From owner-freebsd-questions@freebsd.org  Mon Oct 22 14:05:06 2018
Return-Path: <owner-freebsd-questions@freebsd.org>
Delivered-To: freebsd-questions@mailman.ysv.freebsd.org
Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2610:1c1:1:606c::19:1])
 by mailman.ysv.freebsd.org (Postfix) with ESMTP id 19B74FFD2C6
 for <freebsd-questions@mailman.ysv.freebsd.org>;
 Mon, 22 Oct 2018 14:05:06 +0000 (UTC)
 (envelope-from freebsd@edvax.de)
Received: from mout.kundenserver.de (mout.kundenserver.de [217.72.192.73])
 (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits))
 (Client CN "mout.kundenserver.de",
 Issuer "TeleSec ServerPass DE-2" (verified OK))
 by mx1.freebsd.org (Postfix) with ESMTPS id 7817D7B80C
 for <freebsd-questions@freebsd.org>; Mon, 22 Oct 2018 14:05:05 +0000 (UTC)
 (envelope-from freebsd@edvax.de)
Received: from r56.edvax.de ([92.193.180.181]) by mrelayeu.kundenserver.de
 (mreue107 [212.227.15.183]) with ESMTPA (Nemesis) id
 1MLhwM-1fwvRx2eNU-00HeUj; Mon, 22 Oct 2018 16:04:57 +0200
Received: from r56.edvax.de ([92.193.180.181]) by mrelayeu.kundenserver.de
 (mreue107 [212.227.15.183]) with ESMTPA (Nemesis) id
 1MLhwM-1fwvRx2eNU-00HeUj; Mon, 22 Oct 2018 16:04:57 +0200
Date: Mon, 22 Oct 2018 16:04:57 +0200
From: Polytropon <freebsd@edvax.de>
To: Graham Perrin <grahamperrin@gmail.com>
Cc: freebsd-questions@freebsd.org
Subject: Re: rc.conf(5): comparing kld_list and kldload
Message-Id: <20181022160457.6f44d232.freebsd@edvax.de>
In-Reply-To: <ded0edc1-e6aa-55ee-5b09-e58c11b8240a@gmail.com>
References: <ded0edc1-e6aa-55ee-5b09-e58c11b8240a@gmail.com>
Reply-To: Polytropon <freebsd@edvax.de>
Organization: EDVAX
X-Mailer: Sylpheed 3.1.1 (GTK+ 2.24.5; i386-portbld-freebsd8.2)
Mime-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit
X-Provags-ID: V03:K1:opjAI3ORiCePmrOpwnUFNO641xUYdSnITSrs1rQwXvGAOzbLUN+
 yfSoQ6JNcYvrcK6DO8KZRP1jHyPTAC9etnmNrBThwM/5DUWm4lWNc6ey23psX63u1Gr71Hr
 oZiCRy09L5UN93R7J3m6Pyfsy8q1UMWFrXsrdVgnxQspYOeaX1BR1VwhGB4CvkeulC/KHun
 +4bIndCpetiGvEgLCvX3A==
X-Spam-Flag: NO
X-UI-Out-Filterresults: notjunk:1;V01:K0:KkD0dGqf19A=:/lgJzA4lrDQJR5BqENXrJI
 nFA0WIDFCoEc/W9dI8AyY7sigbWvuepmxsuViBMlm6YT4kIZLjdgPQRtFSnMRJNm3V7VOSJEo
 x+my9eBBZ0fdohdG43rzSQcr5BM6QTwQGosW3o2tmMysnwmHa1GaUmiehxhQKj8KWCphwGRLO
 U6DJdnM0TrqaKc3e0NdsbPUiSAPrhROFnx8XgZTXraAWoEoo1I1tDr4SJrTM5+84JC9ZBK6mY
 aj47w0M4g6sMjdEN4xdOqnBvkbxGqPF4GzV5GlxyFdJ7jazFo4LQr3/5ehIklOpj32RNYdF8W
 DOitVYbI437JS9ZQIs97VBKedGqQSo50I40+7Ey+fIKuclpy5ieRSFx3r52B1lmCFSA7tOacQ
 nK2c1S+vZ2FyDS0eDCzOeuDGjv5EYzEZ/RDJB/t+eGwL92EFTPDpjOJA+uHmXcfmP2ocPX0aH
 Iu5SKQHYquuDlohlm/BTmkJzkJPsYRXHfiq+RGnd2lXW1DaZr1b1CJC3LtcFDtGMdYBtM1bun
 UnhyDpvcMOILuLIcnr68ID4cYoijU7OBG0Dq4FNV6eFlFyN0YY3IXlWq80p8pFhNqCoIjXjZd
 l7s2JwPn5xWW4xN11EXaDlRBLTb1dQ5Pkcs03zA2qaWc7HuQeHJMXI9Reaz4SZEFCgQWx9TaT
 x5Sl6SKqKVD/eLPOTHLgEG2L+2BrG4v1o+Gi3/8TBYRwsb4SDD0E8DZbVMHlDeDSz/HX9DXBA
 tGgIr7bvmGlWV7yg
X-BeenThere: freebsd-questions@freebsd.org
X-Mailman-Version: 2.1.29
Precedence: list
List-Id: User questions <freebsd-questions.freebsd.org>
List-Unsubscribe: <https://lists.freebsd.org/mailman/options/freebsd-questions>, 
 <mailto:freebsd-questions-request@freebsd.org?subject=unsubscribe>
List-Archive: <http://lists.freebsd.org/pipermail/freebsd-questions/>
List-Post: <mailto:freebsd-questions@freebsd.org>
List-Help: <mailto:freebsd-questions-request@freebsd.org?subject=help>
List-Subscribe: <https://lists.freebsd.org/mailman/listinfo/freebsd-questions>, 
 <mailto:freebsd-questions-request@freebsd.org?subject=subscribe>
X-List-Received-Date: Mon, 22 Oct 2018 14:05:06 -0000

On Mon, 22 Oct 2018 05:26:18 +0100, Graham Perrin wrote:
> From <https://www.freebsd.org/cgi/man.cgi?query=rc.conf&sektion=5&manpath=FreeBSD>: 
> 
> > …
> > 
> > kld_list    (str) A list of kernel modules to load right after 
> >             the local disks are mounted.  Loading modules at 
> >             this point in the boot process is much faster than 
> >             doing it via /boot/loader.conf for those modules 
> >             not necessary for mounting local disk.
> > …
> 
> Is there ever any benefit to using kldload instead of kld_list?

It is important when you consider the _time_ during system
startup. Sometimes modules require to be loaded at a certain
time, that's when you can (or cannot) use kld_list, which is
the _default_ method of loading kernel modules.

early: via /boot/loader.conf

intermediate: via kld_list in /etc/rc.conf

almost final: via kldload calls in /etc/rc.local

It's also possible for scripts in /usr/local/etc/rc.d/ to
load kernel modules, and you could even add something to
/etc/rc itself to achieve "really final" loading (even though
manual additions to /etc/rc are discouraged for good reasons).



> Background: difficulty with radeonkms and sddm following a switch
> of -CURRENT to stable/12
> 
> <https://lists.freebsd.org/pipermail/freebsd-current/2018-October/071783.html>
> 
> I'm toying with the possibility that faster is not always best;
> that a specific load/start order might help. 

Yes, this is such a case.



-- 
Polytropon
Magdeburg, Germany
Happy FreeBSD user since 4.0
Andra moi ennepe, Mousa, ...