0
votes
0answers
63 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 ...
4
votes
2answers
104 views

How is the real-time priority of a process set by default?

I understand that, for scheduling purposes, Linux processes have a "nice" value and a real-time priority value and that these can be explicitly altered with the nice and chrt commands. If the user ...
2
votes
1answer
59 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 ...
5
votes
1answer
36 views

How disk IO priority is related with process priority?

I'm running software that overloads disk IO sometimes. I don't need fast response from that software, I need fast response from other applications, so I could set low process priority for that. I want ...
11
votes
2answers
858 views

What does a niceness value of (-) mean?

According to the man page, and wikipedia; nice ranges from -20 to 20. Yet when I run the following command, I find some processes have a non numerical value such as (-). See the sixth column from ...
5
votes
2answers
232 views

Is there a way to really prioritize processes or make Linux respect their priorities?

I know there are process priorities like in other operating systems, going from -20 (most prio) to 19 (less prio) but Linux seems to ignore them. Right now I was building the kernel in the background ...
1
vote
1answer
2k views

Change init scripts priority

I'm running a raspbian (based on debian). I want to change the priority of the init services so the very first script which is run by init is one made for me. How can I do it? On runlevel S I have ...
7
votes
1answer
477 views

Real time priorities in non real time OS

If I do the following command on my standard Linux Mint installation: comp ~ $ ps -eo rtprio,nice,cmd RTPRIO NI CMD ... 99 - [migration/0] 99 - [watchdog/0] 99 - [migration/1] - 0 ...
2
votes
1answer
1k 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 ...
3
votes
1answer
387 views

Is there any use for RLIMIT_NICE?

I am using prlimit in Ubuntu to do some resource restrictions in my sandbox which has been very helpful. However, I am not quite sure what to do with RLIMIT_NICE. The docs say: RLIMIT_NICE (since ...
5
votes
2answers
890 views

Why was fsck priority introduced in /etc/fstab?

Inside the /etc/fstab file, in the sixth column, there is a number that corresponds to whether a filesystem should be scanned for errors. Possible values are: 0 - skip 1 - high priority 2 - low ...
11
votes
2answers
322 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 ...
1
vote
1answer
436 views

Process priority and cpu speed

In some devices the cpu speed is dynamic, being faster when there is more load. I was wondering if it is possible to set nice level or priority of a process so that it does not influence an increase ...
5
votes
3answers
815 views

How to speed up my build

I am doing a build on a Linux machine with ubuntu 10.04 on it. I want to know 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 ...
5
votes
3answers
5k views

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

How can i view the priority of a specific process ?
4
votes
1answer
549 views

Does IO prioritise by the very nature of renicing a task?

The CFQ IO scheduler supports priorities though I am not sure that Deadline does (I believe not). The premise is that when I renice a task it gets a larger share of CPU under the Completely Fair ...
9
votes
2answers
7k views

Run process with higher priority

I want to run mplayer with higher priority than any other processes, including the IO-processes. How can I do that?
7
votes
1answer
2k views

How do I view the IO priority of a process?

How can I view the IO priority of a process? like to see for example if something has been ionice-ed.