tools/perf/tests/shell/trace_exit_race.sh

   1 #!/bin/sh
   2 # perf trace exit race
   3 # SPDX-License-Identifier: GPL-2.0
   4
   5 # Check that the last events of a perf trace'd subprocess are not
   6 # lost. Specifically, trace the exiting syscall of "true" 10 times and ensure
   7 # the output contains 10 correct lines.
   8
   9 # shellcheck source=lib/probe.sh
  10 . "$(dirname $0)"/lib/probe.sh
  11
  12 skip_if_no_perf_trace || exit 2
  13
  14 if [ "$1" = "-v" ]; then
  15         verbose="1"
  16 fi
  17
  18 iter=10
  19 regexp=" +[0-9]+\.[0-9]+ [0-9]+ syscalls:sys_enter_exit_group\(\)$"
  20
  21 trace_shutdown_race() {
  22         for _ in $(seq $iter); do
  23                 perf trace --no-comm -e syscalls:sys_enter_exit_group true 2>>$file
  24         done
  25         result="$(grep -c -E "$regexp" $file)"
  26         [ $result = $iter ]
  27 }
  28
  29
  30 file=$(mktemp /tmp/temporary_file.XXXXX)
  31
  32 # Do not use whatever ~/.perfconfig file, it may change the output
  33 # via trace.{show_timestamp,show_prefix,etc}
  34 export PERF_CONFIG=/dev/null
  35
  36 trace_shutdown_race
  37 err=$?
  38
  39 if [ $err != 0 ] && [ "${verbose}" = "1" ]; then
  40         lines_not_matching=$(mktemp /tmp/temporary_file.XXXXX)
  41         if grep -v -E "$regexp" $file > $lines_not_matching ; then
  42                 echo "Lines not matching the expected regexp: '$regexp':"
  43                 cat $lines_not_matching
  44         else
  45                 echo "Missing output, expected $iter but only got $result"
  46         fi
  47         rm -f $lines_not_matching
  48 fi
  49
  50 rm -f ${file}
  51 exit $err