Tickless Kernel and PowerTOP

One of the first things I started reading about which made Fedora 7 (not Fedora Core 7) was the “tickless kernel”. I had no idea what this meant. The site http://kerneltrap.org/ seems to imply that if nothing requires CPU work for x seconds, then the processor stays idle for that long. This should result in lower CPU temps and longer battery life. So I had to have one.

Tickless Kernel and PowerTOP

I tried to get a FC6 tickless kernel. However, shy of downloading the source and compiling my kernel, this seems impossible. So I did the potentially unintelligent thing and enabled the development Fedora repos. Upon asking for a tickless kernel, I received a Fedora Core 8 kernel. Admittedly it works great. A loud “hissing sound” which appears to be a capacitor on my mobo not liking the kernel frequency is gone. Battery life is now only slightly longer.

I pushed my luck with the devel repos and installed Intel’s PowerTOP. PowerTOP tells what things are stopping your processor from enjoying a more “low-power” day. Presently things that plague my machine are

  1. pcscd which I need to examine
  2. HAL which is apparently polling my DVD/CR-RW and isn’t allowing the SATA power management to work for me.
  3. Ondemand CPU governor is also something which PowerTOP suggests I activate.


The tickless kernel reduced computational load and improved battery life by far.  PowerTOP helped me to recognize things that I needed to improve upon in my laptop.  The asynchronous nature of these kernels continues to persist through modern-day kernels in the Fedora Core/Fedora tree.