On Wednesday 31 August 2005 04:00, Jorge Fábregas wrote:
Hello everyone,
I just noticed the "desktop" kernel parameter on my menu.lst (SUSE 9.0). I did a search on Google but couldn't find that much. What does it affects? or if anyone can point me to the right direction I'll be glad.
It affects the tick frequency (HZ) of the kernel, which is a count of the number of times per second the kernel stops and says "ok, what else needs to be done" With the desktop parameter, HZ is set to 1000, without it it's set to 100. Later kernels have it set to 1000 by default. The theory is that with HZ at 1000 instead of 100, the increased number of checkpoints where the kernel stops and sees if anything has happened increases the responsiveness of the system for a desktop user. The downside is that there is much more overhead, with 900 more interrupt handlers per second being called. I'm not sure if there has been a real study on the effectiveness of this, or the impact on a server where there are more long running jobs that don't need to be interrupted