diff options
Diffstat (limited to 'fs/proc/internal.h')
| -rw-r--r-- | fs/proc/internal.h | 33 |
1 files changed, 33 insertions, 0 deletions
diff --git a/fs/proc/internal.h b/fs/proc/internal.h index a71ac5379584..a8a8576d8592 100644 --- a/fs/proc/internal.h +++ b/fs/proc/internal.h @@ -13,6 +13,7 @@ #include <linux/binfmts.h> #include <linux/sched/coredump.h> #include <linux/sched/task.h> +#include <linux/mm.h> struct ctl_table_header; struct mempolicy; @@ -142,6 +143,38 @@ unsigned name_to_int(const struct qstr *qstr); /* Worst case buffer size needed for holding an integer. */ #define PROC_NUMBUF 13 +/** + * folio_precise_page_mapcount() - Number of mappings of this folio page. + * @folio: The folio. + * @page: The page. + * + * The number of present user page table entries that reference this page + * as tracked via the RMAP: either referenced directly (PTE) or as part of + * a larger area that covers this page (e.g., PMD). + * + * Use this function only for the calculation of existing statistics + * (USS, PSS, mapcount_max) and for debugging purposes (/proc/kpagecount). + * + * Do not add new users. + * + * Returns: The number of mappings of this folio page. 0 for + * folios that are not mapped to user space or are not tracked via the RMAP + * (e.g., shared zeropage). + */ +static inline int folio_precise_page_mapcount(struct folio *folio, + struct page *page) +{ + int mapcount = atomic_read(&page->_mapcount) + 1; + + /* Handle page_has_type() pages */ + if (mapcount < PAGE_MAPCOUNT_RESERVE + 1) + mapcount = 0; + if (folio_test_large(folio)) + mapcount += folio_entire_mapcount(folio); + + return mapcount; +} + /* * array.c */ |