From mboxrd@z Thu Jan 1 00:00:00 1970 From: "Srivatsa S. Bhat" Subject: Re: [RFC PATCH 0/8][Sorted-buddy] mm: Linux VM Infrastructure to support Memory Power Management Date: Mon, 12 Nov 2012 21:44:26 +0530 Message-ID: <50A12062.4070205@linux.vnet.ibm.com> References: <20121106195026.6941.24662.stgit@srivatsabhat.in.ibm.com> <20121108180257.GC8218@suse.de> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Return-path: Received: from e23smtp09.au.ibm.com ([202.81.31.142]:33745 "EHLO e23smtp09.au.ibm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753672Ab2KLQPx (ORCPT ); Mon, 12 Nov 2012 11:15:53 -0500 Received: from /spool/local by e23smtp09.au.ibm.com with IBM ESMTP SMTP Gateway: Authorized Use Only! Violators will be prosecuted for from ; Tue, 13 Nov 2012 02:11:59 +1000 In-Reply-To: Sender: linux-pm-owner@vger.kernel.org List-Id: linux-pm@vger.kernel.org To: SrinivasPandruvada , "akpm@linux-foundation.org" , Mel Gorman , mjg59@srcf.ucam.org, "Paul E. McKenney" , Dave Hansen , maxime.coquelin@stericsson.com, loic.pallardy@stericsson.com, Arjan van de Ven , kmpark@infradead.org, kamezawa.hiroyu@jp.fujitsu.com, Len Brown , "Rafael J. Wysocki" Cc: linux-pm@vger.kernel.org, Ankita Garg , amit.kachhap@linaro.org, Vaidyanathan Srinivasan , thomas.abraham@linaro.org, Santosh Shilimkar , "Srivatsa S. Bhat" , linux-mm@kvack.org, "linux-kernel@vger.kernel.org" , andi@firstfloor.org Hi Srinivas, It looks like your email did not get delivered to the mailing lists (and the people in the CC list) properly. So quoting your entire mail as-it-is here. And thanks a lot for taking a look at this patchset! Regards, Srivatsa S. Bhat On 11/09/2012 10:18 PM, SrinivasPandruvada wrote: > I did like this implementation and think it is valuable. > I am experimenting with one of our HW. This type of partition does help in > saving power. We believe we can save up-to 1W power per DIM with the help > of some HW/BIOS changes. We are only talking about content preserving memory, > so we don't have to be 100% correct. > In my experiments, I tried two methods: > - Similar to approach suggested by Mel Gorman. I have a special sticky > migrate type like CMA. > - Buddy buckets: Buddies are organized into memory region aware buckets. > During allocation it prefers higher order buckets. I made sure that there is > no affect of my change if there are no power saving memory DIMs. The advantage > of this bucket is that I can keep the memory in close proximity for a related > task groups by direct hashing to a bucket. The free list if organized as two > dimensional array with bucket and migrate type for each order. > > In both methods, currently reclaim is targetted to be done by a sysfs interface > similar to memory compaction for a node allowing user space to initiate reclaim. > > Thanks, > Srinivas Pandruvada > Open Source Technology Center, > Intel Corp. >