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Operating System

Segmentation

Segmentation:- Segmentation is a memory-management scheme that supports the user view of memory. A program is a collection of segments. A segment is a logical unit such as the main program, procedure, function, method, object, local variables, global variables, common block, stack, symbol table, arrays, etc. A logical-address space is a collection of segments. Each […]

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Operating System

Non-contiguous memory allocation

Non-contiguous memory allocation             In non-contiguous memory allocation, it is allowed to store the processes in non-contiguous memory locations. There are different techniques used to load processes into memory, as follows: Paging Segmentation Virtual memory paging(Demand paging)   Paging Main memory is divided into a number of equal-sized blocks, are called frames. Each process is […]

Categories
Operating System

Partition Selection policy & Fragmentation

Partition Selection policy: Partition Selection policy, When the multiple memory holes (partitions) are large enough to contain a process, the operating system must use an algorithm to select in which hole the process will be loaded. The partition selection algorithm is as follows: First-fit:  The OS looks at all sections of free memory. The process […]