CentOS - Sep 2016 - how to limit cpu usage for specified processes

Hi,


Is there some tool or method in centos that can limit cpu usage to some
percentage for specified processes that consume large cpu resource?


I found cpulimit which is only able to limit one process. what I want is one
tool that can limit several same processes' cpu usage. Thanks!


Regards


andrew

Hello,

You could do it with Cgroups, if your specified processes run or can be 
made to run in group permissions.

https://access.redhat.com/documentation/en-US/Red_Hat_Enterprise_Linux/6/html/Resource_Management_Guide/sec-cpu_and_memory-use_case.html

Regards,

-- 
Sander Kuusemets
University of Tartu, High Performance Computing, IT Specialist
Skype: sander.kuusemets1
+372 737 5694

On 09/07/2016 10:45 AM, qw wrote:
> Hi,
>
>
> Is there some tool or method in centos that can limit cpu usage to some
percentage for specified processes that consume large cpu resource?
>
>
> I found cpulimit which is only able to limit one process. what I want is
one tool that can limit several same processes' cpu usage. Thanks!
>
>
> Regards
>
>
> andrew
> _______________________________________________
> CentOS mailing list
> CentOS at centos.org
> https://lists.centos.org/mailman/listinfo/centos

On Wed, Sep 7, 2016 at 9:52 AM, Sander Kuusemets <sander.kuusemets at
ut.ee>
wrote:
> Hello,
>
> You could do it with Cgroups, if your specified processes run or can be
> made to run in group permissions.
>
> https://access.redhat.com/documentation/en-US/Red_Hat_Enterp
> rise_Linux/6/html/Resource_Management_Guide/sec-cpu_and_
> memory-use_case.html
>
> Regards,
>
> --
> Sander Kuusemets
> University of Tartu, High Performance Computing, IT Specialist
> Skype: sander.kuusemets1
> +372 737 5694
>
>
hello,
In the past I mainly used blkio controller in control groups, to limit disk
I/O bandwidth of a process.
Just to notice that the cpu controller also has the cfs_quota_us and
cfs_period_us which can provide absolute limits, in respect with relative
ones of the shares parameter.
In Red Hat manual I only see the shares parameter, but you can find more
info about the other two installing kernel-doc package and reading
/usr/share/doc/kernel-doc-2.6.32/Documentation/scheduler/sched-bwc.txt

A rapid test on a CentOS 6.5 system with 2 physical cpus, 8 cores each and
HT enabled

yum install libcgroup

service start cgconfig

cgcreate -g cpu:/half_cpu

echo "2000" > /cgroup/cpu/half_cpu/cpu.cfs_quota_us
echo "4000" > /cgroup/cpu/half_cpu/cpu.cfs_period_us

You can tune latency/burst working on period value... see the doc
I use a program that makes matrix multiplication (1024x1024 in example
below) and fully uses one cpu

./bmm 1024
elapsed 10 seconds
using top during execution I see line detail of this type around the 32
threads:
Cpu18 :100.0%us,  0.0%sy,  0.0%ni,  0.0%id,  0.0%wa,  0.0%hi,  0.0%si,
 0.0%st

cgexec -g cpu:half_cpu ./bmm 1024
elapsed 20 seconds
using top I see line detail of this type during execution:
Cpu0  : 49.8%us,  0.0%sy,  0.0%ni, 50.2%id,  0.0%wa,  0.0%hi,  0.0%si,
 0.0%st

HIH,
Gianluca