This function does not modify its argument; let the callers know that
so they can make better optimisation decisions.
Signed-off-by: Matthew Wilcox (Oracle) <willy@xxxxxxxxxxxxx>
---
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 0163d6da6283..eaecf544039f 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 370ea1711828..a00a2d7d8d9f 100644
--- a/mm/page_alloc.c
+++ b/mm/page_alloc.c
@@ -6786,16 +6786,16 @@ 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;
}
--
2.43.0
