| 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} }" |