263 lines · c
1// SPDX-License-Identifier: GPL-2.02 3#include <subcmd/parse-options.h>4#include <linux/hw_breakpoint.h>5#include <linux/perf_event.h>6#include <linux/time64.h>7#include <sys/syscall.h>8#include <sys/ioctl.h>9#include <sys/time.h>10#include <pthread.h>11#include <stddef.h>12#include <stdlib.h>13#include <unistd.h>14#include <stdio.h>15#include <errno.h>16#include "bench.h"17#include "futex.h"18 19struct {20 unsigned int nbreakpoints;21 unsigned int nparallel;22 unsigned int nthreads;23} thread_params = {24 .nbreakpoints = 1,25 .nparallel = 1,26 .nthreads = 1,27};28 29static const struct option thread_options[] = {30 OPT_UINTEGER('b', "breakpoints", &thread_params.nbreakpoints,31 "Specify amount of breakpoints"),32 OPT_UINTEGER('p', "parallelism", &thread_params.nparallel, "Specify amount of parallelism"),33 OPT_UINTEGER('t', "threads", &thread_params.nthreads, "Specify amount of threads"),34 OPT_END()35};36 37static const char * const thread_usage[] = {38 "perf bench breakpoint thread <options>",39 NULL40};41 42struct breakpoint {43 int fd;44 char watched;45};46 47static int breakpoint_setup(void *addr)48{49 struct perf_event_attr attr = { .size = 0, };50 int fd;51 52 attr.type = PERF_TYPE_BREAKPOINT;53 attr.size = sizeof(attr);54 attr.inherit = 1;55 attr.exclude_kernel = 1;56 attr.exclude_hv = 1;57 attr.bp_addr = (unsigned long)addr;58 attr.bp_type = HW_BREAKPOINT_RW;59 attr.bp_len = HW_BREAKPOINT_LEN_1;60 fd = syscall(SYS_perf_event_open, &attr, 0, -1, -1, 0);61 62 if (fd < 0)63 fd = -errno;64 65 return fd;66}67 68static void *passive_thread(void *arg)69{70 unsigned int *done = (unsigned int *)arg;71 72 while (!__atomic_load_n(done, __ATOMIC_RELAXED))73 futex_wait(done, 0, NULL, 0);74 return NULL;75}76 77static void *active_thread(void *arg)78{79 unsigned int *done = (unsigned int *)arg;80 81 while (!__atomic_load_n(done, __ATOMIC_RELAXED));82 return NULL;83}84 85static void *breakpoint_thread(void *arg)86{87 unsigned int i, done;88 int *repeat = (int *)arg;89 pthread_t *threads;90 91 threads = calloc(thread_params.nthreads, sizeof(threads[0]));92 if (!threads)93 exit((perror("calloc"), EXIT_FAILURE));94 95 while (__atomic_fetch_sub(repeat, 1, __ATOMIC_RELAXED) > 0) {96 done = 0;97 for (i = 0; i < thread_params.nthreads; i++) {98 if (pthread_create(&threads[i], NULL, passive_thread, &done))99 exit((perror("pthread_create"), EXIT_FAILURE));100 }101 __atomic_store_n(&done, 1, __ATOMIC_RELAXED);102 futex_wake(&done, thread_params.nthreads, 0);103 for (i = 0; i < thread_params.nthreads; i++)104 pthread_join(threads[i], NULL);105 }106 free(threads);107 return NULL;108}109 110// The benchmark creates nbreakpoints inheritable breakpoints,111// then starts nparallel threads which create and join bench_repeat batches of nthreads threads.112int bench_breakpoint_thread(int argc, const char **argv)113{114 unsigned int i, result_usec;115 int repeat = bench_repeat;116 struct breakpoint *breakpoints;117 pthread_t *parallel;118 struct timeval start, stop, diff;119 120 if (parse_options(argc, argv, thread_options, thread_usage, 0)) {121 usage_with_options(thread_usage, thread_options);122 exit(EXIT_FAILURE);123 }124 breakpoints = calloc(thread_params.nbreakpoints, sizeof(breakpoints[0]));125 parallel = calloc(thread_params.nparallel, sizeof(parallel[0]));126 if (!breakpoints || !parallel)127 exit((perror("calloc"), EXIT_FAILURE));128 129 for (i = 0; i < thread_params.nbreakpoints; i++) {130 breakpoints[i].fd = breakpoint_setup(&breakpoints[i].watched);131 132 if (breakpoints[i].fd < 0) {133 if (breakpoints[i].fd == -ENODEV) {134 printf("Skipping perf bench breakpoint thread: No hardware support\n");135 return 0;136 }137 exit((perror("perf_event_open"), EXIT_FAILURE));138 }139 }140 gettimeofday(&start, NULL);141 for (i = 0; i < thread_params.nparallel; i++) {142 if (pthread_create(¶llel[i], NULL, breakpoint_thread, &repeat))143 exit((perror("pthread_create"), EXIT_FAILURE));144 }145 for (i = 0; i < thread_params.nparallel; i++)146 pthread_join(parallel[i], NULL);147 gettimeofday(&stop, NULL);148 timersub(&stop, &start, &diff);149 for (i = 0; i < thread_params.nbreakpoints; i++)150 close(breakpoints[i].fd);151 free(parallel);152 free(breakpoints);153 switch (bench_format) {154 case BENCH_FORMAT_DEFAULT:155 printf("# Created/joined %d threads with %d breakpoints and %d parallelism\n",156 bench_repeat, thread_params.nbreakpoints, thread_params.nparallel);157 printf(" %14s: %lu.%03lu [sec]\n\n", "Total time",158 (long)diff.tv_sec, (long)(diff.tv_usec / USEC_PER_MSEC));159 result_usec = diff.tv_sec * USEC_PER_SEC + diff.tv_usec;160 printf(" %14lf usecs/op\n",161 (double)result_usec / bench_repeat / thread_params.nthreads);162 printf(" %14lf usecs/op/cpu\n",163 (double)result_usec / bench_repeat /164 thread_params.nthreads * thread_params.nparallel);165 break;166 case BENCH_FORMAT_SIMPLE:167 printf("%lu.%03lu\n", (long)diff.tv_sec, (long)(diff.tv_usec / USEC_PER_MSEC));168 break;169 default:170 fprintf(stderr, "Unknown format: %d\n", bench_format);171 exit(EXIT_FAILURE);172 }173 return 0;174}175 176struct {177 unsigned int npassive;178 unsigned int nactive;179} enable_params = {180 .nactive = 0,181 .npassive = 0,182};183 184static const struct option enable_options[] = {185 OPT_UINTEGER('p', "passive", &enable_params.npassive, "Specify amount of passive threads"),186 OPT_UINTEGER('a', "active", &enable_params.nactive, "Specify amount of active threads"),187 OPT_END()188};189 190static const char * const enable_usage[] = {191 "perf bench breakpoint enable <options>",192 NULL193};194 195// The benchmark creates an inheritable breakpoint,196// then starts npassive threads that block and nactive threads that actively spin197// and then disables and enables the breakpoint bench_repeat times.198int bench_breakpoint_enable(int argc, const char **argv)199{200 unsigned int i, nthreads, result_usec, done = 0;201 char watched;202 int fd;203 pthread_t *threads;204 struct timeval start, stop, diff;205 206 if (parse_options(argc, argv, enable_options, enable_usage, 0)) {207 usage_with_options(enable_usage, enable_options);208 exit(EXIT_FAILURE);209 }210 fd = breakpoint_setup(&watched);211 212 if (fd < 0) {213 if (fd == -ENODEV) {214 printf("Skipping perf bench breakpoint enable: No hardware support\n");215 return 0;216 }217 exit((perror("perf_event_open"), EXIT_FAILURE));218 }219 nthreads = enable_params.npassive + enable_params.nactive;220 threads = calloc(nthreads, sizeof(threads[0]));221 if (!threads)222 exit((perror("calloc"), EXIT_FAILURE));223 224 for (i = 0; i < nthreads; i++) {225 if (pthread_create(&threads[i], NULL,226 i < enable_params.npassive ? passive_thread : active_thread, &done))227 exit((perror("pthread_create"), EXIT_FAILURE));228 }229 usleep(10000); // let the threads block230 gettimeofday(&start, NULL);231 for (i = 0; i < bench_repeat; i++) {232 if (ioctl(fd, PERF_EVENT_IOC_DISABLE, 0))233 exit((perror("ioctl(PERF_EVENT_IOC_DISABLE)"), EXIT_FAILURE));234 if (ioctl(fd, PERF_EVENT_IOC_ENABLE, 0))235 exit((perror("ioctl(PERF_EVENT_IOC_ENABLE)"), EXIT_FAILURE));236 }237 gettimeofday(&stop, NULL);238 timersub(&stop, &start, &diff);239 __atomic_store_n(&done, 1, __ATOMIC_RELAXED);240 futex_wake(&done, enable_params.npassive, 0);241 for (i = 0; i < nthreads; i++)242 pthread_join(threads[i], NULL);243 free(threads);244 close(fd);245 switch (bench_format) {246 case BENCH_FORMAT_DEFAULT:247 printf("# Enabled/disabled breakpoint %d time with %d passive and %d active threads\n",248 bench_repeat, enable_params.npassive, enable_params.nactive);249 printf(" %14s: %lu.%03lu [sec]\n\n", "Total time",250 (long)diff.tv_sec, (long)(diff.tv_usec / USEC_PER_MSEC));251 result_usec = diff.tv_sec * USEC_PER_SEC + diff.tv_usec;252 printf(" %14lf usecs/op\n", (double)result_usec / bench_repeat);253 break;254 case BENCH_FORMAT_SIMPLE:255 printf("%lu.%03lu\n", (long)diff.tv_sec, (long)(diff.tv_usec / USEC_PER_MSEC));256 break;257 default:258 fprintf(stderr, "Unknown format: %d\n", bench_format);259 exit(EXIT_FAILURE);260 }261 return 0;262}263