Pinning parallel process using UNix system calls

Question

for i in `seq 1 8` ; do
    (./runProgram &)
done

Dear Fellows, I know how to create parallel processes by creating 8 independent processes, the next thing I am in search for is how to

i-Run 8 copies concurrently with processor pinning (each copy on is own processor core)

ii-Run 16 copies concurrently with processor pinning (2 copies per core)

iii-Run 8 copies concurrently with processor pinning as per “iii” and flipping processor core to the furthest core after a particular function call in the code.

Current configuration of my cpu is 8 cores.it is running Fedora OS. I dont know the process ids in advance.

please suggest.

Thanks in advance.

Answer 1

The easiest way to achieve i and ii is to use the taskset command:

Case i:

for i in `seq 0 7`; do
  taskset -c $i ./runProgram &
done

Case ii:

for i in `seq 0 7`; do
  taskset -c $i ./runProgram &
  taskset -c $i ./runProgram &
done

Case iii: See the manual pages for sched_getaffinity(2) and sched_setaffinity(2) on how to change the pinning in code.