CODEWITHSUNDEEP
linuxprocessoperating-systemcentoscpu
Geni
Geni

Reputation: 707

How can I dynamically allocate CPU resources to processes in Linux?

In Linux (our system is CentOS5), is it possible to allocation CPU resources to processes? For example, I have one tomcat application, I want all the processes and threads invoked by tomcat has p% of total CPU cycles no matter how many other applications are running. And I want to tune the p% dynamically (e.g., at this time slot, tomcat has 40% cpu cycles, and at the next time slot, it has 70% cpu cycles).

If the above is possible, is it possible to do it conservatively? I mean, even though tomcat has 40% cpu cycles, but if it's current workload only consumes 10%, other applications can use the remaining 30% CPU cycles.

Thank.

Upvotes: 1

Views: 5610

Answers (3)

Johnlcf
Johnlcf

Reputation: 582

If you can use RHEL6/CentOS6 (or upgrade kernel), you can use cgroup to do what you want to do. http://www.kernel.org/doc/Documentation/cgroups/cgroups.txt

https://docs.redhat.com/docs/en-US/Red_Hat_Enterprise_Linux/6/html/Resource_Management_Guide/ch01.html

Upvotes: 3

timday
timday

Reputation: 24892

If you really really wanted to do this (and esnyder's suggestion of prioritising using nice levels is almost certainly a better solution for whatever you're really trying to achieve) AND you're happy to do it at the granularity of 1/number-of-CPUs (e.g on an 8 core system, specify utilisation as a multiple of 12.5% of total CPU resource) then you could use sched_setaffinity to set the CPU affinity mask for the process you want to control (you can do this from another process). (Actually, I think you'd need to identify all that process' threads and invoke it on each of them).

Alternatively, cpusets might be of interest but I've no idea what it takes to enable them or how dynamic they can be.

Upvotes: 1

tamarintech
tamarintech

Reputation: 1992

Are you familiar with the tool nice and niceness levels?

Rather than trying to dictate exact percentages, you might want to check into niceness levels and how to set them in CentOS. Your applications will run as expected with the higher priority processes being able to claim more resources while the lower priority processes will not suffer from lack of resources even when a higher priority process is idle.

Upvotes: 2

Related Questions