tests/benchmark/test_benchmark

   1 #!/bin/bash
   2
   3 # SPDX-FileCopyrightText: 2023 EfficiOS, Inc
   4 #
   5 # SPDX-License-Identifier: LGPL-2.1-only
   6
   7 CURDIR=$(dirname $0)/
   8 TESTDIR=$CURDIR/..
   9 source $TESTDIR/utils/tap.sh
  10
  11 plan_tests 1
  12
  13 : ${ITERS:=10}
  14 : ${DURATION:=2}
  15 : ${NR_THREADS:=1}
  16 : ${NR_CPUS:=$(lscpu | grep "^CPU(s)" | sed 's/^.*:[ \t]*//g')}
  17
  18 : ${TIME:="./$CURDIR/ptime"}
  19
  20 : ${PROG_NOTRACING:="./$CURDIR/bench1 $NR_THREADS $DURATION"}
  21 : ${PROG_TRACING:="./$CURDIR/bench2 $NR_THREADS $DURATION"}
  22
  23 function signal_cleanup ()
  24 {
  25         killall lttng-sessiond
  26         exit
  27 }
  28
  29 trap signal_cleanup SIGTERM SIGINT
  30
  31 CMD_NOTRACING="$TIME '$PROG_NOTRACING'"
  32 CMD_TRACING="$TIME '$PROG_TRACING'"
  33
  34 NR_ACTIVE_CPUS=$(( $NR_CPUS > $NR_THREADS ? $NR_THREADS : $NR_CPUS ))
  35
  36 for i in $(seq $ITERS); do
  37         res=$(sh -c "$CMD_NOTRACING")
  38         loops_notrace[$i]=$(echo "${res}" | grep "^Number of loops:" | sed 's/^.*: //g')
  39         time_notrace[$i]=$(echo "${res}" | grep "^Wall time:" | sed 's/^.*: //g')
  40 done
  41
  42 lttng-sessiond -d --no-kernel
  43 lttng -q create --snapshot
  44 lttng -q enable-event -u -a
  45 lttng -q start
  46
  47 for i in $(seq $ITERS); do
  48         res=$(sh -c "$CMD_TRACING")
  49         loops_trace[$i]=$(echo "${res}" | grep "^Number of loops:" | sed 's/^.*: //g')
  50         time_trace[$i]=$(echo "${res}" | grep "^Wall time:" | sed 's/^.*: //g')
  51 done
  52
  53 lttng -q stop
  54 lttng -q destroy
  55 killall lttng-sessiond
  56
  57 pass "Trace benchmark"
  58
  59 # Multiply the wall time by the number of active CPUs to get the
  60 # overhead of events on each active cpu.
  61
  62 avg_delta=0
  63 for i in $(seq $ITERS); do
  64         delta[$i]=$(echo "((${time_trace[$i]} * ${NR_ACTIVE_CPUS} / ${loops_trace[$i]}) - (${time_notrace[$i]} * ${NR_ACTIVE_CPUS} / ${loops_notrace[$i]}))" | bc -l)
  65         avg_delta=$(echo "(${avg_delta} + ${delta[$i]})" | bc -l)
  66 done
  67 avg_delta=$(echo "(${avg_delta} / $ITERS)" | bc -l)
  68
  69 std_dev=0
  70 for i in $(seq $ITERS); do
  71         dev[$i]=$(echo "(( (${delta[$i]}) - (${avg_delta}) ) ^ 2)" | bc -l)
  72         std_dev=$(echo "( (${std_dev}) + (${dev[i]}) )" | bc -l)
  73 done
  74 std_dev=$(echo "( (${std_dev}) / $ITERS )" | bc -l)
  75 std_dev=$(echo "(sqrt(${std_dev}))" | bc -l)
  76
  77 NS_PER_EVENT=$(echo "($avg_delta * 1000000000)" | bc -l)
  78 # Remove fractions
  79 NS_PER_EVENT=${NS_PER_EVENT%%.*}
  80
  81 STD_DEV_NS_PER_EVENT=$(echo "($std_dev * 1000000000)" | bc -l)
  82 # Remove fractions
  83 STD_DEV_NS_PER_EVENT=${STD_DEV_NS_PER_EVENT%%.*}
  84
  85 diag "Average tracing overhead per event is ${NS_PER_EVENT}ns, std.dev.: ${STD_DEV_NS_PER_EVENT}ns { NR_THREADS=${NR_THREADS}, NR_ACTIVE_CPUS=${NR_ACTIVE_CPUS} }"