From mboxrd@z Thu Jan 1 00:00:00 1970 From: Dave Chinner Subject: Re: [RFC v2 02/10] vfs: add support for updating access frequency Date: Thu, 27 Sep 2012 12:19:19 +1000 Message-ID: <20120927021919.GJ15236@dastard> References: <1348404995-14372-1-git-send-email-zwu.kernel@gmail.com> <1348404995-14372-3-git-send-email-zwu.kernel@gmail.com> <20120925091739.GB29154@dastard> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Cc: linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org, linux-btrfs@vger.kernel.org, linux-ext4@vger.kernel.org, linuxram@linux.vnet.ibm.com, viro@zeniv.linux.org.uk, cmm@us.ibm.com, tytso@mit.edu, marco.stornelli@gmail.com, stroetmann@ontolinux.com, diegocg@gmail.com, chris@csamuel.org, Zhi Yong Wu To: Zhi Yong Wu Return-path: Content-Disposition: inline In-Reply-To: Sender: linux-kernel-owner@vger.kernel.org List-Id: linux-fsdevel.vger.kernel.org On Wed, Sep 26, 2012 at 10:53:07AM +0800, Zhi Yong Wu wrote: > On Tue, Sep 25, 2012 at 5:17 PM, Dave Chinner wrote: > > On Sun, Sep 23, 2012 at 08:56:27PM +0800, zwu.kernel@gmail.com wrote: > > I note that the code will always insert range items of a length > > RANGE_SIZE. This means you have a fixed object granularity and hence > > you have no need for a range based search. That is, you could use a > > radix tree where each entry in the radix tree points directly to the > > range object similar to how the page cache uses a radix tree for > > indexing pages. That brings the possibility of lockless range item > > lookups.... > Great suggestion, but can we temporarily put it in TODO list? because > it will bring one big code change. Sure. I just wanted to point out that there are better choices for indexing fixed size elements than rb-trees and why it might make sense to use a different type of tree. Cheers, Dave. -- Dave Chinner david@fromorbit.com