DragonFly kernel List (threaded) for 2004-04
Re: devfs vs udev/hotplug
Matthew Dillon <dillon@xxxxxxxxxxxxxxxxxxxx> writes:
> I wasn't even thinking of a userland file server. I was simply thinking
> of a userland demon which creates and destroys CHR special files based
> on instructions from the kernel.
Oh I see... a "thingy" that handles MAKEDEV :). That's not going to have
much in the way of problem and is probably very easily implementable.
> Devices are not created and destroyed all that often, so performance
> isn't really an issue.
Sure.. unless you like to plug in and unplug your USB keyboard a lot and very
> Matthew Dillon
> :> Doesn't this sort of design imply that the kernel is instructing a daemon
> :> to make kernel calls to service the requests? Isn't that a lot of
> :> address space crossing or do I not understand how a userland file "server"
> :> would work? I realize that this will be done with fast messages but such
> :> designs leave me with "speed" doubts. This might be a bad example for when
> :> that speed matters though.
> :> Dave
> : I don't think speed will be much of an issue, once Async
> : messaging and a Shared Memory Segment between userland and
> : kernel is implemented. One can utilize that.
> : Regards,
> : -Hiten