From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-pa0-f50.google.com (mail-pa0-f50.google.com [209.85.220.50]) by kanga.kvack.org (Postfix) with ESMTP id F17996B0032 for ; Thu, 26 Sep 2013 15:00:14 -0400 (EDT) Received: by mail-pa0-f50.google.com with SMTP id fb1so1714386pad.37 for ; Thu, 26 Sep 2013 12:00:14 -0700 (PDT) Received: from /spool/local by e28smtp02.in.ibm.com with IBM ESMTP SMTP Gateway: Authorized Use Only! Violators will be prosecuted for from ; Fri, 27 Sep 2013 00:30:09 +0530 Received: from d28relay01.in.ibm.com (d28relay01.in.ibm.com [9.184.220.58]) by d28dlp02.in.ibm.com (Postfix) with ESMTP id 29E62394005A for ; Fri, 27 Sep 2013 00:29:52 +0530 (IST) Received: from d28av03.in.ibm.com (d28av03.in.ibm.com [9.184.220.65]) by d28relay01.in.ibm.com (8.13.8/8.13.8/NCO v10.0) with ESMTP id r8QJ2PRS31588596 for ; Fri, 27 Sep 2013 00:32:25 +0530 Received: from d28av03.in.ibm.com (localhost [127.0.0.1]) by d28av03.in.ibm.com (8.14.4/8.14.4/NCO v10.0 AVout) with ESMTP id r8QJ069B018180 for ; Fri, 27 Sep 2013 00:30:07 +0530 Message-ID: <52448340.7060802@linux.vnet.ibm.com> Date: Fri, 27 Sep 2013 00:26:00 +0530 From: "Srivatsa S. Bhat" MIME-Version: 1.0 Subject: Re: [Results] [RFC PATCH v4 00/40] mm: Memory Power Management References: <20130925231250.26184.31438.stgit@srivatsabhat.in.ibm.com> <52437128.7030402@linux.vnet.ibm.com> <20130925164057.6bbaf23bdc5057c42b2ab010@linux-foundation.org> <20130925234734.GK18242@two.firstfloor.org> <52438AA9.3020809@linux.intel.com> <20130925182129.a7db6a0fd2c7cc3b43fda92d@linux-foundation.org> <20130926015016.GM18242@two.firstfloor.org> <20130925195953.826a9f7d.akpm@linux-foundation.org> <524439D5.8020306@linux.vnet.ibm.com> <52445993.7050608@linux.intel.com> <52446841.2030301@linux.vnet.ibm.com> <524477AC.9090400@linux.intel.com> <52447DED.5080205@linux.vnet.ibm.com> <3908561D78D1C84285E8C5FCA982C28F31D1BA12@ORSMSX106.amr.corp.intel.com> In-Reply-To: <3908561D78D1C84285E8C5FCA982C28F31D1BA12@ORSMSX106.amr.corp.intel.com> Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Sender: owner-linux-mm@kvack.org List-ID: To: "Luck, Tony" Cc: Arjan van de Ven , Andrew Morton , Andi Kleen , "mgorman@suse.de" , "dave@sr71.net" , "hannes@cmpxchg.org" , "matthew.garrett@nebula.com" , "riel@redhat.com" , "srinivas.pandruvada@linux.intel.com" , "willy@linux.intel.com" , "kamezawa.hiroyu@jp.fujitsu.com" , "lenb@kernel.org" , "rjw@sisk.pl" , "gargankita@gmail.com" , "paulmck@linux.vnet.ibm.com" , "svaidy@linux.vnet.ibm.com" , "isimatu.yasuaki@jp.fujitsu.com" , "santosh.shilimkar@ti.com" , "kosaki.motohiro@gmail.com" , "linux-pm@vger.kernel.org" , "linux-mm@kvack.org" , "linux-kernel@vger.kernel.org" , "maxime.coquelin@stericsson.com" , "loic.pallardy@stericsson.com" , "thomas.abraham@linaro.org" , "amit.kachhap@linaro.org" On 09/27/2013 12:20 AM, Luck, Tony wrote: >> And that's it! No other case for page movement. And with this conservative >> approach itself, I'm getting great consolidation ratios! >> I am also thinking of adding more smartness in the code to be very choosy in >> doing the movement, and do it only in cases where it is almost guaranteed to >> be beneficial. For example, I can make the kmempowerd kthread more "lazy" >> while moving/reclaiming stuff; I can bias the page movements such that "cold" >> pages are left around (since they are not expected to be referenced much >> anyway) and only the (few) hot pages are moved... etc. > > Can (or should) this migrator coordinate with khugepaged - I'd hate to see them > battling over where to move pages ... or undermining each other (your daemon > frees up a 512MB area ... and khugepaged immediately grabs a couple of 2MB > pages from it to upgrade some process with a scattershot of 4K pages). > That's a very good point! I need to look into it to see how such sub-optimal behavior can be avoided (perhaps by making khugepaged region-aware)... Hmmm.. Thanks for bringing it up! Regards, Srivatsa S. Bhat -- 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