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System Job in MiSTer SMSQ/E
Posted: Sun Dec 15, 2024 9:10 pm
by dex
In SMSQ/E on MiSTer, there is one button just next to the Free mem button.
Its job name is System Job, it is associated with file “systemjob106”, and shows some numbers, probably free time available for the job number 0, in some units.
What it does exactly, and what units are used?
Re: System Job in MiSTer SMSQ/E
Posted: Mon Dec 16, 2024 10:00 am
by Derek_Stewart
Is this a executable program that is loaded at boot up?
Re: System Job in MiSTer SMSQ/E
Posted: Mon Dec 16, 2024 10:44 am
by desin
Hi
on Mister Windows+PRT SC generates a screenshot
it will be saved under media/fat /screenshots/QL/
make one
do you mean this one ?
Greetings from Switzerland
Markus
Re: System Job in MiSTer SMSQ/E
Posted: Mon Dec 16, 2024 2:14 pm
by dex
Derek_Stewart wrote: Mon Dec 16, 2024 10:00 am
Is this a executable program that is loaded at boot up?
Yes, EXEP “systemjob106”.
Looks like the one on the srceenshot (but with different values - we had up to 498) except the version difference (our is probably 1.06, but 1.01 on the screenshot).
It can be seen (again with different values) in the video
https://youtu.be/qeIM09cj97o?si=r1oaqbyt1Tl7lxHl
Re: System Job in MiSTer SMSQ/E
Posted: Mon Dec 16, 2024 3:42 pm
by tofro
If I remember right, the System Job simply shows the number of poll cycles the computer was busy elsewhere (i.e., not running this job). So, it's basically a load average - the lower the number, the better. What exact units it uses, I don't recall.
Re: System Job in MiSTer SMSQ/E
Posted: Mon Dec 16, 2024 4:34 pm
by desin
Re: System Job in MiSTer SMSQ/E
Posted: Mon Dec 16, 2024 5:38 pm
by dex
Great! Thanks.
Re: System Job in MiSTer SMSQ/E
Posted: Mon Dec 16, 2024 5:54 pm
by tofro
After a quick look at the source code, it seems I have to correct myself:
The number displayed seems to be the number of re-schedules per second. So, in principle, how often the scheduler has kicked in the last second. That would in fact mean: "The higher, he better".
However: Apparently, QPC for example, slows down the emulated CPU to reduce the load on the host system when waiting for input - So, if SMSQ/E has nothing to do, the number gets lower because the host system will lower the amount of CPU it hands over to the emulator as a whole - Which makes the numbers displayed look wrong (Or: exactly opposite to what they actually mean: On an S*Basic prompt without any significant load, it goes down to 260 on my system, as soon as I touch the keyboard, the number goes negative [i.e., very high], so the program is really not particularly useful on QPC.)
Re: System Job in MiSTer SMSQ/E
Posted: Mon Dec 16, 2024 9:20 pm
by logout
Hello everyone,
and thanks for all the replies. Me and Dex tried to figure out what the value means on a local Sinclair meet-up last weekend and while it was obvious what it does, the exact meaning of the number was unclear.
I do not understand 68k assembly, but I understand German and the comment in the source says that the number is "frequency of the scheduler", meaning how many times per second is the scheduler loop running and it should decrease with every task running.
However it seems that Minerva ROM is capable of ten times more loops than SMSQ/E on the same MiSTer configuration.
Re: System Job in MiSTer SMSQ/E
Posted: Mon Dec 16, 2024 9:29 pm
by tofro
logout wrote: Mon Dec 16, 2024 9:20 pm
However it seems that Minerva ROM is capable of ten times more loops than SMSQ/E on the same MiSTer configuration.
That's not saying a lot. Remember the scheduler as such is actually OS overhead doing nothing (but checking if another job should run). When the scheduler is executed, your application code is obviously not, but running the scheduler more often (thus checking less jobs per invocation, but invoke it more frequently) can make a system more responsive on slow CPUs. Without the exact same implementation in the scheduler, you cannot really compare the two.