Commit 3a37469e authored by Matthew Wilcox (Oracle)'s avatar Matthew Wilcox (Oracle) Committed by Andrew Morton
Browse files

mm: constify compound_order() and page_size() 

Patch series "Small cleanups".

These small cleanups can be applied now to reduce conflicts during the
next merge window.  They're all from various efforts to split struct page
from other memdescs.  Thanks to Vlastimil for the suggestion.


This patch (of 3):

These functions do not modify their arguments.  Telling the compiler this
may improve code generation, and allows us to pass const arguments from
other functions.

Link: https://lkml.kernel.org/r/20250910142923.2465470-1-willy@infradead.org
Link: https://lkml.kernel.org/r/20250910142923.2465470-2-willy@infradead.org


Signed-off-by: default avatarMatthew Wilcox (Oracle) <willy@infradead.org>
Reviewed-by: default avatarZi Yan <ziy@nvidia.com>
Acked-by: default avatarDavid Hildenbrand <david@redhat.com>
Acked-by: default avatarVlastimil Babka <vbabka@suse.cz>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
parent b3393938

include/linux/mm.h

+3 −3
Original line number Diff line number Diff line
@@ -1036,9 +1036,9 @@ static inline unsigned long folio_large_nr_pages(const struct folio *folio) 
 * set before the order is initialised, or this may be a tail page.

 * See compaction.c for some good examples.

 */

static inline unsigned int compound_order(struct page *page)

static inline unsigned int compound_order(const struct page *page)

{

	struct folio *folio = (struct folio *)page;

	const struct folio *folio = (struct folio *)page;



	if (!test_bit(PG_head, &folio->flags.f))

		return 0;
@@ -1256,7 +1256,7 @@ int folio_mc_copy(struct folio *dst, struct folio *src); 
unsigned long nr_free_buffer_pages(void);



/* Returns the number of bytes in this potentially compound page. */

static inline unsigned long page_size(struct page *page)

static inline unsigned long page_size(const struct page *page)

{

	return PAGE_SIZE << compound_order(page);

}