diff options
| author | Matthew Wilcox (Oracle) <willy@infradead.org> | 2024-08-21 18:39:10 +0100 |
|---|---|---|
| committer | Andrew Morton <akpm@linux-foundation.org> | 2024-09-03 21:15:42 -0700 |
| commit | e880034cf7182aa35962bd30dfc9fa60476d56a4 (patch) | |
| tree | 55148be6aa56f0c4bf523dc7c6df26135454499c /include/linux | |
| parent | e27ad6560e4b5993315b56d6884ca5a4652468f4 (diff) | |
| download | lwn-e880034cf7182aa35962bd30dfc9fa60476d56a4.tar.gz lwn-e880034cf7182aa35962bd30dfc9fa60476d56a4.zip | |
mm: introduce page_mapcount_is_type()
Resolve the awkward "and add one to this opaque constant" test into a
self-documenting inline function.
Link: https://lkml.kernel.org/r/20240821173914.2270383-3-willy@infradead.org
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Acked-by: David Hildenbrand <david@redhat.com>
Cc: Hyeonggon Yoo <42.hyeyoo@gmail.com>
Cc: Kent Overstreet <kent.overstreet@linux.dev>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Diffstat (limited to 'include/linux')
| -rw-r--r-- | include/linux/mm.h | 3 | ||||
| -rw-r--r-- | include/linux/page-flags.h | 12 |
2 files changed, 10 insertions, 5 deletions
diff --git a/include/linux/mm.h b/include/linux/mm.h index 0fde51c0532f..6f6053d7ea6f 100644 --- a/include/linux/mm.h +++ b/include/linux/mm.h @@ -1228,8 +1228,7 @@ static inline int folio_mapcount(const struct folio *folio) if (likely(!folio_test_large(folio))) { mapcount = atomic_read(&folio->_mapcount) + 1; - /* Handle page_has_type() pages */ - if (mapcount < PAGE_MAPCOUNT_RESERVE + 1) + if (page_mapcount_is_type(mapcount)) mapcount = 0; return mapcount; } diff --git a/include/linux/page-flags.h b/include/linux/page-flags.h index 2515ae85f191..0b5484fdbca1 100644 --- a/include/linux/page-flags.h +++ b/include/linux/page-flags.h @@ -956,12 +956,18 @@ enum pagetype { #define folio_test_type(folio, flag) \ ((READ_ONCE(folio->page.page_type) & (PAGE_TYPE_BASE | flag)) == PAGE_TYPE_BASE) -static inline int page_type_has_type(unsigned int page_type) +static inline bool page_type_has_type(int page_type) { - return (int)page_type < PAGE_MAPCOUNT_RESERVE; + return page_type < PAGE_MAPCOUNT_RESERVE; } -static inline int page_has_type(const struct page *page) +/* This takes a mapcount which is one more than page->_mapcount */ +static inline bool page_mapcount_is_type(unsigned int mapcount) +{ + return page_type_has_type(mapcount - 1); +} + +static inline bool page_has_type(const struct page *page) { return page_type_has_type(READ_ONCE(page->page_type)); } |