From: Greg Freemyer Subject: Re: [PATCH 01/11 RESEND] libe2p: Add new function get_fragment_score() Date: Sat, 18 Jun 2011 13:00:54 -0400 Message-ID: References: <4DF8522F.2020304@sx.jp.nec.com> <20110617031814.GA31884@thunk.org> <4DFB62C7.5070008@redhat.com> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: QUOTED-PRINTABLE Cc: Eric Sandeen , "Ted Ts'o" , Kazuya Mio , ext4 To: Andreas Dilger Return-path: Received: from mail-bw0-f46.google.com ([209.85.214.46]:60015 "EHLO mail-bw0-f46.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751105Ab1FRRBZ convert rfc822-to-8bit (ORCPT ); Sat, 18 Jun 2011 13:01:25 -0400 Received: by bwz15 with SMTP id 15so1401479bwz.19 for ; Sat, 18 Jun 2011 10:01:24 -0700 (PDT) In-Reply-To: Sender: linux-ext4-owner@vger.kernel.org List-ID: On Sat, Jun 18, 2011 at 3:19 AM, Andreas Dilger wr= ote: > I was thinking about this, and am wondering if it makes sense to have= an absolute score for fragmentation instead of a relative one? > > By absolute I mean something like fragments per MB or similar. A bad = score might be anything > 1. For files smaller than 1 MB in size it wou= ld scale the ratio to the equivalent if the file was 1MB in size (e.g. = a 16kB file with 4 fragments would have a score of 256, which is clearl= y bad). =A0Large files can have a score much less than 1, which is good= =2E > > Cheers, Andreas Shouldn't be based on fragments per max extent size for ext4? And I think the max extent size for a 4KB page is 128 MB, right? Greg -- To unsubscribe from this list: send the line "unsubscribe linux-ext4" i= n the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html