Re: No 100 HZ timer !

[John Alvord]

On Thu, 02 Aug 2001 09:36:07 -0700, george anzinger
<[e-mail]> wrote:
 ...
>  The timing
>tests (800MHZ PIII) show the whole setup taking an average of about 1.16
>micro seconds.  the problem is that this happens, under kernel compile,
>~300 times per second, so the numbers add up.  Note that the ticked
>system timer overhead (interrupts, time keeping, timers, the works) is
>about 0.12% of the available cpu.  Under heavy load this raises to about
>0.24% according to my measurments.  The tick less system overhead under
>the same kernel compile load is about 0.12%.  No load is about 0.012%,
>but heavy load can take it to 12% or more, most of this comming from the
>accounting overhead in schedule().  Is it worth it?

I thought the claimed advantage was on certain S/390 configurations
(running 100s of Linux/390 images under VM) where the cost is
multiplied by the number of images. A measurement on another platform
may be interesting but not conclusive.

john alvord