Looking much better, but still some fairness issues with more complex
setups.
pid 2477 in A, others in B
2477 99.5%
2478 49.9%
2479 49.9%
move 2478 to A
2479 99.9%
2477 49.9%
2478 49.9%
So far so good. I then created C, and moved 2478 to it. A 3-second
"top" gave almost a 15% error from the desired behaviour for one group:
2479 76.2%
2477 72.2%
2478 51.0%
A 10-sec average was better, but we still see errors of 6%:
2478 72.8%
2477 64.0%
2479 63.2%
I then set up a scenario with 3 tasks in A, 2 in B, and 1 in C. A
10-second "top" gave errors of up to 6.5%:
2500 60.1%
2491 37.5%
2492 37.4%
2489 25.0%
2488 19.9%
2490 19.9%
a re-test gave errors of up to 8.1%:
2534 74.8%
2533 30.1%
2532 30.0%
2529 25.0%
2530 20.0%
2531 20.0%
Another retest gave perfect results initially:
2559 66.5%
2560 33.4%
2561 33.3%
2564 22.3%
2562 22.2%
2563 22.1%
but moving 2564 from group A to C and then back to A disturbed the
perfect division of time and resulted in almost the same utilization
pattern as above:
2559 74.9%
2560 30.0%
2561 29.6%
2564 25.3%
2562 20.0%
2563 20.0%
It looks like perfect balancing is a metastable state where it can stay
happily for some time, but any small disturbance may be enough to kick
it over into a more stable but incorrect state. Once we get into such
an incorrect division of time, it appears very difficult to return to
perfect balancing.
Chris
--
