Importance of Addressing Memory Management Requirements When Building an Operating System.

POS/355 University of Phoenix, Axia

Importance of Addressing Memory Management Requirements When Building an Operating System.

The Memory is the most important part of the CPU. The CPU has a program called a memory manager which is needed to keep track of what the memory is being used on and how much. When building an Operating System you must keep some things in mind such as basic cache structure, and content- addressable memory. With basic cache structure it is used by cache memory which is similar to virtual memory. It takes low speed memory which is duplicated and stored in a high speed cache memory. When it request memory the request first goes to the cache memory and if it doesn’t respond it is then sent to the main memory. With content-addressable memory (CAM) it is a special type of memory which is used in very high speed applications. It is better known as associative array which is used for programming data structure.

You must also keep in mind that address mapping and relocation is also important in the management of memory. To have the Operating system send out the information it must know the locations of process control information, the execution stack, and code entry. Inside the program may be memory references in various instructions. Say you put something in your documents but you put it in another name such as birds. You can type birds in the search in your search program with in your Operating System and it will search the name of the file which will bring up all the files with the name. The file name is the address which gives the location. It is also like using Google Maps. Where with Google Maps you put in an address and it gives you the directions.
You must also think about the space and how it is used in the processes. There are 3 different strategies for this such as first fit, best fit, and worst fit. With First fit it allocates the first hole big enough. The search can begin where the first fit previously ended or at the beginning of the set of holes. With best fit the smallest hole that is big enough is used. It searches the whole list of holes unless it is sorted by size which produces the smallest leftover holes. With worst fit the largest hole is found to produce the largest leftover hole which could have room for another process.
Segmentation is also important when addressing memory management. Segmentation divides a program into several segments similar to partition of varied sizes. It avoids internal fragmentation that is present in fixed partitioning and paging but it suffers from external fragmentation. It is not a serious problem due to a process that may be broken into a number of smaller pieces which results to external holes being much smaller. Segmentation is visible based on the programmers’ logical view of the programs. They will assign programs and data to different segments giving a major advantage of segmentation to make the supported easier protection and sharing. Segmentation has been combined with Paging to eliminate external and internal fragmentation and give programmers more control on programs.
This is just a few things I have found that help manage memory better when building an Operating System. I seem to think that these things are the most important when building Operating Systems. Even though this is our first week in class I think my research has me in the right direction as far as this subject.

REFERENCES

Niu, J. (October 29, 2003). Memory Management. Retrieved from http://www.sci.brooklyn.cuny.edu/~jniu/teaching/csc33200/files/1027-MemoryManagement.pdf