From mboxrd@z Thu Jan 1 00:00:00 1970 From: Alberich de megres Subject: Re: ext4 allocator Date: Mon, 25 Jan 2010 23:44:08 +0100 Message-ID: <12d708831001251444y5eaad686we802e3c0d2af34ae@mail.gmail.com> References: <12d708831001251314i2b3d1f27o22d43c006165826@mail.gmail.com> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: QUOTED-PRINTABLE Cc: linux-fsdevel@vger.kernel.org To: Andreas Dilger Return-path: Received: from mail-ew0-f219.google.com ([209.85.219.219]:43901 "EHLO mail-ew0-f219.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751027Ab0AYWoJ convert rfc822-to-8bit (ORCPT ); Mon, 25 Jan 2010 17:44:09 -0500 Received: by ewy19 with SMTP id 19so307474ewy.21 for ; Mon, 25 Jan 2010 14:44:08 -0800 (PST) In-Reply-To: Sender: linux-fsdevel-owner@vger.kernel.org List-ID: Wow, how newbie i am... Thanks man!! On Mon, Jan 25, 2010 at 10:37 PM, Andreas Dilger wrot= e: > On 2010-01-25, at 14:14, Alberich de megres wrote: >> >> I'm studyng ext4 code, and i got a doubt on a situation: >> >> Supposing a 4K page size, and a fs with 8K.. when we are filling pag= e >> info,: >> >> { 4K page }{ 4K page }{ 4K page }{ 4K page } >> [ =A0 group 0 bitmap =A0 ][ =A0 group 0 buddy =A0 =A0] >> >> Clearly bitmap and buddy info don't fits on a single page, but e4b >> structure saves only one page address. >> >> How mb allocator menages this situation?? > > > ext4, and the Linux VM/block layer in general, do not support disk bl= ock > size larger than the page size. =A0That has been a restriction for a = long time > already, and there have been various patches/proposals to fix that, b= ut > nothing that ever made it into the mainline kernel. > > Cheers, Andreas > -- > Andreas Dilger > Sr. Staff Engineer, Lustre Group > Sun Microsystems of Canada, Inc. > > -- To unsubscribe from this list: send the line "unsubscribe linux-fsdevel= " in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html