pagemap: export KPF_THP

This flag shows that a given page is a subpage of a transparent hugepage.
It helps us debug and test the kernel by showing physical address of thp.

Signed-off-by: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com>
Reviewed-by: Wu Fengguang <fengguang.wu@intel.com>
Reviewed-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Acked-by: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Cc: David Rientjes <rientjes@google.com>
Cc: Andi Kleen <andi@firstfloor.org>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This commit is contained in:
Naoya Horiguchi 2012-03-21 16:33:58 -07:00 committed by Linus Torvalds
parent 025c5b2451
commit e873c49fbf
2 changed files with 3 additions and 0 deletions

View file

@ -115,6 +115,8 @@ u64 stable_page_flags(struct page *page)
u |= 1 << KPF_COMPOUND_TAIL;
if (PageHuge(page))
u |= 1 << KPF_HUGE;
else if (PageTransCompound(page))
u |= 1 << KPF_THP;
/*
* Caveats on high order pages: page->_count will only be set

View file

@ -30,6 +30,7 @@
#define KPF_NOPAGE 20
#define KPF_KSM 21
#define KPF_THP 22
/* kernel hacking assistances
* WARNING: subject to change, never rely on them!