added instructions for benchmarking

benchmark_python/bench.py

@@ -1,6 +1,23 @@
 #!/usr/bin/python3
-# Run it with
-# export CPU=0; /usr/bin/taskset --cpu-list $CPU ./bench.py $CPU
+# Commands and ideas from: https://llvm.org/docs/Benchmarking.html
+# we assume that CPU 0 and 1 are together in an intel SMT-pair (hyperthreading)
+# - Disable address space randomization:
+#     echo 0 > /proc/sys/kernel/randomize_va_space
+# - Set scaling governor to performance for CPU 0
+#     echo performance > /sys/devices/system/cpu/cpu0/cpufreq/scaling_governor
+# - Reserve CPU 0 fro our benchmark
+#     cset shield --cpu 0 --kthread=on
+# - Disable the SMT-peer of CPU 0, i.e. CPU 1
+#     echo 0 > /sys/devices/system/cpu/cpu1/online
+# - Disable turbo mode (works only on Intel):
+#     echo 1 > /sys/devices/system/cpu/intel_pstate/no_turbo
+# - Run with
+#    cset shield --exec -- ./bench.py
+#
+
+# To use the full power of the CPU, skip all the other steps and
+# just run with
+#    taskset --cpu-list 0 ./bench.py
 import os
 import sys
 import timeit