From: Zheng Liu Subject: Extent tree status asking Date: Tue, 17 Apr 2012 01:55:34 +0800 Message-ID: <20120416175534.GA5533@gmail.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Cc: linux-ext4 To: Allison Henderson Return-path: Received: from mail-pz0-f52.google.com ([209.85.210.52]:47321 "EHLO mail-pz0-f52.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755102Ab2DPRtI (ORCPT ); Mon, 16 Apr 2012 13:49:08 -0400 Received: by dake40 with SMTP id e40so7214486dak.11 for ; Mon, 16 Apr 2012 10:49:08 -0700 (PDT) Content-Disposition: inline Sender: linux-ext4-owner@vger.kernel.org List-ID: Hi Allison, Currently I am trying to reduce the lock contention of direct I/O in ext4 because it is a bottleneck. A trivial idea is that a new fucntion is defined to replace the generic_file_aio_write, which do some write operations with acquiring i_data_sem lock in inode. I know that you are trying to implement extent tree, and I have seen your patch set '[PATCH] Rename delayed extents to status extents'. After extent tree is made, the implementation of direct I/O without i_mutex and range lock is straightforward and it is better than my trivial idea. I think that maybe I can borrow you works. So could you please share me your schedule and/or other information? Last month on ext4 workshop, we discuss the extent tree, range lock and I/O tree. Obviously, I/O tree is used to store I/O operations, which can track delay allocation, do unwritten->written conversion and implement range lock. It is very useful for ext4 and I am interested in this proposal. I know that you have begun to do some works. So would you like to tell me the status of extent tree? I don't know whether or not there has some things that I can be involved. If you have some advices or there is something that I can help, please let me know. Thank you and looking forward your reply. Regards, Zheng