MLFQ - doubt (or bug?)

[ibrahim5253]

Okay, so, I am having some trouble understanding the trace. Here's the setup - 2 queues, 2 jobs - one CPU bound (no IO) with runtime 9 and another with IO frequency 2 (duration 1) and runtime 4. Quantum is 3 for each of the queues, allotment 1. We do Stay and Boost priorities every 5 seconds.

$ ./mlfq.py -n 2 -l 0,9,0:0,4,2 -q 3 -c -i 1 -S -B 5
Here is the list of inputs:
OPTIONS jobs 2
OPTIONS queues 2
OPTIONS allotments for queue  1 is   1
OPTIONS quantum length for queue  1 is   3
OPTIONS allotments for queue  0 is   1
OPTIONS quantum length for queue  0 is   3
OPTIONS boost 5
OPTIONS ioTime 1
OPTIONS stayAfterIO True
OPTIONS iobump False


For each job, three defining characteristics are given:
  startTime : at what time does the job enter the system
  runTime   : the total CPU time needed by the job to finish
  ioFreq    : every ioFreq time units, the job issues an I/O
              (the I/O takes ioTime units to complete)

Job List:
  Job  0: startTime   0 - runTime   9 - ioFreq   0
  Job  1: startTime   0 - runTime   4 - ioFreq   2


Execution Trace:

[ time 0 ] JOB BEGINS by JOB 0
[ time 0 ] JOB BEGINS by JOB 1
[ time 0 ] Run JOB 0 at PRIORITY 1 [ TICKS 2 ALLOT 1 TIME 8 (of 9) ]
[ time 1 ] Run JOB 0 at PRIORITY 1 [ TICKS 1 ALLOT 1 TIME 7 (of 9) ]
[ time 2 ] Run JOB 0 at PRIORITY 1 [ TICKS 0 ALLOT 1 TIME 6 (of 9) ]
[ time 3 ] Run JOB 1 at PRIORITY 1 [ TICKS 2 ALLOT 1 TIME 3 (of 4) ]
[ time 4 ] Run JOB 1 at PRIORITY 1 [ TICKS 1 ALLOT 1 TIME 2 (of 4) ]
[ time 5 ] IO_START by JOB 1
IO DONE
[ time 5 ] BOOST ( every 5 )
[ time 5 ] Run JOB 0 at PRIORITY 1 [ TICKS 0 ALLOT 1 TIME 5 (of 9) ]
[ time 6 ] IO_DONE by JOB 1
[ time 6 ] Run JOB 1 at PRIORITY 1 [ TICKS 0 ALLOT 1 TIME 1 (of 4) ]
[ time 7 ] Run JOB 0 at PRIORITY 0 [ TICKS 2 ALLOT 1 TIME 4 (of 9) ]
[ time 8 ] Run JOB 0 at PRIORITY 0 [ TICKS 1 ALLOT 1 TIME 3 (of 9) ]
[ time 9 ] Run JOB 0 at PRIORITY 0 [ TICKS 0 ALLOT 1 TIME 2 (of 9) ]
[ time 10 ] BOOST ( every 5 )
[ time 10 ] Run JOB 1 at PRIORITY 1 [ TICKS 0 ALLOT 1 TIME 0 (of 4) ]
[ time 11 ] FINISHED JOB 1
[ time 11 ] Run JOB 0 at PRIORITY 1 [ TICKS 0 ALLOT 1 TIME 1 (of 9) ]
[ time 12 ] Run JOB 0 at PRIORITY 0 [ TICKS 2 ALLOT 1 TIME 0 (of 9) ]
[ time 13 ] FINISHED JOB 0

Final statistics:
  Job  0: startTime   0 - response   0 - turnaround  13
  Job  1: startTime   0 - response   3 - turnaround  11

  Avg  1: startTime n/a - response 1.50 - turnaround 12.00

At time 5, why is TICKS 0? Since JOB 0 just got switched in, shouldn't it have the entire quantum? Same at time 6.