From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754149AbaAUJjL (ORCPT ); Tue, 21 Jan 2014 04:39:11 -0500 Received: from e39.co.us.ibm.com ([32.97.110.160]:49601 "EHLO e39.co.us.ibm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753973AbaAUJjH (ORCPT ); Tue, 21 Jan 2014 04:39:07 -0500 Date: Tue, 21 Jan 2014 17:38:59 +0800 From: Han Pingtian To: linux-kernel@vger.kernel.org Cc: Andrew Morton , Michal Hocko , Mel Gorman , linux-mm@kvack.org, Dave Hansen , David Rientjes Subject: [RFC] restore user defined min_free_kbytes when disabling thp Message-ID: <20140121093859.GA7546@localhost.localdomain> Mail-Followup-To: linux-kernel@vger.kernel.org, Andrew Morton , Michal Hocko , Mel Gorman , linux-mm@kvack.org, Dave Hansen , David Rientjes MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline User-Agent: Mutt/1.5.21 (2010-09-15) X-TM-AS-MML: disable X-Content-Scanned: Fidelis XPS MAILER x-cbid: 14012109-9332-0000-0000-000002D50FDD Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org The testcase 'thp04' of LTP will enable THP, do some testing, then disable it if it wasn't enabled. But this will leave a different value of min_free_kbytes if it has been set by admin. So I think it's better to restore the user defined value after disabling THP. --- thp increases the value of min_free_kbytes in initialization. This will change the user defined value of min_free_kbytes. So try to restore the value when disabling thp. Signed-off-by: Han Pingtian --- mm/huge_memory.c | 9 +++++++++ 1 files changed, 9 insertions(+), 0 deletions(-) diff --git a/mm/huge_memory.c b/mm/huge_memory.c index 94a824f..276180b 100644 --- a/mm/huge_memory.c +++ b/mm/huge_memory.c @@ -164,6 +164,15 @@ static int start_khugepaged(void) } else if (khugepaged_thread) { kthread_stop(khugepaged_thread); khugepaged_thread = NULL; + + if (user_min_free_kbytes >= 0) { + pr_info("restore min_free_kbytes from %d to user " + "defined %d when stopping khugepaged\n", + min_free_kbytes, user_min_free_kbytes); + + min_free_kbytes = user_min_free_kbytes; + setup_per_zone_wmarks(); + } } return err; -- 1.7.7.6