devfs vs udev/hotplug

Diego Calleja García diegocg at teleline.es
Thu Apr 22 10:05:40 PDT 2004


El Wed, 21 Apr 2004 10:36:24 -0700 (PDT) Matthew Dillon <dillon at xxxxxxxxxxxxxxxxxxxx> escribió:

>     I wasn't even thinking of a userland file server.  I was simply thinking


There's one thing that devfs did and udev can't do (and it won't
do because it's not its task; but there's not a replacement)

With devfs you can "unload" (or not load at all) modules, so when
a program try to access ej: a (already connected) USB stick
devfs loads its module and all works. udev however relies on
all modules being loaded; if a module isn't loaded and a 
program try to access that usb stick it will fail because
nobody will load the module (and hence udev will not create
the device node). This seems to be important on embedded
devices where memory is a precious resource and you wouldn't
want to load all the modules at the same time to save a few
KB of mem.

How would solve this the (future) Dragonfly's VFS model?






More information about the Kernel mailing list