Re: [Discuss-gnuradio] Realtime Scheduling Problem

[Tom Rondeau]

On Tue, Jul 29, 2014 at 9:13 AM, Sabathy Mischa <address@hidden> wrote:

Dear All,

 

I am running GNU Radio 3.7.3 on a Debian Wheezy System with XFCE Desktop.

In the setup I have, a USRP N210 with a SBX daughterboard is used. The USRP samples at 25 MSPS and pretty big processing chain in GNU Radio takes place, which uses about 40 percent of every of the total 8 CPUS.

The realtime Scheduling worked once I did the steps described in the UHD.

This worked now for several days.

Yesterday I tried to restart the GNURadio script, no error regarding realtime scheduling appeared or any other one, but only one CPU was used.

Of course this was not enough so I lost many samples.

Once I changed “realtime scheduling” to “off” it worked again. The only command I did in between was a sudo apt-get update which normally only updates the packet list.

A restart of the PC did not helped. So at the moment I have no realtime scheduling, but it seems to work so far.

 

Can anybody help me with this? Do I have to recompile GNU Radio? Had somebody a similar issue? Realtime scheduling is only to maximize the guarantee to get enough CPU resources right?

 

Thanks for the replies.

BR

Mischa

There is no reason that enabling realtime scheduling should affect the scheduling of blocks among processor cores. The thread-per-block scheduler creates threads and leaves it up to your OS to distribute them properly among the cores available for scheduling. So this sounds like an OS issue.

For advanced control, you /can/ tell each block which cores it can use, but this would mean hand tuning everything. That can work and improve results, but becomes hardware-specific.

http://gnuradio.org/doc/doxygen/page_affinity.html

Tom