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) <willy@infradead.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
This commit is contained in:
Matthew Wilcox (Oracle) 2024-03-26 17:10:27 +00:00 committed by Andrew Morton
parent e3089fd0b0
commit 2ace5a670e
2 changed files with 5 additions and 5 deletions

View File

@ -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);

View File

@ -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;
}