Arch Linux

tavianator

Member

From: Waterloo, ON, Canada

Registered: 2007-08-21

Posts: 858

Website

Udev uevents [SOLVED]

I noticed that you guys did excellent work optimizing the udev scripts; uevent processing time went from 20s to 5s on my laptop.  However, there's only an improvement when my laptop it plugged in.  On battery, it's still 13-15s.  Any ideas on how I can speed that up?

Last edited by tavianator (2008-07-20 22:33:23)

tavianator

Member

From: Waterloo, ON, Canada

Registered: 2007-08-21

Posts: 858

Website

Re: Udev uevents [SOLVED]

Okay, well, I figured it out.  Initially, I thought it was a bad udev rule that was holding it up, so I added "/sbin/udevadm monitor &" to /etc/rc.sysinit, between "/sbin/udevadm trigger" and "/sbin/udevadm settle".  However, when I rebooted on battery power, there wasn't one rule that held it up; the whole process just seemed slower.  When I booted on AC power, everything just happened faster.

The next thing I did was check dmesg to see if there were any errors or warnings, and I noticed this line:

Initializing CPU#0
PID hash table entries: 4096 (order: 12, 16384 bytes)
Detected 599.511 MHz processor.

Since my processor is 2 GHz, this struck me as odd.  I then checked my BIOS and sure enough, it was set to "Max Battery Life" or something when on battery.  I switched it to the high performance setting, and that fixed everything.

tigrmesh

IRC Op

From: Florida, US

Registered: 2007-12-11

Posts: 794

Re: Udev uevents [SOLVED]

It's great that you figured it out.  Please mark this thread as solved.  Thank you.