[prev in list] [next in list] [prev in thread] [next in thread] 

List:       gentoo-dev
Subject:    Re: [gentoo-dev] Re: [gentoo-desktop] X freezing?
From:       Luke-Jr <luke-jr () utopios ! org>
Date:       2004-10-28 17:55:37
Message-ID: 200410281755.37740.luke-jr () utopios ! org
[Download RAW message or body]

On Thursday 28 October 2004 5:24 pm, Greg KH wrote:
> On Thu, Oct 28, 2004 at 04:16:14PM +0000, Luke-Jr wrote:
> > > On Thu, Oct 28, 2004 at 02:05:37AM +0000, Luke-Jr wrote:
> > > > On Thursday 28 October 2004 1:53 am, you wrote:
> > > > sysfs works great. I use it regardless of udev. The main problem is
> > > > that udev defeats the entire purpose of modules. Using udev, you must
> > > > preload any modules you want to use manually. If you do that, you
> > > > might as well compile them into your kernel. I'd much rather not have
> > > > the driver for any of my devices loaded until I actually need them.
> > >
> > > See the udev FAQ for the answers to this question.  In short, no, udev
> > > does NOT "defeat the entire purpose of modules."  Geesh, where do
> > > people get ideas like this from...
> > >
> > >From udev FAQ:
> > >Q: But udev will not automatically load a driver if a /dev node is
> > > opened when it is not present like devfs will do.
> > >A: If you really require this functionality, then use devfs.  It is
> > > still present in the kernel."
> >
> > In short, the "solution" to that problem according to the udev FAQ is to
> > not use udev.
>
> If you want to rely on such a broken, antiquated system, sure, don't use
> udev.

At least it does what is neccesary, even if it is broken. If udev lacks the 
neccesarily functionality, it doesn't matter that it works.

>
> > >Q: Oh come on, pretty please.  It can't be that hard to do.
> > >A: Such a functionality isn't needed on a properly configured system.
> > > All devices present on the system should generate hotplug events,
> > > loading the appropriate driver, and udev will notice and create the
> > >   appropriate device node.  If you don't want to keep all drivers for
> > > your hardware in memory, then use something else to manage your modules
> > > (scripts, modules.conf, etc.)  This is not a task for udev.
> >
> > What makes you think I want the drivers loaded just because the device is
> > connected/available? It may be insignificantly small, but I don't see a
> > reason to use the RAM neccesary nor decrease the stability of my systems
> > for something I'm not using.
> > For example, my motherboard has a parallel port, but I don't want the
> > driver loaded unless I'm actually using it (which is fairly rare).
>
> Great, then have a "load lp module" script that you run to load the
> driver. 

Nor do I wish to be aware of software using it.

> Don't rely on accessing the device node to load a module for you. 

Why not? Makes perfect sense.

> It's just wrong, and is not the way the Linux kernel has been evolving over
> the past 4 years. 

How do you figure this? Linux has done automatic module loading for quite a 
while, even before devfs. Even if udev simply created the device nodes for 
unloaded modules, it would still work.

> > > > > But they would still be using sysfs.  Also I am curious as to what
> > > > > "new" USB Mass Storage driver you are referring to?  The current
> > > > > mainstream kernel's driver was updated about 4 months ago, and
> > > > > still presents itself as a low level scsi driver to the kernel
> > > > > (meaning it needs scsi.ko and sd.ko)
> > > >
> > > > Well, I noticed they were suddenly "udX" when I moved to 2.6.9...
> > >
> > > "ubX", not "udX".  And that happened because you selected the block UB
> > > driver.  So you asked the kernel to do this, nothing "sudden" about it
> > > at all.
> > >
> > >From kernel configuration:
> > >Low Performance USB Block driver (BLK_DEV_UB)
> > >
> > >This driver supports certain USB attached storage devices
> > >such as flash keys.
> >
> > It was newly available and the description implies that it is a desirable
> > option.
>
> "Low Performance" is a desirable option?  "flash keys" for your
> IDE/SCSI/USB bridge device?

I also use Flash keys. I had no intention of using this module for the bridge, 
but for those.
-- 
Luke-Jr
Developer, Utopios
http://utopios.org/

--
gentoo-dev@gentoo.org mailing list

[prev in list] [next in list] [prev in thread] [next in thread]