From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752135AbbIQVfp (ORCPT ); Thu, 17 Sep 2015 17:35:45 -0400 Received: from mail-wi0-f175.google.com ([209.85.212.175]:33544 "EHLO mail-wi0-f175.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751478AbbIQVfn (ORCPT ); Thu, 17 Sep 2015 17:35:43 -0400 From: Ebru Akagunduz To: linux-mm@kvack.org Cc: riel@redhat.com, akpm@linux-foundation.org, rientjes@google.com, oleg@redhat.com, kirill.shutemov@linux.intel.com, dave@stgolabs.net, denc716@gmail.com, ldufour@linux.vnet.ibm.com, sasha.levin@oracle.com, viro@zeniv.linux.org.uk, linux-kernel@vger.kernel.org, Ebru Akagunduz Subject: [PATCH] doc: add information about max_ptes_swap Date: Fri, 18 Sep 2015 00:34:58 +0300 Message-Id: <1442525698-22598-1-git-send-email-ebru.akagunduz@gmail.com> X-Mailer: git-send-email 1.9.1 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org max_ptes_swap specifies how many pages can be brought in from swap when collapsing a group of pages into a transparent huge page. /sys/kernel/mm/transparent_hugepage/khugepaged/max_ptes_swap A higher value can cause excessive swap IO and waste memory. A lower value can prevent THPs from being collapsed, resulting fewer pages being collapsed into THPs, and lower memory access performance. Signed-off-by: Ebru Akagunduz --- Documentation/vm/transhuge.txt | 10 ++++++++++ 1 file changed, 10 insertions(+) diff --git a/Documentation/vm/transhuge.txt b/Documentation/vm/transhuge.txt index 8143b9e..8a28268 100644 --- a/Documentation/vm/transhuge.txt +++ b/Documentation/vm/transhuge.txt @@ -170,6 +170,16 @@ A lower value leads to gain less thp performance. Value of max_ptes_none can waste cpu time very little, you can ignore it. +max_ptes_swap specifies how many pages can be brought in from +swap when collapsing a group of pages into a transparent huge page. + +/sys/kernel/mm/transparent_hugepage/khugepaged/max_ptes_swap + +A higher value can cause excessive swap IO and waste +memory. A lower value can prevent THPs from being +collapsed, resulting fewer pages being collapsed into +THPs, and lower memory access performance. + == Boot parameter == You can change the sysfs boot time defaults of Transparent Hugepage -- 1.9.1