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2 votes
2 answers
140 views

nftables priority filter: what does this mean?

The nftables wiki explains the priorities here. Clearly, the priority is a numeric value like -10, 0 or 10. The Red Hat nftables documentation does the same. Priorities remain numeric in the examples ...
0 votes
1 answer
72 views

When/where to set network bond (active-backup) interface priorities on boot?

This is a follow-up to linux bonding active-backup mode set priority for multiple interfaces? I'm too new to post a comment there. I've confirmed that ip link set dev <x> type bond_slave prio &...
0 votes
1 answer
670 views

Give user permission to change priority of an IRQ/root process

Is it possible, in Linux, to allow an user to change the priority of a process owned by root? More specifically an IRQ process? For an embedded real-time application I want to raise the priority of ...
0 votes
0 answers
153 views

How to set default metric on IPv6 route received by RA message

I have two ipv6 interfaces(eth1 and eth2), that receives an IP via DHCP(dhclient is used), but the routes are received via RA messages from switch, to which these interfaces are connected. Since RA ...
0 votes
0 answers
42 views

How to tune BFQ schduler to prevent a single low priority process from severely degrading system performance?

I have been trying to use nice/ionice for a while and it turns out that bfq ignores ionice parameters. So how do I prevent a low priority process from consuming all the io bandwith to the detriment of ...
0 votes
0 answers
95 views

dhcpcd: set priority for link-local connections

I see that there is a metric keyword in the dhcpcd.conf (as explained e.g. https://unix.stackexchange.com/a/413036/47009), which allows me to set the routing priority for a given interface. However, i ...
23 votes
4 answers
32k views

Run Linux process at very very low priority?

I have a regular process that's not so important but will consume very much CPU power. I have another process which is really important, but it spends most of the time idle, but when it gets a job it ...
0 votes
2 answers
168 views

How to find PID of all processes related to a given process?

How can I go about finding the PID or other information about a process that is doing the work of another process? I'm talking about kworker threads, for example, or any other threads/processes that ...
23 votes
6 answers
86k views

What is a command to find priority of process in Linux?

How can i view the priority of a specific process ?
1 vote
1 answer
8k views

Custom priority value: is a pthread high sched prio positive or negative?

I’m trying to reimplement in a backward-compatible way the RobotC API from C (although some details would better fit or would be easier with C++), and trying to reimplement their multithreading API in ...
0 votes
1 answer
849 views

Changing CPU affinity on they fly has no result

so I am creating my own script to set priority and cpu affinity for important processes on my system, and I tried using taskset command, but it seems to do nothing. Here's sample: import psutil import ...
28 votes
7 answers
63k views

How do I start a process with a nice value of -20 and not give it root privilege?

I would like to start a process with a nice value of -20. This requires me to use a command like sudo nice -n -20 matlab However, this starts matlab as root too. Is there a way to have matlab as non-...
10 votes
1 answer
5k 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 timeslice,...
0 votes
0 answers
209 views

How can I make my game's FPS be virtually unaffected by a low priority background task?

I'm running a desktop system where I often have long-running compilation tasks in the background. I'd like to play CPU-limited games while they're running without a significant drop in FPS (the game ...
3 votes
0 answers
227 views

How do I flag a process to avoid hyperthreading (SMT)?

Suppose I have an 18 core CPU with SMT enabled, and there are 18 long runnning processes, all using ~100% of a thread. If I start a 19th process, the kernel will schedule it to run on one of the cores,...
1 vote
1 answer
2k views

nftables table and chain priority

I have a problem with my nftables setup. I have two tables, each one has a chain with the same hook but a different name and priority. The tables are in different files which are loaded by an include ...
1 vote
0 answers
174 views

does pthread_setschedparam can change the priority on the fly once the thread is running? how can I change the thread priority for a running thread

I want to change a thread priority and I have found many examples using pthread_setschedparam, but I need to confirm if the priority can be changed on the fly if the thread is already running. In the ...
1 vote
0 answers
342 views

Netplan: give IPv6 priority over IPv4

On a dual-stack workstation (single interface, Ubuntu 18.04), I'd like IPv6 to be chosen first, before IPv4. I guess that means essentially to have domains being resolved first by DNS6, and then by ...
2 votes
0 answers
227 views

Slurm multifactor priority - how to configure Slurm to consider past usage?

I'm trying to configure our Slurm to allocate users' jobs according to past usage. The goal is to have the job priority consider past time usage of mainly GPUs. I understand I must use the FairShare ...
0 votes
1 answer
169 views

in what situations will ni% in top is not 0

I learnt that ni represents the cpu used for userspace processes whose niceness or priority value is changed, but in my system, which is CentOS Linux release 7.9.2009 (Core), I did below test, all the ...
1 vote
1 answer
342 views

OpenBSD threads priorities

Can anybody explain how to work with thread priorities in OpenBSD? Information about this question in MAN pages is poor, it does not give clear understanding. In particular: sched_get_priority_min/...
6 votes
1 answer
25k views

What is swap priority and why does it matter

While seeing the manual for swapon command the priorty option is described as -p, --priority priority Specify the priority of the swap device. priority is a value ...
14 votes
1 answer
2k views

User-based GPU priority

I have a computer running Linux (Kubuntu 14.04.3 LTS x64), where I use the CUDA toolkit to perform some computations on some Nvidia GPUs. I share the computer with a few other users. How can I define ...
5 votes
1 answer
18k views

Why highest priority threads are displayed with RT in top and htop?

In the top and htop tools, processes (or/and threads depending on display settings) having the highest realtime priority (99 from the userland API point of view) with either the scheduling policy ...
7 votes
2 answers
3k views

Assign a higher priority to a specific process by default

I would like to configure my desktop Linux system so that whenever I start running a specific program (run that processes of this program) the respective process gets assigned a high priority. How to ...
4 votes
2 answers
1k views

How is process priority calculated?

Can someone explain how "real" process priority (i.e. pri_baz field of ps) is calculated? My guess is: pri_baz = 99 - static_priority # if static_priority > 0 (real-time process) pri_baz = 100 + ...
2 votes
0 answers
810 views

Is pulseaudio's default nice value (-11) actually ineffective due to autogroup?

The pulseaudio daemon runs with nice level -11 by default, via rtkit. However, I'm noticing choppy audio at times of high cpu load, and decreasing the nice value even further by setting high-priority ...
1 vote
1 answer
134 views

There is a high priority keys combination for the opening terminal in Linux if UI is hanging on?

Several times I've run into with the problem of Ubuntu hanging when a memory leak happens in some application process (Chrome/Sublime/etc.). As a result, the keyboard and mouse stop reacting. I even ...
0 votes
1 answer
544 views

Is it possible to give a program priority without running as root?

I want to give a program I'm running in linux priority over other programs. I have sudo access and tried using sudo and the nice command. Specifically I ran a bash script file called RUN.sh that has ...
1 vote
1 answer
431 views

How to prioritize packages installed from files in APT?

I want to have packages installed manually via dpkg -i not being updated. I figured the most elegant way to do this would to pin them to a high priority. The manpage of apt_preferences says Assign ...
1 vote
1 answer
1k views

SCHED_RR and SCHED_FIFO only work on "prempt kernal"?

I am running a python program on the raspberry Pi (Raspbian) that I would like to give higher priority. I want to run the following command : $ sudo chrt --rr 50 python3 loopExample.py I have read ...
12 votes
1 answer
8k views

controlling priority of applications using cgroups

I would like to understand cgroups better and would like to understand the use-cases for applying cgroups. Are cgroups a good way for prioritizing different applications (i.e, giving higher priority ...
0 votes
0 answers
44 views

Why a long type memory is reserved to nice value in the PCB in Linux?

All right, my question is not sufficiently specific. I've not mentioned the kernel version, the distribution and other potentially interesting things. But, anyway... these are important but doesn't ...
1 vote
1 answer
390 views

Can same level runlevel scripts have the same priority?

Can same level runlevel scripts have the same priority? For instance, can say runlevel x have these 2 scripts: S10ScriptName1 and S10ScriptName2 ? If so, what is the execution order?
3 votes
1 answer
1k views

How does the kernel assign the nice value to a process after it has been executed?

The Linux kernel implements two separate priority ranges. The first is the nice value, a number from –20 to +19 with a default of 0. Nice values are the standard priority range used in all Unix ...
2 votes
1 answer
759 views

Among these two in my ps output, which real-time process will be preempted over the other by linux?

I have got some idea from: https://stackoverflow.com/questions/8887531/which-real-time-priority-is-the-highest-priority-in-linux about how the real time priority values assigned to different ...
2 votes
0 answers
48 views

Incorrect Top? or manpage?

According to top's manpage: 16. PR -- Priority The scheduling priority of the task. If you see `rt' in this field, it means the task is running under real time scheduling priority. ...
4 votes
2 answers
4k views

What makes it possible for a `pulseaudio' process to get the nice level of -11?

I noticed that a pulseaudio process on my Gentoo Linux machine has the nice level of -11. But I don't know how it has gained such a high priority regardless of being owned by a normal user. I know a ...
0 votes
1 answer
2k views

Is it recommended to use param.sched_priority in Linux FIFO during thread creation?

In my embedded device I absorb strange behaviour with the protocol we use, sometimes it takes a while to send the data via serial device using FIFO. My suspicion is Linux is not real-time OS and why ...
1 vote
1 answer
65 views

Beside username and password, what information are involved in permission management of journal filesystem?

In journal filesystem(for example ext4, XFS, ZFS, JFS, btrfs), there are file access permission rules. Hence if I mount a HDD which include a unix OS on it, when I access the file on this disk ...
2 votes
1 answer
479 views

lxc and sched_setscheduler

I am trying to run an application inside a Centos container and needs to run in real time. I googled around and the suggestion was to add lxc.cap.keep = sys_nice. After I did it, lxc-start complains ...
1 vote
0 answers
170 views

Per user priority of access to a file system

Please, let me know if there is a tool, which allows to give different reading (writing) priority to different users on Linux. I am looking for something similar to 'ionice' but able to set I/O ...
12 votes
2 answers
1k views

What are the effects, if any, of scheduler priorities and policies for threads in an uncontended cpuset?

I have a Linux system where we have used cgroups to create two cpu_exclusive cpusets, A and B, and where we have migrated all user threads and all unbound kernel threads to a cgroup attached to cpuset ...
2 votes
1 answer
3k views

How to change order to process priority on top command?

I have the below output from top command. Where is the process priority of the processes? Mem: 678048K used, 336240K free, 0K shrd, 4K buff, 523012K cached CPU: 0.5% usr 26.1% sys 0.0% nic 72.9% ...
2 votes
0 answers
849 views

Suddenly I see a lot of involuntary context switches for multi threaded app

I have a multi-threaded app, with 4 worker threads that until recently performed very well on my 4-core CPU. The system is running Ubuntu 16.04.3 LTS. Today I updated my OS with sudo apt-get dist-...
1 vote
0 answers
549 views

Prioritize UDP over FTP, SCP, etc. in Linux

I have a setup wherein one "master" Linux system communicates with 3 "slave" systems also running Linux on a dedicated Ethernet interface(just the master & the 3 slaves). The slaves send data to ...
2 votes
0 answers
729 views

Does it make sense to combine chrt and nice?

I want a CPU-intensive process to have the lowest possible impact on other processes. I can use nice -19 for maximum niceness and chrt -i 0 to give the process a SCHED_IDLE priority. Which is more ...
4 votes
1 answer
2k views

Lower priority thread appears to block higher priority thread? [closed]

I have 2 threads, each set to a different real-time priority using SCHED_FIFO. Thread throttling has been disabled, so theoretically the highest priority thread should be able to use 100% of CPU ...
5 votes
3 answers
5k views

How to speed up my build

I am doing a build on a Linux machine with Ubuntu 10.04 on it. How can I really speed up my build? I have 4 CPUs and lots of RAM. I already reniced the process group to -20. Is there something else I ...
3 votes
0 answers
426 views

macOS: nice/renice not working -- no actual effect on cputime?

Although I can see a "nice" value ("NI") via ps, it seems to have no effect on the actual cpu-time used by a process: PID %CPU PRI NI COMM 57081 77.6 12 10 cpu-chew 57080 77.1 12 0 cpu-chew ...