Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932321Ab2JBVQ2 (ORCPT ); Tue, 2 Oct 2012 17:16:28 -0400 Received: from mail.linuxfoundation.org ([140.211.169.12]:53119 "EHLO mail.linuxfoundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751553Ab2JBVQ1 (ORCPT ); Tue, 2 Oct 2012 17:16:27 -0400 Date: Tue, 2 Oct 2012 14:16:26 -0700 From: Andrew Morton To: Ed Cashin Cc: linux-kernel@vger.kernel.org Subject: Re: [PATCH 2/7] aoe: retain static block device numbers for backwards compatibility Message-Id: <20121002141626.4ac3c537.akpm@linux-foundation.org> In-Reply-To: <1dd6f0e49b1c1fb151ba57df86bff4b81aa0b258.1349104674.git.ecashin@coraid.com> References: <3c9c2338b9c963e1d5f19cc9ed51b01cf829eeee.1349104674.git.ecashin@coraid.com> <1dd6f0e49b1c1fb151ba57df86bff4b81aa0b258.1349104674.git.ecashin@coraid.com> X-Mailer: Sylpheed 3.0.2 (GTK+ 2.20.1; x86_64-pc-linux-gnu) Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 981 Lines: 24 On Mon, 1 Oct 2012 19:01:15 -0700 Ed Cashin wrote: > The old mapping between AoE target shelf and slot addresses and > the block device minor number is retained as a > backwards-compatible feature, with a new "aoe_dyndevs" module > parameter available for enabling dynamic block device minor > numbers. OK, so the default behaviour is unchanged and users opt into the new behaviour by providing this module parameter? Why is this worth doing? What behaviour changes would users see if we defaulted to dynamic minors? I'm surprised we don't have some library code somewhere for managing a map of minor numbers - it's an operation which is common to so many drivers. It would be bitmap or IDR based, I expect. -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/