Re: [gentoo-dev] Re: [gentoo-desktop] X freezing?

[Luke-Jr]

On Thursday 28 October 2004 2:50 pm, you wrote:
> [yeah, it went to the wrong list, but I might as well address the issues
> involved...]

How is -dev any less appropriate for this than -desktop?

>
> On Thu, Oct 28, 2004 at 02:05:37AM +0000, Luke-Jr wrote:
> > On Thursday 28 October 2004 1:53 am, you wrote:
> > > Are they sysfs design flaws or udev design flaws.  The reason I ask, is
> > > that a bunch of kernel developers were talking about rewriting the
> > > current hotplug/udev system.
>
> No we were not.

I think he meant some Linux kernel developers, not neccesarilly Gentoo, though 
I'm not on LKML or any such lists personally.

>
> > 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.

>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).

>
> > > 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.

>
> > Now that I think of it, I'm not sure I tested 2.6.9 w/o udev, so it
> > might have been a udev naming thing that I just assumed meant the
> > device was a USB disk (w/o emulation)... Either way, it didn't work
> > very well for me (e.g. I couldn't use my IDE->USB adaptor).
>
> Stick with the usb-storage driver if you don't like the ub driver.  It's
> not for everyone (as the documentation for the driver states.)

Usually, stuff that doesn't work is marked EXPERIMENTAL or such. Nothing to 
suggest that in the summary. Using a bunch of greps on the Documentation 
directory, there does not seem to be additional documentation for the ub 
stuff. Where does it state that it shouldn't be used (outside of the default 
N)?
-- 
Luke-Jr
Developer, Utopios
http://utopios.org/

--
gentoo-dev@g.o mailing list