PL147744%TECMTYVM.BITNET@cunyvm.cuny.edu (Marcela Bonilla J.) (04/22/89)
The problem is : Modify the scheduler of Minix to keep the control of the CPU time that each user's process has had recently. When any of the tasks or servers want to get the CPU, the user process with the less CPU time will get it. A friend and I thought that maybe building the ready queue ordered by those CPU times must be the solution. We will modify the "ready" and "sched" procedures of the "kernel/proc.c" file in those parts in which it modifies the pointers "ready_head(USER_Q)" and "ready_tail(USER_Q)". But.. how can we now how much CPU does a process has had ? We thought that the variable "user_time" could help us in this, but we are still without knowing if this user_time is the CPU time of the process or what... another friend told us that this variable can be modify by other processes plus the accounting routine of the clock's task. Can anybody tell me if this is a good solution ? Is "user_time" the real CPU time of each process ? If not... how can I know it ? Any hint to prove that the sched is working as I want.... Thanks for any help... =) May