Operating Systems Questions

In a multiprocessor system there exist several caches each may containing a copy of same variable A. Then a change in one cache should immediately be reflected in all other caches this process of maintaining the same value of a data in all the caches s called cache-coherency.

Transferring the control from one process to other process requires saving the state of the old process and loading the saved state for new process. This task is known as context switching.

DDks are device driver kits, which are equivalent to SDKs for writing device drivers. Windows NT includes DDks.

Fragmentation occurs in a dynamic memory allocation system when many of the free blocks are too small to satisfy any request.

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Main memory - only large storage media that the CPU can access directly.

Secondary storage - extension of main memory that provides large nonvolatile storage capacity.

Paging is solution to external fragmentation problem which is to permit the logical address space of a process to be noncontiguous, thus allowing a process to be allocating physical memory wherever the latter is available.

In batched operating system the users gives their jobs to the operator who sorts the programs according to their requirements and executes them. This is time consuming but makes the CPU busy all the time.