scheduling

Process Scheduling from Processor point of view

由 蓝咒 提交于 2019-12-07 12:32:18
问题 I understand that the scheduling is done by the kernel. Let us suppose a process (P1) in Linux is currently executing on the processor. Since the current process doesn't know anything about the time slice and the kernel is currently not executing on the processor, how does the kernel schedule the next process to execute? Is there some kind of interrupt to tell the processor to switch to execute the kernel or any other mechanism for the purpose? 回答1: In brief, it is an interrupt which gives

Task Schedulers

由 你离开我真会死。 提交于 2019-12-07 09:44:15
问题 Had an interesting discussion with some colleagues about the best scheduling strategies for realtime tasks, but not everyone had a good understanding of the common or useful scheduling strategies. For your answer, please choose one strategy and go over it in some detail, rather than giving a little info on several strategies. If you have something to add to someone else's description and it's short, add a comment rather than a new answer (if it's long or useful, or simply a much better

Throttle CPU usage of only one thread intentionally

由 ↘锁芯ラ 提交于 2019-12-07 09:19:27
There are a couple of other similar questions on SO, but none of them have satisfactory/relevant answers. I have a single threaded C++ program which does something essentially like this: while(true) { //do things which are cpu bound } The problem is that when I run this program it is usually the only process on my whole computer that is doing active work. With nothing else to schedule, the OS naturally schedules this program heavily and my CPU usage shoots through the roof, which I do not want . Naturally, my fan starts whirring too which is especially annoying. The way I am combating this is

Priority of kernel modules and SCHED_RR threads

由 风流意气都作罢 提交于 2019-12-07 01:56:12
问题 I have an embedded Linux platform (the Beagleboard, running Angstrom Linux) with two devices connected: a Laser range finder (Hokuyo UTM 30) connected via USB a custom external board connected via SPI We have a written a Linux kernel module which is responsible for the SPI data transfer. It has an IRQ handler in which spi_async is called which in turn causes an async callback method to be called. My C++ application consists of three threads: a main thread for data processing a laser polling

Scheduling in Linux: run a task when computer is idle (= no user input)

由 落爺英雄遲暮 提交于 2019-12-06 23:49:14
问题 I want to run Folding@home client on my Ubuntu 8.10 box only when it's idle because of the program's heavy RAM consumption. By "idle" I mean the state when there's no user activity (keyboard, mouse or any other else). It's ok for other (probably heavy) processes to run at that time since F@H has the lowest CPU priority. The point is just to improve user experience and to do heavy work when the he is away. How to accomplish this? 回答1: When the machine in question is a desktop, you could hook a

Spring Scheduler does not work

由 情到浓时终转凉″ 提交于 2019-12-06 17:02:49
问题 I have a problem with Spring's annotation based task scheduler - I can't get it working, I don't see any problem here... application-context.xml <task:scheduler id="taskScheduler" /> <task:executor id="taskExecutor" pool-size="1" /> <task:annotation-driven executor="taskExecutor" scheduler="taskScheduler" /> bean @Service public final class SchedulingTest { private static final Logger logger = Logger.getLogger(SchedulingTest.class); @Scheduled(fixedRate = 1000) public void test() { logger

how to add my scheduler to linux kernel

由 巧了我就是萌 提交于 2019-12-06 15:52:00
问题 I'm working on a research on linux kernel. I should add a scheduler algorithm to linux kernel, like SJF, SRT and any other algorithms. After some searches I found that linux kernel has tow schedulers: CFS and real-time scheduler. but what is difference between this tow scheduler? How should write my scheduler code? where I should add my scheduler code, CFS or real-time? should I do this work before compiling linux kernel? and any other things that I need to do this work... I'm using linux

Why am I getting this error: dereferencing pointer to incomplete type

由 邮差的信 提交于 2019-12-06 15:07:57
问题 I am working on a project for class with probably the WORST instruction ever where we have to implement a simple scheduler.. although C programming is not a prereq for the course, that is the language of the scheduler and I'm not necessarily a C programmer.. Anyhow, I am trying to debug this by printing out the task so I can trace it through the program, but I keep getting the following compile-time error: schedule.c:61:48: error: dereferencing pointer to incomplete type This is the task

Outlook Automation from a web application to create appointments

由 孤者浪人 提交于 2019-12-06 14:36:45
问题 Is it a standard practice to automate outlook from a web application using ActiveX technology? How does this compare with a web scheduler like telerik's RadScheduler + telerik's Exchange Provider to schedule an appointment from the web application itself? Thanks, Sendhil 回答1: You will need to provide more details about what you are trying to accomplish rather then just stating automation of outlook within a web application. The reason I say this is because it really depends on what you are

These days, what are good reasons for setting thread affinity rather than leaving it to the OS?

由 喜欢而已 提交于 2019-12-06 11:11:20
Searching answers here for "thread affinity", I see a lot of interest in doing it but little justification for it save possibly getting stable QueryPerformanceTimer results. Assuming a modern OS and a modern 2-4 socket workstation/server class machine with modern 4-6 core CPUs, what good reasons would anyone have for thinking they know better than their OS's scheduler ? Are there any real world situations where taking more control of thead affinity is the right thing to do ? What sort of performance benefits can be demonstrated ? The last time I saw a really good case for setting thread
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