[PATCH -mm] mm, THP, doc: Add document for thp_swpout/thp_swpout_fallback

* [PATCH -mm] mm, THP, doc: Add document for thp_swpout/thp_swpout_fallback
@ 2018-05-09  8:23 Huang, Ying
  2018-05-10 20:06 ` Jonathan Corbet
  0 siblings, 1 reply; 2+ messages in thread
From: Huang, Ying @ 2018-05-09  8:23 UTC (permalink / raw)
  To: Andrew Morton, Jonathan Corbet
  Cc: linux-mm, linux-doc, linux-kernel, Huang Ying,
	Kirill A. Shutemov, Andrea Arcangeli, Johannes Weiner

From: Huang Ying <ying.huang@intel.com>

Add document for newly added thp_swpout, thp_swpout_fallback fields in
/proc/vmstat.

Signed-off-by: "Huang, Ying" <ying.huang@intel.com>
Cc: "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
---
 Documentation/vm/transhuge.rst | 9 +++++++++
 1 file changed, 9 insertions(+)

diff --git a/Documentation/vm/transhuge.rst b/Documentation/vm/transhuge.rst
index 569d182cc973..2c6867fca6ff 100644
--- a/Documentation/vm/transhuge.rst
+++ b/Documentation/vm/transhuge.rst
@@ -355,6 +355,15 @@ thp_zero_page_alloc_failed
 	is incremented if kernel fails to allocate
 	huge zero page and falls back to using small pages.
 
+thp_swpout
+	is incremented every time a huge page is swapout in one
+	piece without splitting.
+
+thp_swpout_fallback
+	is incremented if a huge page has to be split before swapout.
+	Usually because failed to allocate some continuous swap space
+	for the huge page.
+
 As the system ages, allocating huge pages may be expensive as the
 system uses memory compaction to copy data around memory to free a
 huge page for use. There are some counters in ``/proc/vmstat`` to help
-- 
2.16.1

^ permalink raw reply related	[flat|nested] 2+ messages in thread