linux normal/real time schedulin

[Mo]

hi,
on the fall 2004 exam, number 7,
part a. why is there a re-credit after P2(3)
part a. and b. where are the wait times for the processes? they are
not listed in the solution

thanks

[Daniel Ramsbrock]

Mo,

I don't see the wait times in the solution either, but I can tell you
why there is a re-credit. At time 23 (right after P2(3)), both P1 and P3
have zero credits left. P2 still has 1 credit, but it is blocked on I/O
for 1 time unit (see the question prompt: there is always a 1-unit I/O
request in between bursts). It won't be back on the run queue until time
24. Thus, no runnable processes with > 0 credits exist at time 23,
meeting the condition for a re-credit to occur.

Daniel

Post by Mo
hi,
on the fall 2004 exam, number 7,
part a. why is there a re-credit after P2(3)
part a. and b. where are the wait times for the processes? they are
not listed in the solution
thanks