# multiple udevd processes

## sphakka

Hi there,

Today I discovered that there are 3 udevd processes running on my box (dual-core AMD):

```

$ ps aux | grep udevd

$ ps auxf | grep udevd

root      1179  0.0  0.0  17292   912 ?        Ss   09:35   0:00 /sbin/udevd --daemon

root     20820  0.0  0.0  17288   572 ?        S    21:16   0:00  \_ /sbin/udevd --daemon

root     20821  0.0  0.0  17288   584 ?        S    21:16   0:00  \_ /sbin/udevd --daemon

```

PID 1179 was started at boot, whereas the other two were possibly forked when the graphical desktop (KDE) is started. Indeed, in console with no xdm running, I was able to kill the forked processes; then, as xdm -> KDE was restarted, they reappeared... I can also kill the two extra process while KDE is running, and everything seems to run fine, though sometimes after a while they're back. Conversely, restarting udev seems to get rid of any clandestine process. I wonder what might trigger this behaviour (I suspect Phonon...)

Is that normal?

  ^s

----------

## gorkypl

Yes, it is normal. At least I have the same and I do not use KDE, just a very simple X session without dbus or anything.

----------

## sphakka

Still puzzled by that...

I can confirm that at least one udevd replica is spawned when XDM starts, so it might be a consequences of X accessing devices: on top of my head, touchpad + keyboard => 2 extra udevd processes?

Anyway, the system looks more responsive after the cleanup (i.e. killing extra processes)...  :Cool: 

----------

## PaulBredbury

Apparently they are worker threads.

----------

## sphakka

 *PaulBredbury wrote:*   

> Apparently they are worker threads.

 

Thanks, now clear! Urgh, udevd is becoming a Web server... worrisome...

----------

## gorkypl

 *sphakka wrote:*   

> udevd is becoming a Web server... worrisome...

 

This has already happened, almost...

http://lwn.net/Articles/490413/

----------

## sphakka

 *gorkypl wrote:*   

>  *sphakka wrote:*   udevd is becoming a Web server... worrisome... 
> 
> This has already happened, almost...
> 
> http://lwn.net/Articles/490413/

 

Indeed, I knew about that famous article! Hopefully, the gentoo folks will conjure up a udev-less configuration  :Wink: 

----------

## khayyam

 *sphakka wrote:*   

> [...] Hopefully, the gentoo folks will conjure up a udev-less configuration

 

sphakka ... its quite possible, see the gentoo wiki article on using mdev (from busybox) as a udev replacement. The problem is that certain things don't (currently) work, such as lvm2.

The problem, I think, is not so much udev (which is little more than a hotplug service) but how the dependencies are being shaped, and mostly this is due to redhat/freedesktop/gnome's desire to create a one-size-fits-all "Desktop". I see this as being driven by two factors: the flawed logic of "usability" and "developing markets". Given the former is a complete abstraction (and should play no role in software developement) and the latter is highly volitile and precarious, it is likely to end in confusion.

best ... khay

----------

