From: Alex Tomas Subject: Re: [RFC] delayed allocation for ext4 Date: Sat, 23 Dec 2006 22:15:43 +0300 Message-ID: References: <20061223033123.GL44411608@melbourne.sgi.com> <20061223092718.GA26276@infradead.org> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Cc: David Chinner , Alex Tomas , linux-ext4@vger.kernel.org, linux-kernel@vger.kernel.org Return-path: Received: from ppp85-141-207-24.pppoe.mtu-net.ru ([85.141.207.24]:37026 "EHLO gw.home.net" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1753683AbWLWTP5 (ORCPT ); Sat, 23 Dec 2006 14:15:57 -0500 To: Christoph Hellwig In-Reply-To: <20061223092718.GA26276@infradead.org> (Christoph Hellwig's message of "Sat\, 23 Dec 2006 09\:27\:18 +0000") Sender: linux-ext4-owner@vger.kernel.org List-Id: linux-ext4.vger.kernel.org >>>>> Christoph Hellwig (CH) writes: CH> Note that recording delayed alloc state at a page granularity in addition CH> to just the buffer heads has a lot of advantages aswell and would help CH> xfs, too. But I think it makes a lot more sense to record it as a radix CH> tree tag to speed up the gang lookups for delalloc conversion. please, exaplein about radix tree tag. in ext4-delalloc I use this bit the only way - to avoid multiple reservation space for same page. I guess you need to find non-allocated pages. probably to flush them and update number of reserved blocks in case of -ENOSPC? thanks, Alex