tests/benchmark/test_benchmark

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