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// SPDX-License-Identifier: GPL-2.0
#include <subcmd/parse-options.h>
#include <linux/hw_breakpoint.h>
#include <linux/perf_event.h>
#include <linux/time64.h>
#include <sys/syscall.h>
#include <sys/ioctl.h>
#include <sys/time.h>
#include <pthread.h>
#include <stddef.h>
#include <stdlib.h>
#include <unistd.h>
#include <stdio.h>
#include <errno.h>
#include "bench.h"
#include "futex.h"
struct {
unsigned int nbreakpoints;
unsigned int nparallel;
unsigned int nthreads;
} thread_params = {
.nbreakpoints = 1,
.nparallel = 1,
.nthreads = 1,
};
static const struct option thread_options[] = {
OPT_UINTEGER('b', "breakpoints", &thread_params.nbreakpoints,
"Specify amount of breakpoints"),
OPT_UINTEGER('p', "parallelism", &thread_params.nparallel, "Specify amount of parallelism"),
OPT_UINTEGER('t', "threads", &thread_params.nthreads, "Specify amount of threads"),
OPT_END()
};
static const char * const thread_usage[] = {
"perf bench breakpoint thread <options>",
NULL
};
struct breakpoint {
int fd;
char watched;
};
static int breakpoint_setup(void *addr)
{
struct perf_event_attr attr = { .size = 0, };
attr.type = PERF_TYPE_BREAKPOINT;
attr.size = sizeof(attr);
attr.inherit = 1;
attr.exclude_kernel = 1;
attr.exclude_hv = 1;
attr.bp_addr = (unsigned long)addr;
attr.bp_type = HW_BREAKPOINT_RW;
attr.bp_len = HW_BREAKPOINT_LEN_1;
return syscall(SYS_perf_event_open, &attr, 0, -1, -1, 0);
}
static void *passive_thread(void *arg)
{
unsigned int *done = (unsigned int *)arg;
while (!__atomic_load_n(done, __ATOMIC_RELAXED))
futex_wait(done, 0, NULL, 0);
return NULL;
}
static void *active_thread(void *arg)
{
unsigned int *done = (unsigned int *)arg;
while (!__atomic_load_n(done, __ATOMIC_RELAXED));
return NULL;
}
static void *breakpoint_thread(void *arg)
{
unsigned int i, done;
int *repeat = (int *)arg;
pthread_t *threads;
threads = calloc(thread_params.nthreads, sizeof(threads[0]));
if (!threads)
exit((perror("calloc"), EXIT_FAILURE));
while (__atomic_fetch_sub(repeat, 1, __ATOMIC_RELAXED) > 0) {
done = 0;
for (i = 0; i < thread_params.nthreads; i++) {
if (pthread_create(&threads[i], NULL, passive_thread, &done))
exit((perror("pthread_create"), EXIT_FAILURE));
}
__atomic_store_n(&done, 1, __ATOMIC_RELAXED);
futex_wake(&done, thread_params.nthreads, 0);
for (i = 0; i < thread_params.nthreads; i++)
pthread_join(threads[i], NULL);
}
free(threads);
return NULL;
}
// The benchmark creates nbreakpoints inheritable breakpoints,
// then starts nparallel threads which create and join bench_repeat batches of nthreads threads.
int bench_breakpoint_thread(int argc, const char **argv)
{
unsigned int i, result_usec;
int repeat = bench_repeat;
struct breakpoint *breakpoints;
pthread_t *parallel;
struct timeval start, stop, diff;
if (parse_options(argc, argv, thread_options, thread_usage, 0)) {
usage_with_options(thread_usage, thread_options);
exit(EXIT_FAILURE);
}
breakpoints = calloc(thread_params.nbreakpoints, sizeof(breakpoints[0]));
parallel = calloc(thread_params.nparallel, sizeof(parallel[0]));
if (!breakpoints || !parallel)
exit((perror("calloc"), EXIT_FAILURE));
for (i = 0; i < thread_params.nbreakpoints; i++) {
breakpoints[i].fd = breakpoint_setup(&breakpoints[i].watched);
if (breakpoints[i].fd == -1)
exit((perror("perf_event_open"), EXIT_FAILURE));
}
gettimeofday(&start, NULL);
for (i = 0; i < thread_params.nparallel; i++) {
if (pthread_create(¶llel[i], NULL, breakpoint_thread, &repeat))
exit((perror("pthread_create"), EXIT_FAILURE));
}
for (i = 0; i < thread_params.nparallel; i++)
pthread_join(parallel[i], NULL);
gettimeofday(&stop, NULL);
timersub(&stop, &start, &diff);
for (i = 0; i < thread_params.nbreakpoints; i++)
close(breakpoints[i].fd);
free(parallel);
free(breakpoints);
switch (bench_format) {
case BENCH_FORMAT_DEFAULT:
printf("# Created/joined %d threads with %d breakpoints and %d parallelism\n",
bench_repeat, thread_params.nbreakpoints, thread_params.nparallel);
printf(" %14s: %lu.%03lu [sec]\n\n", "Total time",
(long)diff.tv_sec, (long)(diff.tv_usec / USEC_PER_MSEC));
result_usec = diff.tv_sec * USEC_PER_SEC + diff.tv_usec;
printf(" %14lf usecs/op\n",
(double)result_usec / bench_repeat / thread_params.nthreads);
printf(" %14lf usecs/op/cpu\n",
(double)result_usec / bench_repeat /
thread_params.nthreads * thread_params.nparallel);
break;
case BENCH_FORMAT_SIMPLE:
printf("%lu.%03lu\n", (long)diff.tv_sec, (long)(diff.tv_usec / USEC_PER_MSEC));
break;
default:
fprintf(stderr, "Unknown format: %d\n", bench_format);
exit(EXIT_FAILURE);
}
return 0;
}
struct {
unsigned int npassive;
unsigned int nactive;
} enable_params = {
.nactive = 0,
.npassive = 0,
};
static const struct option enable_options[] = {
OPT_UINTEGER('p', "passive", &enable_params.npassive, "Specify amount of passive threads"),
OPT_UINTEGER('a', "active", &enable_params.nactive, "Specify amount of active threads"),
OPT_END()
};
static const char * const enable_usage[] = {
"perf bench breakpoint enable <options>",
NULL
};
// The benchmark creates an inheritable breakpoint,
// then starts npassive threads that block and nactive threads that actively spin
// and then disables and enables the breakpoint bench_repeat times.
int bench_breakpoint_enable(int argc, const char **argv)
{
unsigned int i, nthreads, result_usec, done = 0;
char watched;
int fd;
pthread_t *threads;
struct timeval start, stop, diff;
if (parse_options(argc, argv, enable_options, enable_usage, 0)) {
usage_with_options(enable_usage, enable_options);
exit(EXIT_FAILURE);
}
fd = breakpoint_setup(&watched);
if (fd == -1)
exit((perror("perf_event_open"), EXIT_FAILURE));
nthreads = enable_params.npassive + enable_params.nactive;
threads = calloc(nthreads, sizeof(threads[0]));
if (!threads)
exit((perror("calloc"), EXIT_FAILURE));
for (i = 0; i < nthreads; i++) {
if (pthread_create(&threads[i], NULL,
i < enable_params.npassive ? passive_thread : active_thread, &done))
exit((perror("pthread_create"), EXIT_FAILURE));
}
usleep(10000); // let the threads block
gettimeofday(&start, NULL);
for (i = 0; i < bench_repeat; i++) {
if (ioctl(fd, PERF_EVENT_IOC_DISABLE, 0))
exit((perror("ioctl(PERF_EVENT_IOC_DISABLE)"), EXIT_FAILURE));
if (ioctl(fd, PERF_EVENT_IOC_ENABLE, 0))
exit((perror("ioctl(PERF_EVENT_IOC_ENABLE)"), EXIT_FAILURE));
}
gettimeofday(&stop, NULL);
timersub(&stop, &start, &diff);
__atomic_store_n(&done, 1, __ATOMIC_RELAXED);
futex_wake(&done, enable_params.npassive, 0);
for (i = 0; i < nthreads; i++)
pthread_join(threads[i], NULL);
free(threads);
close(fd);
switch (bench_format) {
case BENCH_FORMAT_DEFAULT:
printf("# Enabled/disabled breakpoint %d time with %d passive and %d active threads\n",
bench_repeat, enable_params.npassive, enable_params.nactive);
printf(" %14s: %lu.%03lu [sec]\n\n", "Total time",
(long)diff.tv_sec, (long)(diff.tv_usec / USEC_PER_MSEC));
result_usec = diff.tv_sec * USEC_PER_SEC + diff.tv_usec;
printf(" %14lf usecs/op\n", (double)result_usec / bench_repeat);
break;
case BENCH_FORMAT_SIMPLE:
printf("%lu.%03lu\n", (long)diff.tv_sec, (long)(diff.tv_usec / USEC_PER_MSEC));
break;
default:
fprintf(stderr, "Unknown format: %d\n", bench_format);
exit(EXIT_FAILURE);
}
return 0;
}
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