diff options
Diffstat (limited to 'src/dnsperf.c')
| -rw-r--r-- | src/dnsperf.c | 110 |
1 files changed, 102 insertions, 8 deletions
diff --git a/src/dnsperf.c b/src/dnsperf.c index 90b7874..02bdd2c 100644 --- a/src/dnsperf.c +++ b/src/dnsperf.c @@ -102,6 +102,7 @@ typedef struct { #ifdef USE_HISTOGRAMS bool latency_histogram; #endif + int qps_threshold_wait; } config_t; typedef struct { @@ -437,12 +438,16 @@ print_statistics(const config_t* config, const times_t* times, stats_t* stats, u printf("\n"); - if (!stats->num_conn_completed) { + if (!stats->num_conn_completed && !stats->num_conn_reconnect) { + fflush(stdout); return; } printf("Connection Statistics:\n\n"); - printf(" Reconnections: %" PRIu64 "\n\n", stats->num_conn_reconnect); + printf(" Reconnections: %" PRIu64 " (%.2lf%% of %" PRIu64 " connections)\n\n", + stats->num_conn_reconnect, + PERF_SAFE_DIV(100.0 * stats->num_conn_reconnect, stats->num_conn_completed), + stats->num_conn_completed); latency_avg = PERF_SAFE_DIV(stats->conn_latency_sum, stats->num_conn_completed); printf(" Average Latency (s): %u.%06u", (unsigned int)(latency_avg / MILLION), @@ -466,6 +471,7 @@ print_statistics(const config_t* config, const times_t* times, stats_t* stats, u } printf("\n"); + fflush(stdout); } /* @@ -532,6 +538,40 @@ stringify(unsigned int value) return buf; } +static int +measure_nanosleep(config_t* config) +{ + struct timespec start, stop, wait = { 0, 0 }; + int err; + + int i = 100; + if ((err = clock_gettime(CLOCK_REALTIME, &start))) { + return err; + } + for (; i; i--) { + if ((err = nanosleep(&wait, NULL))) { + return err; + } + } + if ((err = clock_gettime(CLOCK_REALTIME, &stop))) { + return err; + } + + // Total time for 100 nanosleep() + 2 clock_gettime() + config->qps_threshold_wait = ((stop.tv_sec - start.tv_sec) * 1000000000 + stop.tv_nsec - start.tv_nsec) + // divided by 100 runs + / 100 + // add fudge + * 3 + // converted to microseconds + / 1000; + if (config->qps_threshold_wait < 0) { + config->qps_threshold_wait = 0; + } + + return 0; +} + static void setup(int argc, char** argv, config_t* config) { @@ -559,6 +599,8 @@ setup(int argc, char** argv, config_t* config) config->max_outstanding = DEFAULT_MAX_OUTSTANDING; config->mode = sock_udp; + config->qps_threshold_wait = -1; + perf_opt_add('f', perf_opt_string, "family", "address family of DNS transport, inet or inet6", "any", &family); @@ -637,6 +679,8 @@ setup(int argc, char** argv, config_t* config) perf_long_opt_add("latency-histogram", perf_opt_boolean, NULL, "collect and print detailed latency histograms", NULL, &config->latency_histogram); #endif + perf_long_opt_add("qps-threshold-wait", perf_opt_zpint, "microseconds", + "minimum threshold for enabling wait in rate limiting", stringify(config->qps_threshold_wait), &config->qps_threshold_wait); bool log_stdout = false; perf_opt_add('W', perf_opt_boolean, NULL, "log warnings and errors to stdout instead of stderr", NULL, &log_stdout); @@ -730,6 +774,14 @@ setup(int argc, char** argv, config_t* config) perf_log_fatal("Unable to dynamic update, support not built in"); } #endif + + if (config->qps_threshold_wait < 0) { + int err = measure_nanosleep(config); + if (err) { + char __s[256]; + perf_log_fatal("Unable to measure nanosleep(): %s", perf_strerror_r(errno, __s, sizeof(__s))); + } + } } static void @@ -803,7 +855,7 @@ do_send(void* arg) stats_t* stats; unsigned int max_packet_size; perf_buffer_t msg; - uint64_t now, run_time, req_time; + uint64_t now, req_time, wait_us, q_sent = 0, q_step = 0, q_slice; char input_data[MAX_INPUT_DATA]; perf_buffer_t lines; perf_region_t used; @@ -824,8 +876,13 @@ do_send(void* arg) perf_buffer_init(&msg, packet_buffer, max_packet_size); perf_buffer_init(&lines, input_data, sizeof(input_data)); + if (tinfo->max_qps > 0) { + q_step = MILLION / tinfo->max_qps; + } wait_for_start(); - now = perf_get_time(); + now = perf_get_time(); + req_time = now; + q_slice = now + MILLION; while (!interrupted && now < times->stop_time) { /* Avoid flooding the network too quickly. */ if (stats->num_sent < tinfo->max_outstanding && stats->num_sent % 2 == 1) { @@ -838,13 +895,49 @@ do_send(void* arg) /* Rate limiting */ if (tinfo->max_qps > 0) { - run_time = now - times->start_time; - req_time = (MILLION * stats->num_sent) / tinfo->max_qps; - if (req_time > run_time) { - usleep(req_time - run_time); + /* the 1 second time slice where q_sent is calculated over */ + if (q_slice <= now) { + q_slice += MILLION; + q_sent = 0; + req_time = now; // reset stepping, in case of clock sliding + } + /* limit QPS over the 1 second slice */ + if (q_sent >= tinfo->max_qps) { + wait_us = q_slice - now; + if (config->qps_threshold_wait && wait_us > config->qps_threshold_wait) { + wait_us -= config->qps_threshold_wait; + struct timespec ts = { 0, 0 }; + if (wait_us >= MILLION) { + ts.tv_sec = wait_us / MILLION; + ts.tv_nsec = (wait_us % MILLION) * 1000; + } else { + ts.tv_sec = 0; + ts.tv_nsec = wait_us * 1000; + } + nanosleep(&ts, NULL); + } + now = perf_get_time(); + continue; + } + /* handle stepping to the next window to send a query on */ + if (req_time > now) { + wait_us = req_time - now; + if (config->qps_threshold_wait && wait_us > config->qps_threshold_wait) { + wait_us -= config->qps_threshold_wait; + struct timespec ts = { 0, 0 }; + if (wait_us >= MILLION) { + ts.tv_sec = wait_us / MILLION; + ts.tv_nsec = (wait_us % MILLION) * 1000; + } else { + ts.tv_sec = 0; + ts.tv_nsec = wait_us * 1000; + } + nanosleep(&ts, NULL); + } now = perf_get_time(); continue; } + req_time += q_step; } PERF_LOCK(&tinfo->lock); @@ -980,6 +1073,7 @@ do_send(void* arg) continue; } stats->num_sent++; + q_sent++; stats->total_request_size += length; } |