CST 334 Week 4

 Memory Virtualization (paging)

This week we continued the topic of memory virtualization with the introduction of paging. Paging simplifies free space management and avoids the fragmentation issues caused by segmentation. By dividing memory into fixed-sized units called pages, paging provides a more flexible and efficient way to manage memory compared to using variable-sized chunks. 

Operating systems use a page table to track where each virtual page is stored in physical memory. The page table maps virtual page numbers (VPNs) to physical frame numbers (PFNs), allowing the system to translate virtual addresses to physical addresses. The offset within the address ensures byte-level precision in memory addressing.

Implementing paging requires careful consideration to avoid excessive memory overhead and performance slowdowns. To mitigate these potential issues, several optimization techniques are employed, such as multi-level page tables and specialized caches within the Memory Management Unit (MMU) called Translation Lookaside Buffers (TLBs). These optimizations help manage the large amount of mapping information and speed up address translation by caching frequently accessed translations.

The topics of the past few weeks have provided foundational insights into system design, performance optimization, and the critical roles of operating systems in managing memory efficiently. Understanding these concepts is essential for anyone involved in operating systems and computer architecture.