Dispatcher o Dispatcher module gives control of the CPU to the process selected by the cpu scheduler;this involves: O switching context switching to user mode jumping to the proper location in the user program to continue the execution of that program o Dispatch latency-time it takes for the dispatcher to stop one process and start another running SHOULD be as fast as possible event response to event response interval process made interrupt available processing real-time dispatch latency process executing conflicts dispatch 陈话兰xlanchen@ustc.edu:cn http/staff.uO1174O1 Operating System操作系统原理 March27.201918/68
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Dispatcher Dispatcher module gives control of the CPU to the process selected by the cpu scheduler; this involves: 1 switching context 2 switching to user mode 3 jumping to the proper location in the user program to continue the execution of that program Dispatch latency – time it takes for the dispatcher to stop one process and start another running ▶ SHOULD be as fast as possible event response to event response interval process made interrupt available processing dispatch latency real-time process executing conflicts dispatch 陈香兰 xlanchen@ustc.edu.cn http://staff.ustc.edu.cn/~xlanchen (Computer Application Laboratory, CS, USTC @ Hefei Embedded System Laboratory, CS, USTC @ Suzhou) 0117401: Operating System 操作系统原理与设计 March 27, 2019 18 / 68
Outline Scheduling Criteria o Scheduling Criteria 口1⊙生年12月00 东香兰xlanchen@ustc,edu.cn http:/staff..u0117401:Operating System操作系统原理 March27.201919/68
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Outline 2 Scheduling Criteria Scheduling Criteria 陈香兰 xlanchen@ustc.edu.cn http://staff.ustc.edu.cn/~xlanchen (Computer Application Laboratory, CS, USTC @ Hefei Embedded System Laboratory, CS, USTC @ Suzhou) 0117401: Operating System 操作系统原理与设计 March 27, 2019 19 / 68
Outline Scheduling Criteria o Scheduling Criteria 口1⊙生年12月00 东香兰xanchen@ustc.edu.cn http:/staff..u011740i:Operating System操作系统原理斐 March27.201920/68
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Outline 2 Scheduling Criteria Scheduling Criteria 陈香兰 xlanchen@ustc.edu.cn http://staff.ustc.edu.cn/~xlanchen (Computer Application Laboratory, CS, USTC @ Hefei Embedded System Laboratory, CS, USTC @ Suzhou) 0117401: Operating System 操作系统原理与设计 March 27, 2019 20 / 68
Scheduling Criteria CPU utilization(CPU利用率) ②Throughput(吞吐率) Turnaround time(周转时间) Waiting time(等待时间) ⑤Response time(响应时i间) 口1⊙生年12月00 陈话兰xlanchen@ustc.edu.cn http/staff.u0117401 Operating System操作系统原理斐 March27.201921/68
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Scheduling Criteria 1 CPU utilization (CPU 利用率) 2 Throughput (吞吐率) 3 Turnaround time (周转时间) 4 Waiting time (等待时间) 5 Response time (响应时间) 陈香兰 xlanchen@ustc.edu.cn http://staff.ustc.edu.cn/~xlanchen (Computer Application Laboratory, CS, USTC @ Hefei Embedded System Laboratory, CS, USTC @ Suzhou) 0117401: Operating System 操作系统原理与设计 March 27, 2019 21 / 68
Scheduling Criteria ●CPU utilization(CPU利用率)-keep the CPU as busy as possible conceptually:0%~100%;in a real system:40%~90% CPU 4核8线程编译Liux内核时的CPU利用率情况(0-7，总) ②Throughput(吞吐率) Turnaround time(周转时间) Waiting time(等待时间) Respense time们a立i间) 东香兰xlanchen@ustc.edu.cn http:/taff.u0117401.Operating System操作系统原理斐 March27,201921/68
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Scheduling Criteria 1 CPU utilization (CPU 利用率)– keep the CPU as busy as possible ▶ conceptually: 0% ∼ 100%; in a real system: 40% ∼ 90% 4核8线程编译Linux内核时的CPU利用率情况（0-7, 总） 2 Throughput (吞吐率) 3 Turnaround time (周转时间) 4 Waiting time (等待时间) 5 Response time (响应时间) 陈香兰 xlanchen@ustc.edu.cn http://staff.ustc.edu.cn/~xlanchen (Computer Application Laboratory, CS, USTC @ Hefei Embedded System Laboratory, CS, USTC @ Suzhou) 0117401: Operating System 操作系统原理与设计 March 27, 2019 21 / 68