advent-of-code 2022.0.66

#!/bin/sh
set -e -u

CPU_CORE_TO_USE=15

# Disable SMT on core if necessary - https://www.baeldung.com/linux/disable-hyperthreading
if [ -d "/sys/devices/system/cpu/cpu${CPU_CORE_TO_USE}/topology" ] && grep -q ',' "/sys/devices/system/cpu/cpu${CPU_CORE_TO_USE}/topology/thread_siblings_list"; then
    THREAD_SIBLING_TO_DISABLE=$(cat /sys/devices/system/cpu/cpu${CPU_CORE_TO_USE}/topology/thread_siblings_list | cut -d ',' -f 2)
    echo "❌ Need to disable SMT - running: sudo sh -c 'echo 0 > /sys/devices/system/cpu/cpu${THREAD_SIBLING_TO_DISABLE}/online'"
    sudo sh -c "echo 0 > /sys/devices/system/cpu/cpu${THREAD_SIBLING_TO_DISABLE}/online"
else
    echo "✅ SMT already disabled"
fi

# Scaling governors - https://wiki.archlinux.org/title/CPU_frequency_scaling#Scaling_governors
CURRENT_SCALING=$(cat /sys/devices/system/cpu/cpu${CPU_CORE_TO_USE}/cpufreq/scaling_governor)
if [ "${CURRENT_SCALING}" = "performance" ]; then
    echo "✅ Scaling governer is 'performance'"
else
    echo "❌ Current scaling governor is '${CURRENT_SCALING}' - running: sudo sh -c 'echo performance > /sys/devices/system/cpu/cpu${CPU_CORE_TO_USE}/cpufreq/scaling_governor'"
    sudo sh -c "echo performance > /sys/devices/system/cpu/cpu${CPU_CORE_TO_USE}/cpufreq/scaling_governor"
fi

# CPU boosting - https://juliaci.github.io/BenchmarkTools.jl/dev/linuxtips/
if [ "$(cat /sys/devices/system/cpu/cpufreq/boost)" = "0" ]; then
    echo "✅ CPU boosting disabled"
else
    echo "❌ CPU boosting is not disabled - running: sudo sh -c 'echo 0 > /sys/devices/system/cpu/cpufreq/boost'"
    sudo sh -c "echo 0 > /sys/devices/system/cpu/cpufreq/boost"
fi

# TODO: irqbalance
#

# export RUSTFLAGS='-C target-cpu=native'

# To run chrt as non-root: sudo setcap cap_sys_nice=ep `which chrt`
numactl --physcpubind="${CPU_CORE_TO_USE}" --localalloc \
    chrt -f 99 \
        setarch --addr-no-randomize \
         cargo bench --profile=release-quickbuild --bench benchmark "$@"
         #bash -c 'chrt -p $$'
         #bash -c 'awk "{print \$39}" /proc/$$/stat'