From: Robin Dong Subject: Question about BIGALLOC Date: Fri, 5 Aug 2011 15:59:01 +0800 Message-ID: Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1 Cc: linux-ext4@vger.kernel.org To: "Ted Ts'o" Return-path: Received: from mail-qy0-f174.google.com ([209.85.216.174]:41283 "EHLO mail-qy0-f174.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750908Ab1HEH7D (ORCPT ); Fri, 5 Aug 2011 03:59:03 -0400 Received: by qyk38 with SMTP id 38so172325qyk.19 for ; Fri, 05 Aug 2011 00:59:01 -0700 (PDT) Sender: linux-ext4-owner@vger.kernel.org List-ID: Hi, Ted I am doing some test of BIGALLOC using "next" branch of e2fsprogs and kernel (3.0) with 23 bigalloc-patches. Everything seems to work, but I have a question: the "ee_len" of "struct ext4_extent" is used to indicate block numbers not cluster, an ext4_extent in 4K-block-size filesystem can only hold 128MB space at most even with BIGALLOC feature enabled, so we don't have any benefit from this for a file with large number of blocks. Is this the design behavior or you will change it in the next version? -- -- Best Regard Robin Dong