udev/hotplug?

[Joe Smith]

Les wrote:
> Hi, Joe, since hotplugging is a hardware function you might consider
> moving that module down into the hardware section.  It would probably
> simplify some of the arrows as well.  I am assuming that by Hotplug, you
> mean the act of removing and replacing or adding hardware without
> turning the system off.

I'm no expert at all--I made the slides for a talk that I gave primarily 
to teach myself(!), and I still don't understand a lot of what goes on. 
Someone please correct me if I have this mixed up.

My understanding is that, although the initial event is detected by the 
kernel, practically the first thing the kernel does is fire off a _shell 
script_ and the rest of the response is handled from user space. It's a 
bit counter-intuitive that a hardware event should be handled by a 
user-space mechanism, but it's a good design, and that's what the 
diagram tries to show.

Fortunately, there are smarter people than me who make this stuff mostly 
"just work" and I haven't had to look at it in a long time. I see now 
that you brought it up, that at least that part has changed. There is no 
"/sbin/hotplug" anymore. I'll have to grub around again and see what the 
current mechanism is.

I think the relationships between the basic pieces of the diagram are 
still correct, but it obviously needs to be updated. I should take it 
down or add a disclaimer ;-)

Thanks for the feedback!

<Joe