Thanks Mark, I get it now I think. I was envisaging processes remaining in the queue and a pointer selecting each in turn. In fact of course, because it's not a pre-emptive OS, this doesn't occur, the processes are removed (as in fact stated in the book) and put on either the idle or dead queue. Also I was envisaging an equal number of processes in each queue whereas after further consideration I would guess that most processes are high or medium. thanks again, Marc
"Vicuna, Mark" wrote: > > Nope - From step 3&4 in the book. > > There are no counters for critical and high priority queues either. The > 'failsafe' for servicing the medium priority is when all the processes > in the critical and high ready queues have been executed or when a > medium priority instance is found when servicing the low priority queue > (intervleave) - all the medium processes will be executed. > > The scheduler will not service the low priority queue within 15 times of > skipping the low queue - and even then, if the scheduler is executing > low priority instances it will still service a medium (or critical or > high) process if one is found in the ready queue. > > hth, > Mark. Message Posted at: http://www.groupstudy.com/form/read.php?f=7&i=60365&t=60206 -------------------------------------------------- FAQ, list archives, and subscription info: http://www.groupstudy.com/list/cisco.html Report misconduct and Nondisclosure violations to [EMAIL PROTECTED]