Commit e873c49fbfdd595481976b915850e682441bcbec

Authored by Naoya Horiguchi
Committed by Linus Torvalds
1 parent 025c5b2451

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>

Showing 2 changed files with 3 additions and 0 deletions Side-by-side Diff

... ... @@ -115,6 +115,8 @@
115 115 u |= 1 << KPF_COMPOUND_TAIL;
116 116 if (PageHuge(page))
117 117 u |= 1 << KPF_HUGE;
  118 + else if (PageTransCompound(page))
  119 + u |= 1 << KPF_THP;
118 120  
119 121 /*
120 122 * Caveats on high order pages: page->_count will only be set
include/linux/kernel-page-flags.h
... ... @@ -30,6 +30,7 @@
30 30 #define KPF_NOPAGE 20
31 31  
32 32 #define KPF_KSM 21
  33 +#define KPF_THP 22
33 34  
34 35 /* kernel hacking assistances
35 36 * WARNING: subject to change, never rely on them!