Say, P1 requests: R1, R2, R3 and P2 requests R1, R3, R2
p1 acess R1 then prempted then p2 start and will wait for R1,now p1 can finish its execution for any order of remaining 2 resources because both are available ,it means order with this will be deadlock free,why this order is discarded?
according to me all order(arrangement) in which first resource request by p1 and p2 is same will be deadlock free ,because after aceesing first resouce by any one process if prempted,other process will wait without holding any resouce,it means first process that wasprepted can continue its execution without deadlock.
in this way no of order come will be 120*2=240;please explain?