Chapter 13 - Synchronization and scheduling in multiprocessor operating systems. This chapter discusses different kinds of multiprocessor systems, and describes how the OS achieves high throughput and fast response by using special techniques of structuring its kernel, so that many CPUs can execute kernel code in parallel, and of synchronizing and scheduling processes. | PROPRIETARY MATERIAL. © 2007 The McGraw-Hill Companies, Inc. All rights reserved. No part of this PowerPoint slide may be displayed, reproduced or distributed in any form or by any means, without the prior written permission of the publisher, or used beyond the limited distribution to teachers and educators permitted by McGraw-Hill for their individual course preparation. If you are a student using this PowerPoint slide, you are using it without permission. Advantages of multiprocessors Multiprocessor architectures provide three advantages High throughput CPUs can service many processes in parallel Computation speed-up An application may finish early because its processes may be serviced in parallel Graceful degradation Fault in one CPU does not halt the multiprocessor system Classification of multiprocessor systems Multiprocessor systems are classified according to the manner in which CPUs access memory units Uniform memory access (UMA) architecture All CPUs can access the entire . | PROPRIETARY MATERIAL. © 2007 The McGraw-Hill Companies, Inc. All rights reserved. No part of this PowerPoint slide may be displayed, reproduced or distributed in any form or by any means, without the prior written permission of the publisher, or used beyond the limited distribution to teachers and educators permitted by McGraw-Hill for their individual course preparation. If you are a student using this PowerPoint slide, you are using it without permission. Advantages of multiprocessors Multiprocessor architectures provide three advantages High throughput CPUs can service many processes in parallel Computation speed-up An application may finish early because its processes may be serviced in parallel Graceful degradation Fault in one CPU does not halt the multiprocessor system Classification of multiprocessor systems Multiprocessor systems are classified according to the manner in which CPUs access memory units Uniform memory access (UMA) architecture All CPUs can access the entire memory in an identical manner Also called symmetrical multiprocessor (SMP) architecture Non-uniform memory access (NUMA) architecture Nodes have their own memories, called local memories The CPUs in one node can access the local memory of the node faster than the memory of another node No-remote-memory-access (NORMA) architecture CPUs can access memory units of other nodes only over the network Throughput depends on the interconnection network Interconnection networks Common CPU–memory interconnection networks Bus Low cost, high expandability, reasonable access speeds Only one CPU–memory conversation can be in progress at any time Cross-bar switch CPUs connected along one direction, memory units along another High cost, low expandability, high access speeds Many conversations can be in progress at any time Multistage interconnection network (MIN) Hybrid between a bus and a cross-bar switch Each stage consists of many 2 x 2 switches A path is selected through the stages to reach a memory .
