[SOLVED] Multiple processes of udevd loads CPU high

sevs · 05-30-2012, 01:11 PM

Hi there.
I have a PC with Debian Lenny linux upgraded to Squeeze a few days ago.
Upgrade was very smooth. Then I've compiled new kernel (2.6.38.8). Honestly I did only few changes to configfile.

And a few moments ago I've found out that I have a lot of "change" triggers from udevd:

Quote:

debian:~# udevadm monitor
monitor will print the received events for:
UDEV - the event which udev sends out after rule processing
KERNEL - the kernel uevent

KERNEL[1338401059.264891] change /devices/pci0000:00/0000:00:1f.1/ide0/0.1/block/hdb (block)
UDEV [1338401059.288907] change /devices/pci0000:00/0000:00:1f.1/ide0/0.1/block/hdb (block)
KERNEL[1338401059.289415] change /devices/pci0000:00/0000:00:1f.1/ide0/0.1/block/hdb (block)
KERNEL[1338401059.332820] change /devices/pci0000:00/0000:00:1f.1/ide0/0.1/block/hdb (block)
KERNEL[1338401059.362704] change /devices/pci0000:00/0000:00:1f.1/ide0/0.1/block/hdb (block)
UDEV [1338401059.368979] change /devices/pci0000:00/0000:00:1f.1/ide0/0.1/block/hdb (block)
KERNEL[1338401059.412694] change /devices/pci0000:00/0000:00:1f.1/ide0/0.1/block/hdb (block)
... and repeating continiously

I've already did the thing from here
Now I've got CPU load a little less (100% came down to 20% for each of two cores).
I've over-googled at anything about udev and I can't find out the reason of CPU load.
But what I've got is:

Quote:

debian:~# ps aux | grep -in udev
35:root 1169 0.0 0.0 1748 548 ? D< 21:09 0:00 /lib/udev/cdrom_id --export /dev/hdb
37:root 1171 0.0 0.0 3908 752 pts/0 S+ 21:09 0:00 grep -in udev
43:root 11501 5.2 0.6 22516 20912 ? S<s 20:44 1:18 udevd --daemon

Last string is repeated 58 times more (with only linenumber changing).
I think the reason is somehow refers to cdrom.

Any advices?

syg00 · 05-31-2012, 11:59 PM

Is this only happening on your kernel ?. What about if you run the monitor on a Debian kernel and pop the CD in ?.

Diff your config files - I'd be betting libata is the culprit; messing with the initscripts.

sevs · 06-03-2012, 09:34 AM

Yep, that happens only for new kernel, not for Debian's.
And about ATA - I have ATAPI enabled in config file for new kernel.
Could you say something more about that:

Quote:

I'd be betting libata is the culprit; messing with the initscripts.

UPD : Uh, ok. udevd is not the reason for CPU load. But what is the reason for all that messages from udevd?