From 832fc1de01aea28255cb11d270679b7f1273f0d7 Mon Sep 17 00:00:00 2001 From: Naoya Horiguchi Date: Thu, 17 Mar 2016 14:17:41 -0700 Subject: /proc/kpageflags: return KPF_BUDDY for "tail" buddy pages Currently /proc/kpageflags returns nothing for "tail" buddy pages, which is inconvenient when grasping how free pages are distributed. This patch sets KPF_BUDDY for such pages. With this patch: $ grep MemFree /proc/meminfo ; tools/vm/page-types -b buddy MemFree: 3134992 kB flags page-count MB symbolic-flags long-symbolic-flags 0x0000000000000400 779272 3044 __________B_______________________________ buddy 0x0000000000000c00 4385 17 __________BM______________________________ buddy,mmap total 783657 3061 783657 pages is 3134628 kB (roughly consistent with the global counter,) so it's OK. [akpm@linux-foundation.org: update comment, per Naoya] Signed-off-by: Naoya Horiguchi Reviewed-by: Vladimir Davydov > Cc: Konstantin Khlebnikov Cc: Naoya Horiguchi Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- include/linux/page-flags.h | 2 ++ 1 file changed, 2 insertions(+) (limited to 'include') diff --git a/include/linux/page-flags.h b/include/linux/page-flags.h index 19724e6ebd26..597695523679 100644 --- a/include/linux/page-flags.h +++ b/include/linux/page-flags.h @@ -593,6 +593,8 @@ static inline void __ClearPageBuddy(struct page *page) atomic_set(&page->_mapcount, -1); } +extern bool is_free_buddy_page(struct page *page); + #define PAGE_BALLOON_MAPCOUNT_VALUE (-256) static inline int PageBalloon(struct page *page) -- cgit v1.2.3