185 lines · c
1/*2 *3 * syscall.c4 *5 * syscall: Benchmark for system call performance6 */7#include "../perf.h"8#include "../util/util.h"9#include <subcmd/parse-options.h>10#include "../builtin.h"11#include "bench.h"12 13#include <stdio.h>14#include <sys/time.h>15#include <sys/syscall.h>16#include <sys/types.h>17#include <sys/wait.h>18#include <unistd.h>19#include <stdlib.h>20 21#ifndef __NR_fork22#define __NR_fork -123#endif24 25#define LOOPS_DEFAULT 1000000026static int loops = LOOPS_DEFAULT;27 28static const struct option options[] = {29 OPT_INTEGER('l', "loop", &loops, "Specify number of loops"),30 OPT_END()31};32 33static const char * const bench_syscall_usage[] = {34 "perf bench syscall <options>",35 NULL36};37 38static void test_fork(void)39{40 pid_t pid = fork();41 42 if (pid < 0) {43 fprintf(stderr, "fork failed\n");44 exit(1);45 } else if (pid == 0) {46 exit(0);47 } else {48 if (waitpid(pid, NULL, 0) < 0) {49 fprintf(stderr, "waitpid failed\n");50 exit(1);51 }52 }53}54 55static void test_execve(void)56{57 const char *pathname = "/bin/true";58 char *const argv[] = { (char *)pathname, NULL };59 pid_t pid = fork();60 61 if (pid < 0) {62 fprintf(stderr, "fork failed\n");63 exit(1);64 } else if (pid == 0) {65 execve(pathname, argv, NULL);66 fprintf(stderr, "execve /bin/true failed\n");67 exit(1);68 } else {69 if (waitpid(pid, NULL, 0) < 0) {70 fprintf(stderr, "waitpid failed\n");71 exit(1);72 }73 }74}75 76static int bench_syscall_common(int argc, const char **argv, int syscall)77{78 struct timeval start, stop, diff;79 unsigned long long result_usec = 0;80 const char *name = NULL;81 int i;82 83 argc = parse_options(argc, argv, options, bench_syscall_usage, 0);84 85 gettimeofday(&start, NULL);86 87 for (i = 0; i < loops; i++) {88 switch (syscall) {89 case __NR_getppid:90 getppid();91 break;92 case __NR_getpgid:93 getpgid(0);94 break;95 case __NR_fork:96 test_fork();97 /* Only loop 10000 times to save time */98 if (i == 10000)99 loops = 10000;100 break;101 case __NR_execve:102 test_execve();103 /* Only loop 10000 times to save time */104 if (i == 10000)105 loops = 10000;106 break;107 default:108 break;109 }110 }111 112 gettimeofday(&stop, NULL);113 timersub(&stop, &start, &diff);114 115 switch (syscall) {116 case __NR_getppid:117 name = "getppid()";118 break;119 case __NR_getpgid:120 name = "getpgid()";121 break;122 case __NR_fork:123 name = "fork()";124 break;125 case __NR_execve:126 name = "execve()";127 break;128 default:129 break;130 }131 132 switch (bench_format) {133 case BENCH_FORMAT_DEFAULT:134 printf("# Executed %'d %s calls\n", loops, name);135 136 result_usec = diff.tv_sec * 1000000;137 result_usec += diff.tv_usec;138 139 printf(" %14s: %lu.%03lu [sec]\n\n", "Total time",140 (unsigned long) diff.tv_sec,141 (unsigned long) (diff.tv_usec/1000));142 143 printf(" %14lf usecs/op\n",144 (double)result_usec / (double)loops);145 printf(" %'14d ops/sec\n",146 (int)((double)loops /147 ((double)result_usec / (double)1000000)));148 break;149 150 case BENCH_FORMAT_SIMPLE:151 printf("%lu.%03lu\n",152 (unsigned long) diff.tv_sec,153 (unsigned long) (diff.tv_usec / 1000));154 break;155 156 default:157 /* reaching here is something disaster */158 fprintf(stderr, "Unknown format:%d\n", bench_format);159 exit(1);160 break;161 }162 163 return 0;164}165 166int bench_syscall_basic(int argc, const char **argv)167{168 return bench_syscall_common(argc, argv, __NR_getppid);169}170 171int bench_syscall_getpgid(int argc, const char **argv)172{173 return bench_syscall_common(argc, argv, __NR_getpgid);174}175 176int bench_syscall_fork(int argc, const char **argv)177{178 return bench_syscall_common(argc, argv, __NR_fork);179}180 181int bench_syscall_execve(int argc, const char **argv)182{183 return bench_syscall_common(argc, argv, __NR_execve);184}185