I believe you. But aren't we now getting into pretty realtime stuff? Not
sure NetBSD is at all suitable for such applications/environments. As
you say - if this only behaves acceptably if the system is not under
load, then it's not a solution I would go for.
But again - I guess we're talking very personal
opinions/experiences/tradeoffs here.
I still don't really believe we need very high resolution scheduling.
And tickless is sortof a separate topic to this.
Johnny
On 2023-12-31 05:20, Konrad Schroder wrote:
On 12/30/2023 3:42 PM, Johnny Billquist wrote:
On 2023-12-31 00:11, Michael van Elst 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.
I'm not sure about visual and auditory sensation, but haptic VR requires
position updates >= 1000Hz to get texture right. The timing of two
impulses that close together may not be felt as two separate events, but
the frequency of vibrations within the skin when it interacts with a
surface (even through a tool, such as a stylus) is encoded by the nerve
endings in the skin itself. We used to use PHANTOM haptic arms at
$WORK, driven by an Indigo2. If the control loop operated at less than
1000Hz---for example, if the Indigo2 was under load--- it introduced
noticeable differences in the sensation of running the pen over a
virtual object. The simulation was much more sensitive to that than it
was to the timing of the video output, for which anything greater than
72Hz was wasted.
Take care,
-Konrad
--
Johnny Billquist || "I'm on a bus
|| on a psychedelic trip
email: [email protected] || Reading murder books
pdp is alive! || tryin' to stay hip" - B. Idol
