From mboxrd@z Thu Jan 1 00:00:00 1970 From: mingming cao Subject: Re: [LSF/MM TOPIC] VFS hot tracking Date: Thu, 07 Feb 2013 13:04:15 -0800 Message-ID: <511416CF.5080600@oracle.com> References: Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Cc: lsf-pc@lists.linux-foundation.org, linux-fsdevel@vger.kernel.org, chris.mason@fusionio.com, linuxram@linux.vnet.ibm.com To: Zhi Yong Wu Return-path: Received: from aserp1040.oracle.com ([141.146.126.69]:42020 "EHLO aserp1040.oracle.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1759448Ab3BGVEn (ORCPT ); Thu, 7 Feb 2013 16:04:43 -0500 In-Reply-To: Sender: linux-fsdevel-owner@vger.kernel.org List-ID: On 02/07/2013 08:24 AM, Zhi Yong Wu wrote: > HI, > > If some guy is interested in this topic, i would like to talk about > VFS hot tracking. > > The feature will add the support for tracking data temperature > information in VFS layer. Essentially, this means maintaining some key > hot data statistics (like number of reads/writes, last read/write > time, frequency of reads/writes), then distilling those numbers down > to a single "temperature" value that reflects what data is "hot", then > specific FS such as btrfs will take use of the temperature infomation > to move hot data to SSDs, or do the defragmetation. > > In this talk, i would discuss its current implementation and how > its key points are resolved such as memory consumption, how its hot > data is updated periodically, etc. > > If you have any suggestions, pleas let me know, thanks. > > That sounds a good fit for the LSF discussion. I am happy to hear the update of this feature and where it will go from here. Especially discussions of APIs that expose the data hotness and how that information could be used by filesystems and storages. Mingming