From 277bc78f3829c5e129048dc5b241f3ce4a898924 Mon Sep 17 00:00:00 2001 From: Jian Yang Date: Tue, 17 Mar 2020 12:25:09 -0700 Subject: [PATCH] selftests: txtimestamp: print statistics for timestamp events. Statistics on timestamps is useful to quantify average and tail latency. Print timestamp statistics in count/avg/min/max format. Signed-off-by: Jian Yang Acked-by: Willem de Bruijn Acked-by: Soheil Hassas Yeganeh Signed-off-by: David S. Miller --- .../networking/timestamping/txtimestamp.c | 58 +++++++++++++++++++ 1 file changed, 58 insertions(+) diff --git a/tools/testing/selftests/networking/timestamping/txtimestamp.c b/tools/testing/selftests/networking/timestamping/txtimestamp.c index f915f24db3fa..011b0da6b033 100644 --- a/tools/testing/selftests/networking/timestamping/txtimestamp.c +++ b/tools/testing/selftests/networking/timestamping/txtimestamp.c @@ -84,6 +84,17 @@ static struct timespec ts_usr; static int saved_tskey = -1; static int saved_tskey_type = -1; +struct timing_event { + int64_t min; + int64_t max; + int64_t total; + int count; +}; + +static struct timing_event usr_enq; +static struct timing_event usr_snd; +static struct timing_event usr_ack; + static bool test_failed; static int64_t timespec_to_ns64(struct timespec *ts) @@ -96,6 +107,27 @@ static int64_t timespec_to_us64(struct timespec *ts) return ts->tv_sec * USEC_PER_SEC + ts->tv_nsec / NSEC_PER_USEC; } +static void init_timing_event(struct timing_event *te) +{ + te->min = INT64_MAX; + te->max = 0; + te->total = 0; + te->count = 0; +} + +static void add_timing_event(struct timing_event *te, + struct timespec *t_start, struct timespec *t_end) +{ + int64_t ts_delta = timespec_to_ns64(t_end) - timespec_to_ns64(t_start); + + te->count++; + if (ts_delta < te->min) + te->min = ts_delta; + if (ts_delta > te->max) + te->max = ts_delta; + te->total += ts_delta; +} + static void validate_key(int tskey, int tstype) { int stepsize; @@ -187,14 +219,17 @@ static void print_timestamp(struct scm_timestamping *tss, int tstype, case SCM_TSTAMP_SCHED: tsname = " ENQ"; validate_timestamp(&tss->ts[0], 0); + add_timing_event(&usr_enq, &ts_usr, &tss->ts[0]); break; case SCM_TSTAMP_SND: tsname = " SND"; validate_timestamp(&tss->ts[0], cfg_delay_snd); + add_timing_event(&usr_snd, &ts_usr, &tss->ts[0]); break; case SCM_TSTAMP_ACK: tsname = " ACK"; validate_timestamp(&tss->ts[0], cfg_delay_ack); + add_timing_event(&usr_ack, &ts_usr, &tss->ts[0]); break; default: error(1, 0, "unknown timestamp type: %u", @@ -203,6 +238,21 @@ static void print_timestamp(struct scm_timestamping *tss, int tstype, __print_timestamp(tsname, &tss->ts[0], tskey, payload_len); } +static void print_timing_event(char *name, struct timing_event *te) +{ + if (!te->count) + return; + + fprintf(stderr, " %s: count=%d", name, te->count); + fprintf(stderr, ", avg="); + __print_ts_delta_formatted((int64_t)(te->total / te->count)); + fprintf(stderr, ", min="); + __print_ts_delta_formatted(te->min); + fprintf(stderr, ", max="); + __print_ts_delta_formatted(te->max); + fprintf(stderr, "\n"); +} + /* TODO: convert to check_and_print payload once API is stable */ static void print_payload(char *data, int len) { @@ -436,6 +486,10 @@ static void do_test(int family, unsigned int report_opt) char *buf; int fd, i, val = 1, total_len, epfd = 0; + init_timing_event(&usr_enq); + init_timing_event(&usr_snd); + init_timing_event(&usr_ack); + total_len = cfg_payload_len; if (cfg_use_pf_packet || cfg_proto == SOCK_RAW) { total_len += sizeof(struct udphdr); @@ -595,6 +649,10 @@ static void do_test(int family, unsigned int report_opt) while (!recv_errmsg(fd)) {} } + print_timing_event("USR-ENQ", &usr_enq); + print_timing_event("USR-SND", &usr_snd); + print_timing_event("USR-ACK", &usr_ack); + if (close(fd)) error(1, errno, "close");