* LTTng Userspace Tracer (UST) - benchmark tool
*
* Copyright 2010 - Douglas Santos <douglas.santos@polymtl.ca>
+ * Copyright 2021 - Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
#include "ust_tests_benchmark.h"
#endif
-static int nr_cpus;
-static unsigned long nr_events;
+#define printf_verbose(fmt, args...) \
+ do { \
+ if (verbose_mode) \
+ printf(fmt, ## args); \
+ } while (0)
+
+static int verbose_mode;
+
+struct thread_counter {
+ unsigned long long nr_loops;
+};
+
+static int nr_threads;
+static unsigned long duration;
+
+static volatile int test_go, test_stop;
void do_stuff(void)
{
void *function(void *arg)
{
- unsigned long i;
+ unsigned long long nr_loops = 0;
+ struct thread_counter *thread_counter = arg;
- for (i = 0; i < nr_events; i++) {
+ while (!test_go)
+ cmm_barrier();
+
+ for (;;) {
do_stuff();
+ nr_loops++;
+ if (test_stop)
+ break;
}
+ thread_counter->nr_loops = nr_loops;
return NULL;
}
void usage(char **argv) {
- printf("Usage: %s nr_cpus nr_events\n", argv[0]);
+ printf("Usage: %s nr_threads duration(s) <OPTIONS>\n", argv[0]);
+ printf("OPTIONS:\n");
+ printf(" [-v] (verbose output)\n");
+ printf("\n");
}
-
int main(int argc, char **argv)
{
+ unsigned long long total_loops = 0;
+ unsigned long i_thr;
void *retval;
int i;
exit(1);
}
- nr_cpus = atoi(argv[1]);
- printf("using %d processor(s)\n", nr_cpus);
+ nr_threads = atoi(argv[1]);
+ duration = atol(argv[2]);
+
+ for (i = 3; i < argc; i++) {
+ if (argv[i][0] != '-')
+ continue;
+ switch (argv[i][1]) {
+ case 'v':
+ verbose_mode = 1;
+ break;
+ }
+ }
+
+ printf_verbose("using %d thread(s)\n", nr_threads);
+ printf_verbose("for a duration of %lds\n", duration);
- nr_events = atol(argv[2]);
- printf("using %ld events per cpu\n", nr_events);
+ pthread_t thread[nr_threads];
+ struct thread_counter thread_counter[nr_threads];
- pthread_t thread[nr_cpus];
- for (i = 0; i < nr_cpus; i++) {
- if (pthread_create(&thread[i], NULL, function, NULL)) {
+ for (i = 0; i < nr_threads; i++) {
+ thread_counter[i].nr_loops = 0;
+ if (pthread_create(&thread[i], NULL, function, &thread_counter[i])) {
fprintf(stderr, "thread create %d failed\n", i);
exit(1);
}
}
- for (i = 0; i < nr_cpus; i++) {
+ test_go = 1;
+
+ for (i_thr = 0; i_thr < duration; i_thr++) {
+ sleep(1);
+ if (verbose_mode) {
+ fwrite(".", sizeof(char), 1, stdout);
+ fflush(stdout);
+ }
+ }
+ printf_verbose("\n");
+
+ test_stop = 1;
+
+ for (i = 0; i < nr_threads; i++) {
if (pthread_join(thread[i], &retval)) {
fprintf(stderr, "thread join %d failed\n", i);
exit(1);
}
+ total_loops += thread_counter[i].nr_loops;
}
+ printf("Number of loops: %llu\n", total_loops);
return 0;
}
plan_tests 1
: ${ITERS:=10}
-: ${NR_EVENTS:=7000000}
-: ${NR_CPUS:=1}
+: ${DURATION:=2}
+: ${NR_THREADS:=1}
+: ${NR_CPUS:=$(lscpu | grep "^CPU(s)" | sed 's/^.*:[ \t]*//g')}
: ${TIME:="./$CURDIR/ptime"}
-: ${PROG_NOTRACING:="./$CURDIR/bench1 $NR_CPUS $NR_EVENTS"}
-: ${PROG_TRACING:="./$CURDIR/bench2 $NR_CPUS $NR_EVENTS"}
+: ${PROG_NOTRACING:="./$CURDIR/bench1 $NR_THREADS $DURATION"}
+: ${PROG_TRACING:="./$CURDIR/bench2 $NR_THREADS $DURATION"}
function signal_cleanup ()
{
killall lttng-sessiond
+ exit
}
trap signal_cleanup SIGTERM SIGINT
-CMD_NOTRACING="$TIME '$PROG_NOTRACING >/dev/null 2>&1'"
-CMD_TRACING="$TIME '$PROG_TRACING >/dev/null 2>&1'"
+CMD_NOTRACING="$TIME '$PROG_NOTRACING'"
+CMD_TRACING="$TIME '$PROG_TRACING'"
+
+NR_ACTIVE_CPUS=$(( $NR_CPUS > $NR_THREADS ? $NR_THREADS : $NR_CPUS ))
for i in $(seq $ITERS); do
- time_notrace[i]=$(sh -c "$CMD_NOTRACING")
+ res=$(sh -c "$CMD_NOTRACING")
+ loops_notrace[$i]=$(echo "${res}" | grep "^Number of loops:" | sed 's/^.*: //g')
+ time_notrace[$i]=$(echo "${res}" | grep "^Wall time:" | sed 's/^.*: //g')
done
-
lttng-sessiond -d --no-kernel
lttng -q create --snapshot
lttng -q enable-event -u -a
lttng -q start
for i in $(seq $ITERS); do
- time_trace[i]=$(sh -c "$CMD_TRACING")
+ res=$(sh -c "$CMD_TRACING")
+ loops_trace[$i]=$(echo "${res}" | grep "^Number of loops:" | sed 's/^.*: //g')
+ time_trace[$i]=$(echo "${res}" | grep "^Wall time:" | sed 's/^.*: //g')
done
lttng -q stop
pass "Trace benchmark"
+# Multiply the wall time by the number of active CPUs to get the
+# overhead of events on each active cpu.
+
avg_delta=0
for i in $(seq $ITERS); do
- delta[$i]=$(echo "( ((${time_trace[$i]}) - (${time_notrace[$i]})) / $NR_EVENTS)" | bc -l)
+ delta[$i]=$(echo "((${time_trace[$i]} * ${NR_ACTIVE_CPUS} / ${loops_trace[$i]}) - (${time_notrace[$i]} * ${NR_ACTIVE_CPUS} / ${loops_notrace[$i]}))" | bc -l)
avg_delta=$(echo "(${avg_delta} + ${delta[$i]})" | bc -l)
done
avg_delta=$(echo "(${avg_delta} / $ITERS)" | bc -l)
NS_PER_EVENT=${NS_PER_EVENT%%.*}
STD_DEV_NS_PER_EVENT=$(echo "($std_dev * 1000000000)" | bc -l)
+# Remove fractions
STD_DEV_NS_PER_EVENT=${STD_DEV_NS_PER_EVENT%%.*}
-diag "Average tracing overhead per event is ${NS_PER_EVENT}ns, std.dev.: ${STD_DEV_NS_PER_EVENT}ns"
+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} }"
projects / deliverable / lttng-ust.git / commitdiff
