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>

3 files changed, 10 insertions, 0 deletions

diff --git a/include/linux/vm_event_item.h b/include/linux/vm_event_item.h
index ec084321fe09..42604173f122 100644
--- a/include/linux/vm_event_item.h
+++ b/include/linux/vm_event_item.h
@@ -70,6 +70,8 @@ enum vm_event_item { PGPGIN, PGPGOUT, PSWPIN, PSWPOUT,
                 THP_FAULT_FALLBACK,
                 THP_COLLAPSE_ALLOC,
                 THP_COLLAPSE_ALLOC_FAILED,
+                THP_FILE_ALLOC,
+                THP_FILE_MAPPED,
                 THP_SPLIT_PAGE,
                 THP_SPLIT_PAGE_FAILED,
                 THP_DEFERRED_SPLIT_PAGE,
@@ -100,4 +102,9 @@ enum vm_event_item { PGPGIN, PGPGOUT, PSWPIN, PSWPOUT,
                 NR_VM_EVENT_ITEMS
 };
 
+#ifndef CONFIG_TRANSPARENT_HUGEPAGE
+#define THP_FILE_ALLOC ({ BUILD_BUG(); 0; })
+#define THP_FILE_MAPPED ({ BUILD_BUG(); 0; })
+#endif
+
 #endif          /* VM_EVENT_ITEM_H_INCLUDED */
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;
diff --git a/mm/vmstat.c b/mm/vmstat.c
index 2a0f26bdae39..cff2f4ec9cce 100644
--- a/mm/vmstat.c
+++ b/mm/vmstat.c
@@ -817,6 +817,8 @@ const char * const vmstat_text[] = {
         "thp_fault_fallback",
         "thp_collapse_alloc",
         "thp_collapse_alloc_failed",
+        "thp_file_alloc",
+        "thp_file_mapped",
         "thp_split_page",
         "thp_split_page_failed",
         "thp_deferred_split_page",