[zeromq-dev] ZeroMQ scalability over connections quantity

[Martin Sustrik]

Hi Peter,

>  >thr.sh zmq local
> running local (receiver)
> sched_setscheduler: Operation not permitted
> failed to set pid 0's policy
> sched_setscheduler: Operation not permitted
> failed to set pid 0's policy
> sched_setscheduler: Operation not permitted
> failed to set pid 0's policy
> ...
>  
> and
>  
> thr.sh zmq remote
> running remote (sender)
> sched_setscheduler: Operation not permitted
> failed to set pid 0's policy
> sched_setscheduler: Operation not permitted
> failed to set pid 0's policy
> sched_setscheduler: Operation not permitted
> failed to set pid 0's policy
> ...
>  
> Please, advise.

Check the thr.sh script. Have a look at the following lines:

LOCAL_THR_BIN="taskset -c 1,3,5,7 chrt --fifo 1 
/home/sustrik/zeromq/perf/tests/zmq/local_thr"
REMOTE_THR_BIN="taskset -c 1,3,5,7 chrt --fifo 1 
/home/sustrik/zeromq/perf/tests/zmq/remote_thr"

taskset command binds the executable to a set of CPU cores.
chrt selects kernel scheduling policy for the application.

The easiest way to deal with the problem is to remove both taskset and chrt.

Use them only in the case you need a highly tuned environment and run it 
under root. And be sure you know what you are doing. Messing with system 
scheduler can lead to unpleasant surprises :)

Martin