Memory Management: Translation Lookaside Buffer Explained

This lecture covers the concept of the Translation Lookaside Buffer (TLB) in computer systems, focusing on its role in memory management. The instructor begins by discussing the logical process of memory access, where the CPU requests data at a virtual address. The Memory Management Unit (MMU) translates this virtual address to a physical address, which involves walking through the Page Table Entry (PTE) tree. The lecture highlights the inefficiency of this process, particularly in 32-bit and 48-bit architectures, where multiple memory references are required. To mitigate this, the TLB acts as a cache for recent virtual-to-physical address mappings, significantly speeding up memory access. The instructor explains the implications of TLB hits and misses, emphasizing the importance of locality of reference for high hit rates. Additionally, the lecture addresses TLB invalidation during context switches and the management of page tables, concluding with a discussion on the size and structure of page tables in modern systems. The lecture underscores the efficiency of TLBs in enabling paging without significant performance costs.