hotplug,hwdetect,shd.....

holskoiff · 2005-12-05 14:29:33

Ok, I know that lshwd and hwdetect are much faster than hotplug... but what's the difference that causes this... is it something on the detection method or actually the modules lookup? Does anybody know it?

brain0 · 2005-12-05 14:55:06

holskoiff wrote:

Ok, I know that lshwd and hwdetect are much faster than hotplug... but what's the difference that causes this...

I'm not sure about hotplug. afaik, hotplug just tries to load very many modules and if they succeed to load, there is probably a device that uses the module (as I said, I'm not sure if this is true, but that would explain why hotplug is so damn slow).

hwd relies on tables where usb/pci/whatever device IDs are mapped to drivers. Something that's not in the list will not be detected (but hwd is still useful to find out more about your hardware)

hwdetect is superior to them, because it uses a new feature introduced in 2.6.12: modalias. modalias files are in sysfs and hwdetect finds them and determines which modules have to be loaded. So there is no actual detection going on in hwdetect, but it only works with the stuff that the kernel already knows.

Gullible Jones · 2005-12-06 20:37:22

Wait a minute... Quoeth the note on the front page:

Hello Archers,
The latest version of udev is sitting in Testing now. As of version 076, udev will now perform all the functions that hotplug used to handle, thus removing the need for it. As well, the latest udev will want to remove pcmcia-cs since it has been deprecated in favor of pcmciautils.

Is this an Arch Linux patch, or is it an upstream change? Has udev finally made itself a worthy replacement for devfs?

(And why isn't the new version in Current? Does it still have bugs?)

brain0 · 2005-12-07 15:44:35

Gullible Jones wrote:

Is this an Arch Linux patch, or is it an upstream change? Has udev finally made itself a worthy replacement for devfs?
(And why isn't the new version in Current? Does it still have bugs?)

As for udev, it seams to be an upstream change, udev is supposed to replace hotplug. AFAIK, it only depends on having the right rules that call the right helper apps (like modprobe, the firmware helper etc).
udev does not only replace devfs, it is even more powerful, as it does everything that hotplug did (you can not say this about devfs).

I haven't experienced any bugs so far, but you never now ....

Gullible Jones · 2005-12-07 20:10:04

Okay, now devfs can properly be said to be obsolete. 8)

soloport · 2005-12-08 01:18:26

So is it necessary to call out:
DAEMONS=(syslog-ng !hotplug !pcmcia network netfs [etc.] )

What's the diff if I simply use:
DAEMONS=(syslog-ng network netfs [etc.] )

Snowman · 2005-12-08 02:04:38

soloport wrote:

So is it necessary to call out:
DAEMONS=(syslog-ng !hotplug !pcmcia network netfs [etc.] )

Yes. If you use hwdetect and the udev in testing, then you shouldn't use the hotplug and pcmcia daemons as they might cause conflicts/interferences.

soloport wrote:

What's the diff if I simply use:
DAEMONS=(syslog-ng network netfs [etc.] )

In both cases, the hotplog and pcmcia daemons are not started. The second DAEMONS line is prefered as both hotplug and pcmcia-cs will be removed when you'll upgrade to the udev in testing. So rc.conf will be cleaner.

Arch Linux

#26 2005-12-05 14:29:33

Re: hotplug,hwdetect,shd.....

#27 2005-12-05 14:55:06

Re: hotplug,hwdetect,shd.....

#28 2005-12-06 20:37:22

Re: hotplug,hwdetect,shd.....

#29 2005-12-07 15:44:35

Re: hotplug,hwdetect,shd.....

#30 2005-12-07 20:10:04

Re: hotplug,hwdetect,shd.....

#31 2005-12-08 01:18:26

Re: hotplug,hwdetect,shd.....

#32 2005-12-08 02:04:38

Re: hotplug,hwdetect,shd.....

Board footer