John, On Friday 01 October 2004 17:59, John Andersen wrote:
On Friday 01 October 2004 04:00 pm, Randall R Schulz wrote:
Hi,
On Friday 01 October 2004 15:29, Pieter Hulshoff wrote:
On Saturday 02 October 2004 00:20, Bahram Alinezhad wrote:
If we continue to defend disadvantages with prejudice or dogma, we'll have never improvements.
I agree. :)
One thing that occurs to me about SuSE (vs. an unknown set of other distributions that don't do this) is its default use of the "desktop" kernel option.
As I understand this option, it increases the rate of some periodic kernel actions such as process scheduling to produce a more responsive feel for interactive operation. I'm not sure I remember this correctly, but I think it produces a ten-fold reduction in the CPU scheduling quantum (or, viewed the other way around, ten times more potential reschedulings per second). For a processor such as Bahram's "Ultra high speed CPU" (an AMD K6 at 550 MHz) that could account for a good bit of overhead when viewed as a percentage of available CPU cycles.
...
Regards,
My machine is not much faster than what Bahram reported and I was wondering why it was so slow lately. Your post reminded me to check, and sure enough DESKTOP was missing from the boot line in /boot/grub/menu.lst I added it back in and the machine is way more responsive. Thanks.
From my long ago reading of Linus's emailings on this subject he did not see any advantage to this option on his "ridiculous hardware" (quad processor) but saw much improvement on slower boxes.
But my results show everything you do on the desktop to be much snappier with desktop on than with it off.
Well, that's great. But my hypothesis was that the "desktop" kernel option would slow a machine down by increasing the kernel scheduler overhead. But if using "desktop" is better for you than than not using it, then great. It's not suprising that things are more responsive, but it doesn't make sense to me that things like boot-up or program launching time would improve. By the way, I have a 3.0 GHz hyperthreading P4, but I removed the "desktop" option. Most of what I do is long-running, CPU-intensive stuff, so I like to squeeze out ever iota of overhead I can. (Well, if that were really true, I'd build a custom kernel with P4 optimizations, but I've so far resisted opening that particular can of worms / pandora's box.) Randall Schulz