From 2ace5a670e2a0f3a6029bc6cf91dc14202074e7a Mon Sep 17 00:00:00 2001 From: "Matthew Wilcox (Oracle)" Date: Tue, 26 Mar 2024 17:10:27 +0000 Subject: [PATCH] mm: make is_free_buddy_page() take a const argument 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@infradead.org Signed-off-by: Matthew Wilcox (Oracle) Signed-off-by: Andrew Morton --- include/linux/page-flags.h | 2 +- mm/page_alloc.c | 8 ++++---- 2 files changed, 5 insertions(+), 5 deletions(-) diff --git a/include/linux/page-flags.h b/include/linux/page-flags.h index 0163d6da6283cc..eaecf544039fec 100644 --- a/include/linux/page-flags.h +++ b/include/linux/page-flags.h @@ -1088,7 +1088,7 @@ static inline bool is_page_hwpoison(const struct page *page) 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); diff --git a/mm/page_alloc.c b/mm/page_alloc.c index daab8cab91ccf2..6a8593aef29776 100644 --- a/mm/page_alloc.c +++ b/mm/page_alloc.c @@ -6745,16 +6745,16 @@ void __offline_isolated_pages(unsigned long start_pfn, unsigned long end_pfn) /* * 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; }