Multiprocesssor systems have emerged as an important computing means for real-time applications and have received increasing attention than before. However, until now, little research has been done on the problem of on-line scheduling of parallel tasks with deadlines in partitionable multiprocessor systems. In this paper, we propose a new on-line scheduling algorithm, called Deferred Earliest Deadline First (DEDF) for such systems. The main idea of the DEDF algorithm is to defer the scheduling as late as possible, so that a set of jobs as scheduled at a time instead of one at a time. For processor allocation using DEDF, we have introduced a new concept -Available Tame Window (ATW). By using ATW, the system utilization can be improved and thereby enabling the system t o meet the deadline of more number of tasks. Simulation results for a hypercube indicate that the DEDF algorithm performs significantly better than the earlier proposed Buddy/RT and Stacking algorithms for a wide range of workloads. 0-8186-7683-3/96 $05.00 0 1996 IEEE

A novel algorithm for next-hop selection over a set of Equal Cost Multiple Paths (ECMP) in a router is presented, which provides for load sharing among multiple routes. The main idea of proposed algorithm called Prime number Modulo-N Load Balance(PMN-LB) is that the remainders are distributed equally when the multiples of a number are divided by prime number. Based on this specific property, PMN-LB assigns incoming flows to a next-hop selected. The hashed value of flow is divided by the number of multiple paths. If a next-hop pointed the remainder is available, this next-hop selected to forward packet. But if not, the prime number not less than the number of available multiple paths divides the hashed value and a next-hop is selected using this remainder. If the previous calculation is failed, the hashed value is divided by the number of available multiple paths. The disruption characteristic is remarkably improved using prime number division scheme The lookup performance of PMN-LB is an optimal 0(1) and disruptive behavior is between 0.125 and 0.500 in case N is the number of next-hops and N is equal to eight. As compared with other algorithm decided which next-hop to use, the performance of PMN-LB like modulo-N is an optimal 0(1), disruptive behavior of PMN-LB is better than that of modulo-N and that of hashthreshold algorithm. But Highest Random Weight (HRW)'s disruptive behavior with 1/N is better than that of PMN-LB. The load balancing between next-hops is nearly good.

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