1 /* 2 ** Copyright 2010 The Android Open Source Project 3 ** 4 ** Licensed under the Apache License, Version 2.0 (the "License"); 5 ** you may not use this file except in compliance with the License. 6 ** You may obtain a copy of the License at 7 ** 8 ** http://www.apache.org/licenses/LICENSE-2.0 9 ** 10 ** Unless required by applicable law or agreed to in writing, software 11 ** distributed under the License is distributed on an "AS IS" BASIS, 12 ** WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 13 ** See the License for the specific language governing permissions and 14 ** limitations under the License. 15 */ 16 17 18 /* Opens /proc/sched_stat and diff's the counters. 19 Currently support version 15, modify parse() to support other 20 versions 21 */ 22 23 #include <stdlib.h> 24 #include <stdio.h> 25 #include <errno.h> 26 #include <sys/uio.h> 27 #include <unistd.h> 28 #include <sys/time.h> 29 #include <fcntl.h> 30 31 #define MAX_CPU 2 32 33 struct cpu_stat { 34 /* sched_yield() stats */ 35 unsigned int yld_count; /* sched_yield() called */ 36 37 /* schedule() stats */ 38 unsigned int sched_switch; /* switched to expired queue and reused it */ 39 unsigned int sched_count; /* schedule() called */ 40 unsigned int sched_goidle; /* schedule() left the cpu idle */ 41 42 /* try_to_wake_up() stats */ 43 unsigned int ttwu_count; /* try_to_wake_up() called */ 44 /* try_to_wake_up() called and found the process being awakened last ran on 45 * the waking cpu */ 46 unsigned int ttwu_local; 47 48 /* latency stats */ 49 unsigned long long cpu_time; /* time spent running by tasks (ms) */ 50 unsigned long long run_delay; /* time spent waiting to run by tasks (ms) */ 51 unsigned long pcount; /* number of tasks (not necessarily unique) given */ 52 }; 53 54 struct cpu_stat cpu_prev[MAX_CPU]; 55 struct cpu_stat cpu_delta[MAX_CPU]; 56 struct cpu_stat tmp; 57 58 static const char *next_line(const char *b) { 59 while (1) { 60 switch (*b) { 61 case '\n': 62 return b + 1; 63 case '\0': 64 return NULL; 65 } 66 b++; 67 } 68 } 69 static int print() { 70 int i; 71 72 printf("CPU yield() schedule() switch idle ttwu() local cpu_time wait_time timeslices\n"); 73 for (i=0; i<MAX_CPU; i++) { 74 printf(" %2d %7u %10u %6u %4u %8u %5u %9llu %9llu %10lu\n", 75 i, 76 cpu_delta[i].yld_count, 77 cpu_delta[i].sched_count, cpu_delta[i].sched_switch, cpu_delta[i].sched_goidle, 78 cpu_delta[i].ttwu_count, cpu_delta[i].ttwu_local, 79 cpu_delta[i].cpu_time / 1000000, cpu_delta[i].run_delay / 1000000, cpu_delta[i].pcount); 80 } 81 return 0; 82 } 83 84 static int parse_cpu_v15(const char *b) { 85 int cpu; 86 87 if (sscanf(b, "cpu%d %u %u %u %u %u %u %llu %llu %lu\n", 88 &cpu, &tmp.yld_count, 89 &tmp.sched_switch, &tmp.sched_count, &tmp.sched_goidle, 90 &tmp.ttwu_count, &tmp.ttwu_local, 91 &tmp.cpu_time, &tmp.run_delay, &tmp.pcount) != 10) { 92 printf("Could not parse %s\n", b); 93 return -1; 94 } 95 96 cpu_delta[cpu].yld_count = tmp.yld_count - cpu_prev[cpu].yld_count; 97 cpu_delta[cpu].sched_switch = tmp.sched_switch - cpu_prev[cpu].sched_switch; 98 cpu_delta[cpu].sched_count = tmp.sched_count - cpu_prev[cpu].sched_count; 99 cpu_delta[cpu].sched_goidle = tmp.sched_goidle - cpu_prev[cpu].sched_goidle; 100 cpu_delta[cpu].ttwu_count = tmp.ttwu_count - cpu_prev[cpu].ttwu_count; 101 cpu_delta[cpu].ttwu_local = tmp.ttwu_local - cpu_prev[cpu].ttwu_local; 102 cpu_delta[cpu].cpu_time = tmp.cpu_time - cpu_prev[cpu].cpu_time; 103 cpu_delta[cpu].run_delay = tmp.run_delay - cpu_prev[cpu].run_delay; 104 cpu_delta[cpu].pcount = tmp.pcount - cpu_prev[cpu].pcount; 105 106 cpu_prev[cpu] = tmp; 107 return 0; 108 } 109 110 111 static int parse(const char *b) { 112 unsigned int version; 113 unsigned long long ts; 114 115 if (sscanf(b, "version %u\n", &version) != 1) { 116 printf("Could not parse version\n"); 117 return -1; 118 } 119 switch (version) { 120 case 15: 121 b = next_line(b); 122 if (!b || sscanf(b, "timestamp %llu\n", &ts) != 1) { 123 printf("Could not parse timestamp\n"); 124 return -1; 125 } 126 while (1) { 127 b = next_line(b); 128 if (!b) break; 129 if (b[0] == 'c') { 130 if (parse_cpu_v15(b)) return -1; 131 } 132 } 133 break; 134 default: 135 printf("Can not handle version %u\n", version); 136 return -1; 137 } 138 return 0; 139 } 140 141 int main(int argc, char **argv) { 142 int i; 143 int fd; 144 char buf[4096]; 145 146 while (1) { 147 fd = open("/proc/schedstat", O_RDONLY); 148 if (fd < 0) return -1; 149 i = read(fd, buf, sizeof(buf) - 1); 150 close(fd); 151 buf[i] = '\0'; 152 if (parse(buf)) return -1; 153 print(); 154 sleep(1); 155 } 156 return 0; 157 } 158
