Questions tagged [scheduler]

29 questions
18
votes
3 answers

Why does Ubuntu 16.04 set all drive IO schedulers to "deadline"?

I just installed Xubuntu 16.04-64bit to a second partition on my laptop. I noticed it seemed a bit slow at times, so I checked which IO scheduler it was using for that drive, which turns out to be deadline for all drives. I do have a couple of…
curt54
  • 183
11
votes
1 answer

rcu_sched self-detected stall on CPU + watchdog: BUG: soft lockup - CPU#3 stuck for 22s

Being unable to ssh into a machine I connected it to a monitor and found the following: The machine is running Ubuntu Server 18.04 LTS and is a first generation 8 core Ryzen 1700. I've restarted the machine since and it works fine but am not sure…
Greg
  • 298
9
votes
1 answer

Cron/Anacron vs. Systemd

Linux provides three different job schedulers i.e. Cron, Anacron and Systemd-Timer. What are the benefits of Cron/Anacron vs. Systemd-Timer?
5
votes
1 answer

Where are I/O schedulers set permanently? Kubuntu 20.04.1 64 bit

I want to use two schedulers since I have a two Disks set for my system due to a separate HOME disk. Meaning I have SDA and SDB Doing echo noop /sys/block/sda/queue/scheduler says permission denied with SUDO I tried the suggested solution but it…
userDepth
  • 2,040
5
votes
1 answer

On Ubuntu 16.04, with Samsung 850 EVO SSD, is any post configuration needed?

The Samsung Evo 850 http://www.samsung.com/semiconductor/minisite/ssd/product/consumer/850evo.html The following post suggests that with Ubuntu 16.04 and the 850 EVO, TRIM is enabled by default. However, cat…
5
votes
2 answers

How to get I/O priority to work on Ubuntu?

Ubuntu has ionice, but as far as I can tell, it does absolutely nothing. I suspect this is because Ubuntu replaced cfq with deadline and deadline doesn't support priorities. Is there any possible way to have prioritized I/O on Ubuntu anymore? EDIT:…
4
votes
1 answer

task scheduler in ubuntu

I have a python script and would like to run it every day at 3:00 AM but I can't schedule tasks on linux the same on windows. I tried to execute the following command in terminal sudo apt-get install gnome-schedule he returns me error E: Unable to…
3
votes
2 answers

System becomes completely unresponsive minutes after starting 7z - how to work around or fix this?

I've never encountered this before, but most of the time I was careful to stick a nice ionice -c3 in front of the command to be executed. But this time the use of nice and ionice merely delayed the effect. Either way, I am using Ubuntu 20.04 as my…
0xC0000022L
  • 5,870
2
votes
3 answers

Why does my CPU only primarily use one core?

It loads 100% from one of the CPUs at a time. Is that on purpose? Shouldn't it try to do 25/25/25/25? It's an Intel i5-3320M - 2,60GHz x 4 My friend on a win10 is load-balancing 'correct' loading the same file. (it's an insanely huge .osm that we're…
Seyb
  • 33
2
votes
0 answers

OS Schedules almost all work on a single CPU core after upgrading from Ubuntu 20.05 LTS to Ubuntu 22.05 LTS

As stated in the title, my OS automatically schedules almost all work on a single CPU core after upgrading from Ubuntu 20.05 LTS to Ubuntu 22.05 LTS. I've provided a few screen shots from htop to explain the problem. In the following example I've…
samzapo
  • 21
2
votes
1 answer

installing job submission management (eg slurm) on ubuntu 20.04

My lab is currently working with an ubuntu based distribution in 20.04 on a machine with 72 cores. We'd like to setup a job scheduler so we could submit computing jobs to each of the different cores. I've gone through the slurm quickstart but have…
2
votes
3 answers

can't set CFQ elevator on Kubuntu 19.04

You can not choose CFQ scheduler in Kubuntu 19.04 since it has been removed from the 5.0 kernel. In my case I need CFQ because it gives the best performance with my rotating hard drive when running a virtual machine with Windows 10 as guest S.O, the…
Horacyo
  • 23
1
vote
1 answer

how to run linshed simulator?

I'm trying to developed multi-core scheduling algorithm. For that, I need a linshed simulator. I cloned it to my PC. But there aren't many details about how to run the simulator.
1
vote
1 answer

Can't find `min_granularity_ns`(sched) on Ubuntu 24.04

In previous LTS of Ubuntu with the newer version of Linux kernel /proc/sys/kernel/sched_min_granularity_ns has been moved to /sys/kernel/debug/sched/min_granularity_ns. In Ubuntu 24.04, this parameter/file vanished from…
Arseniy
  • 11
1
vote
1 answer

Ubuntu 22.10 with intel 13900K system is unresponsive at full load

We got a workstation pc with i9 13900k and ubuntu 22.10 is installed. When all cores at their max, system becomes unresponsive. Rejects all ssh connections and keyboard and mouse does not work. Tried to troubleshoot it but wasnt able to as we cannot…
batu
  • 11
1
2