From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-pl0-f72.google.com (mail-pl0-f72.google.com [209.85.160.72]) by kanga.kvack.org (Postfix) with ESMTP id 04EF26B039E for ; Wed, 9 May 2018 04:24:06 -0400 (EDT) Received: by mail-pl0-f72.google.com with SMTP id d9-v6so3357104plj.4 for ; Wed, 09 May 2018 01:24:05 -0700 (PDT) Received: from mga14.intel.com (mga14.intel.com. [192.55.52.115]) by mx.google.com with ESMTPS id 32-v6si14910130plc.252.2018.05.09.01.24.04 for (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Wed, 09 May 2018 01:24:04 -0700 (PDT) From: "Huang, Ying" Subject: [PATCH -mm] mm, THP, doc: Add document for thp_swpout/thp_swpout_fallback Date: Wed, 9 May 2018 16:23:41 +0800 Message-Id: <20180509082341.13953-1-ying.huang@intel.com> Sender: owner-linux-mm@kvack.org List-ID: To: Andrew Morton , Jonathan Corbet Cc: linux-mm@kvack.org, linux-doc@vger.kernel.org, linux-kernel@vger.kernel.org, Huang Ying , "Kirill A. Shutemov" , Andrea Arcangeli , Johannes Weiner From: Huang Ying Add document for newly added thp_swpout, thp_swpout_fallback fields in /proc/vmstat. Signed-off-by: "Huang, Ying" Cc: "Kirill A. Shutemov" Cc: Andrea Arcangeli Cc: Johannes Weiner --- 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