Nick Pelly | 6ca26ef | 2010-08-26 11:21:29 -0700 | [diff] [blame] | 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 | } |