* First patch reworks time measurements in pgbench.
* Second patch adds a barrier before starting the bench
It applies on top of the previous one. The initial imbalance due to
thread creation times is smoothed.
The usecs patch fails to apply to HEAD, can you please submit a rebased version
of this patchset. Also, when doing so, can you please rename the patches such
that sort alphabetically in the order in which they are intended to be applied.
The CFBot patch tester will otherwise try to apply them out of order which
cause errors.
Ok. Attached.
--
Fabien.
diff --git a/doc/src/sgml/ref/pgbench.sgml b/doc/src/sgml/ref/pgbench.sgml
index 8e728dc094..3c5ef9c27e 100644
--- a/doc/src/sgml/ref/pgbench.sgml
+++ b/doc/src/sgml/ref/pgbench.sgml
@@ -58,8 +58,10 @@ number of clients: 10
number of threads: 1
number of transactions per client: 1000
number of transactions actually processed: 10000/10000
-tps = 85.184871 (including connections establishing)
-tps = 85.296346 (excluding connections establishing)
+latency average = 11.013 ms
+latency stddev = 7.351 ms
+initial connection time = 45.758 ms
+tps = 896.967014 (without initial connection establishing)
</screen>
The first six lines report some of the most important parameter
@@ -2226,7 +2228,6 @@ END;
<para>
For the default script, the output will look similar to this:
<screen>
-starting vacuum...end.
transaction type: <builtin: TPC-B (sort of)>
scaling factor: 1
query mode: simple
@@ -2234,22 +2235,22 @@ number of clients: 10
number of threads: 1
number of transactions per client: 1000
number of transactions actually processed: 10000/10000
-latency average = 15.844 ms
-latency stddev = 2.715 ms
-tps = 618.764555 (including connections establishing)
-tps = 622.977698 (excluding connections establishing)
+latency average = 10.870 ms
+latency stddev = 7.341 ms
+initial connection time = 30.954 ms
+tps = 907.949122 (without initial connection establishing)
statement latencies in milliseconds:
- 0.002 \set aid random(1, 100000 * :scale)
- 0.005 \set bid random(1, 1 * :scale)
- 0.002 \set tid random(1, 10 * :scale)
- 0.001 \set delta random(-5000, 5000)
- 0.326 BEGIN;
- 0.603 UPDATE pgbench_accounts SET abalance = abalance + :delta WHERE aid = :aid;
- 0.454 SELECT abalance FROM pgbench_accounts WHERE aid = :aid;
- 5.528 UPDATE pgbench_tellers SET tbalance = tbalance + :delta WHERE tid = :tid;
- 7.335 UPDATE pgbench_branches SET bbalance = bbalance + :delta WHERE bid = :bid;
- 0.371 INSERT INTO pgbench_history (tid, bid, aid, delta, mtime) VALUES (:tid, :bid, :aid, :delta, CURRENT_TIMESTAMP);
- 1.212 END;
+ 0.001 \set aid random(1, 100000 * :scale)
+ 0.001 \set bid random(1, 1 * :scale)
+ 0.001 \set tid random(1, 10 * :scale)
+ 0.000 \set delta random(-5000, 5000)
+ 0.046 BEGIN;
+ 0.151 UPDATE pgbench_accounts SET abalance = abalance + :delta WHERE aid = :aid;
+ 0.107 SELECT abalance FROM pgbench_accounts WHERE aid = :aid;
+ 4.241 UPDATE pgbench_tellers SET tbalance = tbalance + :delta WHERE tid = :tid;
+ 5.245 UPDATE pgbench_branches SET bbalance = bbalance + :delta WHERE bid = :bid;
+ 0.102 INSERT INTO pgbench_history (tid, bid, aid, delta, mtime) VALUES (:tid, :bid, :aid, :delta, CURRENT_TIMESTAMP);
+ 0.974 END;
</screen>
</para>
diff --git a/src/bin/pgbench/pgbench.c b/src/bin/pgbench/pgbench.c
index 08a5947a9e..46be67adaf 100644
--- a/src/bin/pgbench/pgbench.c
+++ b/src/bin/pgbench/pgbench.c
@@ -291,9 +291,9 @@ typedef struct SimpleStats
*/
typedef struct StatsData
{
- time_t start_time; /* interval start time, for aggregates */
- int64 cnt; /* number of transactions, including skipped */
- int64 skipped; /* number of transactions skipped under --rate
+ pg_time_usec_t start_time; /* interval start time, for aggregates */
+ int64 cnt; /* number of transactions, including skipped */
+ int64 skipped; /* number of transactions skipped under --rate
* and --latency-limit */
SimpleStats latency;
SimpleStats lag;
@@ -416,11 +416,11 @@ typedef struct
int nvariables; /* number of variables */
bool vars_sorted; /* are variables sorted by name? */
- /* various times about current transaction */
- int64 txn_scheduled; /* scheduled start time of transaction (usec) */
- int64 sleep_until; /* scheduled start time of next cmd (usec) */
- instr_time txn_begin; /* used for measuring schedule lag times */
- instr_time stmt_begin; /* used for measuring statement latencies */
+ /* various times about current transaction in microseconds */
+ pg_time_usec_t txn_scheduled; /* scheduled start time of transaction */
+ pg_time_usec_t sleep_until; /* scheduled start time of next cmd */
+ pg_time_usec_t txn_begin; /* used for measuring schedule lag times */
+ pg_time_usec_t stmt_begin; /* used for measuring statement latencies */
bool prepared[MAX_SCRIPTS]; /* whether client prepared the script */
@@ -449,13 +449,16 @@ typedef struct
RandomState ts_sample_rs; /* random state for log sampling */
int64 throttle_trigger; /* previous/next throttling (us) */
- FILE *logfile; /* where to log, or NULL */
+ FILE *logfile; /* where to log, or NULL */
+
+ /* per thread collected stats in microseconds */
+ pg_time_usec_t create_time; /* thread creation time */
+ pg_time_usec_t started_time; /* thread is running */
+ pg_time_usec_t bench_start; /* thread is benchmarking */
+ pg_time_usec_t conn_duration; /* cumulated connection and deconnection delays */
- /* per thread collected stats */
- instr_time start_time; /* thread start time */
- instr_time conn_time;
StatsData stats;
- int64 latency_late; /* executed but late transactions */
+ int64 latency_late; /* count executed but late transactions */
} TState;
#define INVALID_THREAD ((pthread_t) 0)
@@ -597,10 +600,10 @@ static void setIntValue(PgBenchValue *pv, int64 ival);
static void setDoubleValue(PgBenchValue *pv, double dval);
static bool evaluateExpr(CState *st, PgBenchExpr *expr,
PgBenchValue *retval);
-static ConnectionStateEnum executeMetaCommand(CState *st, instr_time *now);
+static ConnectionStateEnum executeMetaCommand(CState *st, pg_time_usec_t *now);
static void doLog(TState *thread, CState *st,
StatsData *agg, bool skipped, double latency, double lag);
-static void processXactStats(TState *thread, CState *st, instr_time *now,
+static void processXactStats(TState *thread, CState *st, pg_time_usec_t *now,
bool skipped, StatsData *agg);
static void append_fillfactor(char *opts, int len);
static void addScript(ParsedScript script);
@@ -1105,9 +1108,9 @@ mergeSimpleStats(SimpleStats *acc, SimpleStats *ss)
* the given value.
*/
static void
-initStats(StatsData *sd, time_t start_time)
+initStats(StatsData *sd, pg_time_usec_t start)
{
- sd->start_time = start_time;
+ sd->start_time = start;
sd->cnt = 0;
sd->skipped = 0;
initSimpleStats(&sd->latency);
@@ -2878,7 +2881,6 @@ evaluateSleep(CState *st, int argc, char **argv, int *usecs)
static void
advanceConnectionState(TState *thread, CState *st, StatsData *agg)
{
- instr_time now;
/*
* gettimeofday() isn't free, so we get the current timestamp lazily the
@@ -2888,7 +2890,7 @@ advanceConnectionState(TState *thread, CState *st, StatsData *agg)
* means "not set yet". Reset "now" when we execute shell commands or
* expressions, which might take a non-negligible amount of time, though.
*/
- INSTR_TIME_SET_ZERO(now);
+ pg_time_usec_t now = 0;
/*
* Loop in the state machine, until we have to wait for a result from the
@@ -2923,29 +2925,30 @@ advanceConnectionState(TState *thread, CState *st, StatsData *agg)
/* Start new transaction (script) */
case CSTATE_START_TX:
+ pg_time_now_lazy(&now);
/* establish connection if needed, i.e. under --connect */
if (st->con == NULL)
{
- instr_time start;
+ pg_time_usec_t start = now;
- INSTR_TIME_SET_CURRENT_LAZY(now);
- start = now;
if ((st->con = doConnect()) == NULL)
{
pg_log_error("client %d aborted while establishing connection", st->id);
st->state = CSTATE_ABORTED;
break;
}
- INSTR_TIME_SET_CURRENT(now);
- INSTR_TIME_ACCUM_DIFF(thread->conn_time, now, start);
+
+ /* reset now after connection */
+ now = pg_time_now();
+
+ thread->conn_duration += now - start;
/* Reset session-local state */
memset(st->prepared, 0, sizeof(st->prepared));
}
/* record transaction start time */
- INSTR_TIME_SET_CURRENT_LAZY(now);
st->txn_begin = now;
/*
@@ -2953,7 +2956,7 @@ advanceConnectionState(TState *thread, CState *st, StatsData *agg)
* scheduled start time.
*/
if (!throttle_delay)
- st->txn_scheduled = INSTR_TIME_GET_MICROSEC(now);
+ st->txn_scheduled = now;
/* Begin with the first command */
st->state = CSTATE_START_COMMAND;
@@ -2989,12 +2992,9 @@ advanceConnectionState(TState *thread, CState *st, StatsData *agg)
*/
if (latency_limit)
{
- int64 now_us;
+ pg_time_now_lazy(&now);
- INSTR_TIME_SET_CURRENT_LAZY(now);
- now_us = INSTR_TIME_GET_MICROSEC(now);
-
- while (thread->throttle_trigger < now_us - latency_limit &&
+ while (thread->throttle_trigger < now - latency_limit &&
(nxacts <= 0 || st->cnt < nxacts))
{
processXactStats(thread, st, &now, true, agg);
@@ -3027,9 +3027,9 @@ advanceConnectionState(TState *thread, CState *st, StatsData *agg)
* Wait until it's time to start next transaction.
*/
case CSTATE_THROTTLE:
- INSTR_TIME_SET_CURRENT_LAZY(now);
+ pg_time_now_lazy(&now);
- if (INSTR_TIME_GET_MICROSEC(now) < st->txn_scheduled)
+ if (now < st->txn_scheduled)
return; /* still sleeping, nothing to do here */
/* done sleeping, but don't start transaction if we're done */
@@ -3052,7 +3052,7 @@ advanceConnectionState(TState *thread, CState *st, StatsData *agg)
/* record begin time of next command, and initiate it */
if (report_per_command)
{
- INSTR_TIME_SET_CURRENT_LAZY(now);
+ pg_time_now_lazy(&now);
st->stmt_begin = now;
}
@@ -3217,8 +3217,8 @@ advanceConnectionState(TState *thread, CState *st, StatsData *agg)
* instead of CSTATE_START_TX.
*/
case CSTATE_SLEEP:
- INSTR_TIME_SET_CURRENT_LAZY(now);
- if (INSTR_TIME_GET_MICROSEC(now) < st->sleep_until)
+ pg_time_now_lazy(&now);
+ if (now < st->sleep_until)
return; /* still sleeping, nothing to do here */
/* Else done sleeping. */
st->state = CSTATE_END_COMMAND;
@@ -3238,13 +3238,12 @@ advanceConnectionState(TState *thread, CState *st, StatsData *agg)
{
Command *command;
- INSTR_TIME_SET_CURRENT_LAZY(now);
+ pg_time_now_lazy(&now);
command = sql_script[st->use_file].commands[st->command];
/* XXX could use a mutex here, but we choose not to */
addToSimpleStats(&command->stats,
- INSTR_TIME_GET_DOUBLE(now) -
- INSTR_TIME_GET_DOUBLE(st->stmt_begin));
+ PG_TIME_GET_DOUBLE(now - st->stmt_begin));
}
/* Go ahead with next command, to be executed or skipped */
@@ -3270,7 +3269,7 @@ advanceConnectionState(TState *thread, CState *st, StatsData *agg)
if (is_connect)
{
finishCon(st);
- INSTR_TIME_SET_ZERO(now);
+ now = 0;
}
if ((st->cnt >= nxacts && duration <= 0) || timer_exceeded)
@@ -3308,7 +3307,7 @@ advanceConnectionState(TState *thread, CState *st, StatsData *agg)
* take no time to execute.
*/
static ConnectionStateEnum
-executeMetaCommand(CState *st, instr_time *now)
+executeMetaCommand(CState *st, pg_time_usec_t *now)
{
Command *command = sql_script[st->use_file].commands[st->command];
int argc;
@@ -3350,8 +3349,8 @@ executeMetaCommand(CState *st, instr_time *now)
return CSTATE_ABORTED;
}
- INSTR_TIME_SET_CURRENT_LAZY(*now);
- st->sleep_until = INSTR_TIME_GET_MICROSEC(*now) + usec;
+ pg_time_now_lazy(now);
+ st->sleep_until = (*now) + usec;
return CSTATE_SLEEP;
}
else if (command->meta == META_SET)
@@ -3454,7 +3453,7 @@ executeMetaCommand(CState *st, instr_time *now)
* executing the expression or shell command might have taken a
* non-negligible amount of time, so reset 'now'
*/
- INSTR_TIME_SET_ZERO(*now);
+ *now = 0;
return CSTATE_END_COMMAND;
}
@@ -3464,14 +3463,15 @@ executeMetaCommand(CState *st, instr_time *now)
*
* We print Unix-epoch timestamps in the log, so that entries can be
* correlated against other logs. On some platforms this could be obtained
- * from the instr_time reading the caller has, but rather than get entangled
- * with that, we just eat the cost of an extra syscall in all cases.
+ * from the caller, but rather than get entangled with that, we just eat
+ * the cost of an extra syscall in all cases.
*/
static void
doLog(TState *thread, CState *st,
StatsData *agg, bool skipped, double latency, double lag)
{
FILE *logfile = thread->logfile;
+ pg_time_usec_t now = pg_time_now();
Assert(use_log);
@@ -3491,13 +3491,12 @@ doLog(TState *thread, CState *st,
* any empty intervals in between (this may happen with very low tps,
* e.g. --rate=0.1).
*/
- time_t now = time(NULL);
while (agg->start_time + agg_interval <= now)
{
/* print aggregated report to logfile */
- fprintf(logfile, "%ld " INT64_FORMAT " %.0f %.0f %.0f %.0f",
- (long) agg->start_time,
+ fprintf(logfile, INT64_FORMAT " " INT64_FORMAT " %.0f %.0f %.0f %.0f",
+ agg->start_time,
agg->cnt,
agg->latency.sum,
agg->latency.sum2,
@@ -3525,17 +3524,13 @@ doLog(TState *thread, CState *st,
else
{
/* no, print raw transactions */
- struct timeval tv;
-
- gettimeofday(&tv, NULL);
if (skipped)
fprintf(logfile, "%d " INT64_FORMAT " skipped %d %ld %ld",
- st->id, st->cnt, st->use_file,
- (long) tv.tv_sec, (long) tv.tv_usec);
+ st->id, st->cnt, st->use_file, now / 1000000, now % 1000000);
else
fprintf(logfile, "%d " INT64_FORMAT " %.0f %d %ld %ld",
st->id, st->cnt, latency, st->use_file,
- (long) tv.tv_sec, (long) tv.tv_usec);
+ now / 1000000, now % 1000000);
if (throttle_delay)
fprintf(logfile, " %.0f", lag);
fputc('\n', logfile);
@@ -3549,7 +3544,7 @@ doLog(TState *thread, CState *st,
* Note that even skipped transactions are counted in the "cnt" fields.)
*/
static void
-processXactStats(TState *thread, CState *st, instr_time *now,
+processXactStats(TState *thread, CState *st, pg_time_usec_t *now,
bool skipped, StatsData *agg)
{
double latency = 0.0,
@@ -3559,11 +3554,11 @@ processXactStats(TState *thread, CState *st, instr_time *now,
if (detailed && !skipped)
{
- INSTR_TIME_SET_CURRENT_LAZY(*now);
+ pg_time_now_lazy(now);
/* compute latency & lag */
- latency = INSTR_TIME_GET_MICROSEC(*now) - st->txn_scheduled;
- lag = INSTR_TIME_GET_MICROSEC(st->txn_begin) - st->txn_scheduled;
+ latency = (*now) - st->txn_scheduled;
+ lag = st->txn_begin - st->txn_scheduled;
}
if (thread_details)
@@ -3826,10 +3821,7 @@ initGenerateDataClientSide(PGconn *con)
int64 k;
/* used to track elapsed time and estimate of the remaining time */
- instr_time start,
- diff;
- double elapsed_sec,
- remaining_sec;
+ pg_time_usec_t start;
int log_interval = 1;
/* Stay on the same line if reporting to a terminal */
@@ -3879,7 +3871,7 @@ initGenerateDataClientSide(PGconn *con)
}
PQclear(res);
- INSTR_TIME_SET_CURRENT(start);
+ start = pg_time_now();
for (k = 0; k < (int64) naccounts * scale; k++)
{
@@ -3904,11 +3896,8 @@ initGenerateDataClientSide(PGconn *con)
*/
if ((!use_quiet) && (j % 100000 == 0))
{
- INSTR_TIME_SET_CURRENT(diff);
- INSTR_TIME_SUBTRACT(diff, start);
-
- elapsed_sec = INSTR_TIME_GET_DOUBLE(diff);
- remaining_sec = ((double) scale * naccounts - j) * elapsed_sec / j;
+ double elapsed_sec = PG_TIME_GET_DOUBLE(pg_time_now() - start);
+ double remaining_sec = ((double) scale * naccounts - j) * elapsed_sec / j;
fprintf(stderr, INT64_FORMAT " of " INT64_FORMAT " tuples (%d%%) done (elapsed %.2f s, remaining %.2f s)%c",
j, (int64) naccounts * scale,
@@ -3918,11 +3907,8 @@ initGenerateDataClientSide(PGconn *con)
/* let's not call the timing for each row, but only each 100 rows */
else if (use_quiet && (j % 100 == 0))
{
- INSTR_TIME_SET_CURRENT(diff);
- INSTR_TIME_SUBTRACT(diff, start);
-
- elapsed_sec = INSTR_TIME_GET_DOUBLE(diff);
- remaining_sec = ((double) scale * naccounts - j) * elapsed_sec / j;
+ double elapsed_sec = PG_TIME_GET_DOUBLE(pg_time_now() - start);
+ double remaining_sec = ((double) scale * naccounts - j) * elapsed_sec / j;
/* have we reached the next interval (or end)? */
if ((j == scale * naccounts) || (elapsed_sec >= log_interval * LOG_STEP_SECONDS))
@@ -4118,10 +4104,8 @@ runInitSteps(const char *initialize_steps)
for (step = initialize_steps; *step != '\0'; step++)
{
- instr_time start;
char *op = NULL;
-
- INSTR_TIME_SET_CURRENT(start);
+ pg_time_usec_t start = pg_time_now();
switch (*step)
{
@@ -4163,12 +4147,7 @@ runInitSteps(const char *initialize_steps)
if (op != NULL)
{
- instr_time diff;
- double elapsed_sec;
-
- INSTR_TIME_SET_CURRENT(diff);
- INSTR_TIME_SUBTRACT(diff, start);
- elapsed_sec = INSTR_TIME_GET_DOUBLE(diff);
+ double elapsed_sec = PG_TIME_GET_DOUBLE(pg_time_now() - start);
if (!first)
appendPQExpBufferStr(&stats, ", ");
@@ -5090,12 +5069,12 @@ addScript(ParsedScript script)
* progress report. On exit, they are updated with the new stats.
*/
static void
-printProgressReport(TState *threads, int64 test_start, int64 now,
+printProgressReport(TState *threads, int64 test_start, pg_time_usec_t now,
StatsData *last, int64 *last_report)
{
/* generate and show report */
- int64 run = now - *last_report,
- ntx;
+ pg_time_usec_t run = now - *last_report;
+ int64 ntx;
double tps,
total_run,
latency,
@@ -5142,16 +5121,7 @@ printProgressReport(TState *threads, int64 test_start, int64 now,
if (progress_timestamp)
{
- /*
- * On some platforms the current system timestamp is available in
- * now_time, but rather than get entangled with that, we just eat the
- * cost of an extra syscall in all cases.
- */
- struct timeval tv;
-
- gettimeofday(&tv, NULL);
- snprintf(tbuf, sizeof(tbuf), "%ld.%03ld s",
- (long) tv.tv_sec, (long) (tv.tv_usec / 1000));
+ snprintf(tbuf, sizeof(tbuf), "%.3f s", PG_TIME_GET_DOUBLE(now));
}
else
{
@@ -5191,21 +5161,18 @@ printSimpleStats(const char *prefix, SimpleStats *ss)
/* print out results */
static void
-printResults(StatsData *total, instr_time total_time,
- instr_time conn_total_time, int64 latency_late)
+printResults(StatsData *total,
+ pg_time_usec_t total_duration, /* benchmarking time */
+ pg_time_usec_t conn_total_duration, /* is_connect */
+ pg_time_usec_t conn_elapsed_duration, /* !is_connect */
+ int64 latency_late)
{
- double time_include,
- tps_include,
- tps_exclude;
+ /* tps is about actually executed transactions during benchmarking */
int64 ntx = total->cnt - total->skipped;
+ double bench_duration = PG_TIME_GET_DOUBLE(total_duration);
+ double tps = ntx / bench_duration;
- time_include = INSTR_TIME_GET_DOUBLE(total_time);
-
- /* tps is about actually executed transactions */
- tps_include = ntx / time_include;
- tps_exclude = ntx /
- (time_include - (INSTR_TIME_GET_DOUBLE(conn_total_time) / nclients));
-
+ printf("pgbench (PostgreSQL) %d.%d\n", PG_VERSION_NUM / 10000, PG_VERSION_NUM % 100);
/* Report test parameters. */
printf("transaction type: %s\n",
num_scripts == 1 ? sql_script[0].desc : "multiple scripts");
@@ -5236,8 +5203,7 @@ printResults(StatsData *total, instr_time total_time,
if (throttle_delay && latency_limit)
printf("number of transactions skipped: " INT64_FORMAT " (%.3f %%)\n",
- total->skipped,
- 100.0 * total->skipped / total->cnt);
+ total->skipped, 100.0 * total->skipped / total->cnt);
if (latency_limit)
printf("number of transactions above the %.1f ms latency limit: " INT64_FORMAT "/" INT64_FORMAT " (%.3f %%)\n",
@@ -5250,7 +5216,7 @@ printResults(StatsData *total, instr_time total_time,
{
/* no measurement, show average latency computed from run time */
printf("latency average = %.3f ms\n",
- 1000.0 * time_include * nclients / total->cnt);
+ 0.001 * total_duration * nclients / total->cnt);
}
if (throttle_delay)
@@ -5265,8 +5231,25 @@ printResults(StatsData *total, instr_time total_time,
0.001 * total->lag.sum / total->cnt, 0.001 * total->lag.max);
}
- printf("tps = %f (including connections establishing)\n", tps_include);
- printf("tps = %f (excluding connections establishing)\n", tps_exclude);
+ /*
+ * Under -C/--connect, each transaction incurs a significant connection cost,
+ * it would not make much sense to ignore it in tps, and it would not be tps
+ * anyway.
+ *
+ * Otherwise connections are made just once at the beginning of the run
+ * and should not impact performance but for very short run, so they are
+ * (right)fully ignored in tps.
+ */
+ if (is_connect)
+ {
+ printf("average connection time = %.3f ms\n", 0.001 * conn_total_duration / total->cnt);
+ printf("tps = %f (including reconnection times)\n", tps);
+ }
+ else
+ {
+ printf("initial connection time = %.3f ms\n", 0.001 * conn_elapsed_duration);
+ printf("tps = %f (without initial connection establishing)\n", tps);
+ }
/* Report per-script/command statistics */
if (per_script_stats || report_per_command)
@@ -5287,7 +5270,7 @@ printResults(StatsData *total, instr_time total_time,
100.0 * sql_script[i].weight / total_weight,
sstats->cnt,
100.0 * sstats->cnt / total->cnt,
- (sstats->cnt - sstats->skipped) / time_include);
+ (sstats->cnt - sstats->skipped) / bench_duration);
if (throttle_delay && latency_limit && sstats->cnt > 0)
printf(" - number of transactions skipped: " INT64_FORMAT " (%.3f%%)\n",
@@ -5335,10 +5318,7 @@ set_random_seed(const char *seed)
if (seed == NULL || strcmp(seed, "time") == 0)
{
/* rely on current time */
- instr_time now;
-
- INSTR_TIME_SET_CURRENT(now);
- iseed = (uint64) INSTR_TIME_GET_MICROSEC(now);
+ iseed = pg_time_now();
}
else if (strcmp(seed, "rand") == 0)
{
@@ -5441,9 +5421,10 @@ main(int argc, char **argv)
CState *state; /* status of clients */
TState *threads; /* array of thread */
- instr_time start_time; /* start up time */
- instr_time total_time;
- instr_time conn_total_time;
+ pg_time_usec_t
+ start_time, /* start up time */
+ bench_start = 0, /* first recorded benchmarking time */
+ conn_total_duration; /* cumulated connection time in threads */
int64 latency_late = 0;
StatsData stats;
int weight;
@@ -6126,67 +6107,53 @@ main(int argc, char **argv)
/* all clients must be assigned to a thread */
Assert(nclients_dealt == nclients);
- /* get start up time */
- INSTR_TIME_SET_CURRENT(start_time);
+ /* get start up time for the whole computation */
+ start_time = pg_time_now();
/* set alarm if duration is specified. */
if (duration > 0)
setalarm(duration);
- /* start threads */
#ifdef ENABLE_THREAD_SAFETY
- for (i = 0; i < nthreads; i++)
+ /* start all threads but thread 0 which is executed directly later */
+ for (i = 1; i < nthreads; i++)
{
TState *thread = &threads[i];
+ int err;
- INSTR_TIME_SET_CURRENT(thread->start_time);
+ thread->create_time = pg_time_now();
+ err = pthread_create(&thread->thread, NULL, threadRun, thread);
- /* compute when to stop */
- if (duration > 0)
- end_time = INSTR_TIME_GET_MICROSEC(thread->start_time) +
- (int64) 1000000 * duration;
-
- /* the first thread (i = 0) is executed by main thread */
- if (i > 0)
- {
- int err = pthread_create(&thread->thread, NULL, threadRun, thread);
-
- if (err != 0 || thread->thread == INVALID_THREAD)
- {
- pg_log_fatal("could not create thread: %m");
- exit(1);
- }
- }
- else
+ if (err != 0 || thread->thread == INVALID_THREAD)
{
- thread->thread = INVALID_THREAD;
+ pg_log_fatal("could not create thread: %m");
+ exit(1);
}
}
#else
- INSTR_TIME_SET_CURRENT(threads[0].start_time);
+ Assert(nthreads == 1);
+#endif /* ENABLE_THREAD_SAFETY */
+
/* compute when to stop */
+ threads[0].create_time = pg_time_now();
if (duration > 0)
- end_time = INSTR_TIME_GET_MICROSEC(threads[0].start_time) +
- (int64) 1000000 * duration;
+ end_time = threads[0].create_time + (int64) 1000000 * duration;
+
+ /* run thread 0 directly */
threads[0].thread = INVALID_THREAD;
-#endif /* ENABLE_THREAD_SAFETY */
+ (void) threadRun(&threads[0]);
- /* wait for threads and accumulate results */
+ /* wait for other threads and accumulate results */
initStats(&stats, 0);
- INSTR_TIME_SET_ZERO(conn_total_time);
+ conn_total_duration = 0;
+
for (i = 0; i < nthreads; i++)
{
TState *thread = &threads[i];
#ifdef ENABLE_THREAD_SAFETY
- if (threads[i].thread == INVALID_THREAD)
- /* actually run this thread directly in the main thread */
- (void) threadRun(thread);
- else
- /* wait of other threads. should check that 0 is returned? */
+ if (i > 0)
pthread_join(thread->thread, NULL);
-#else
- (void) threadRun(thread);
#endif /* ENABLE_THREAD_SAFETY */
for (int j = 0; j < thread->nstate; j++)
@@ -6199,23 +6166,24 @@ main(int argc, char **argv)
stats.cnt += thread->stats.cnt;
stats.skipped += thread->stats.skipped;
latency_late += thread->latency_late;
- INSTR_TIME_ADD(conn_total_time, thread->conn_time);
+ conn_total_duration += thread->conn_duration;
+
+ /* first recorded benchmarking start time */
+ if (bench_start == 0 || thread->bench_start < bench_start)
+ bench_start = thread->bench_start;
}
+
+ /* XXX should this be connection time? */
disconnect_all(state, nclients);
/*
- * XXX We compute results as though every client of every thread started
- * and finished at the same time. That model can diverge noticeably from
- * reality for a short benchmark run involving relatively many threads.
- * The first thread may process notably many transactions before the last
- * thread begins. Improving the model alone would bring limited benefit,
- * because performance during those periods of partial thread count can
- * easily exceed steady state performance. This is one of the many ways
- * short runs convey deceptive performance figures.
+ * Beware that performance of short benchmarks with many threads and possibly
+ * long transactions can be deceptive because threads do not start and finish
+ * at the exact same time. The total duration computed here encompasses all
+ * transactions so that tps shown is somehow slightly underestimated.
*/
- INSTR_TIME_SET_CURRENT(total_time);
- INSTR_TIME_SUBTRACT(total_time, start_time);
- printResults(&stats, total_time, conn_total_time, latency_late);
+ printResults(&stats, pg_time_now() - bench_start, conn_total_duration,
+ bench_start - start_time, latency_late);
if (exit_code != 0)
pg_log_fatal("Run was aborted; the above results are incomplete.");
@@ -6228,34 +6196,16 @@ threadRun(void *arg)
{
TState *thread = (TState *) arg;
CState *state = thread->state;
- instr_time start,
- end;
+ pg_time_usec_t start;
int nstate = thread->nstate;
int remains = nstate; /* number of remaining clients */
socket_set *sockets = alloc_socket_set(nstate);
- int i;
-
- /* for reporting progress: */
- int64 thread_start = INSTR_TIME_GET_MICROSEC(thread->start_time);
- int64 last_report = thread_start;
- int64 next_report = last_report + (int64) progress * 1000000;
+ int64 thread_start,
+ last_report,
+ next_report;
StatsData last,
aggs;
- /*
- * Initialize throttling rate target for all of the thread's clients. It
- * might be a little more accurate to reset thread->start_time here too.
- * The possible drift seems too small relative to typical throttle delay
- * times to worry about it.
- */
- INSTR_TIME_SET_CURRENT(start);
- thread->throttle_trigger = INSTR_TIME_GET_MICROSEC(start);
-
- INSTR_TIME_SET_ZERO(thread->conn_time);
-
- initStats(&aggs, time(NULL));
- last = aggs;
-
/* open log file if requested */
if (use_log)
{
@@ -6276,32 +6226,51 @@ threadRun(void *arg)
}
}
+ /* explicitly initialize the state machines */
+ for (int i = 0; i < nstate; i++)
+ {
+ state[i].state = CSTATE_CHOOSE_SCRIPT;
+ }
+
+ /* READY */
+ thread_start = pg_time_now();
+ thread->started_time = thread_start;
+ last_report = thread_start;
+ next_report = last_report + (int64) 1000000 * progress;
+
+ /* STEADY */
if (!is_connect)
{
/* make connections to the database before starting */
- for (i = 0; i < nstate; i++)
+ for (int i = 0; i < nstate; i++)
{
if ((state[i].con = doConnect()) == NULL)
goto done;
}
+
+ /* compute connection delay */
+ thread->conn_duration = pg_time_now() - thread->started_time;
}
-
- /* time after thread and connections set up */
- INSTR_TIME_SET_CURRENT(thread->conn_time);
- INSTR_TIME_SUBTRACT(thread->conn_time, thread->start_time);
-
- /* explicitly initialize the state machines */
- for (i = 0; i < nstate; i++)
+ else
{
- state[i].state = CSTATE_CHOOSE_SCRIPT;
+ /* no connection delay to record */
+ thread->conn_duration = 0;
}
+
+ start = pg_time_now();
+ thread->bench_start = start;
+ thread->throttle_trigger = start;
+
+ initStats(&aggs, start);
+ last = aggs;
+
/* loop till all clients have terminated */
while (remains > 0)
{
int nsocks; /* number of sockets to be waited for */
- int64 min_usec;
- int64 now_usec = 0; /* set this only if needed */
+ pg_time_usec_t min_usec;
+ pg_time_usec_t now = 0; /* set this only if needed */
/*
* identify which client sockets should be checked for input, and
@@ -6310,27 +6279,21 @@ threadRun(void *arg)
clear_socket_set(sockets);
nsocks = 0;
min_usec = PG_INT64_MAX;
- for (i = 0; i < nstate; i++)
+ for (int i = 0; i < nstate; i++)
{
CState *st = &state[i];
if (st->state == CSTATE_SLEEP || st->state == CSTATE_THROTTLE)
{
/* a nap from the script, or under throttling */
- int64 this_usec;
+ pg_time_usec_t this_usec;
/* get current time if needed */
- if (now_usec == 0)
- {
- instr_time now;
-
- INSTR_TIME_SET_CURRENT(now);
- now_usec = INSTR_TIME_GET_MICROSEC(now);
- }
+ pg_time_now_lazy(&now);
/* min_usec should be the minimum delay across all clients */
this_usec = (st->state == CSTATE_SLEEP ?
- st->sleep_until : st->txn_scheduled) - now_usec;
+ st->sleep_until : st->txn_scheduled) - now;
if (min_usec > this_usec)
min_usec = this_usec;
}
@@ -6365,19 +6328,12 @@ threadRun(void *arg)
/* also wake up to print the next progress report on time */
if (progress && min_usec > 0 && thread->tid == 0)
{
- /* get current time if needed */
- if (now_usec == 0)
- {
- instr_time now;
+ pg_time_now_lazy(&now);
- INSTR_TIME_SET_CURRENT(now);
- now_usec = INSTR_TIME_GET_MICROSEC(now);
- }
-
- if (now_usec >= next_report)
+ if (now >= next_report)
min_usec = 0;
- else if ((next_report - now_usec) < min_usec)
- min_usec = next_report - now_usec;
+ else if ((next_report - now) < min_usec)
+ min_usec = next_report - now;
}
/*
@@ -6426,7 +6382,7 @@ threadRun(void *arg)
/* ok, advance the state machine of each connection */
nsocks = 0;
- for (i = 0; i < nstate; i++)
+ for (int i = 0; i < nstate; i++)
{
CState *st = &state[i];
@@ -6464,11 +6420,8 @@ threadRun(void *arg)
/* progress report is made by thread 0 for all threads */
if (progress && thread->tid == 0)
{
- instr_time now_time;
- int64 now;
+ pg_time_usec_t now = pg_time_now();
- INSTR_TIME_SET_CURRENT(now_time);
- now = INSTR_TIME_GET_MICROSEC(now_time);
if (now >= next_report)
{
/*
@@ -6486,17 +6439,17 @@ threadRun(void *arg)
*/
do
{
- next_report += (int64) progress * 1000000;
+ next_report += (int64) 1000000 * progress;
} while (now >= next_report);
}
}
}
done:
- INSTR_TIME_SET_CURRENT(start);
+ start = pg_time_now();
disconnect_all(state, nstate);
- INSTR_TIME_SET_CURRENT(end);
- INSTR_TIME_ACCUM_DIFF(thread->conn_time, end, start);
+ thread->conn_duration += pg_time_now() - start;
+
if (thread->logfile)
{
if (agg_interval > 0)
diff --git a/src/include/portability/instr_time.h b/src/include/portability/instr_time.h
index d6459327cc..fcc0bdda28 100644
--- a/src/include/portability/instr_time.h
+++ b/src/include/portability/instr_time.h
@@ -253,4 +253,32 @@ GetTimerFrequency(void)
#define INSTR_TIME_SET_CURRENT_LAZY(t) \
(INSTR_TIME_IS_ZERO(t) ? INSTR_TIME_SET_CURRENT(t), true : false)
+/*
+ * Simpler convenient interface
+ *
+ * The instr_time type is expensive when dealing with time arithmetic.
+ * Define a type to hold microseconds on top of this, suitable for
+ * benchmarking performance measures, eg in "pgbench".
+ *
+ * Type int64 is good enough for about 584500 years.
+ */
+typedef int64 pg_time_usec_t;
+
+static inline pg_time_usec_t
+pg_time_now(void)
+{
+ instr_time now;
+
+ INSTR_TIME_SET_CURRENT(now);
+ return (pg_time_usec_t) INSTR_TIME_GET_MICROSEC(now);
+}
+
+static inline void
+pg_time_now_lazy(pg_time_usec_t *now)
+{
+ if ((*now) == 0)
+ (*now) = pg_time_now();
+}
+
+#define PG_TIME_GET_DOUBLE(t) (0.000001 * (t))
#endif /* INSTR_TIME_H */
diff --git a/src/bin/pgbench/pgbench.c b/src/bin/pgbench/pgbench.c
index 46be67adaf..79a2a10dee 100644
--- a/src/bin/pgbench/pgbench.c
+++ b/src/bin/pgbench/pgbench.c
@@ -113,18 +113,29 @@ typedef struct socket_set
*/
#ifdef WIN32
+#define PTHREAD_BARRIER_SERIAL_THREAD (-1)
+
/* Use native win32 threads on Windows */
typedef struct win32_pthread *pthread_t;
typedef int pthread_attr_t;
+typedef SYNCHRONIZATION_BARRIER pthread_barrier_t;
static int pthread_create(pthread_t *thread, pthread_attr_t *attr, void *(*start_routine) (void *), void *arg);
static int pthread_join(pthread_t th, void **thread_return);
+
+static int pthread_barrier_init(pthread_barrier_t *barrier, void *unused, int nthreads);
+static int pthread_barrier_wait(pthread_barrier_t *barrier);
+static int pthread_barrier_destroy(pthread_barrier_t *barrier);
#elif defined(ENABLE_THREAD_SAFETY)
/* Use platform-dependent pthread capability */
#include <pthread.h>
#else
/* No threads implementation, use none (-j 1) */
#define pthread_t void *
+#define pthread_barrier_t void *
+#define pthread_barrier_init(a, b, c) /* ignore */
+#define pthread_barrier_wait(a) /* ignore */
+#define pthread_barrier_destroy(a) /* ignore */
#endif
@@ -310,6 +321,9 @@ typedef struct RandomState
/* Various random sequences are initialized from this one. */
static RandomState base_random_sequence;
+/* Synchronization barrier for start and connection */
+static pthread_barrier_t barrier;
+
/*
* Connection state machine states.
*/
@@ -453,8 +467,8 @@ typedef struct
/* per thread collected stats in microseconds */
pg_time_usec_t create_time; /* thread creation time */
- pg_time_usec_t started_time; /* thread is running */
- pg_time_usec_t bench_start; /* thread is benchmarking */
+ pg_time_usec_t started_time; /* thread is running after start barrier */
+ pg_time_usec_t bench_start; /* thread is benchmarking after connection barrier */
pg_time_usec_t conn_duration; /* cumulated connection and deconnection delays */
StatsData stats;
@@ -6114,6 +6128,8 @@ main(int argc, char **argv)
if (duration > 0)
setalarm(duration);
+ pthread_barrier_init(&barrier, NULL, nthreads);
+
#ifdef ENABLE_THREAD_SAFETY
/* start all threads but thread 0 which is executed directly later */
for (i = 1; i < nthreads; i++)
@@ -6185,6 +6201,8 @@ main(int argc, char **argv)
printResults(&stats, pg_time_now() - bench_start, conn_total_duration,
bench_start - start_time, latency_late);
+ pthread_barrier_destroy(&barrier);
+
if (exit_code != 0)
pg_log_fatal("Run was aborted; the above results are incomplete.");
@@ -6233,6 +6251,8 @@ threadRun(void *arg)
}
/* READY */
+ pthread_barrier_wait(&barrier);
+
thread_start = pg_time_now();
thread->started_time = thread_start;
last_report = thread_start;
@@ -6257,6 +6277,8 @@ threadRun(void *arg)
thread->conn_duration = 0;
}
+ /* GO */
+ pthread_barrier_wait(&barrier);
start = pg_time_now();
thread->bench_start = start;
@@ -6762,4 +6784,26 @@ pthread_join(pthread_t th, void **thread_return)
return 0;
}
+static int
+pthread_barrier_init(pthread_barrier_t *barrier, void *unused, int nthreads)
+{
+ /* no spinning: threads are not expected to arrive at the barrier together */
+ bool ok = InitializeSynchronizationBarrier(barrier, nthreads, 0);
+ return 0;
+}
+
+static int
+pthread_barrier_wait(pthread_barrier_t *barrier)
+{
+ bool last = EnterSynchronizationBarrier(barrier, SYNCHRONIZATION_BARRIER_FLAGS_BLOCK_ONLY);
+ return last ? PTHREAD_BARRIER_SERIAL_THREAD : 0;
+}
+
+static int
+pthread_barrier_destroy(pthread_barrier_t *barrier)
+{
+ (void) DeleteSynchronizationBarrier(barrier);
+ return 0;
+}
+
#endif /* WIN32 */
