PX4-Autopilot/src/lib/perf/perf_counter.cpp
2019-03-16 11:47:15 -04:00

632 lines
15 KiB
C++

/****************************************************************************
*
* Copyright (c) 2012-2016 PX4 Development Team. All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
*
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in
* the documentation and/or other materials provided with the
* distribution.
* 3. Neither the name PX4 nor the names of its contributors may be
* used to endorse or promote products derived from this software
* without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
* "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
* LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
* FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
* COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
* BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS
* OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
* AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN
* ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
* POSSIBILITY OF SUCH DAMAGE.
*
****************************************************************************/
/**
* @file perf_counter.c
*
* @brief Performance measuring tools.
*/
#include <stdlib.h>
#include <stdio.h>
#include <string.h>
#include <sys/queue.h>
#include <drivers/drv_hrt.h>
#include <math.h>
#include <pthread.h>
#include <systemlib/err.h>
#include "perf_counter.h"
/* latency histogram */
const uint16_t latency_bucket_count = LATENCY_BUCKET_COUNT;
const uint16_t latency_buckets[LATENCY_BUCKET_COUNT] = { 1, 2, 5, 10, 20, 50, 100, 1000 };
__EXPORT uint32_t latency_counters[LATENCY_BUCKET_COUNT + 1];
#ifdef __PX4_QURT
// There is presumably no dprintf on QURT. Therefore use the usual output to mini-dm.
#define dprintf(_fd, _text, ...) ((_fd) == 1 ? PX4_INFO((_text), ##__VA_ARGS__) : (void)(_fd))
#endif
/**
* Header common to all counters.
*/
struct perf_ctr_header {
sq_entry_t link; /**< list linkage */
enum perf_counter_type type; /**< counter type */
const char *name; /**< counter name */
};
/**
* PC_EVENT counter.
*/
struct perf_ctr_count : public perf_ctr_header {
uint64_t event_count{0};
};
/**
* PC_ELAPSED counter.
*/
struct perf_ctr_elapsed : public perf_ctr_header {
uint64_t event_count{0};
uint64_t time_start{0};
uint64_t time_total{0};
uint32_t time_least{0};
uint32_t time_most{0};
float mean{0.0f};
float M2{0.0f};
};
/**
* PC_INTERVAL counter.
*/
struct perf_ctr_interval : public perf_ctr_header {
uint64_t event_count{0};
uint64_t time_event{0};
uint64_t time_first{0};
uint64_t time_last{0};
uint32_t time_least{0};
uint32_t time_most{0};
float mean{0.0f};
float M2{0.0f};
};
/**
* List of all known counters.
*/
static sq_queue_t perf_counters = { nullptr, nullptr };
/**
* mutex protecting access to the perf_counters linked list (which is read from & written to by different threads)
*/
pthread_mutex_t perf_counters_mutex = PTHREAD_MUTEX_INITIALIZER;
// FIXME: the mutex does **not** protect against access to/from the perf
// counter's data. It can still happen that a counter is updated while it is
// printed. This can lead to inconsistent output, or completely bogus values
// (especially the 64bit values which are in general not atomically updated).
// The same holds for shared perf counters (perf_alloc_once), that can be updated
// concurrently (this affects the 'ctrl_latency' counter).
perf_counter_t
perf_alloc(enum perf_counter_type type, const char *name)
{
perf_counter_t ctr = nullptr;
switch (type) {
case PC_COUNT:
ctr = new perf_ctr_count();
break;
case PC_ELAPSED:
ctr = new perf_ctr_elapsed();
break;
case PC_INTERVAL:
ctr = new perf_ctr_interval();
break;
default:
break;
}
if (ctr != nullptr) {
ctr->type = type;
ctr->name = name;
pthread_mutex_lock(&perf_counters_mutex);
sq_addfirst(&ctr->link, &perf_counters);
pthread_mutex_unlock(&perf_counters_mutex);
}
return ctr;
}
perf_counter_t
perf_alloc_once(enum perf_counter_type type, const char *name)
{
pthread_mutex_lock(&perf_counters_mutex);
perf_counter_t handle = (perf_counter_t)sq_peek(&perf_counters);
while (handle != nullptr) {
if (!strcmp(handle->name, name)) {
if (type == handle->type) {
/* they are the same counter */
pthread_mutex_unlock(&perf_counters_mutex);
return handle;
} else {
/* same name but different type, assuming this is an error and not intended */
pthread_mutex_unlock(&perf_counters_mutex);
return nullptr;
}
}
handle = (perf_counter_t)sq_next(&handle->link);
}
pthread_mutex_unlock(&perf_counters_mutex);
/* if the execution reaches here, no existing counter of that name was found */
return perf_alloc(type, name);
}
void
perf_free(perf_counter_t handle)
{
if (handle == nullptr) {
return;
}
pthread_mutex_lock(&perf_counters_mutex);
sq_rem(&handle->link, &perf_counters);
pthread_mutex_unlock(&perf_counters_mutex);
delete handle;
}
void
perf_count(perf_counter_t handle)
{
if (handle == nullptr) {
return;
}
switch (handle->type) {
case PC_COUNT:
((struct perf_ctr_count *)handle)->event_count++;
break;
case PC_INTERVAL: {
struct perf_ctr_interval *pci = (struct perf_ctr_interval *)handle;
hrt_abstime now = hrt_absolute_time();
switch (pci->event_count) {
case 0:
pci->time_first = now;
break;
case 1:
pci->time_least = (uint32_t)(now - pci->time_last);
pci->time_most = (uint32_t)(now - pci->time_last);
pci->mean = pci->time_least / 1e6f;
pci->M2 = 0;
break;
default: {
hrt_abstime interval = now - pci->time_last;
if ((uint32_t)interval < pci->time_least) {
pci->time_least = (uint32_t)interval;
}
if ((uint32_t)interval > pci->time_most) {
pci->time_most = (uint32_t)interval;
}
// maintain mean and variance of interval in seconds
// Knuth/Welford recursive mean and variance of update intervals (via Wikipedia)
float dt = interval / 1e6f;
float delta_intvl = dt - pci->mean;
pci->mean += delta_intvl / pci->event_count;
pci->M2 += delta_intvl * (dt - pci->mean);
break;
}
}
pci->time_last = now;
pci->event_count++;
break;
}
default:
break;
}
}
void
perf_begin(perf_counter_t handle)
{
if (handle == nullptr) {
return;
}
switch (handle->type) {
case PC_ELAPSED:
((struct perf_ctr_elapsed *)handle)->time_start = hrt_absolute_time();
break;
default:
break;
}
}
void
perf_end(perf_counter_t handle)
{
if (handle == nullptr) {
return;
}
switch (handle->type) {
case PC_ELAPSED: {
struct perf_ctr_elapsed *pce = (struct perf_ctr_elapsed *)handle;
if (pce->time_start != 0) {
int64_t elapsed = hrt_absolute_time() - pce->time_start;
if (elapsed >= 0) {
pce->event_count++;
pce->time_total += elapsed;
if ((pce->time_least > (uint32_t)elapsed) || (pce->time_least == 0)) {
pce->time_least = elapsed;
}
if (pce->time_most < (uint32_t)elapsed) {
pce->time_most = elapsed;
}
// maintain mean and variance of the elapsed time in seconds
// Knuth/Welford recursive mean and variance of update intervals (via Wikipedia)
float dt = elapsed / 1e6f;
float delta_intvl = dt - pce->mean;
pce->mean += delta_intvl / pce->event_count;
pce->M2 += delta_intvl * (dt - pce->mean);
pce->time_start = 0;
}
}
}
break;
default:
break;
}
}
void
perf_set_elapsed(perf_counter_t handle, int64_t elapsed)
{
if (handle == nullptr) {
return;
}
switch (handle->type) {
case PC_ELAPSED: {
struct perf_ctr_elapsed *pce = (struct perf_ctr_elapsed *)handle;
if (elapsed >= 0) {
pce->event_count++;
pce->time_total += elapsed;
if ((pce->time_least > (uint32_t)elapsed) || (pce->time_least == 0)) {
pce->time_least = elapsed;
}
if (pce->time_most < (uint32_t)elapsed) {
pce->time_most = elapsed;
}
// maintain mean and variance of the elapsed time in seconds
// Knuth/Welford recursive mean and variance of update intervals (via Wikipedia)
float dt = elapsed / 1e6f;
float delta_intvl = dt - pce->mean;
pce->mean += delta_intvl / pce->event_count;
pce->M2 += delta_intvl * (dt - pce->mean);
pce->time_start = 0;
}
}
break;
default:
break;
}
}
void
perf_set_count(perf_counter_t handle, uint64_t count)
{
if (handle == nullptr) {
return;
}
switch (handle->type) {
case PC_COUNT: {
((struct perf_ctr_count *)handle)->event_count = count;
}
break;
default:
break;
}
}
void
perf_cancel(perf_counter_t handle)
{
if (handle == nullptr) {
return;
}
switch (handle->type) {
case PC_ELAPSED: {
struct perf_ctr_elapsed *pce = (struct perf_ctr_elapsed *)handle;
pce->time_start = 0;
}
break;
default:
break;
}
}
void
perf_reset(perf_counter_t handle)
{
if (handle == nullptr) {
return;
}
switch (handle->type) {
case PC_COUNT:
((struct perf_ctr_count *)handle)->event_count = 0;
break;
case PC_ELAPSED: {
struct perf_ctr_elapsed *pce = (struct perf_ctr_elapsed *)handle;
pce->event_count = 0;
pce->time_start = 0;
pce->time_total = 0;
pce->time_least = 0;
pce->time_most = 0;
break;
}
case PC_INTERVAL: {
struct perf_ctr_interval *pci = (struct perf_ctr_interval *)handle;
pci->event_count = 0;
pci->time_event = 0;
pci->time_first = 0;
pci->time_last = 0;
pci->time_least = 0;
pci->time_most = 0;
break;
}
}
}
void
perf_print_counter(perf_counter_t handle)
{
if (handle == nullptr) {
return;
}
perf_print_counter_fd(1, handle);
}
void
perf_print_counter_fd(int fd, perf_counter_t handle)
{
if (handle == nullptr) {
return;
}
switch (handle->type) {
case PC_COUNT:
dprintf(fd, "%s: %llu events\n",
handle->name,
(unsigned long long)((struct perf_ctr_count *)handle)->event_count);
break;
case PC_ELAPSED: {
struct perf_ctr_elapsed *pce = (struct perf_ctr_elapsed *)handle;
float rms = sqrtf(pce->M2 / (pce->event_count - 1));
dprintf(fd, "%s: %llu events, %lluus elapsed, %.2fus avg, min %lluus max %lluus %5.3fus rms\n",
handle->name,
(unsigned long long)pce->event_count,
(unsigned long long)pce->time_total,
(pce->event_count == 0) ? 0 : (double)pce->time_total / (double)pce->event_count,
(unsigned long long)pce->time_least,
(unsigned long long)pce->time_most,
(double)(1e6f * rms));
break;
}
case PC_INTERVAL: {
struct perf_ctr_interval *pci = (struct perf_ctr_interval *)handle;
float rms = sqrtf(pci->M2 / (pci->event_count - 1));
dprintf(fd, "%s: %llu events, %.2fus avg, min %lluus max %lluus %5.3fus rms\n",
handle->name,
(unsigned long long)pci->event_count,
(pci->event_count == 0) ? 0 : (double)(pci->time_last - pci->time_first) / (double)pci->event_count,
(unsigned long long)pci->time_least,
(unsigned long long)pci->time_most,
(double)(1e6f * rms));
break;
}
default:
break;
}
}
int
perf_print_counter_buffer(char *buffer, int length, perf_counter_t handle)
{
int num_written = 0;
if (handle == nullptr) {
return 0;
}
switch (handle->type) {
case PC_COUNT:
num_written = snprintf(buffer, length, "%s: %llu events",
handle->name,
(unsigned long long)((struct perf_ctr_count *)handle)->event_count);
break;
case PC_ELAPSED: {
struct perf_ctr_elapsed *pce = (struct perf_ctr_elapsed *)handle;
float rms = sqrtf(pce->M2 / (pce->event_count - 1));
num_written = snprintf(buffer, length, "%s: %llu events, %lluus elapsed, %.2fus avg, min %lluus max %lluus %5.3fus rms",
handle->name,
(unsigned long long)pce->event_count,
(unsigned long long)pce->time_total,
(pce->event_count == 0) ? 0 : (double)pce->time_total / (double)pce->event_count,
(unsigned long long)pce->time_least,
(unsigned long long)pce->time_most,
(double)(1e6f * rms));
break;
}
case PC_INTERVAL: {
struct perf_ctr_interval *pci = (struct perf_ctr_interval *)handle;
float rms = sqrtf(pci->M2 / (pci->event_count - 1));
num_written = snprintf(buffer, length, "%s: %llu events, %.2f avg, min %lluus max %lluus %5.3fus rms",
handle->name,
(unsigned long long)pci->event_count,
(pci->event_count == 0) ? 0 : (double)(pci->time_last - pci->time_first) / (double)pci->event_count,
(unsigned long long)pci->time_least,
(unsigned long long)pci->time_most,
(double)(1e6f * rms));
break;
}
default:
break;
}
buffer[length - 1] = 0; // ensure 0-termination
return num_written;
}
uint64_t
perf_event_count(perf_counter_t handle)
{
if (handle == nullptr) {
return 0;
}
switch (handle->type) {
case PC_COUNT:
return ((struct perf_ctr_count *)handle)->event_count;
case PC_ELAPSED: {
struct perf_ctr_elapsed *pce = (struct perf_ctr_elapsed *)handle;
return pce->event_count;
}
case PC_INTERVAL: {
struct perf_ctr_interval *pci = (struct perf_ctr_interval *)handle;
return pci->event_count;
}
default:
break;
}
return 0;
}
void
perf_iterate_all(perf_callback cb, void *user)
{
pthread_mutex_lock(&perf_counters_mutex);
perf_counter_t handle = (perf_counter_t)sq_peek(&perf_counters);
while (handle != nullptr) {
cb(handle, user);
handle = (perf_counter_t)sq_next(&handle->link);
}
pthread_mutex_unlock(&perf_counters_mutex);
}
void
perf_print_all(int fd)
{
pthread_mutex_lock(&perf_counters_mutex);
perf_counter_t handle = (perf_counter_t)sq_peek(&perf_counters);
while (handle != nullptr) {
perf_print_counter_fd(fd, handle);
handle = (perf_counter_t)sq_next(&handle->link);
}
pthread_mutex_unlock(&perf_counters_mutex);
}
void
perf_print_latency(int fd)
{
dprintf(fd, "bucket [us] : events\n");
for (int i = 0; i < latency_bucket_count; i++) {
dprintf(fd, " %4i : %li\n", latency_buckets[i], (long int)latency_counters[i]);
}
// print the overflow bucket value
dprintf(fd, " >%4i : %i\n", latency_buckets[latency_bucket_count - 1], latency_counters[latency_bucket_count]);
}
void
perf_reset_all(void)
{
pthread_mutex_lock(&perf_counters_mutex);
perf_counter_t handle = (perf_counter_t)sq_peek(&perf_counters);
while (handle != nullptr) {
perf_reset(handle);
handle = (perf_counter_t)sq_next(&handle->link);
}
pthread_mutex_unlock(&perf_counters_mutex);
for (int i = 0; i <= latency_bucket_count; i++) {
latency_counters[i] = 0;
}
}