Warning about "Lowering scheduler type"

Submitted by guoliang liu on Thu, 2009-02-12 13:10

Hi,all,
Today I built a NonPeriodicActivity for serial port and it's working. It's my first Orocos component..I am quite happy..
But it still has some warnings that I can not understand,which are:

<code>


0.003 [ Warning][SingleThread] Lowering scheduler type to SCHED_OTHER for non-privileged users..
0.004 [ Warning][NonPeriodicActivity] Lowering scheduler type to SCHED_OTHER for non-privileged users..

</code>


Is that meaning I can not use SCHED_RT and what's the non-privileged users?
How should I make these warnings disappear?

Best,
GL

‹ Calling commands through CORBA motion specification framework ›
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Warning about "Lowering scheduler type"

Submitted by snrkiwi on Thu, 2009-02-12 13:30.

On Feb 12, 2009, at 08:06 , guoliang liu wrote:

> Hi,all,
> Today I built a NonPeriodicActivity for serial port and it's
> working. It's my first Orocos component..I am quite happy..
> But it still has some warnings that I can not understand,which are:
>
> 

>
> 0.003 [ Warning][SingleThread] Lowering scheduler type to  
> SCHED_OTHER for non-privileged users..
> 0.004 [ Warning][NonPeriodicActivity] Lowering scheduler type to  
> SCHED_OTHER for non-privileged users..
>
>

>
> Is that meaning I can not use SCHED_RT and what's the non-privileged
> users?
> How should I make these warnings disappear?

If you are running on Linux, then you either need to be root/sudo to
use the real-time scheduler, or you need to modify /etc/security/
limits.conf (IIRC) and set your "rtprio" limit (then reboot). Then use
"ulimit -r xxx" to actully set your limit to xxx within a shell. Then
you can use the real-time scheduler as a non-priveleged user and you
won't get the above warnings.

There should be plenty of additional advice/details out there under
google ...
S

PS: We obviously need to document this somewhere as this is the second
instance of this question in just a couple of months ... maybe a
questions/troubleshooting section on the wiki?

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