Messages in this thread | | | Date | Tue, 7 Oct 2003 10:53:10 -0700 | From | Greg KH <> | Subject | Re: devfs vs. udev |
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On Tue, Oct 07, 2003 at 02:38:27PM +0200, Måns Rullgård wrote: > > I noticed this in the help text for devfs in 2.6.0-test6: > > Note that devfs has been obsoleted by udev, > <http://www.kernel.org/pub/linux/utils/kernel/hotplug/>. > It has been stripped down to a bare minimum and is only provided for > legacy installations that use its naming scheme which is > unfortunately different from the names normal Linux installations > use. > > Now, this puzzles me, for a few of reasons. Firstly, not long ago, > devfs was spoken of as the way to go, and all drivers were rewritten > to support it. Why this sudden change?
A few things happened: - the devfs maintainer/author disappeared and stoped maintaining the code. - devfs was found to have unfixable bugs - it was determined that the same thing could be done in userspace (like udev.)
> Secondly, that link only leads me to a package describing itself as an > experimental proof-of-concept thing, not to be used for anything > serious. How can something that incomplete obsolete a working system > like devfs?
I didn't send that patch to the kernel to mark devfs as such.
Actually devfs is still very much "experimental" and "proof-of-concept" if you have ever looked at it's code :)
> Thirdly, udev appears to respond to hotplug events only. How is it > supposed to handle device files not corresponding to any physical > device?
Like what? Anything that shows up in sysfs, udev will handle. It's only a matter of getting everything to show up in sysfs now... It's almost all there.
> Finally, I quite liked the idea of a virtual filesystem for /dev. It > reduced the clutter quite a bit. As for the naming scheme, it could > easily be changed.
devfs's naming scheme could easily be changed? Hahaha...
udev will be a major factor of improvement for changable naming schemes. Please read the OLS paper for more details.
thanks,
greg k-h - 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/
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