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Questions tagged [cfs]

Completely Fair Scheduler (CFS) is the default CPU Linux scheduler

The Completely Fair Scheduler (CFS) is a process scheduler which was merged into the 2.6.23 release of the Linux kernel and is the default scheduler. It handles CPU resource allocation for executing processes, and aims to maximize overall CPU utilization while also maximizing interactive performance.

See here for further details.

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the running time is small than TICK_time ,why it seized by barad_agent?

the CONFIG_HZ=250, i think the processor running time should > tick cycle ( > 4ms) but why the stress 4132364 only running 996us then seized by barad_agent ?
cuijier
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Compile 32 bit application on 64 bit ubuntu

I am trying to build NASA cFS version 6.5 which uses 32bit applications on a 64 bit Jetson TX2 running Ubuntu. I was getting the error "gcc: error: unrecognized command line option -m32". I tried installing the gcc-multilib but I get: Package…
effendi
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disabling preemption while executing schedule() function

The scheduler entry in Linux starts with executing schedule() which then calls the __schedule() function. It is defined as : asmlinkage __visible void __sched schedule(void) { struct task_struct *tsk = current; sched_submit_work(tsk); …
Lucifer Poltergeist
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difference between update_rq_clock and update_rq_clock_task

I understand the notion of update_rq_clock as it updates the run queue clock on system tick periodically. But this function calls update_rq_clock_task(). What is the purpose behind this function?
Lucifer Poltergeist
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Linux CFS scheduling of cron-job vs console

I've created some job (weather forecasting) and it is a heavy load, mostly CPU and memory, for a long(er) time. I notice that when I'm running the job from the cli I can still use my browser without stuttering. But when I move the same job to a cron…
David H
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Why Linux CFS not allocating Free CPU to other available process of run queue in Core2Duo?

I am working in Core2Duo,2.20GHz system which has Ubuntu-12.04 OS, 3.18.26 kernel. I made some changes in Linux kernel source code. To get all the processes involved (which gets scheduled and which is de-scheduled) in context switching , I made…
bholanath
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Do two SCHED_FIFO tasks with equal priority get processing time within each period in Linux?

Do two SCHED_FIFO tasks with equal priority get processing time within each period in Linux, granted neither of the tasks finish before the period ends? Linux documentation says SCHED_FIFO processes can get preempted only by processes with higher…
Teemv Teeccary
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Where is the linux scheduler triggered?

Currently, I want to dive into the Linux scheduling. I have a test setup with lubuntu and a 4.10.0-37-generic Kernel. I want to know how long the minimum time of execution with a CFS task could be without self yielding. Here a good overview is given…
user3191169
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Does Linux system load account for throttling of the Completely Fair Scheduler?

On Linux, system load is defined as the exponentially decaying average of num runnable processes + num uninterruptable processes. I am wondering if it will correctly account for CFS cgroup quota used to limit the number of cpu shares a group of…
Stephan Erb
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How to determine time quantum used by SCHED_NORMAL?

I'm trying to figure out what is possible value of time quantum that process scheduler use. SCHED_NORMAL is used, which as I understand is CFS by default, kernel.sched_min_granularity_ns = 3000000 ... and kernel.sched_latency_ns = 24000000 Do I…
Aleksander Alekseev
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Scheduler data structures

Does any body know that where CFS scheduling algorithm's data (for example content of suspend or ready queue, task duration, ...) is stored in Linux? (Is there any special file or data structure for this goal?) Thanks.
sami
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Who calls fair.c for a process to run on linux?

Can someone please explain the real call stack of linux for process from creation to scheduling over CPU along with code reference. I don't need theoretical explanation. I tried reading fair.c but it didn't worked well for me.
Shashank Maurya
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Do small .NET Core async continuations on Linux with CFS qoutas end up slotting directly into time slices?

There was (and maybe still based on open github issues) an issue with CFS where CPU throttling would occur in some unexpected ways. I realize this original reference is a little different than it currently works after a couple rounds of fixing that…
Joshua Enfield
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How qnx schedule threads

The applications are using pthread lib, in case process A has 100 threads ready, after that process B has one thread ready to run, will scheduler 1) pick and execute thread(s) from process A maxmumlly to one time slice, then pick process B thread.…
Leslie Li
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CFS initialization problem in WordPress. How to get field in get_page_by_path?

I have problem with cfs(custom field suit) in wordpress. I need to get data from cfs field: get('new-serv-page1')); ?> It not works because the CFS object isn't inicilized at that moment. If i do like…
Dmitry Kozlov
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