Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754254Ab0H3AtN (ORCPT ); Sun, 29 Aug 2010 20:49:13 -0400 Received: from v002983.home.net.pl ([212.85.107.189]:58648 "HELO v002983.home.net.pl" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with SMTP id S1753828Ab0H3AtL convert rfc822-to-8bit (ORCPT ); Sun, 29 Aug 2010 20:49:11 -0400 From: Hubert Kario To: Shaohua Li Subject: Re: [RFC v2 PATCH 0/6] Btrfs: Add hot data relocation functionality Date: Mon, 30 Aug 2010 02:42:26 +0200 User-Agent: KMail/1.13.5 (Linux/2.6.34-ARCH; KDE/4.4.5; i686; ; ) Cc: "bchociej@gmail.com" , "chris.mason@oracle.com" , "linux-btrfs@vger.kernel.org" , "linux-fsdevel@vger.kernel.org" , "linux-kernel@vger.kernel.org" , "cmm@us.ibm.com" , "bcchocie@us.ibm.com" , "mrlupfer@us.ibm.com" , "crscott@us.ibm.com" , "mlupfer@gmail.com" , "conscott@vt.edu" References: <1281651726-23501-1-git-send-email-bchociej@gmail.com> <20100826021343.GA452@sli10-conroe.sh.intel.com> In-Reply-To: <20100826021343.GA452@sli10-conroe.sh.intel.com> Organization: QBS Jan =?utf-8?q?Kuba=C5=84?= MIME-Version: 1.0 Content-Type: Text/Plain; charset="iso-8859-1" Content-Transfer-Encoding: 8BIT Message-Id: <201008300242.27331.hka@qbs.com.pl> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1536 Lines: 41 On Thursday 26 of August 2010 04:13:43 Shaohua Li wrote: > On Fri, Aug 13, 2010 at 06:22:00AM +0800, bchociej@gmail.com wrote: > > - Hooks in existing Btrfs functions to track data access frequency > > > > (btrfs_direct_IO, btrfs_readpages, and extent_write_cache_pages) > > > > - New rbtrees for tracking access frequency of inodes and sub-file > > > > ranges (hotdata_map.c) > > > > - A hash list for indexing data by its temperature (hotdata_hash.c) > > > > - A debugfs interface for dumping data from the rbtrees (debugfs.c) > > > > - A background kthread for relocating data to faster media based on > > > > temperature > > Hi, > I'm wondering if the temperature info can be exported to userspace, and > let a daemon to do the relocation (by ioctl). A userspace daemon is more > flexible. Flexibility of userspace daemon is one thing, the ability to let the admin precisely control on which drive data is placed could be really beneficial in some scenarios is another thing. This would also allow online defragmentation, together with access to statistics, one that (for quick runs) has really good time/performance benefit ratio. -- Hubert Kario QBS - Quality Business Software 02-656 Warszawa, ul. Ksawer?w 30/85 tel. +48 (22) 646-61-51, 646-74-24 www.qbs.com.pl -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/