Re: HZ, preferably as small as possible

yodaiken
2002-07-15T19:59:54Z

On Mon, Jul 15, 2002 at 03:52:37PM -0400, mbs wrote:
> On Monday 15 July 2002 14:56, Linus Torvalds wrote:
> > (*) Which is a lot less than the hw can generate, since you mustn't allow
> > users to bog down the system in timer interrupts by just using
> > "itimer(ITIMER_REAL, .. fine-resolution..)".
>
> actually, that is an interesting philosophical argument.
>
> in an embedded system, it is sometimes more useful to not put artificial

That's why we have RTLinux.

> in an embedded system a "tickless" system is sometimes preferable to a ticked
> system. there is often only one or a very small number of processes/threads
> running and the extra overhead of 10 surplus clock ticks per process quantum
> is a waste of cycles. (also when using a ppc or similar modern chip(flame
> on;-), there is no need to keep a software wall clock, as the cpu has a 64bit
> free running counter)

Right: but "one or a very small number of processes/threads" does not apply to
Linux.

--
---------------------------------------------------------
Victor Yodaiken
Finite State Machine Labs: The RTLinux Company.
www.fsmlabs.com www.rtlinux.com