From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S934092AbeEIIYI (ORCPT ); Wed, 9 May 2018 04:24:08 -0400 Received: from mga02.intel.com ([134.134.136.20]:45755 "EHLO mga02.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S933811AbeEIIYF (ORCPT ); Wed, 9 May 2018 04:24:05 -0400 X-Amp-Result: SKIPPED(no attachment in message) X-Amp-File-Uploaded: False X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.49,381,1520924400"; d="scan'208";a="47858160" From: "Huang, Ying" 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 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> X-Mailer: git-send-email 2.16.1 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 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