filename is mm-make-is_free_buddy_page-take-a-const-argument.patch This patch will shortly appear at https://git.kernel.org/pub/scm/linux/kernel/git/akpm/25-new.git/tree/patches/mm-make-is_free_buddy_page-take-a-const-argument.patch This patch will later appear in the mm-unstable branch at git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm Before you just go and hit "reply", please: a) Consider who else should be cc'ed b) Prefer to cc a suitable mailing list as well c) Ideally: find the original patch on the mailing list and do a reply-to-all to that, adding suitable additional cc's *** Remember to use Documentation/process/submit-checklist.rst when testing your code *** The -mm tree is included into linux-next via the mm-everything branch at git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm and is updated there every 2-3 working days ------------------------------------------------------ From: "Matthew Wilcox (Oracle)" <willy@xxxxxxxxxxxxx> Subject: mm: make is_free_buddy_page() take a const argument Date: Tue, 26 Mar 2024 17:10:27 +0000 This function does not modify its argument; let the callers know that so they can make better optimisation decisions. Link: https://lkml.kernel.org/r/20240326171045.410737-6-willy@xxxxxxxxxxxxx Signed-off-by: Matthew Wilcox (Oracle) <willy@xxxxxxxxxxxxx> Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> --- include/linux/page-flags.h | 2 +- mm/page_alloc.c | 8 ++++---- 2 files changed, 5 insertions(+), 5 deletions(-) --- a/include/linux/page-flags.h~mm-make-is_free_buddy_page-take-a-const-argument +++ a/include/linux/page-flags.h @@ -1088,7 +1088,7 @@ static inline bool is_page_hwpoison(cons return folio_test_hugetlb(folio) && PageHWPoison(&folio->page); } -extern bool is_free_buddy_page(struct page *page); +bool is_free_buddy_page(const struct page *page); PAGEFLAG(Isolated, isolated, PF_ANY); --- a/mm/page_alloc.c~mm-make-is_free_buddy_page-take-a-const-argument +++ a/mm/page_alloc.c @@ -6750,16 +6750,16 @@ void __offline_isolated_pages(unsigned l /* * This function returns a stable result only if called under zone lock. */ -bool is_free_buddy_page(struct page *page) +bool is_free_buddy_page(const struct page *page) { unsigned long pfn = page_to_pfn(page); unsigned int order; for (order = 0; order < NR_PAGE_ORDERS; order++) { - struct page *page_head = page - (pfn & ((1 << order) - 1)); + const struct page *head = page - (pfn & ((1 << order) - 1)); - if (PageBuddy(page_head) && - buddy_order_unsafe(page_head) >= order) + if (PageBuddy(head) && + buddy_order_unsafe(head) >= order) break; } _ 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