[ Thanks to Jeremy
Andrews for this link. ]
“A recent posting to the lkml suggested that the udev project
has unfairly hijacked the devfs project, leading into yet another
lengthy discussion comparing udev to devfs, and questioning why the
latter has been deprecated. Linux devfs was written by Richard
Gooch and merged into the 2.3.46 kernel in February of 2000. Since
that time, Richard has stopped maintaining it, though a number of
issues remain. During the 2.5 release cycle others such as Andrey
Borzenkov have contributed fixes, though problems evidently remain
with the actual design.“As early as 2001, Greg Kroah-Hartman began developing udev,
working to implement the same functionality as devfs, but in
userspace. Currently at version 010, though not complete, udev is
quite functional. For a good understanding of how it works, refer
to this pdf from Greg’s 2003 OLS talk. During the recent lkml
discussion, 2.6 maintainer Andrew Morton acknowledged that though
it has ‘architectural/cleanliness issues […] devfs shall remain
in 2.6 and shall continue to be supported.’ He went on to
explain:“‘Nor would I recommend that devfs be removed early
from 2.7.x. We should wait until the proposed udev/sysfs solutions
have matured in 2.6 and have proven themselves in the field. Only
then will we be in a position to confirm that devfs can be removed
without causing some people unacceptable levels of grief. There is
no rush…'”