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|
/*
* schbench.c
*
* Copyright (C) 2016 Facebook
* Chris Mason <clm@fb.com>
*
* GPLv2, portions copied from the kernel and from Jens Axboe's fio
*
* gcc -Wall -O0 -W schbench.c -o schbench -lpthread
*/
#include <stdio.h>
#include <stdlib.h>
#include <pthread.h>
#include <fcntl.h>
#include <unistd.h>
#include <errno.h>
#include <getopt.h>
#include <sys/time.h>
#include <time.h>
#include <string.h>
#include <math.h>
#include <linux/futex.h>
#include <sys/syscall.h>
#include <sys/sysinfo.h>
#define PLAT_BITS 8
#define PLAT_VAL (1 << PLAT_BITS)
#define PLAT_GROUP_NR 19
#define PLAT_NR (PLAT_GROUP_NR * PLAT_VAL)
#define PLAT_LIST_MAX 20
/* when -p is on, how much do we send back and forth */
#define PIPE_TRANSFER_BUFFER (1 * 1024 * 1024)
#define USEC_PER_SEC (1000000)
/* -m number of message threads */
static int message_threads = 1;
/* -t number of workers per message thread */
static int worker_threads = 0;
/* -r seconds */
static int runtime = 30;
/* -w seconds */
static int warmuptime = 0;
/* -i seconds */
static int intervaltime = 10;
/* -z seconds */
static int zerotime = 0;
/* -f cache_footprint_kb */
static unsigned long cache_footprint_kb = 256;
/* -n operations */
static unsigned long operations = 5;
/* -A, int percentage busy */
static int auto_rps = 0;
static int auto_rps_target_hit = 0;
/* -p bytes */
static int pipe_test = 0;
/* -R requests per sec */
static int requests_per_sec = 0;
/* -C bool for calibration mode */
static int calibrate_only = 0;
/* -L bool no locking during CPU work */
static int skip_locking = 0;
/* the message threads flip this to true when they decide runtime is up */
static volatile unsigned long stopping = 0;
/* size of matrices to multiply */
static unsigned long matrix_size = 0;
struct per_cpu_lock {
pthread_mutex_t lock;
} __attribute__((aligned));
static struct per_cpu_lock *per_cpu_locks;
static int num_cpu_locks;
/*
* one stat struct per thread data, when the workers sleep this records the
* latency between when they are woken up and when they actually get the
* CPU again. The message threads sum up the stats of all the workers and
* then bubble them up to main() for printing
*/
struct stats {
unsigned int plat[PLAT_NR];
unsigned long nr_samples;
unsigned int max;
unsigned int min;
};
struct stats rps_stats;
/* this defines which latency profiles get printed */
#define PLIST_20 (1 << 0)
#define PLIST_50 (1 << 1)
#define PLIST_90 (1 << 2)
#define PLIST_99 (1 << 3)
#define PLIST_99_INDEX 3
#define PLIST_999 (1 << 4)
#define PLIST_FOR_LAT (PLIST_50 | PLIST_90 | PLIST_99 | PLIST_999)
#define PLIST_FOR_RPS (PLIST_20 | PLIST_50 | PLIST_90)
static double plist[PLAT_LIST_MAX] = { 20.0, 50.0, 90.0, 99.0, 99.9 };
enum {
HELP_LONG_OPT = 1,
};
char *option_string = "p:m:t:Cr:R:w:i:z:A:n:F:L";
static struct option long_options[] = {
{"pipe", required_argument, 0, 'p'},
{"message-threads", required_argument, 0, 'm'},
{"threads", required_argument, 0, 't'},
{"runtime", required_argument, 0, 'r'},
{"rps", required_argument, 0, 'R'},
{"auto-rps", required_argument, 0, 'A'},
{"cache_footprint", required_argument, 0, 'f'},
{"calibrate", no_argument, 0, 'C'},
{"no-locking", no_argument, 0, 'L'},
{"operations", required_argument, 0, 'n'},
{"warmuptime", required_argument, 0, 'w'},
{"intervaltime", required_argument, 0, 'i'},
{"zerotime", required_argument, 0, 'z'},
{"help", no_argument, 0, HELP_LONG_OPT},
{0, 0, 0, 0}
};
static void print_usage(void)
{
fprintf(stderr, "schbench usage:\n"
"\t-C (--calibrate): run our work loop and report on timing\n"
"\t-L (--no-locking): don't spinlock during CPU work (def: locking on)\n"
"\t-m (--message-threads): number of message threads (def: 1)\n"
"\t-t (--threads): worker threads per message thread (def: num_cpus)\n"
"\t-r (--runtime): How long to run before exiting (seconds, def: 30)\n"
"\t-F (--cache_footprint): cache footprint (kb, def: 256)\n"
"\t-n (--operations): think time operations to perform (def: 5)\n"
"\t-A (--auto-rps): grow RPS until cpu utilization hits target (def: none)\n"
"\t-p (--pipe): transfer size bytes to simulate a pipe test (def: 0)\n"
"\t-R (--rps): requests per second mode (count, def: 0)\n"
"\t-w (--warmuptime): how long to warmup before resetting stats (seconds, def: 0)\n"
"\t-i (--intervaltime): interval for printing latencies (seconds, def: 10)\n"
"\t-z (--zerotime): interval for zeroing latencies (seconds, def: never)\n"
);
exit(1);
}
static void parse_options(int ac, char **av)
{
int c;
int found_warmuptime = -1;
while (1) {
int option_index = 0;
c = getopt_long(ac, av, option_string,
long_options, &option_index);
if (c == -1)
break;
switch(c) {
case 'C':
calibrate_only = 1;
break;
case 'L':
skip_locking = 1;
break;
case 'A':
auto_rps = atoi(optarg);
warmuptime = 0;
if (requests_per_sec == 0)
requests_per_sec = 10;
break;
case 'p':
pipe_test = atoi(optarg);
if (pipe_test > PIPE_TRANSFER_BUFFER) {
fprintf(stderr, "pipe size too big, using %d\n",
PIPE_TRANSFER_BUFFER);
pipe_test = PIPE_TRANSFER_BUFFER;
}
warmuptime = 0;
break;
case 'w':
found_warmuptime = atoi(optarg);
break;
case 'm':
message_threads = atoi(optarg);
break;
case 't':
worker_threads = atoi(optarg);
break;
case 'r':
runtime = atoi(optarg);
break;
case 'i':
intervaltime = atoi(optarg);
break;
case 'z':
zerotime = atoi(optarg);
break;
case 'R':
requests_per_sec = atoi(optarg);
break;
case 'n':
operations = atoi(optarg);
break;
case 'F':
cache_footprint_kb = atoi(optarg);
break;
case '?':
case HELP_LONG_OPT:
print_usage();
break;
default:
break;
}
}
/*
* by default pipe mode zeros out some options. This
* sets them to any args that were actually passed in
*/
if (found_warmuptime >= 0)
warmuptime = found_warmuptime;
if (calibrate_only)
skip_locking = 1;
if (runtime < 30)
warmuptime = 0;
if (optind < ac) {
fprintf(stderr, "Error Extra arguments '%s'\n", av[optind]);
exit(1);
}
}
void tvsub(struct timeval * tdiff, struct timeval * t1, struct timeval * t0)
{
tdiff->tv_sec = t1->tv_sec - t0->tv_sec;
tdiff->tv_usec = t1->tv_usec - t0->tv_usec;
if (tdiff->tv_usec < 0 && tdiff->tv_sec > 0) {
tdiff->tv_sec--;
tdiff->tv_usec += USEC_PER_SEC;
if (tdiff->tv_usec < 0) {
fprintf(stderr, "lat_fs: tvsub shows test time ran backwards!\n");
exit(1);
}
}
/* time shouldn't go backwards!!! */
if (tdiff->tv_usec < 0 || t1->tv_sec < t0->tv_sec) {
tdiff->tv_sec = 0;
tdiff->tv_usec = 0;
}
}
/*
* returns the difference between start and stop in usecs. Negative values
* are turned into 0
*/
unsigned long long tvdelta(struct timeval *start, struct timeval *stop)
{
struct timeval td;
unsigned long long usecs;
tvsub(&td, stop, start);
usecs = td.tv_sec;
usecs *= USEC_PER_SEC;
usecs += td.tv_usec;
return (usecs);
}
/* mr axboe's magic latency histogram */
static unsigned int plat_val_to_idx(unsigned int val)
{
unsigned int msb, error_bits, base, offset;
/* Find MSB starting from bit 0 */
if (val == 0)
msb = 0;
else
msb = sizeof(val)*8 - __builtin_clz(val) - 1;
/*
* MSB <= (PLAT_BITS-1), cannot be rounded off. Use
* all bits of the sample as index
*/
if (msb <= PLAT_BITS)
return val;
/* Compute the number of error bits to discard*/
error_bits = msb - PLAT_BITS;
/* Compute the number of buckets before the group */
base = (error_bits + 1) << PLAT_BITS;
/*
* Discard the error bits and apply the mask to find the
* index for the buckets in the group
*/
offset = (PLAT_VAL - 1) & (val >> error_bits);
/* Make sure the index does not exceed (array size - 1) */
return (base + offset) < (PLAT_NR - 1) ?
(base + offset) : (PLAT_NR - 1);
}
/*
* Convert the given index of the bucket array to the value
* represented by the bucket
*/
static unsigned int plat_idx_to_val(unsigned int idx)
{
unsigned int error_bits, k, base;
if (idx >= PLAT_NR) {
fprintf(stderr, "idx %u is too large\n", idx);
exit(1);
}
/* MSB <= (PLAT_BITS-1), cannot be rounded off. Use
* all bits of the sample as index */
if (idx < (PLAT_VAL << 1))
return idx;
/* Find the group and compute the minimum value of that group */
error_bits = (idx >> PLAT_BITS) - 1;
base = 1 << (error_bits + PLAT_BITS);
/* Find its bucket number of the group */
k = idx % PLAT_VAL;
/* Return the mean of the range of the bucket */
return base + ((k + 0.5) * (1 << error_bits));
}
static unsigned int calc_percentiles(unsigned int *io_u_plat, unsigned long nr,
unsigned int **output,
unsigned long **output_counts)
{
unsigned long sum = 0;
unsigned int len, i, j = 0;
unsigned int oval_len = 0;
unsigned int *ovals = NULL;
unsigned long *ocounts = NULL;
unsigned long last = 0;
int is_last;
len = 0;
while (len < PLAT_LIST_MAX && plist[len] != 0.0)
len++;
if (!len)
return 0;
/*
* Calculate bucket values, note down max and min values
*/
is_last = 0;
for (i = 0; i < PLAT_NR && !is_last; i++) {
sum += io_u_plat[i];
while (sum >= (plist[j] / 100.0 * nr)) {
if (j == oval_len) {
oval_len += 100;
ovals = realloc(ovals, oval_len * sizeof(unsigned int));
ocounts = realloc(ocounts, oval_len * sizeof(unsigned long));
}
ovals[j] = plat_idx_to_val(i);
ocounts[j] = sum;
is_last = (j == len - 1);
if (is_last)
break;
j++;
}
}
for (i = 1; i < len; i++) {
last += ocounts[i - 1];
ocounts[i] -= last;
}
*output = ovals;
*output_counts = ocounts;
return len;
}
static void show_latencies(struct stats *s, char *label, char *units,
unsigned long long runtime, unsigned long mask,
unsigned long star)
{
unsigned int *ovals = NULL;
unsigned long *ocounts = NULL;
unsigned int len, i;
len = calc_percentiles(s->plat, s->nr_samples, &ovals, &ocounts);
if (len) {
fprintf(stderr, "%s percentiles (%s) runtime %llu (s) (%lu total samples)\n",
label, units, runtime, s->nr_samples);
for (i = 0; i < len; i++) {
unsigned long bit = 1 << i;
if (!(mask & bit))
continue;
fprintf(stderr, "\t%s%2.1fth: %-10u (%lu samples)\n",
bit == star ? "* " : " ",
plist[i], ovals[i], ocounts[i]);
}
}
if (ovals)
free(ovals);
if (ocounts)
free(ocounts);
fprintf(stderr, "\t min=%u, max=%u\n", s->min, s->max);
}
/* fold latency info from s into d */
void combine_stats(struct stats *d, struct stats *s)
{
int i;
for (i = 0; i < PLAT_NR; i++)
d->plat[i] += s->plat[i];
d->nr_samples += s->nr_samples;
if (s->max > d->max)
d->max = s->max;
if (d->min == 0 || s->min < d->min)
d->min = s->min;
}
/* record a latency result into the histogram */
static void add_lat(struct stats *s, unsigned int us)
{
int lat_index = 0;
if (us > s->max)
s->max = us;
if (s->min == 0 || us < s->min)
s->min = us;
lat_index = plat_val_to_idx(us);
__sync_fetch_and_add(&s->plat[lat_index], 1);
__sync_fetch_and_add(&s->nr_samples, 1);
}
struct request {
struct timeval start_time;
struct request *next;
};
/*
* every thread has one of these, it comes out to about 19K thanks to the
* giant stats struct
*/
struct thread_data {
pthread_t tid;
/* ->next is for placing us on the msg_thread's list for waking */
struct thread_data *next;
/* ->request is all of our pending request */
struct request *request;
/* our parent thread and messaging partner */
struct thread_data *msg_thread;
/*
* the msg thread stuffs gtod in here before waking us, so we can
* measure scheduler latency
*/
struct timeval wake_time;
/* keep the futex and the wake_time in the same cacheline */
int futex;
/* mr axboe's magic latency histogram */
struct stats wakeup_stats;
struct stats request_stats;
unsigned long long loop_count;
unsigned long long runtime;
unsigned long pending;
char pipe_page[PIPE_TRANSFER_BUFFER];
/* matrices to multiply */
unsigned long *data;
};
/* we're so fancy we make our own futex wrappers */
#define FUTEX_BLOCKED 0
#define FUTEX_RUNNING 1
static int futex(int *uaddr, int futex_op, int val,
const struct timespec *timeout, int *uaddr2, int val3)
{
return syscall(SYS_futex, uaddr, futex_op, val, timeout, uaddr2, val3);
}
/*
* wakeup a process waiting on a futex, making sure they are really waiting
* first
*/
static void fpost(int *futexp)
{
int s;
if (__sync_bool_compare_and_swap(futexp, FUTEX_BLOCKED,
FUTEX_RUNNING)) {
s = futex(futexp, FUTEX_WAKE_PRIVATE, 1, NULL, NULL, 0);
if (s == -1) {
perror("FUTEX_WAKE");
exit(1);
}
}
}
/*
* wait on a futex, with an optional timeout. Make sure to set
* the futex to FUTEX_BLOCKED beforehand.
*
* This will return zero if all went well, or return -ETIMEDOUT if you
* hit the timeout without getting posted
*/
static int fwait(int *futexp, struct timespec *timeout)
{
int s;
while (1) {
/* Is the futex available? */
if (__sync_bool_compare_and_swap(futexp, FUTEX_RUNNING,
FUTEX_BLOCKED)) {
break; /* Yes */
}
/* Futex is not available; wait */
s = futex(futexp, FUTEX_WAIT_PRIVATE, FUTEX_BLOCKED, timeout, NULL, 0);
if (s == -1 && errno != EAGAIN) {
if (errno == ETIMEDOUT)
return -ETIMEDOUT;
perror("futex-FUTEX_WAIT");
exit(1);
}
}
return 0;
}
/*
* cmpxchg based list prepend
*/
static void xlist_add(struct thread_data *head, struct thread_data *add)
{
struct thread_data *old;
struct thread_data *ret;
while (1) {
old = head->next;
add->next = old;
ret = __sync_val_compare_and_swap(&head->next, old, add);
if (ret == old)
break;
}
}
/*
* xchg based list splicing. This returns the entire list and
* replaces the head->next with NULL
*/
static struct thread_data *xlist_splice(struct thread_data *head)
{
struct thread_data *old;
struct thread_data *ret;
while (1) {
old = head->next;
ret = __sync_val_compare_and_swap(&head->next, old, NULL);
if (ret == old)
break;
}
return ret;
}
/*
* cmpxchg based list prepend
*/
static struct request *request_add(struct thread_data *head, struct request *add)
{
struct request *old;
struct request *ret;
while (1) {
old = head->request;
add->next = old;
ret = __sync_val_compare_and_swap(&head->request, old, add);
if (ret == old)
return old;
}
}
/*
* xchg based list splicing. This returns the entire list and
* replaces the head->request with NULL. The list is reversed before
* returning
*/
static struct request *request_splice(struct thread_data *head)
{
struct request *old;
struct request *ret;
struct request *reverse = NULL;
while (1) {
old = head->request;
ret = __sync_val_compare_and_swap(&head->request, old, NULL);
if (ret == old)
break;
}
while(ret) {
struct request *tmp = ret;
ret = ret->next;
tmp->next = reverse;
reverse = tmp;
}
return reverse;
}
static struct request *allocate_request(void)
{
struct request *ret = malloc(sizeof(*ret));
if (!ret) {
perror("malloc");
exit(1);
}
gettimeofday(&ret->start_time, NULL);
ret->next = NULL;
return ret;
}
/*
* Wake everyone currently waiting on the message list, filling in their
* thread_data->wake_time with the current time.
*
* It's not exactly the current time, it's really the time at the start of
* the list run. We want to detect when the scheduler is just preempting the
* waker and giving away the rest of its timeslice. So we gtod once at
* the start of the loop and use that for all the threads we wake.
*
* Since pipe mode ends up measuring this other ways, we do the gtod
* every time in pipe mode
*/
static void xlist_wake_all(struct thread_data *td)
{
struct thread_data *list;
struct thread_data *next;
struct timeval now;
list = xlist_splice(td);
gettimeofday(&now, NULL);
while (list) {
next = list->next;
list->next = NULL;
if (pipe_test) {
memset(list->pipe_page, 1, pipe_test);
gettimeofday(&list->wake_time, NULL);
} else {
memcpy(&list->wake_time, &now, sizeof(now));
}
fpost(&list->futex);
list = next;
}
}
/*
* called by worker threads to send a message and wait for the answer.
* In reality we're just trading one cacheline with the gtod and futex in
* it, but that's good enough. We gtod after waking and use that to
* record scheduler latency.
*/
static struct request *msg_and_wait(struct thread_data *td)
{
struct request *req;
struct timeval now;
unsigned long long delta;
if (pipe_test)
memset(td->pipe_page, 2, pipe_test);
/* set ourselves to blocked */
td->futex = FUTEX_BLOCKED;
gettimeofday(&td->wake_time, NULL);
/* add us to the list */
if (requests_per_sec) {
td->pending = 0;
req = request_splice(td);
if (req) {
td->futex = FUTEX_RUNNING;
return req;
}
} else {
xlist_add(td->msg_thread, td);
}
fpost(&td->msg_thread->futex);
/*
* don't wait if the main threads are shutting down,
* they will never kick us fpost has a full barrier, so as long
* as the message thread walks his list after setting stopping,
* we shouldn't miss the wakeup
*/
if (!stopping) {
/* if he hasn't already woken us up, wait */
fwait(&td->futex, NULL);
}
gettimeofday(&now, NULL);
delta = tvdelta(&td->wake_time, &now);
if (delta > 0)
add_lat(&td->wakeup_stats, delta);
return NULL;
}
/*
* read /proc/stat, return the percentage of non-idle time since
* the last read.
*/
float read_busy(int fd, char *buf, int len,
unsigned long long *total_time_ret,
unsigned long long *idle_time_ret)
{
unsigned long long total_time = 0;
unsigned long long idle_time = 0;
unsigned long long delta;
unsigned long long delta_idle;
unsigned long long val;
int col = 1;
int ret;
char *c;
char *save = NULL;
ret = lseek(fd, 0, SEEK_SET);
if (ret < 0) {
perror("lseek");
exit(1);
}
ret = read(fd, buf, len-1);
if (ret < 0) {
perror("failed to read /proc/stat");
exit(1);
}
buf[ret] = '\0';
/* find the newline */
c = strchr(buf, '\n');
if (c == NULL) {
perror("unable to parse /proc/stat");
exit(1);
}
*c = '\0';
/* cpu 590315893 45841886 375984879 82585100131 166708940 0 5453892 0 0 0 */
c = strtok_r(buf, " ", &save);
if (strcmp(c, "cpu") != 0) {
perror("unable to parse summary in /proc/stat");
exit(1);
}
while (c != NULL) {
c = strtok_r(NULL, " ", &save);
if (!c)
break;
val = atoll(c);
if (col++ == 4)
idle_time = val;
total_time += val;
}
if (*total_time_ret == 0) {
*total_time_ret = total_time;
*idle_time_ret = idle_time;
return 0.0;
}
/* delta is the total time spent doing everything */
delta = total_time - *total_time_ret;
delta_idle = idle_time - *idle_time_ret;
*total_time_ret = total_time;
*idle_time_ret = idle_time;
return 100.00 - ((float)delta_idle/(float)delta) * 100.00;
}
#if defined(__x86_64__) || defined(__i386__)
#define nop __asm__ __volatile__("rep;nop": : :"memory")
#elif defined(__aarch64__)
#define nop __asm__ __volatile__("yield" ::: "memory")
#elif defined(__powerpc64__)
#define nop __asm__ __volatile__("nop": : :"memory")
#else
#error Unsupported architecture
#endif
/*
* once the message thread starts all his children, this is where he
* loops until our runtime is up. Basically this sits around waiting
* for posting by the worker threads, and replying to their messages.
*/
static void run_msg_thread(struct thread_data *td)
{
while (1) {
td->futex = FUTEX_BLOCKED;
xlist_wake_all(td);
if (stopping) {
xlist_wake_all(td);
break;
}
fwait(&td->futex, NULL);
}
}
void auto_scale_rps(int *proc_stat_fd,
unsigned long long *total_time,
unsigned long long *total_idle)
{
int fd = *proc_stat_fd;
float busy = 0;
char proc_stat_buf[512];
int first_run = 0;
float delta;
float target = 1;
if (fd == -1) {
fd = open("/proc/stat", O_RDONLY);
if (fd < 0) {
perror("unable to open /proc/stat");
exit(1);
}
*proc_stat_fd = fd;
first_run = 1;
}
busy = read_busy(fd, proc_stat_buf, 512, total_time, total_idle);
if (first_run)
return;
if (busy < auto_rps) {
delta = (float)auto_rps / busy;
/* delta is > 1 */
if (delta > 3) {
delta = 3;
} else if (delta < 1.2) {
delta = 1 + (delta - 1) / 8;
if (delta < 1.05 && !auto_rps_target_hit) {
auto_rps_target_hit = 1;
memset(&rps_stats, 0, sizeof(rps_stats));
}
} else if (delta < 1.5) {
delta = 1 + (delta - 1) / 4;
}
target = ceilf((float)requests_per_sec * delta);
if (target >= (1ULL << 31)) {
/*
* sometimes we don't have enough threads to hit the
* target load
*/
target = requests_per_sec;
}
} else if (busy > auto_rps) {
/* delta < 1 */
delta = (float)auto_rps / busy;
if (delta < 0.3) {
delta = 0.3;
} else if (delta > .9) {
delta += (1 - delta) / 8;
if (delta > .95 && !auto_rps_target_hit) {
auto_rps_target_hit = 1;
memset(&rps_stats, 0, sizeof(rps_stats));
}
} else if (delta > .8) {
delta += (1 - delta) / 4;
}
target = floorf((float)requests_per_sec * delta);
if (target <= 0)
target = 0;
} else {
target = requests_per_sec;
if (!auto_rps_target_hit) {
auto_rps_target_hit = 1;
memset(&rps_stats, 0, sizeof(rps_stats));
}
}
requests_per_sec = target;
}
/*
* once the message thread starts all his children, this is where he
* loops until our runtime is up. Basically this sits around waiting
* for posting by the worker threads, replying to their messages.
*/
static void run_rps_thread(struct thread_data *worker_threads_mem)
{
/* start and end of the thread run */
struct timeval start;
struct timeval now;
struct request *request;
unsigned long long delta;
/* how long do we sleep between each wake */
unsigned long sleep_time;
int batch = 8;
int cur_tid = 0;
int i;
while (1) {
gettimeofday(&start, NULL);
sleep_time = (USEC_PER_SEC / requests_per_sec) * batch;
for (i = 1; i < requests_per_sec + 1; i++) {
struct thread_data *worker;
gettimeofday(&now, NULL);
worker = worker_threads_mem + cur_tid % worker_threads;
cur_tid++;
/* at some point, there's just too much, don't queue more */
if (worker->pending > 8) {
continue;
}
worker->pending++;
request = allocate_request();
request_add(worker, request);
memcpy(&worker->wake_time, &now, sizeof(now));
fpost(&worker->futex);
if ((i % batch) == 0)
usleep(sleep_time);
}
gettimeofday(&now, NULL);
delta = tvdelta(&start, &now);
while (delta < USEC_PER_SEC) {
delta = USEC_PER_SEC - delta;
usleep(delta);
gettimeofday(&now, NULL);
delta = tvdelta(&start, &now);
}
if (stopping) {
for (i = 0; i < worker_threads; i++)
fpost(&worker_threads_mem[i].futex);
break;
}
}
if (auto_rps)
fprintf(stderr, "final rps goal was %d\n", requests_per_sec);
}
/*
* multiply two matrices in a naive way to emulate some cache footprint
*/
static void do_some_math(struct thread_data *thread_data)
{
unsigned long i, j, k;
unsigned long *m1, *m2, *m3;
m1 = &thread_data->data[0];
m2 = &thread_data->data[matrix_size * matrix_size];
m3 = &thread_data->data[2 * matrix_size * matrix_size];
for (i = 0; i < matrix_size; i++) {
for (j = 0; j < matrix_size; j++) {
m3[i * matrix_size + j] = 0;
for (k = 0; k < matrix_size; k++)
m3[i * matrix_size + j] +=
m1[i * matrix_size + k] *
m2[k * matrix_size + j];
}
}
}
static pthread_mutex_t *lock_this_cpu(void)
{
int cpu;
int cur_cpu;
pthread_mutex_t *lock;
again:
cpu = sched_getcpu();
if (cpu < 0) {
perror("sched_getcpu failed\n");
exit(1);
}
lock = &per_cpu_locks[cpu].lock;
while (pthread_mutex_trylock(lock) != 0)
nop;
cur_cpu = sched_getcpu();
if (cur_cpu < 0) {
perror("sched_getcpu failed\n");
exit(1);
}
if (cur_cpu != cpu) {
/* we got the lock but we migrated */
pthread_mutex_unlock(lock);
goto again;
}
return lock;
}
/*
* spin or do some matrix arithmetic
*/
static void do_work(struct thread_data *td)
{
pthread_mutex_t *lock = NULL;
unsigned long i;
/* using --calibrate or --no-locking skips the locks */
if (!skip_locking)
lock = lock_this_cpu();
for (i = 0; i < operations; i++)
do_some_math(td);
if (!skip_locking)
pthread_mutex_unlock(lock);
}
/*
* the worker thread is pretty simple, it just does a single spin and
* then waits on a message from the message thread
*/
void *worker_thread(void *arg)
{
struct thread_data *td = arg;
struct timeval now;
struct timeval work_start;
struct timeval start;
unsigned long long delta;
struct request *req = NULL;
gettimeofday(&start, NULL);
while(1) {
if (stopping)
break;
req = msg_and_wait(td);
if (requests_per_sec && !req)
continue;
do {
struct request *tmp;
if (pipe_test) {
gettimeofday(&work_start, NULL);
} else {
if (calibrate_only) {
/*
* in calibration mode, don't include the
* usleep in the timing
*/
usleep(100);
gettimeofday(&work_start, NULL);
} else {
/*
* lets start off with some simulated networking,
* and also make sure we get a fresh clean timeslice
*/
gettimeofday(&work_start, NULL);
usleep(100);
}
do_work(td);
}
gettimeofday(&now, NULL);
td->runtime = tvdelta(&start, &now);
if (req) {
tmp = req->next;
free(req);
req = tmp;
}
td->loop_count++;
delta = tvdelta(&work_start, &now);
if (delta > 0)
add_lat(&td->request_stats, delta);
} while (req);
}
gettimeofday(&now, NULL);
td->runtime = tvdelta(&start, &now);
return NULL;
}
/*
* the message thread starts his own gaggle of workers and then sits around
* replying when they post him. He collects latency stats as all the threads
* exit
*/
void *message_thread(void *arg)
{
struct thread_data *td = arg;
struct thread_data *worker_threads_mem = NULL;
int i;
int ret;
worker_threads_mem = td + 1;
if (!worker_threads_mem) {
perror("unable to allocate ram");
pthread_exit((void *)-ENOMEM);
}
for (i = 0; i < worker_threads; i++) {
pthread_t tid;
worker_threads_mem[i].data = malloc(3 * sizeof(unsigned long) * matrix_size * matrix_size);
if (!worker_threads_mem[i].data) {
perror("unable to allocate ram");
pthread_exit((void *)-ENOMEM);
}
worker_threads_mem[i].msg_thread = td;
ret = pthread_create(&tid, NULL, worker_thread,
worker_threads_mem + i);
if (ret) {
fprintf(stderr, "error %d from pthread_create\n", ret);
exit(1);
}
worker_threads_mem[i].tid = tid;
}
if (requests_per_sec)
run_rps_thread(worker_threads_mem);
else
run_msg_thread(td);
for (i = 0; i < worker_threads; i++) {
fpost(&worker_threads_mem[i].futex);
pthread_join(worker_threads_mem[i].tid, NULL);
}
return NULL;
}
static char *units[] = { "B", "KB", "MB", "GB", "TB", "PB", "EB", NULL};
static double pretty_size(double number, char **str)
{
int divs = 0;
while(number >= 1024) {
if (units[divs + 1] == NULL)
break;
divs++;
number /= 1024;
}
*str = units[divs];
return number;
}
/*
* we want to calculate RPS more often than the full message stats,
* so this is a less expensive walk through all the message threads
* to pull that out
*/
static void combine_message_thread_rps(struct thread_data *thread_data,
unsigned long long *loop_count)
{
struct thread_data *worker;
int i;
int msg_i;
int index = 0;
*loop_count = 0;
for (msg_i = 0; msg_i < message_threads; msg_i++) {
index++;
for (i = 0; i < worker_threads; i++) {
worker = thread_data + index++;
*loop_count += worker->loop_count;
}
}
}
static void combine_message_thread_stats(struct stats *wakeup_stats,
struct stats *request_stats,
struct thread_data *thread_data,
unsigned long long *loop_count,
unsigned long long *loop_runtime)
{
struct thread_data *worker;
int i;
int msg_i;
int index = 0;
*loop_count = 0;
*loop_runtime = 0;
for (msg_i = 0; msg_i < message_threads; msg_i++) {
index++;
for (i = 0; i < worker_threads; i++) {
worker = thread_data + index++;
combine_stats(wakeup_stats, &worker->wakeup_stats);
combine_stats(request_stats, &worker->request_stats);
*loop_count += worker->loop_count;
*loop_runtime += worker->runtime;
}
}
}
static void reset_thread_stats(struct thread_data *thread_data)
{
struct thread_data *worker;
int i;
int msg_i;
int index = 0;
memset(&rps_stats, 0, sizeof(rps_stats));
for (msg_i = 0; msg_i < message_threads; msg_i++) {
index++;
for (i = 0; i < worker_threads; i++) {
worker = thread_data + index++;
memset(&worker->wakeup_stats, 0, sizeof(worker->wakeup_stats));
memset(&worker->request_stats, 0, sizeof(worker->request_stats));
}
}
}
/* runtime from the command line is in seconds. Sleep until its up */
static void sleep_for_runtime(struct thread_data *message_threads_mem)
{
struct timeval now;
struct timeval zero_time;
struct timeval last_calc;
struct timeval last_rps_calc;
struct timeval start;
struct stats wakeup_stats;
struct stats request_stats;
unsigned long long last_loop_count = 0;
unsigned long long loop_count;
unsigned long long loop_runtime;
unsigned long long delta;
unsigned long long runtime_delta;
unsigned long long runtime_usec = runtime * USEC_PER_SEC;
unsigned long long warmup_usec = warmuptime * USEC_PER_SEC;
unsigned long long interval_usec = intervaltime * USEC_PER_SEC;
unsigned long long zero_usec = zerotime * USEC_PER_SEC;
int warmup_done = 0;
int total_intervals = 0;
/* if we're autoscaling RPS */
int proc_stat_fd = -1;
unsigned long long total_time = 0;
unsigned long long total_idle = 0;
int done = 0;
memset(&wakeup_stats, 0, sizeof(wakeup_stats));
gettimeofday(&start, NULL);
last_calc = start;
last_rps_calc = start;
zero_time = start;
while(!done) {
gettimeofday(&now, NULL);
runtime_delta = tvdelta(&start, &now);
if (runtime_usec && runtime_delta >= runtime_usec)
done = 1;
if (!requests_per_sec && !pipe_test &&
runtime_delta > warmup_usec &&
!warmup_done && warmuptime) {
warmup_done = 1;
fprintf(stderr, "warmup done, zeroing stats\n");
zero_time = now;
reset_thread_stats(message_threads_mem);
} else if (!pipe_test) {
double rps;
/* count our RPS every round */
delta = tvdelta(&last_rps_calc, &now);
combine_message_thread_rps(message_threads_mem, &loop_count);
rps = (double)((loop_count - last_loop_count) * USEC_PER_SEC) / delta;
last_loop_count = loop_count;
last_rps_calc = now;
if (!auto_rps || auto_rps_target_hit)
add_lat(&rps_stats, rps);
delta = tvdelta(&last_calc, &now);
if (delta >= interval_usec) {
memset(&wakeup_stats, 0, sizeof(wakeup_stats));
memset(&request_stats, 0, sizeof(request_stats));
combine_message_thread_stats(&wakeup_stats,
&request_stats, message_threads_mem,
&loop_count, &loop_runtime);
last_calc = now;
show_latencies(&wakeup_stats, "Wakeup Latencies",
"usec", runtime_delta / USEC_PER_SEC,
PLIST_FOR_LAT, PLIST_99);
show_latencies(&request_stats, "Request Latencies",
"usec", runtime_delta / USEC_PER_SEC,
PLIST_FOR_LAT, PLIST_99);
show_latencies(&rps_stats, "RPS",
"requests", runtime_delta / USEC_PER_SEC,
PLIST_FOR_RPS, PLIST_50);
fprintf(stderr, "current rps: %.2f\n", rps);
total_intervals++;
}
}
if (zero_usec) {
unsigned long long zero_delta;
zero_delta = tvdelta(&zero_time, &now);
if (zero_delta > zero_usec) {
zero_time = now;
reset_thread_stats(message_threads_mem);
}
}
if (auto_rps)
auto_scale_rps(&proc_stat_fd, &total_time, &total_idle);
if (!done)
sleep(1);
}
if (proc_stat_fd >= 0)
close(proc_stat_fd);
__sync_synchronize();
stopping = 1;
}
int main(int ac, char **av)
{
int i;
int ret;
struct thread_data *message_threads_mem = NULL;
struct stats wakeup_stats;
struct stats request_stats;
double loops_per_sec;
unsigned long long loop_count;
unsigned long long loop_runtime;
parse_options(ac, av);
if (worker_threads == 0) {
worker_threads = get_nprocs();
fprintf(stderr, "setting worker threads to %d\n", worker_threads);
}
matrix_size = sqrt(cache_footprint_kb * 1024 / 3 / sizeof(unsigned long));
num_cpu_locks = get_nprocs();
per_cpu_locks = calloc(num_cpu_locks, sizeof(struct per_cpu_lock));
if (!per_cpu_locks) {
perror("unable to allocate memory for per cpu locks\n");
exit(1);
}
for (i = 0; i < num_cpu_locks; i++) {
pthread_mutex_t *lock = &per_cpu_locks[i].lock;
ret = pthread_mutex_init(lock, NULL);
if (ret) {
perror("mutex init failed\n");
exit(1);
}
}
requests_per_sec /= message_threads;
loops_per_sec = 0;
stopping = 0;
memset(&wakeup_stats, 0, sizeof(wakeup_stats));
memset(&request_stats, 0, sizeof(request_stats));
memset(&rps_stats, 0, sizeof(rps_stats));
message_threads_mem = calloc(message_threads * worker_threads + message_threads,
sizeof(struct thread_data));
if (!message_threads_mem) {
perror("unable to allocate message threads");
exit(1);
}
/* start our message threads, each one starts its own workers */
for (i = 0; i < message_threads; i++) {
pthread_t tid;
int index = i * worker_threads + i;
ret = pthread_create(&tid, NULL, message_thread,
message_threads_mem + index);
if (ret) {
fprintf(stderr, "error %d from pthread_create\n", ret);
exit(1);
}
message_threads_mem[index].tid = tid;
}
sleep_for_runtime(message_threads_mem);
for (i = 0; i < message_threads; i++) {
int index = i * worker_threads + i;
fpost(&message_threads_mem[index].futex);
pthread_join(message_threads_mem[index].tid, NULL);
}
memset(&wakeup_stats, 0, sizeof(wakeup_stats));
memset(&request_stats, 0, sizeof(request_stats));
combine_message_thread_stats(&wakeup_stats, &request_stats,
message_threads_mem,
&loop_count, &loop_runtime);
loops_per_sec = loop_count * USEC_PER_SEC;
loops_per_sec /= loop_runtime;
free(message_threads_mem);
if (pipe_test) {
char *pretty;
double mb_per_sec;
show_latencies(&wakeup_stats, "Wakeup Latencies", "usec", runtime,
PLIST_20 | PLIST_FOR_LAT, PLIST_99);
mb_per_sec = (loop_count * pipe_test * USEC_PER_SEC) / loop_runtime;
mb_per_sec = pretty_size(mb_per_sec, &pretty);
fprintf(stderr, "avg worker transfer: %.2f ops/sec %.2f%s/s\n",
loops_per_sec, mb_per_sec, pretty);
} else {
show_latencies(&wakeup_stats, "Wakeup Latencies", "usec", runtime,
PLIST_FOR_LAT, PLIST_99);
show_latencies(&request_stats, "Request Latencies", "usec", runtime,
PLIST_FOR_LAT, PLIST_99);
show_latencies(&rps_stats, "RPS", "requests", runtime,
PLIST_FOR_RPS, PLIST_50);
if (!auto_rps)
fprintf(stderr, "average rps: %.2f\n",
(double)(loop_count) / runtime);
}
return 0;
}
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