In Process Scheduling , Which scheduler's decision lasts for a long time and why ?
Long Term Scheduler. Because L.T.S. is responsible for loading processes from the secondary memory to the main memory , so it decides the degree of MultiProgramming (#of processes can be present in the main memory at a time)
Once LTS brings the processes in the M.M. then duty is delegated to STS
Why not Short Term Scheduler ? : because it is ONLY responsible for dispatching a process from the running to ready and reverse , it depends on scheduling algorithm. so decision of STS lasts for a short time , yes it affects the efficiency if there are lot of context swithes involved