CST 334 - Operating Systems - Week 3

 

This week, we learned about memory virtualization, which is an important concept in operating systems because it provides an abstraction of physical memory, enabling efficient and flexible memory management. The key idea behind memory virtualization is to give each process the illusion of having a large, private address space, even though physical memory may be shared among multiple processes. This is achieved through address translation, where the operating system and hardware work together to map virtual addresses to physical addresses. I learned about the different types of memory such as stack and heap memory, and the various system calls and functions involved in memory management, including `malloc` and `free`. Also, I learned more about memory management, starting from early systems where memory layout was simple, to multiprogramming and time sharing that needed more sophisticated memory management techniques. The introduction of the address space abstraction by the OS has been a significant advancement, allowing processes to operate in isolation and providing protection against unauthorized access. 

This week’s lectures and readings emphasized the goals of transparency, efficiency, and protection in virtual memory systems. I also learned about segmentation, a method that divides memory into segments, each with its own base and bounds, offering advantages like dynamic relocation and efficient sharing, but also with challenges such as external fragmentation. For this week’s assignments, we had to write some code that involved creating a memory allocation library. We developed functions similar to `malloc()` and `free()`. This assignment was challenging, but it helped us gain a deeper understanding of how these two functions work behind the scenes. Additionally, my teammates and I started brainstorming about which paper to select for our group project. There were many suggestions, making it difficult to choose just one. Some of the papers we are considering include Hot Storage 23, OSDI 23, Hot OS 15, Hot OS XV, Hot Cloud, and several others. All these papers sound interesting, so we’ll ensure to select the one that seems most engaging for our audience (classmates).