thp, vmstats: add counters for huge file pages

THP_FILE_ALLOC: how many times huge page was allocated and put page
cache.

THP_FILE_MAPPED: how many times file huge page was mapped.

Link: http://lkml.kernel.org/r/1466021202-61880-13-git-send-email-kirill.shutemov@linux.intel.com
Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

1 files changed, 1 insertions, 0 deletions

diff --git a/mm/memory.c b/mm/memory.c
index 650622a3a0a1..10a424eca8a4 100644
--- a/mm/memory.c
+++ b/mm/memory.c
@@ -2968,6 +2968,7 @@ static int do_set_pmd(struct fault_env *fe, struct page *page)
 
         /* fault is handled */
         ret = 0;
+        count_vm_event(THP_FILE_MAPPED);
 out:
         spin_unlock(fe->ptl);
         return ret;