diff options
Diffstat (limited to 'include')
| -rw-r--r-- | include/linux/mm.h | 18 |
1 files changed, 18 insertions, 0 deletions
diff --git a/include/linux/mm.h b/include/linux/mm.h index 0e266fe1b4c..a17b147c61e 100644 --- a/include/linux/mm.h +++ b/include/linux/mm.h @@ -296,6 +296,24 @@ void put_pages_list(struct list_head *pages); void split_page(struct page *page, unsigned int order); /* + * Compound pages have a destructor function. Provide a + * prototype for that function and accessor functions. + * These are _only_ valid on the head of a PG_compound page. + */ +typedef void compound_page_dtor(struct page *); + +static inline void set_compound_page_dtor(struct page *page, + compound_page_dtor *dtor) +{ + page[1].lru.next = (void *)dtor; +} + +static inline compound_page_dtor *get_compound_page_dtor(struct page *page) +{ + return (compound_page_dtor *)page[1].lru.next; +} + +/* * Multiple processes may "see" the same page. E.g. for untouched * mappings of /dev/null, all processes see the same page full of * zeroes, and text pages of executables and shared libraries have |