From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-wr0-f198.google.com (mail-wr0-f198.google.com [209.85.128.198]) by kanga.kvack.org (Postfix) with ESMTP id 7549A6B04E3 for ; Tue, 11 Jul 2017 07:07:02 -0400 (EDT) Received: by mail-wr0-f198.google.com with SMTP id x23so30920196wrb.6 for ; Tue, 11 Jul 2017 04:07:02 -0700 (PDT) Received: from mx0a-001b2d01.pphosted.com (mx0b-001b2d01.pphosted.com. [148.163.158.5]) by mx.google.com with ESMTPS id c47si10249336wrc.110.2017.07.11.04.07.00 for (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Tue, 11 Jul 2017 04:07:01 -0700 (PDT) Received: from pps.filterd (m0098414.ppops.net [127.0.0.1]) by mx0b-001b2d01.pphosted.com (8.16.0.21/8.16.0.21) with SMTP id v6BB4dKn125748 for ; Tue, 11 Jul 2017 07:07:00 -0400 Received: from e23smtp08.au.ibm.com (e23smtp08.au.ibm.com [202.81.31.141]) by mx0b-001b2d01.pphosted.com with ESMTP id 2bmv0bbga9-1 (version=TLSv1.2 cipher=AES256-SHA bits=256 verify=NOT) for ; Tue, 11 Jul 2017 07:06:59 -0400 Received: from localhost by e23smtp08.au.ibm.com with IBM ESMTP SMTP Gateway: Authorized Use Only! Violators will be prosecuted for from ; Tue, 11 Jul 2017 21:06:57 +1000 Received: from d23av01.au.ibm.com (d23av01.au.ibm.com [9.190.234.96]) by d23relay10.au.ibm.com (8.14.9/8.14.9/NCO v10.0) with ESMTP id v6BB6rIA22872192 for ; Tue, 11 Jul 2017 21:06:53 +1000 Received: from d23av01.au.ibm.com (localhost [127.0.0.1]) by d23av01.au.ibm.com (8.14.4/8.14.4/NCO v10.0 AVout) with ESMTP id v6BB6qH3005451 for ; Tue, 11 Jul 2017 21:06:53 +1000 Subject: Re: [RFC] mm/mremap: Remove redundant checks inside vma_expandable() References: <20170710111059.30795-1-khandual@linux.vnet.ibm.com> <20170710134917.GB19645@dhcp22.suse.cz> <20170711060354.GA24852@dhcp22.suse.cz> <4c182da0-6c84-df67-b173-6960fac0544a@suse.cz> <20170711065030.GE24852@dhcp22.suse.cz> From: Anshuman Khandual Date: Tue, 11 Jul 2017 16:36:40 +0530 MIME-Version: 1.0 In-Reply-To: <20170711065030.GE24852@dhcp22.suse.cz> Content-Type: text/plain; charset=windows-1252 Content-Transfer-Encoding: 7bit Message-Id: Sender: owner-linux-mm@kvack.org List-ID: To: Michal Hocko , Vlastimil Babka Cc: Anshuman Khandual , linux-mm@kvack.org, linux-kernel@vger.kernel.org, akpm@linux-foundation.org, mike.kravetz@oracle.com On 07/11/2017 12:20 PM, Michal Hocko wrote: > On Tue 11-07-17 08:26:40, Vlastimil Babka wrote: >> On 07/11/2017 08:03 AM, Michal Hocko wrote: >>> On Tue 11-07-17 09:58:42, Anshuman Khandual wrote: >>>>> here. This is hardly something that would save many cycles in a >>>>> relatively cold path. >>>> Though I have not done any detailed instruction level measurement, >>>> there is a reduction in real and system amount of time to execute >>>> the test with and without the patch. >>>> >>>> Without the patch >>>> >>>> real 0m2.100s >>>> user 0m0.162s >>>> sys 0m1.937s >>>> >>>> With this patch >>>> >>>> real 0m0.928s >>>> user 0m0.161s >>>> sys 0m0.756s >>> Are you telling me that two if conditions cause more than a second >>> difference? That sounds suspicious. >> It's removing also a call to get_unmapped_area(), AFAICS. That means a >> vma search? > Ohh, right. I have somehow missed that. Is this removal intentional? The > changelog is silent about it. Yeah it was. -- 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