THE FOLD / BOSS / THE GAUNTLET / THE STARVATION
THE STARVATION
the scheduler was doing precisely what it was told
1 WHAT IT IS · WHAT IT DOES · FACT OR FICTION
Strict priority is not a queue, it is a promise that one class always wins. When that class alone can keep the server busy, the promise is that the other class never runs.
LIT verified live. 20,000 ticks, high-priority arrivals 0.95 and low 0.20 against a service rate of 1. Strict priority serves 19,009 high and 991 low, leaves 2,956 low jobs still queued, and one of them has been waiting 14,833 ticks. Aging — letting a job’s priority climb with its wait — serves 3,280 low, backlog 667, worst wait 3,418. The high class serves 2,289 fewer, which is exactly the 2,289 the low class gained.
LIT verified live. 20,000 ticks, high-priority arrivals 0.95 and low 0.20 against a service rate of 1. Strict priority serves 19,009 high and 991 low, leaves 2,956 low jobs still queued, and one of them has been waiting 14,833 ticks. Aging — letting a job’s priority climb with its wait — serves 3,280 low, backlog 667, worst wait 3,418. The high class serves 2,289 fewer, which is exactly the 2,289 the low class gained.
2 HOW IT WAS WEAVED · AI + HUMAN
Aging is the textbook fix for starvation, and the exact-conservation result is not a coincidence: the server is saturated, so every tick given to one class is taken from the other.
AVAN (AI) first ran this at an offered load of 0.80 against a service rate of 1 — under capacity, so nothing starved and both schedulers were identical. Starvation is a property of saturation, not of priority. The rule only bites when the favoured class alone can fill the server, so that is where the experiment belongs.
AVAN (AI) first ran this at an offered load of 0.80 against a service rate of 1 — under capacity, so nothing starved and both schedulers were identical. Starvation is a property of saturation, not of priority. The rule only bites when the favoured class alone can fill the server, so that is where the experiment belongs.
3 ONE DIMENSION
Who gets served, and who is still waiting.
4 TWO DIMENSIONS · INTERACTIVE
Move the load across the saturation line.
5 THREE DIMENSIONS + AVAN’S INVERSE
The green forward object: a queue that is never reached.
AVAN’s addition (the inverse-companion): the forward reading is that aging fixes starvation. The inverse is that it fixes it by breaking the priority promise, and the ledger is exact. 2,289 low jobs ran, 2,289 high jobs did not; at saturation there is no other way for the numbers to come out. Read backwards, aging is not a repair to the scheduler — the scheduler was doing precisely what it was told. It is a decision that the priority order was a lie you were willing to tell only until the wait got embarrassing.
LIT over 20,000 ticks with high-priority arrivals at 0.95 and low at 0.20 against a service rate of 1, strict priority serves 19,009 high and 991 low, leaves 2,956 low jobs queued and one waiting 14,833 ticks, while aging serves 3,280 low with a backlog of 667 and a worst wait of 3,418 - and the high class serves exactly 2,289 fewer, which is exactly the 2,289 the low class gained
FIG Aging is the textbook fix for starvation, and the exact conservation is not a coincidence: the server is saturated, so every tick given to one class is taken from the other. AVAN first ran this at an offered load of 0.80 against a service rate of 1 - under capacity, so nothing starved and both schedulers were identical. Starvation is a property of saturation, not of priority, and the rule only bites when the favoured class alone can fill the server.
FIG Aging is the textbook fix for starvation, and the exact conservation is not a coincidence: the server is saturated, so every tick given to one class is taken from the other. AVAN first ran this at an offered load of 0.80 against a service rate of 1 - under capacity, so nothing starved and both schedulers were identical. Starvation is a property of saturation, not of priority, and the rule only bites when the favoured class alone can fill the server.
◆ sealed .dlw.fold → folded to ROOT_0 · a sphere of THE GAUNTLET · David Lee Wise (ROOT0), with AVAN