From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755648Ab0EUNhu (ORCPT ); Fri, 21 May 2010 09:37:50 -0400 Received: from cantor.suse.de ([195.135.220.2]:45621 "EHLO mx1.suse.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753829Ab0EUNht (ORCPT ); Fri, 21 May 2010 09:37:49 -0400 From: Nikanth Karthikesan Organization: suse.de To: Kay Sievers Subject: Re: add devname module aliases to allow module on-demand auto-loading Date: Fri, 21 May 2010 19:09:28 +0530 User-Agent: KMail/1.12.4 (Linux/2.6.31.12-0.2-desktop; KDE/4.3.5; x86_64; ; ) Cc: Alasdair G Kergon , "linux-kernel" , "Greg Kroah-Hartman" , "David S. Miller" , Miklos Szeredi , Chris Mason , Tigran Aivazian , Ian Kent References: <1274371640.302.5.camel@yio.site> In-Reply-To: MIME-Version: 1.0 Content-Type: Text/Plain; charset="utf-8" Content-Transfer-Encoding: 7bit Message-Id: <201005211909.29326.knikanth@suse.de> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Friday 21 May 2010 18:41:38 Kay Sievers wrote: > On Fri, May 21, 2010 at 13:51, Kay Sievers wrote: > > On Fri, May 21, 2010 at 13:34, Alasdair G Kergon wrote: > > > > There is no harm to make a well-know device node static, it just > > solves a lot of problems, and also makes it possible to work off of a > > static /dev. > > To illustrate: > > On my box without this patch: > dmsetup version > Library version: 1.02.42 (2010-01-14) > /proc/misc: No entry for device-mapper found > Is device-mapper driver missing from kernel? > Failure to communicate with kernel device-mapper driver. > > And the same box just with this patch, nothing else changed: > dmsetup version > Library version: 1.02.42 (2010-01-14) > Driver version: 4.17.0 > > But its up to you to care if device-mapper just works, or if there is > stuff like an init script with modprobe needed to load stuff that > might never be needed. :) > If this is needed, the dmsetup itself can do a `modprobe dm` instead of printing the message, "Is device-mapper driver missing from kernel?"? > This is surely not about dynamic vs. static, it is about race-free > on-demand activation of services and subsystems. > Loading dm-mod alone is enough for `dmsetup version`. But for other operations dm-mod may not be enough, as various other modules like dm-crypt, dm- mirror,... would also be required, depending on the dm table, which may or may not be installed. Thanks Nikanth > Thanks, > Kay > -- > 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/ >