A technique for scheduling tasks to be run at a specific time or on a specific event.

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Excluding specific date and time in cronjob

I am trying to schedule a cron job where the requirement is the job has to run every day, every month and every min and every hour EXCEPT 2nd and 4th sunday of every month from 1 to 3 AM. Is there a ...
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2answers
132 views

How does the Linux scheduler determine if a process is I/O bound or CPU bound

Adding to this question, how does the scheduler determine if a process is I/O bound or CPU bound? Mr. Love in this article, says "schedulers often employ complex algorithms to determine the most ...
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2answers
141 views

Start/stop a systemd.service at specific times

I want to start and stop a systemd.service at specific times. Presumably I will use a .timer unit to start the job, but is there a built in way to stop the job after a specific duration, or at a ...
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1answer
1k views

Using sched_rt_period_us for setting maximum time between task calls of order of 10ms

I realize sched_rt_period_us and sched_rt_runtime_us are meant to prevent freezing the system in case of runaway RT task. I wonder though, if it's possible to use a small value of sched_rt_period_us ...
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671 views

Why isn't the -rt (RT-Preempt) kernel patch included by default in the mainline kernel?

According to https://rt.wiki.kernel.org/index.php/RT_PREEMPT_HOWTO , the RT-Preempt patch converts Linux into a fully preemptible kernel. The magic is done by: Making in-kernel locking-primitives (...
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1answer
105 views

Can a real-time process exist in the 'expired' queue of linux kernel?

In the Linux kernel 2.4: Real-time processes are given a priority of 0-99 and they co-exist in the ready queue along with the nice processes (who's priority goes between 100 and 139). But real-time ...
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1answer
165 views

How does handling an interrupt affects a multi-threaded user space process?

Say, I put a breakpoint (int 3 from now on) somewhere in a user space process code. One of the threads hits the breakpoint... And what happens next? My judgement is: this is an interrupt, so it is ...
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1answer
414 views

Run command after nice command has finished

I have 3 nice commands that are dumping some databases, and compress assets for a backup. After that, the files should be copied to another server. I'm using this command: nice mysqldump -u user1 -p'...
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1answer
457 views

How to trace process scheduling of certain process?

For a project at my university I am researching ways to trace, log and manipulate the process scheduling of certain processes. I would like to launch an number of applications, everyone in a single ...
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1answer
58 views

Midi and Scheduler on Linux / Raspberry Pi

I'm fairly new to MIDI and Linux. I have an Akai MPX8 with a bunch of individual WAV files loaded onto it. The WAV files play well over the existing audio system. The audio files are launched by ...
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47 views

Scheduling gFTP Download

My current set up involved two HP laptops running Linux Mint 13 (one 32-bit, the other 64-bit) and a Mint 13 server in the cloud. I have been using gFTP for transferring files without problem. However ...
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43 views

Is there such a scheduler and is it feasible?

I read about a scheduling algorithm called EDD which always works on the next deadline and that is feasible. Would it also be feasible to within each time windows or slice, work on all processor or ...
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Does linux stops processing related to GUI when we remove the desktop screen from connection from cabinet(CPU box)?

When there is big non interactive software running and if I required more processing power then, after removing the desktop screen does kernel stops processing related to GUI(graphical user interface) ...
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0answers
51 views

Job queueing on a single machine

I have a shiny new server for running simulations on, with a pair of Tesla GPUs and 32 cores, running CentOS 7.2. I'd like for multiple users to be able to submit jobs to the server that get queued up ...
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0answers
84 views

System time in Minix with best precision

I'm working on a project to modify the scheduler in MINIX 3. So to test it I need to analyse the wait time and turnaround time. To calculate the wait time I'm storing the system time when the process ...
3
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0answers
1k views

Does the timeslice depend on process priority or not under Completely Fair Scheduling?

I'm trying to understand the Completely Fair Scheduler (CFS). According to Robert Love in Linux Kernel Development, 3rd edition(italics his, bold mine): Rather than assign each process a ...
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0answers
56 views

Is “top” accounting for Kernel Interrupts?

I have a simple interrupt that is triggered by a GPIO-input. The IRQ only increments a variable and returns. When I turn the frequency of the interrupts up to somewhere around 10-20 kHz, the system ...
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0answers
387 views

Catch the kill signal when a process is in S state [interruptible sleep]

This is the process group : (ps -ejH) xxxx xxxx xxxx ? 00:00:00 sshd yyyy yyyy yyyy ? 00:00:00 sshd 8713 8713 8713 pts/0 00:00:00 bash 1234 1234 1234 ? ...
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173 views

Configure job to expire

I'm learning Linux at the moment and were doing some exercises scheduling jobs with cron and crontab, but I'm wondering if it's possible to limit the amount of times that the scheduled job is ran. ...
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0answers
327 views

What is the minimum round robin scheduing interval supported by Linux?

For some reason, I want to have 10 processes share the same CPU core by affinity. As you know, to achieve CPU sharing between processes, we can exploit the Linux round robin (RR) scheduling policy. ...
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0answers
555 views

how to stop kernel threads preempting real time user space processes?

I created some processes in user space and tried to visualize its working in kernelshark with the trace recorded using trace-cmd. But kernel processes like the ones shown below are preempting my ...
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0answers
222 views

So the design of client-server separation is not the bottleneck of X Window?

In the answer of this, it mentioned: People also hear that X uses the "network" and think this is going to be a performance bottleneck. "Network" here means local UNIX domain socket, which has ...
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44 views

Round Robin vs FIFO

recently I had to do some reports about scheduling processes in Linux, and to do so, we were asked to turn off all cpu except 0 to show how processes are running for cpu. But there is one thing which ...
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125 views

Understanding Linux Perf sched-switch and context-switches

I've been trying to enable context switch events on perf and use perf script's dump from perf.data to investigate thread blocked time. So far the only two recording options that seem to be helpful ...
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66 views

Process scheduling and core allocation on big.LITTLE CPUs

Recent ARM chips, like the Qualcomm Snapdragon 810, seem to be using a hybrid architecture called "big.LITTLE" with cores of different architectures and speeds combined into one CPU. On a Linux (or ...
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151 views

How to set a process’s sched method to fifo and priority when cgroup are on?

I’m using CentOS 6.6, I want to set the sched method of my kvm VM to FIFO with priority 1. First, I use chrt and get error: chrt(): "failed to set pid XXX's policy" I find here: chrt(): "...
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28 views

expanding the priorities table in runqueue in Linux kernel

I have a hw assignment that I'm having really hard time with, probably since I'm new to the whole Linux kernel thing. we're supposed to add a new scheduling policy to the existing scheduling ...
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31 views

Spawning processes on a job stack

I have a hobbyist server on which I want users to upload a file, and then receive the overcome of some processing (server-side) over the given file. I am doing the processing synchronously so that for ...
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0answers
113 views

at daemon creates empty tasks

I have problem with atd daemon. If at is called by non-root, it creates task, but it is empty (content of /var/spool/atd). I do not remember what I have done before it broke that way. What else ...
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166 views

Client-server app for sending and monitoring asynchronous jobs

I am looking for a desktop app/IDE in which you can: Maintain a list of UNIX/Linux connections Be able to write a script locally in a local editor, not SCP files to the host or writing them on the ...
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36 views

Setscheduler for non root user and encrypted home directory

I have an application for which I would like to use a FIFO scheduler. My code looks as follow: int maxPriority = sched_get_priority_max(SCHED_FIFO); // Max is the highest priority sched_param ...
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27 views

How to Check next day Schedule

I check the previous day schedule from a TSM server by: q eve * * begind=-1 How to check the next days schedule?
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Who controls the thread activity?

I know that there is a program called scheduler which controls the process activity within a system. But which part of the system controls the activity of threads within a process? By the way, do or ...
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105 views

CPU Scheduling incredibly slow with large difference between total execution time and actual CPU time - Ubuntu Full-Disk Encryption enabled

Admittedly, I am running on a build that is no younger than five years old at this point and the system is not going to be incredibly fast. However, at the same time, the run-times I am observing are ...
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52 views

Linux Fedora 20: how can I find out what is happening behind the scenes

I have Fedora 20 installed, using MATE desktop and zshell and something weird is going on. I get lots of odd unexplained beeps from my speakers, even though the volume is turned down to zero, so ...