Chapter 6

Section 6.1

Taxonomy of Parallel Architectures: SISD, SIMD, MISD, MIMD

Memory organizations: centralized shared-memory and symmetric (shared-memory) multiprocessors (SMPs), and distributed-memory multiprocessors

Models for communication and memory architectures for multiprocessors: distributed shared-memory (DSM), message-passing multiprocessors (multicomputers/clusters)

Advantages of shared-memory communication and message-passing comunications

Challenges of parallel processing: limited parallelism of a program and high cost of communications

General idea of Amdahl's law

Section 6.2: Characteristics of Application Domains

There won't be much on the test directly related to this section, but I suggest you read it to get a feel for the type of benchmark applications.

Section 6.3 Symmetric Shared-Memory Architectures

Understanding of the general idea of multiprocessor cache coherence problem

Basic cache coherence schemes: directory based and snoopy

Performance of invalidate vs. write update snoopy protocols

Implementation of invalidate protocol (Figures 16.11 and Figures 16.12)

Section 6.4 Performance of Symmetric Shared-Memory Multiprocessors

general idea of coherence misses and false sharing

The details of the commercial workloads is not something I would expect you to remember.

Section 6.5 Distributed Shared-Memory Architectures

Directory-based cache-coherence protocol implementation

(Figures 6.28, 6.29, and 6.30)

Section 6.6 Performance of Distributed Shared-Memory Multiprocessors

Again, details are not something I expect you to remember.

Section 6.7 Synchronization

Synchronization on small SMP: spinlock using atomic exchange (bottom of page 593), load linked/store conditional primitives

Reasons that spin lock techniques don't scale up well: contention for lock and serialization of lock access

sense-barrier code (figures 6.38 and 6.39)

Synchronization mechanisms for large-scale multiprocessors: software implementations (spinlock with exponiential backoff, queuing locks, and combining tree), and hardware implementations (queuing locks)

Section 6.8 Models of Memory Consistency: An introduction

general problem idea

Sequential consistency