Case Study no. 5 in Operating Systems

This is the fixed (pre-determined) partition of the memory:

Memory Block	Size
Block 1	50K
Block 2	200K
Block 3	70K
Block 4	115K
Block 5	15K

______________________________________________________________________________

A. Using best-fit allocation:

Memory Block	Size
Job 3	35K
Job 1	100K
Job 8	55K
Job 10	100K
Job 4	15K

Waiting List:

Job 2 – 10K

Job 5 – 23K

Job 6 – 6K

Job 7 – 25K

Job 9 – 88K

______________________________________________________________________________

Memory Block	Size
Job 3	35K
Job 1	100K
Job 8	55K
Job 10	100K
Job 2	10K

Waiting List:

Job 5 – 23K

Job 6 – 6K

Job 7 – 25K

Job 9 – 88K

______________________________________________________________________________

Memory Block	Size
Job 7	25K
Job 1	100K
---	---
Job 10	100K
Job 6	6K

Waiting List:

Job 5 – 23K

Job 9 – 88K

______________________________________________________________________________

Memory Block	Size
Job 5	23K
---	---
---	---
Job 9	88K
---	---

Waiting List:

No jobs remaining

______________________________________________________________________________

B. Using first-fit allocation:

Memory Block	Size
Job 3	35K
Job 10	100K
Job 8	55K
Job 1	115K
Job 4	15K

Waiting List:

Job 2 – 10K

Job 5 – 25K

Job 6 – 6K

Job 7 – 25K

Job 9 – 88K

______________________________________________________________________________

Memory Block	Size
Job 3	35K
Job 10	100K
Job 8	55K
Job 1	100K
Job 2	10K

Waiting List:

Job 5 – 25K

Job 6 – 6K

Job 7 – 25K

Job 9 – 88K

______________________________________________________________________________

Memory Block	Size
Job 5	25K
Job 10	100K
Job 7	25K
Job 1	100K
Job 6	6K

Waiting List:

Job 9 – 88K

______________________________________________________________________________

Memory Block	Size
Job 5	25K
---	---
---	---
Job 9	88K
---	---

Waiting List:

No jobs remaining

______________________________________________________________________________

C. Using worst-fit allocation method:

Memory Block	Size
Job 2	10K
Job 9	88K
Job 5	23K
Job 8	55K
Job 6	6K

Waiting List:

Job 1 – 100K

Job 3 – 35K

Job 4 – 15K

Job 7 – 25K

Job 10 – 100K

______________________________________________________________________________

Memory Block	Size
Job 3	35K
Job 9	88K
Job 5	23K
Job 8	55K
Job 4	15 K

Waiting List:

Job 1 – 100K

Job 7 – 25K

Job 10 – 100K

______________________________________________________________________________

Memory Block	Size
Job 3	35K
Job 9	88K
Job 7	25K
Job 1	100K
---	---

Waiting list:

Job 10 – 100K

___________________________________________________________________________

Memory Block	Size
---	---
Job 10	100K
---	---
Job 1	100K
---	---

Waiting List:

No jobs remaining