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 <jianyang@google.com>
Acked-by: Willem de Bruijn <willemb@google.com>
Acked-by: Soheil Hassas Yeganeh <soheil@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
This commit is contained in:
Jian Yang 2020-03-17 12:25:09 -07:00 committed by David S. Miller
parent e64be6dea6
commit 277bc78f38

View File

@ -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");