PSA: Clock drift and pkgin

On Sun, Dec 31, 2023 at 12:42:29AM +0100, Johnny Billquist wrote:
> > Better than 100Hz is possible and still precise. Something around 1000Hz
> > is necessary for human interaction. Modern hardware could easily do 100kHz.
> 
> ? If I remember right, anything less than 200ms is immediate response for a
> human brain. Which means you can get away with much coarser than even 100Hz.
> And there are certainly lots of examples of older computers with clocks
> running in the 10s of ms, where human interaction feels perfect.

You may not be able to react faster than 200ms, but you can notice
shorter time periods.


> I think that is a separate question/problem/issue. That we fail when guest
> and host run at the same rate is something I consider a flaw in the system.

With a fixed tick, they cannot run at the same speed. This becomes
obvious when you try to run at different speeds that aren't just
integer multiples.

N.B. my m68k emulator runs a HZ=100 guest without a problem. But that's
a fake, in reality it only runs 100 ticks per second on average, In
particular when the guest becomes idle.


Greetings,
-- 
                                Michael van Elst
Internet: [email protected]
                                "A potential Snark may lurk in every tree."