Commit bb4b8f96 authored by Ian Rogers's avatar Ian Rogers Committed by Namhyung Kim
Browse files

perf test: Extra verbosity and hypervisor skip for tpebs test 



When not running as root and with higher perf event paranoia values
the perf record forked by TPEBS can fail to attach to the process. Skip
the test in these scenarios.

Intel TPEBS test skips on non-Intel CPUs. On Intel CPUs under a
hypervisor the cache-misses event may not be present or precise. Skip
the test under this condition.

Refactor the output code to be placed in a file so that on a signal
the file can be dumped. This was necessary to catch the issue above as
the failing perf record command would fail without output.

Signed-off-by: default avatarIan Rogers <irogers@google.com>
Tested-by: default avatarThomas Falcon <thomas.falcon@intel.com>
Cc: Weilin Wang <weilin.wang@intel.com>
Cc: James Clark <james.clark@linaro.org>
Link: https://lore.kernel.org/r/20250130170135.5817-1-irogers@google.com


Signed-off-by: default avatarNamhyung Kim <namhyung@kernel.org>
parent 4c4c0724

tools/perf/tests/shell/test_stat_intel_tpebs.sh

+76 −13
Original line number Diff line number Diff line
@@ -3,20 +3,83 @@ 
# SPDX-License-Identifier: GPL-2.0



set -e

grep -q GenuineIntel /proc/cpuinfo || { echo Skipping non-Intel; exit 2; }



# Use this event for testing because it should exist in all platforms

event=cache-misses:R

ParanoidAndNotRoot() {

  [ "$(id -u)" != 0 ] && [ "$(cat /proc/sys/kernel/perf_event_paranoid)" -gt $1 ]

}



# Hybrid platforms output like "cpu_atom/cache-misses/R", rather than as above

alt_name=/cache-misses/R

if ! grep -q GenuineIntel /proc/cpuinfo

then

  echo "Skipping non-Intel"

  exit 2

fi



# Without this cmd option, default value or zero is returned

#echo "Testing without --record-tpebs"

#result=$(perf stat -e "$event" true 2>&1)

#[[ "$result" =~ $event || "$result" =~ $alt_name ]] || exit 1

if ParanoidAndNotRoot 0

then

  echo "Skipping paranoid >0 and not root"

  exit 2

fi



# In platforms that do not support TPEBS, it should execute without error.

stat_output=$(mktemp /tmp/__perf_stat_tpebs_output.XXXXX)



cleanup() {

  rm -rf "${stat_output}"

  trap - EXIT TERM INT

}



trap_cleanup() {

  echo "Unexpected signal in ${FUNCNAME[1]}"

  cat "${stat_output}"

  cleanup

  exit 1

}

trap trap_cleanup EXIT TERM INT



# Event to be used in tests

event=cache-misses



if ! perf record -e "${event}:p" -a -o /dev/null sleep 0.01 > "${stat_output}" 2>&1

then

  echo "Missing ${event} support"

  cleanup

  exit 2

fi



test_with_record_tpebs() {

  echo "Testing with --record-tpebs"

result=$(perf stat -e "$event" --record-tpebs -a sleep 0.01 2>&1)

[[ "$result" =~ "perf record" && "$result" =~ $event || "$result" =~ $alt_name ]] || exit 1
 
  if ! perf stat -e "${event}:R" --record-tpebs -a sleep 0.01 > "${stat_output}" 2>&1

  then

    echo "Testing with --record-tpebs [Failed perf stat]"

    cat "${stat_output}"

    exit 1

  fi



  # Expected output:

  # $ perf stat --record-tpebs -e cache-misses:R -a sleep 0.01

  # Events enabled

  # [ perf record: Woken up 2 times to write data ]

  # [ perf record: Captured and wrote 0.056 MB - ]

  #

  #  Performance counter stats for 'system wide':

  #

  #                  0      cache-misses:R

  #

  #        0.013963299 seconds time elapsed

  if ! grep "perf record" "${stat_output}"

  then

    echo "Testing with --record-tpebs [Failed missing perf record]"

    cat "${stat_output}"

    exit 1

  fi

  if ! grep "${event}:R" "${stat_output}" && ! grep "/${event}/R" "${stat_output}"

  then

    echo "Testing with --record-tpebs [Failed missing event name]"

    cat "${stat_output}"

    exit 1

  fi

  echo "Testing with --record-tpebs [Success]"

}



test_with_record_tpebs

cleanup

exit 0