DOCSLIB.ORG

Interrupt Latency of ZTP/RZK

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text
Interrupt Latency of ZTP/RZK Technical Note Measuring the Interrupt Latency of ZTP/RZK TN004901-0206 Introduction One of the important characteristics of a real-time operating system is the interrupt latency, which is the time taken for a system to launch an interrupt service routine, or in a multitasking system, to schedule an interrupt handler task. Measuring interrupt latency can provide valuable insight into the way a system will perform when running real-time applications. Interrupt latency indicates the performance capabilities and the effectiveness of a real time operating system that deals with extremely high-priority interrupts. This technical note discusses the method for measuring the best and the worst case interrupt latency of ZTP1.6 on RZK1.2.1. Interrupt Latency Interrupt latency is defined as the time elapsed between an interrupt and the execution of the first instruction in the corresponding interrupt service routine. In other words, it refers to the amount of time or delay between when an interrupt is triggered and when the interrupt is served by the CPU and software. Generally this delay depends on the machine state at the moment the interrupt was acknowledged by the CPU. Some of the factors that affects the interrupt latency are listed below: • Context switch time • Time caused by blocking • Time caused by preemption • Data dependency • Criticality of tasks Interrupt latency do not have a fixed length. By definition, interrupt latency is an asynchronous event and depends on the state of the machine. This state of machine is a function of both the hardware and the software used in the system. An embedded system application may have different types of interrupts as a result of using many hardware devices or the processors on-chip resources. Some interrupt have higher priority and require a faster response time than others. ZiLOG Worldwide Headquarters • 532 Race Street • San Jose, CA 95126 Telephone: 408.558.8500 • Fax: 408.558.8300 • www.ZiLOG.com Measuring the Interrupt Latency of ZTP/RZK Technical Note All the maskable interrupts are disabled when internal kernel data structure is being manipulated. The system’s interrupt latency is directly related to the length of the longest critical section in the kernel. The Figure 1 shows a pictorial representation of the interrupt latency. t1 t2 Time A B Interrupt Service Interrupt Task Routine Latency Thread Latency #1: Figure 1. Representation of Interrupt Latency In Figure 1, t1- represents the time at which the hardware asserts the IRQ input (that is an interrupt is triggered). t2- represents the time at which the interrupt thread starts its execution. Measuring the Interrupt Latency This section discusses the method for measuring the interrupt latency using Timer 2 interrupt. Timer 2 registers are initialized to generate interrupt at every 50 ms. The code snippet listed in the appendix causes an interrupt to be generated when Timer 2 register overflows. In the Timer 2 interrupt service routine, the current value of the hardware timer count is stored in a global variable tmr2_data.The interrupt generation is disabled and the interrupt task is scheduled for execution. The interrupt task then compares the last count value obtained in the interrupt service routine with the lowest value obtained. If the current value is less, it becomes the new lowest value and the interrupt task displays the new count. Once the complete comparison is done, timer interrupt generation is re-enabled. The timer is set to a reload value of 0 and a div16 prescaler is used. The timer will cycle from 0 to 65536 values with the following time-out period: 16*65536 / 50000000 = 20.97152 ms TN004901-0206 2 Measuring the Interrupt Latency of ZTP/RZK Technical Note Therefore, almost 50 Timer 2 interrupts are generated for each second and each timer tick corresponds to 320 ns. While running the stack, the lowest value that is displayed will be 0xFF61, corresponding to an interrupt latency: = (0 - 0xFF61) ticks * 320 ns per tick = 159 * 0.32 µs = just over 50 µs Measuring the Best Case Latency Download the complete ZTP demo to the eZ80F91 development kit. The code resides in RAM area and the best case interrupt latency number provided in this technical note is for the codes executing in the RAM area. While measuring the best case latency no threads other than Timer 2 and the system timer thread are in execution (System timer generates base timings for RZK). Best case interrupt latency value The best case interrupt latency: 2 to 3 µs Measuring the Worst Case Latency Worst case interrupt latency is measured by loading the ZTP stack with maximum traffic. As maximum traffic is very specific to the application that is being used, the term worst case interrupt latency becomes a relative term. In this technical note, a particular example is considered for measuring the worst case interrupt latency. Here the system is loaded by gradually increasing the network traffic using the following methods: • Pinging • Continuously downloading the web page hosted on eZ80® through hypertext transfer protocol (HTTP) • Connecting through point to point protocol (PPP) Pinging Ping is a network tool used on TCP/IP networks (such as the Internet) to verify the IP-level connectivity. It verifies whether a particular target host is operating properly and is reachable on the network from the testing host. Ping provides estimates of the round-trip time and packet loss rate between the hosts. Ping works by sending Internet control message protocol (ICMP) echo request packets to the target host and waits for the ICMP echo response packets to be received. TN004901-0206 3 Measuring the Interrupt Latency of ZTP/RZK Technical Note All the machines supporting TCP/IP should be able to ping the ez80F91 web server (i.e., eZ80F91 development kit on which the ZTP stack has been loaded). Ping (send ICMP echo request packets) to the ez80F91 web server with an appropriate IP address and the ez80F91 web server responds to the pinging machine by sending the ICMP echo response packet. The network is kept busy by Pinging method as given below. On a host computer, run two instances of ping test over ethernet with the following settings: • Size of each ping packet:1400 bytes • Ping interval:10 ms • Time-out: 1000 ms On the same host computer, run one instance of ping test over ethernet with the following settings: • Size of each ping packet: 4000 bytes • Ping interval: 200 ms • Timeout:1000 ms Once the PPP connection is established between host computer and eZ80F91, from the host computer run three instance of DOS Ping (use the PPP interface IP address). Each ping should be 1400 bytes repeating at one second interval. Invoking the PPP and continuous download of web page through HTTP Establish a PPP connection to a host computer using direct cable connection (DCC) and HyperTerminal setting at 57600 baud rate, no parity, 8 bit data and 1 stop bit and no flow control. DCC is used to eliminate slow down arising because of the modem. On a host computer, run one instance of the EtherPeek (ethernet network analyser software) HTTP throughput test (continuous refresh of HTTP web page) over ethernet. On the same host computer to which the PPP connection was established, run one instance of the EtherPeek HTTP throughput test over PPP. Make sure to execute the program for about 15 to 20 minutes, which is close to the breaking point of traffic that the stack can handle. You can see few no buffer avail messages indicating some dropped packets. Similarly, as no flow control is used over PPP, few serial overrun errors will appear. The key point over here is to not overload the stack, just bring it close to the breaking point. While the Ethernet and PPP traffic is running, note down the latency reported by the Timer 2 program. TN004901-0206 4 Measuring the Interrupt Latency of ZTP/RZK Technical Note Worst case interrupt latency value The worst case interrupt latency obtained using the above mentioned tests is 18us but this value may differ depending on the conditions like (different protocols being used, different thread priorities, number of applications being run on eZ80®). You can refer to appendix for the code snippets used to measure the interrupt latency. Summary It is always not possible to guarantee the best case or maximum interrupt latency for the ZTP/RZK, but it is possible to draw some general conclusions for a typical system. Measurement of interrupt latency amounts to making a measurement of an extreme condition. It is not a measure of the average performance of a CPU. i.e., it does not reflect the ability of a CPU to compute. Increasing the CPU’s clock speed increases the average performance level of a system but does not significantly affect the speed at which a CPU will respond to an asynchronous event, such as an interrupt. TN004901-0206 5 Measuring the Interrupt Latency of ZTP/RZK Technical Note Appendix - Code Snippets The code snippets used for measuring the interrupt latency are listed below. /********************************************************************* * *Description: The code snippets used for measuring the interrupt *latency are listed below * *Copyright 2006 ZiLOG Inc. ALL RIGHTS RESERVED. * *This file contains unpublished confidential and proprietary *information of ZiLOG, Inc. *NO PART OF THIS WORK MAY BE DUPLICATED, STORED, PUBLISHED OR DISCLOSED *IN ANY FORM WITHOUT THE PRIOR WRITTEN CONSENT OF ZiLOG, INC. *This is not a license and no use of any kind of this work is *authorized in the absence of a written license granted by ZiLOG, Inc. *in ZiLOG's
Load more

Recommended publications
  • Demystifying the Real-Time Linux Scheduling Latency
    Demystifying the Real-Time Linux Scheduling Latency Daniel Bristot de Oliveira Red Hat, Italy [email protected] Daniel Casini Scuola Superiore Sant’Anna, Italy [email protected] Rômulo Silva de Oliveira Universidade Federal de Santa Catarina, Brazil [email protected] Tommaso Cucinotta Scuola Superiore Sant’Anna, Italy [email protected] Abstract Linux has become a viable operating system for many real-time workloads. However, the black-box approach adopted by cyclictest, the tool used to evaluate the main real-time metric of the kernel, the scheduling latency, along with the absence of a theoretically-sound description of the in-kernel behavior, sheds some doubts about Linux meriting the real-time adjective. Aiming at clarifying the PREEMPT_RT Linux scheduling latency, this paper leverages the Thread Synchronization Model of Linux to derive a set of properties and rules defining the Linux kernel behavior from a scheduling perspective. These rules are then leveraged to derive a sound bound to the scheduling latency, considering all the sources of delays occurring in all possible sequences of synchronization events in the kernel. This paper also presents a tracing method, efficient in time and memory overheads, to observe the kernel events needed to define the variables used in the analysis. This results in an easy-to-use tool for deriving reliable scheduling latency bounds that can be used in practice. Finally, an experimental analysis compares the cyclictest and the proposed tool, showing that the proposed method can find sound bounds faster with acceptable overheads. 2012 ACM Subject Classification Computer systems organization → Real-time operating systems Keywords and phrases Real-time operating systems, Linux kernel, PREEMPT_RT, Scheduling latency Digital Object Identifier 10.4230/LIPIcs.ECRTS.2020.9 Supplementary Material ECRTS 2020 Artifact Evaluation approved artifact available at https://doi.org/10.4230/DARTS.6.1.3.
    [Show full text]
  • Interrupt Handling in Linux
    Department Informatik Technical Reports / ISSN 2191-5008 Valentin Rothberg Interrupt Handling in Linux Technical Report CS-2015-07 November 2015 Please cite as: Valentin Rothberg, “Interrupt Handling in Linux,” Friedrich-Alexander-Universitat¨ Erlangen-Nurnberg,¨ Dept. of Computer Science, Technical Reports, CS-2015-07, November 2015. Friedrich-Alexander-Universitat¨ Erlangen-Nurnberg¨ Department Informatik Martensstr. 3 · 91058 Erlangen · Germany www.cs.fau.de Interrupt Handling in Linux Valentin Rothberg Distributed Systems and Operating Systems Dept. of Computer Science, University of Erlangen, Germany [email protected] November 8, 2015 An interrupt is an event that alters the sequence of instructions executed by a processor and requires immediate attention. When the processor receives an interrupt signal, it may temporarily switch control to an inter- rupt service routine (ISR) and the suspended process (i.e., the previously running program) will be resumed as soon as the interrupt is being served. The generic term interrupt is oftentimes used synonymously for two terms, interrupts and exceptions [2]. An exception is a synchronous event that occurs when the processor detects an error condition while executing an instruction. Such an error condition may be a devision by zero, a page fault, a protection violation, etc. An interrupt, on the other hand, is an asynchronous event that occurs at random times during execution of a pro- gram in response to a signal from hardware. A proper and timely handling of interrupts is critical to the performance, but also to the security of a computer system. In general, interrupts can be emitted by hardware as well as by software. Software interrupts (e.g., via the INT n instruction of the x86 instruction set architecture (ISA) [5]) are means to change the execution context of a program to a more privileged interrupt context in order to enter the kernel and, in contrast to hardware interrupts, occur synchronously to the currently running program.
    [Show full text]
  • Microkernel Mechanisms for Improving the Trustworthiness of Commodity Hardware
    Microkernel Mechanisms for Improving the Trustworthiness of Commodity Hardware Yanyan Shen Submitted in fulfilment of the requirements for the degree of Doctor of Philosophy School of Computer Science and Engineering Faculty of Engineering March 2019 Thesis/Dissertation Sheet Surname/Family Name : Shen Given Name/s : Yanyan Abbreviation for degree as give in the University calendar : PhD Faculty : Faculty of Engineering School : School of Computer Science and Engineering Microkernel Mechanisms for Improving the Trustworthiness of Commodity Thesis Title : Hardware Abstract 350 words maximum: (PLEASE TYPE) The thesis presents microkernel-based software-implemented mechanisms for improving the trustworthiness of computer systems based on commercial off-the-shelf (COTS) hardware that can malfunction when the hardware is impacted by transient hardware faults. The hardware anomalies, if undetected, can cause data corruptions, system crashes, and security vulnerabilities, significantly undermining system dependability. Specifically, we adopt the single event upset (SEU) fault model and address transient CPU or memory faults. We take advantage of the functional correctness and isolation guarantee provided by the formally verified seL4 microkernel and hardware redundancy provided by multicore processors, design the redundant co-execution (RCoE) architecture that replicates a whole software system (including the microkernel) onto different CPU cores, and implement two variants, loosely-coupled redundant co-execution (LC-RCoE) and closely-coupled redundant co-execution (CC-RCoE), for the ARM and x86 architectures. RCoE treats each replica of the software system as a state machine and ensures that the replicas start from the same initial state, observe consistent inputs, perform equivalent state transitions, and thus produce consistent outputs during error-free executions.
    [Show full text]
  • Process Scheduling Ii
    PROCESS SCHEDULING II CS124 – Operating Systems Spring 2021, Lecture 12 2 Real-Time Systems • Increasingly common to have systems with real-time scheduling requirements • Real-time systems are driven by specific events • Often a periodic hardware timer interrupt • Can also be other events, e.g. detecting a wheel slipping, or an optical sensor triggering, or a proximity sensor reaching a threshold • Event latency is the amount of time between an event occurring, and when it is actually serviced • Usually, real-time systems must keep event latency below a minimum required threshold • e.g. antilock braking system has 3-5 ms to respond to wheel-slide • The real-time system must try to meet its deadlines, regardless of system load • Of course, may not always be possible… 3 Real-Time Systems (2) • Hard real-time systems require tasks to be serviced before their deadlines, otherwise the system has failed • e.g. robotic assembly lines, antilock braking systems • Soft real-time systems do not guarantee tasks will be serviced before their deadlines • Typically only guarantee that real-time tasks will be higher priority than other non-real-time tasks • e.g. media players • Within the operating system, two latencies affect the event latency of the system’s response: • Interrupt latency is the time between an interrupt occurring, and the interrupt service routine beginning to execute • Dispatch latency is the time the scheduler dispatcher takes to switch from one process to another 4 Interrupt Latency • Interrupt latency in context: Interrupt! Task
    [Show full text]
  • Efficient Interrupts on Cortex-M Microcontrollers
    Efficient Interrupts on Cortex-M Microcontrollers Chris Shore Training Manager ARM Ltd Cambridge, UK [email protected] Abstract—The design of real-time embedded systems involves So, assuming that we have a system which is powerful a constant trade-off between meeting real-time design goals and enough to meet all its real-time design constraints, we have a operating within power and energy budgets. This paper explores secondary problem. how the architectural features of ARM® Cortex®-M microcontrollers can be used to maximize power efficiency while That problem is making the system as efficient as possible. ensuring that real-time goals are met. If we have sufficient processing power, it is relatively trivial to conceive and implement a design which meets all time-related Keywords—interrupts; microcontroller; real-time; power goals but such a system might be extremely inefficient when it efficiency. comes to energy consumption. The requirement to minimize energy consumption introduces another set of goals and I. INTRODUCTION constraints. It requires us to make use of sleep modes and low A “real-time” system is one which has to react to external power modes in the hardware, to use the most efficient events within certain time constraints. Wikipedia says: methods for switching from one event to another and to maximize “idle time” in the design to make opportunities to “A system is real-time if the total correctness on an use low power modes. operation depends not only on its logical correctness but also upon the time in which it is performed.” The battle is between meeting the time constraints while using the least amount of energy in doing so.
    [Show full text]
  • Thread Verification Vs. Interrupt Verification
    Thread Verification vs. Interrupt Verification John Regehr School of Computing University of Utah ABSTRACT to verifiers for thread-based programs that per- Interrupts are superficially similar to threads, but there are mit them to also check interrupt-based programs. subtle semantic differences between the two abstractions. A secondary goal is to exploit the semantics of This paper compares and contrasts threads and interrupts interrupts to make checking faster and more pre- from the point of view of verifying the absence of race con- cise. ditions. We identify a small set of extensions that permit Of course, threads come in many flavors. In this paper thread verification tools to also verify interrupt-driven soft- we’ll assume POSIX-style threads [5]: preemptively sched- ware, and we present examples of source-to-source trans- uled blocking threads, scheduled either in the kernel or at formations that turn interrupt-driven code into semanti- user level. cally equivalent thread-based code that can be checked by a thread verifier. 2. THREADS AND INTERRUPTS 1. INTRODUCTION The following are some significant ways in which threads For programs running on general-purpose operating sys- differ from interrupts. tems on PC-class hardware, threads are probably the most important abstraction supporting concurrent programming. Blocking. Interrupt cannot block: they run to completion On the other hand, interrupts are the dominant method for unless preempted by other interrupts. The inability to block expressing concurrency in embedded systems, particularly is very inconvenient, and it is one of the main reasons that those based on small microcontroller units (MCUs). All complex logic should not be implemented in interrupt code.
    [Show full text]
  • Simulation and Comparison of Various Scheduling Algorithm for Improving the Interrupt Latency of Real –Time Kernal
    Journal of Computer Science and Applications. ISSN 2231-1270 Volume 6, Number 2 (2014), pp. 115-123 © International Research Publication House http://www.irphouse.com Simulation And Comparison of Various Scheduling Algorithm For Improving The Interrupt Latency of Real –Time Kernal 1.Lavanya Dhanesh 2.Dr.P.Murugesan 1.Research Scholar, Sathyabama University, Chennai, India. 2.Professor, S.A. Engineering College, Chennai, India. Email:1. [email protected] Abstract The main objective of the research is to improve the performance of the Real- time Interrupt Latency using Pre-emptive task Scheduling Algorithm. Interrupt Latency provides an important metric in increasing the performance of the Real Time Kernal So far the research has been investigated with respect to real-time latency reduction to improve the task switching as well the performance of the CPU. Based on the literature survey, the pre-emptive task scheduling plays an vital role in increasing the performance of the interrupt latency. A general disadvantage of the non-preemptive discipline is that it introduces additional blocking time in higher priority tasks, so reducing schedulability . If the interrupt latency is increased the task switching delay shall be increasing with respect to each task. Hence most of the research work has been focussed to reduce interrupt latency by many methods. The key area identified is, we cannot control the hardware interrupt delay but we can improve the Interrupt service as quick as possible by reducing the no of preemptions. Based on this idea, so many researches has been involved to optimize the pre-emptive scheduling scheme to reduce the real-time interrupt latency.
    [Show full text]
  • Integrated Task and Interrupt Management for Real-Time Systems
    Integrated Task and Interrupt Management for Real-Time Systems LUIS E. LEYVA-DEL-FOYO, Universidad Aut´onoma Metropolitana—Unidad Cuajimalpa PEDRO MEJIA-ALVAREZ, CINVESTAV-IPN DIONISIO DE NIZ, Carnegie Mellon University Real-time scheduling algorithms like RMA or EDF and their corresponding schedulability test have proven to be powerful tools for developing predictable real-time systems. However, the traditional interrupt man- agement model presents multiple inconsistencies that break the assumptions of many of the real-time scheduling tests, diminishing its utility. In this article, we analyze these inconsistencies and present a model that resolves them by integrating interrupts and tasks in a single scheduling model. We then use the RMA theory to calculate the cost of the model and analyze the circumstances under which it can provide the most value. This model was implemented in a kernel module. The portability of the design of our module is discussed in terms of its independence from both the hardware and the kernel. We also discuss the imple- mentation issues of the model over conventional PC hardware, along with its cost and novel optimizations for reducing the overhead. Finally, we present our experimental evaluation to show evidence of its temporal determinism and overhead. Categories and Subject Descriptors: D.4.7 [Operating Systems]: Organization and Design—Real-time systems and embedded systems; D.4.1 [Operating Systems]: Process Management—Scheduling, threads; D.4.4 [Operating Systems]: Communications Management—Input/output; D.4.8 [Operating Systems]: Performance—Modeling and prediction General Terms: Algorithms, Design, Experimentation, Performance Additional Key Words and Phrases: Predictability, interrupt scheduling, programmable interrupt controller ACM Reference Format: Leyva-del-Foyo, L.
    [Show full text]
  • Quantifying the Latency and Possible Throughput of External Interrupts on Cyber-Physical Systems
    Quantifying the Latency and Possible Throughput of External Interrupts on Cyber-Physical Systems Oliver Horst Raphael Wild Johannes Wiesböck Uwe Baumgarten fortiss GmbH Technical University of Munich Research Institute of the Free State of Bavaria Department of Informatics Munich, Germany Garching, Germany {horst,wiesboeck}@fortiss.org {raphael.wild,baumgaru}@tum.de ABSTRACT which requires an in-depth understanding of the hardware to ob- An important characteristic of cyber-physical systems is their capa- tain precise measurements [22]. This expert knowledge, however, bility to respond, in-time, to events from their physical environment. is reserved for the system on chip (SoC) and processor intellectual However, to the best of our knowledge there exists no benchmark property (IP) vendors. Hence, we see the need for a measurement for assessing and comparing the interrupt handling performance method that allows to accurately measure and properly stress the of different software stacks. Hence, we present a flexible evalua- interrupt handling process of today’s SoCs without expert knowl- tion method for measuring the interrupt latency and throughput edge. Accordingly, we present a flexible interrupt performance on ARMv8-A based platforms. We define and validate seven test- measurement method that can be applied to ARMv8-A IP-core cases that stress individual parts of the overall process and combine based platforms that provide a physical trace-port. As we see an them to three benchmark functions that provoke the minimal and increasing market share of ARM based systems [20] and their wide maximal interrupt latency, and maximal interrupt throughput. adoption in automotive CPSs [9, 25, 28] we strongly believe that our method helps in analyzing a multitude of relevant systems.
    [Show full text]
  • (RTOS) Is an Operating System (OS) Intended to Serve Real-Time Application Requests
    Page 1 of 7 Real-time operating systems 6.1 Introduction: A real-time operating system (RTOS) is an operating system (OS) intended to serve real-time application requests. It must be able to process data as it comes in, typically without buffering delays. Processing time requirements (including any OS delay) are measured in tenths of seconds or shorter. A key characteristic of an RTOS is the level of its consistency concerning the amount of time it takes to accept and complete an application's task; the variability is jitter. A hard real-time operating system has less jitter than a soft real-time operating system. The chief design goal is not high throughput, but rather a guarantee of a soft or hard performance category. An RTOS that can usually or generally meet a deadline is a soft real-time OS, but if it can meet a deadline deterministically it is a hard real-time OS. An RTOS has an advanced algorithm for scheduling. Scheduler flexibility enables a wider, computer-system orchestration of process priorities, but a real-time OS is more frequently dedicated to a narrow set of applications. Key factors in a real- time OS are minimal interrupt latency and minimal thread switching latency; a real-time OS is valued more for how quickly or how predictably it can respond than for the amount of work it can perform in a given period of time. 6.2 Design philosophies The most common designs are: Event-driven which switches tasks only when an event of higher priority needs servicing, called preemptive priority, or priority scheduling.
    [Show full text]
  • Real Time Performance Measurements of EPICS Ioccore 2 of 6
    10th ICALEPCS Int. Conf. on Accelerator & Large Expt. Physics Control Systems. Geneva, 10 - 14 Oct 2005, PO2.075-5 (2005) REAL-TIME PERFORMANCE MEASUREMENTS OF EPICS IOCCORE * Shifu Xu, Martin R. Kraimer Argonne National Laboratory, Argonne, Illinois 60439 USA ABSTRACT As the Experimental Physics and Industrial Control System (EPICS) is used in an increasing number of accelerator control systems, EPICS IOCcore is ported to a wider variety of OS platforms and thus the performance of EPICS IOCcore on different hardware and software platforms becomes more important. This paper provides real-time performance measurements of EPICS IOCcore on a VME hardware platform and on three different OS platforms: vxWorks, RTEMS, and Linux. INTRODUCTION EPICS Input/Output Controller core (IOCcore) software has been ported to several different operating systems (OSs) and many hardware platforms [1]. This paper compares the EPICS IOCcore runtime performance on one hardware platform (MVME2100 PowerPC) and three popular Operating Systems: vxWorks, RTEMS, and Linux. For Linux the following versions were tested: Linux 2.4.2 hard hat 2.0, standard Linux 2.4.30, and Linux 2.6.13. For Linux 2.6.13, the kernel was built both preemptive and non-preemptive. Three real-time parameters are measured: interrupt, context switch, and total response latency. On Linux, more detailed interrupt latencies are measured: interrupt top half to bottom half, and interrupt bottom half to user space interrupt service routine. To implement the tests, several software components were developed. In order to port to other operating systems or hardware platforms only, one component has to be implemented. PARAMETERS MEASURED Interrupt Latency Interrupt latency is the time from interrupt generation until the interrupt service routine starts executing.
    [Show full text]
  • Benchmarking Real-Time Operating Systems for Use in Radio Base Station Applications Master of Science Thesis
    Benchmarking Real-time Operating Systems for use in Radio Base Station applications Master of Science Thesis OSKAR ÖRNVALL Chalmers University of Technology University of Gothenburg Department of Computer Science and Engineering Göteborg, Sweden, March 2012 The Author grants to Chalmers University of Technology and University of Gothenburg the non-exclusive right to publish the Work electronically and in a non-commercial purpose make it accessible on the Internet. The Author warrants that he/she is the author to the Work, and warrants that the Work does not contain text, pictures or other material that violates copyright law. The Author shall, when transferring the rights of the Work to a third party (for example a publisher or a company), acknowledge the third party about this agreement. If the Author has signed a copyright agreement with a third party regarding the Work, the Author warrants hereby that he/she has obtained any necessary permission from this third party to let Chalmers University of Technology and University of Gothenburg store the Work electronically and make it accessible on the Internet. Benchmarking Real-time Operating Systems for use in Radio Base Station applications OSKAR ÖRNVALL © OSKAR ÖRNVALL, March 2012 Examiner: ROGER JOHANSSON Chalmers University of Technology University of Gothenburg Department of Computer Science and Engineering SE-412 96 Göteborg Sweden Telephone + 46 (0)31-772 1000 Department of Computer Science and Engineering Göteborg, Sweden March 2012 Abstract The support systems for Radio Base Stations (RBS) are getting increasingly advanced. There are demands to support numerous RBS congurations, multiple and alternative energy sources such as wind a solar, dierent cooling systems and alarm handling.
    [Show full text]