From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S263025AbTDFPwf (for ); Sun, 6 Apr 2003 11:52:35 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S263026AbTDFPwe (for ); Sun, 6 Apr 2003 11:52:34 -0400 Received: from ns.virtualhost.dk ([195.184.98.160]:4519 "EHLO virtualhost.dk") by vger.kernel.org with ESMTP id S263025AbTDFPwc (for ); Sun, 6 Apr 2003 11:52:32 -0400 Date: Sun, 6 Apr 2003 18:04:09 +0200 From: Jens Axboe To: John Bradford Cc: Alan Cox , linux-kernel@vger.kernel.org Subject: Re: [PATCH] take 48-bit lba a bit further Message-ID: <20030406160409.GP786@suse.de> References: <1049639724.962.7.camel@dhcp22.swansea.linux.org.uk> <200304061547.h36FlvbL000563@81-2-122-30.bradfords.org.uk> <20030406155941.GO786@suse.de> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20030406155941.GO786@suse.de> Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org On Sun, Apr 06 2003, Jens Axboe wrote: > On Sun, Apr 06 2003, John Bradford wrote: > > I originally thought that we might only be honouring 512Kb requests > > for blocks over the 28-bit limit, which Jens corrected me on, but > > maybe we *should* only do 512Kb requests on high block number, where > > we have to use 48-bit anyway. > > That makes little sense in practice, and is not currently even doable > within the block layer. You got the limits wrong, btw, it's 128kb max > for 28-bit. A single 512KiB request will have a lower per-kb overhead > with 48-bit lba than a single 128kb on 28-bit would. I should mention that the 512KiB number is one I chose, as a good large request size. You could as high as 32MiB. -- Jens Axboe