tests/benchmark/test_benchmark

   1 #!/bin/bash
   2 #
   3 # SPDX-License-Identifier: LGPL-2.1-only
   4
   5 CURDIR=$(dirname $0)/
   6 TESTDIR=$CURDIR/..
   7 source $TESTDIR/utils/tap.sh
   8
   9 plan_tests 1
  10
  11 : ${ITERS:=10}
  12 : ${NR_EVENTS:=7000000}
  13 : ${NR_CPUS:=1}
  14
  15 : ${TIME:="./$CURDIR/ptime"}
  16
  17 : ${PROG_NOTRACING:="./$CURDIR/bench1 $NR_CPUS $NR_EVENTS"}
  18 : ${PROG_TRACING:="./$CURDIR/bench2 $NR_CPUS $NR_EVENTS"}
  19
  20 function signal_cleanup ()
  21 {
  22         killall lttng-sessiond
  23 }
  24
  25 trap signal_cleanup SIGTERM SIGINT
  26
  27 CMD_NOTRACING="$TIME '$PROG_NOTRACING >/dev/null 2>&1'"
  28 CMD_TRACING="$TIME '$PROG_TRACING >/dev/null 2>&1'"
  29
  30 for i in $(seq $ITERS); do
  31         time_notrace[i]=$(sh -c "$CMD_NOTRACING")
  32 done
  33
  34
  35 lttng-sessiond -d --no-kernel
  36 lttng -q create --snapshot
  37 lttng -q enable-event -u -a
  38 lttng -q start
  39
  40 for i in $(seq $ITERS); do
  41         time_trace[i]=$(sh -c "$CMD_TRACING")
  42 done
  43
  44 lttng -q stop
  45 lttng -q destroy
  46 killall lttng-sessiond
  47
  48 pass "Trace benchmark"
  49
  50 avg_delta=0
  51 for i in $(seq $ITERS); do
  52         delta[$i]=$(echo "( ((${time_trace[$i]}) - (${time_notrace[$i]})) / $NR_EVENTS)" | bc -l)
  53         avg_delta=$(echo "(${avg_delta} + ${delta[$i]})" | bc -l)
  54 done
  55 avg_delta=$(echo "(${avg_delta} / $ITERS)" | bc -l)
  56
  57 std_dev=0
  58 for i in $(seq $ITERS); do
  59         dev[$i]=$(echo "(( (${delta[$i]}) - (${avg_delta}) ) ^ 2)" | bc -l)
  60         std_dev=$(echo "( (${std_dev}) + (${dev[i]}) )" | bc -l)
  61 done
  62 std_dev=$(echo "( (${std_dev}) / $ITERS )" | bc -l)
  63 std_dev=$(echo "(sqrt(${std_dev}))" | bc -l)
  64
  65 NS_PER_EVENT=$(echo "($avg_delta * 1000000000)" | bc -l)
  66 # Remove fractions
  67 NS_PER_EVENT=${NS_PER_EVENT%%.*}
  68
  69 STD_DEV_NS_PER_EVENT=$(echo "($std_dev * 1000000000)" | bc -l)
  70 STD_DEV_NS_PER_EVENT=${STD_DEV_NS_PER_EVENT%%.*}
  71
  72 diag "Average tracing overhead per event is ${NS_PER_EVENT}ns, std.dev.: ${STD_DEV_NS_PER_EVENT}ns"