Lecture

Memory Virtualization

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In course

CS-522: Principles of computer systems

This advanced graduate course teaches the key design principles underlying successful computer and communication systems, and shows how to solve real problems with ideas, techniques, and algorithms from operating systems, networks, databases, programming l ...

Description

This lecture delves into the intricate world of memory virtualization, exploring how modern operating systems achieve memory virtualization through the clever use of naming and abstraction. The instructor explains the importance of address spaces, page tables, caching, and system design constants in optimizing memory performance and reliability. The lecture also covers the role of the Memory Management Unit (MMU) in translating virtual addresses to physical addresses, the concept of virtual memory, and the significance of TLBs in reducing the overhead of virtual-to-physical address translation. Additionally, the lecture touches upon cache structures, aliasing problems, and the trade-offs involved in designing memory systems.

Instructor

George Candea

George Candea heads the Dependable Systems Lab, where he develops techniques and abstractions for building efficient and trustworthy computer systems. His current work focuses on making performance and energy programmable, i.e., providing first-class abstractions to capture a system’s performance and energy behavior (as interfaces do for functionality) and to use them dependably to design, code, and operate efficient systems.In the recent past, George also served as CEO and later Chief Scientist of Cyberhav

Official source

Ontological neighbourhood

Computer engineering

High-performance computing: Real-time computing

Related concepts (32)

Virtual memory

In computing, virtual memory, or virtual storage, is a memory management technique that provides an "idealized abstraction of the storage resources that are actually available on a given machine" which "creates the illusion to users of a very large (main) memory". The computer's operating system, using a combination of hardware and software, maps memory addresses used by a program, called virtual addresses, into physical addresses in computer memory.

Memory paging

In computer operating systems, memory paging (or swapping on some Unix-like systems) is a memory management scheme by which a computer stores and retrieves data from secondary storage for use in main memory. In this scheme, the operating system retrieves data from secondary storage in same-size blocks called pages. Paging is an important part of virtual memory implementations in modern operating systems, using secondary storage to let programs exceed the size of available physical memory.

Page (computer memory)

A page, memory page, or virtual page is a fixed-length contiguous block of virtual memory, described by a single entry in the page table. It is the smallest unit of data for memory management in a virtual memory operating system. Similarly, a page frame is the smallest fixed-length contiguous block of physical memory into which memory pages are mapped by the operating system. A transfer of pages between main memory and an auxiliary store, such as a hard disk drive, is referred to as paging or swapping.

Input–output memory management unit

In computing, an input–output memory management unit (IOMMU) is a memory management unit (MMU) connecting a direct-memory-access–capable (DMA-capable) I/O bus to the main memory. Like a traditional MMU, which translates CPU-visible virtual addresses to physical addresses, the IOMMU maps device-visible virtual addresses (also called device addresses or memory mapped I/O addresses in this context) to physical addresses. Some units also provide memory protection from faulty or malicious devices.

Address space

In computing, an address space defines a range of discrete addresses, each of which may correspond to a network host, peripheral device, disk sector, a memory cell or other logical or physical entity. For software programs to save and retrieve stored data, each datum must have an address where it can be located. The number of address spaces available depends on the underlying address structure, which is usually limited by the computer architecture being used.

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Virtual Memory

Covers virtual memory, program relocation, memory protection, TLB, and memory hierarchy interactions.

Memory Hierarchy and Cache Performance

Explores virtual memory, page tables, TLB, and cache memory in computer systems.

Paging

Introduces paging in operating systems, explaining memory management units, address space abstraction, page tables, and TLB.

Virtual Memory: Address Translation and Page Tables

Explores virtual memory systems, address translation, page tables, and hierarchical schemes in memory management.

Virtual Memory: Principles and Mechanisms