From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-wi0-f180.google.com (mail-wi0-f180.google.com [209.85.212.180]) by kanga.kvack.org (Postfix) with ESMTP id 45D176B0038 for ; Thu, 17 Sep 2015 17:35:44 -0400 (EDT) Received: by wicgb1 with SMTP id gb1so8212027wic.1 for ; Thu, 17 Sep 2015 14:35:43 -0700 (PDT) Received: from mail-wi0-x236.google.com (mail-wi0-x236.google.com. [2a00:1450:400c:c05::236]) by mx.google.com with ESMTPS id ea14si2011844wjb.214.2015.09.17.14.35.42 for (version=TLSv1.2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Thu, 17 Sep 2015 14:35:43 -0700 (PDT) Received: by wicge5 with SMTP id ge5so8343550wic.0 for ; Thu, 17 Sep 2015 14:35:42 -0700 (PDT) From: 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> Sender: owner-linux-mm@kvack.org List-ID: 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 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 -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: email@kvack.org