From: Theodore Tso Subject: Re: Question on block group allocation Date: Wed, 29 Apr 2009 15:16:47 -0400 Message-ID: <20090429191646.GF14264@mit.edu> References: <6601abe90904230941x5cdd590ck2d51410326df2fc5@mail.gmail.com> <20090423190817.GN3209@webber.adilger.int> <6601abe90904231502y393155dbrf8913b728c704320@mail.gmail.com> <20090427021411.GA9059@mit.edu> <6601abe90904262229w602e17d8s51ceae05c2895ce5@mail.gmail.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Cc: Andreas Dilger , ext4 development To: Curt Wohlgemuth Return-path: Received: from THUNK.ORG ([69.25.196.29]:56839 "EHLO thunker.thunk.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751545AbZD2TQy (ORCPT ); Wed, 29 Apr 2009 15:16:54 -0400 Content-Disposition: inline In-Reply-To: <6601abe90904262229w602e17d8s51ceae05c2895ce5@mail.gmail.com> Sender: linux-ext4-owner@vger.kernel.org List-ID: On Sun, Apr 26, 2009 at 11:29:39PM -0600, Curt Wohlgemuth wrote: > The random read throughput on the 10GB file went from ~16 MB/s to ~22 > MB/s after Andreas' patch; the total fragmentation of the file was > much lower than before his patch. > > However, the number of extents went up by quite a bit (I don't have > the debugfs output in front of me at the moment, sorry). It seemed > that no extent crossed a block group; I didn't have time to see if > Andreas' patch disabled flex BGs or not, as to what was going on. > > I'll be able to send details out on Tuesday. Hi Curt, When you have a chance, can you send out the details from your test run? Many thanks, - Ted