taskset(1)
Set cpu affinity for new processes or already running ones.
# Pin all (-a) tasks of new command on cores 0,1,2,4.
taskset -ac 0-2,4 CMD [ARGS]
# Pin all tasks of running PID onto cores 0,2,4.
taskset -ac 0-5:2 -p PID
Example
Utility script to extract cpu lists grouped by the last-level-cache.
import subprocess
res = subprocess.run(["lscpu", "-p=cpu,cache"], capture_output=True, check=True)
LLC2CPU = dict()
for line in res.stdout.decode().splitlines():
if line.startswith("#"):
continue
cpu, cache = line.split(",")
llc = cache.split(":")[-1]
LLC2CPU.setdefault(llc, list()).append(int(cpu))
LLC2RANGE = dict()
for llc, cpus in LLC2CPU.items():
first_cpu = cpus[0]
prev_cpu = cpus[0]
for cpu in cpus[1:]:
if cpu != prev_cpu + 1:
LLC2RANGE.setdefault(llc, list()).append(f"{first_cpu}-{prev_cpu}")
# New range begins.
first_cpu = cpu
prev_cpu = cpu
# Trailing range.
LLC2RANGE.setdefault(llc, list()).append(f"{first_cpu}-{prev_cpu}")
print(LLC2RANGE)