UHD Warning: Unable to set the thread priority

Hi:
I had some trouble when running my C++ program. The console message
is:
UHD Warning:
Unable to set the thread priority. Performance may be negatively
affected.Please see the general application notes in the manual for
instructions.EnvironmentError: OSError: error in pthread_setschedparam.
I have tried the method as:

<<<Add the following line to /etc/security/limits.conf:

@myusername - rtprio 99>>>

but it doesn’t seem to work.

     I  ran the program with Eclipse in Linux(Ubuntu)

environment,Can anyone give me some suggestions about this?

Best regards!!

Yang