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