#!/bin/bash# perf record offcpu profiling tests (exclusive)# SPDX-License-Identifier: GPL-2.0 set -e err=0perfdata=$(mktemp /tmp/__perf_test.perf.data.XXXXX) ts=$(printf "%u" $((~0 << 32))) # OFF_CPU_TIMESTAMPdummy_timestamp=${ts%???} # remove the last 3 digits to match perf script cleanup() {  rm -f ${perfdata}  rm -f ${perfdata}.old  trap - EXIT TERM INT} trap_cleanup() {  cleanup  exit 1}trap trap_cleanup EXIT TERM INT test_above_thresh="Threshold test (above threshold)"test_below_thresh="Threshold test (below threshold)" test_offcpu_priv() {  echo "Checking off-cpu privilege"   if [ "$(id -u)" != 0 ]  then    echo "off-cpu test [Skipped permission]"    err=2    return  fi  if perf version --build-options 2>&1 | grep HAVE_BPF_SKEL | grep -q OFF  then    echo "off-cpu test [Skipped missing BPF support]"    err=2    return  fi} test_offcpu_basic() {  echo "Basic off-cpu test"   if ! perf record --off-cpu -e dummy -o ${perfdata} sleep 0.3 2> /dev/null  then    echo "Basic off-cpu test [Failed record]"    err=1    return  fi  if ! perf evlist -i ${perfdata} | grep -q "offcpu-time"  then    echo "Basic off-cpu test [Failed no event]"    err=1    return  fi  if ! perf report -i ${perfdata} -q --percent-limit=70 | grep -E -q sleep  then    echo "Basic off-cpu test [Failed missing output]"    err=1    return  fi  echo "Basic off-cpu test [Success]"} test_offcpu_child() {  echo "Child task off-cpu test"   # perf bench sched messaging creates 400 processes  if ! perf record --off-cpu -e dummy -o ${perfdata} -- \    perf bench sched messaging -g 10 > /dev/null 2>&1  then    echo "Child task off-cpu test [Failed record]"    err=1    return  fi  if ! perf evlist -i ${perfdata} | grep -q "offcpu-time"  then    echo "Child task off-cpu test [Failed no event]"    err=1    return  fi  # each process waits at least for poll, so it should be more than 400 events  if ! perf report -i ${perfdata} -s comm -q -n -t ';' --percent-limit=90 | \    awk -F ";" '{ if (NF > 3 && int($3) < 400) exit 1; }'  then    echo "Child task off-cpu test [Failed invalid output]"    err=1    return  fi  echo "Child task off-cpu test [Success]"} # task blocks longer than the --off-cpu-thresh, perf should collect a direct sampletest_offcpu_above_thresh() {  echo "${test_above_thresh}"   # collect direct off-cpu samples for tasks blocked for more than 50ms  if ! perf record -e dummy --off-cpu --off-cpu-thresh 50 -o ${perfdata} -- sleep 0.1 2> /dev/null  then    echo "${test_above_thresh} [Failed record]"    err=1    return  fi  # direct sample's timestamp should be lower than the dummy_timestamp of the at-the-end sample  # check if a direct sample exists  if ! perf script --time "0, ${dummy_timestamp}" -i ${perfdata} -F event | grep -q "offcpu-time"  then    echo "${test_above_thresh} [Failed missing direct samples]"    err=1    return  fi  # there should only be one direct sample, and its period should be higher than off-cpu-thresh  if ! perf script --time "0, ${dummy_timestamp}" -i ${perfdata} -F period | \       awk '{ if (int($1) > 50000000) exit 0; else exit 1; }'  then    echo "${test_above_thresh} [Failed off-cpu time too short]"    err=1    return  fi  echo "${test_above_thresh} [Success]"} # task blocks shorter than the --off-cpu-thresh, perf should collect an at-the-end sampletest_offcpu_below_thresh() {  echo "${test_below_thresh}"   # collect direct off-cpu samples for tasks blocked for more than 500ms  if ! perf record -e dummy --off-cpu --off-cpu-thresh 500 -o ${perfdata} -- sleep 0.1 2> /dev/null  then    echo "${test_below_thresh} [Failed record]"    err=1    return  fi  # see if there's an at-the-end sample  if ! perf script --time "${dummy_timestamp}," -i ${perfdata} -F event | grep -q 'offcpu-time'  then    echo "${test_below_thresh} [Failed at-the-end samples cannot be found]"    err=1    return  fi  # plus there shouldn't be any direct samples  if perf script --time "0, ${dummy_timestamp}" -i ${perfdata} -F event | grep -q 'offcpu-time'  then    echo "${test_below_thresh} [Failed direct samples are found when they shouldn't be]"    err=1    return  fi  echo "${test_below_thresh} [Success]"} test_offcpu_priv if [ $err = 0 ]; then  test_offcpu_basicfi if [ $err = 0 ]; then  test_offcpu_childfi if [ $err = 0 ]; then  test_offcpu_above_threshfi if [ $err = 0 ]; then  test_offcpu_below_threshfi cleanupexit $err