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1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 211 212 | // SPDX-License-Identifier: GPL-2.0-only /* * (C) 2004-2009 Dominik Brodowski <linux@dominikbrodowski.de> */ #include <sys/types.h> #include <sys/stat.h> #include <fcntl.h> #include <unistd.h> #include <stdio.h> #include <errno.h> #include <stdlib.h> #include "cpupower.h" #include "cpupower_intern.h" unsigned int cpupower_read_sysfs(const char *path, char *buf, size_t buflen) { ssize_t numread; int fd; fd = open(path, O_RDONLY); if (fd == -1) return 0; numread = read(fd, buf, buflen - 1); if (numread < 1) { close(fd); return 0; } buf[numread] = '\0'; close(fd); return (unsigned int) numread; } unsigned int cpupower_write_sysfs(const char *path, char *buf, size_t buflen) { ssize_t numwritten; int fd; fd = open(path, O_WRONLY); if (fd == -1) return 0; numwritten = write(fd, buf, buflen - 1); if (numwritten < 1) { perror(path); close(fd); return -1; } close(fd); return (unsigned int) numwritten; } /* * Detect whether a CPU is online * * Returns: * 1 -> if CPU is online * 0 -> if CPU is offline * negative errno values in error case */ int cpupower_is_cpu_online(unsigned int cpu) { char path[SYSFS_PATH_MAX]; int fd; ssize_t numread; unsigned long long value; char linebuf[MAX_LINE_LEN]; char *endp; struct stat statbuf; snprintf(path, sizeof(path), PATH_TO_CPU "cpu%u", cpu); if (stat(path, &statbuf) != 0) return 0; /* * kernel without CONFIG_HOTPLUG_CPU * -> cpuX directory exists, but not cpuX/online file */ snprintf(path, sizeof(path), PATH_TO_CPU "cpu%u/online", cpu); if (stat(path, &statbuf) != 0) return 1; fd = open(path, O_RDONLY); if (fd == -1) return -errno; numread = read(fd, linebuf, MAX_LINE_LEN - 1); if (numread < 1) { close(fd); return -EIO; } linebuf[numread] = '\0'; close(fd); value = strtoull(linebuf, &endp, 0); if (value > 1) return -EINVAL; return value; } /* returns -1 on failure, 0 on success */ static int sysfs_topology_read_file(unsigned int cpu, const char *fname, int *result) { char linebuf[MAX_LINE_LEN]; char *endp; char path[SYSFS_PATH_MAX]; snprintf(path, sizeof(path), PATH_TO_CPU "cpu%u/topology/%s", cpu, fname); if (cpupower_read_sysfs(path, linebuf, MAX_LINE_LEN) == 0) return -1; *result = strtol(linebuf, &endp, 0); if (endp == linebuf || errno == ERANGE) return -1; return 0; } static int __compare(const void *t1, const void *t2) { struct cpuid_core_info *top1 = (struct cpuid_core_info *)t1; struct cpuid_core_info *top2 = (struct cpuid_core_info *)t2; if (top1->pkg < top2->pkg) return -1; else if (top1->pkg > top2->pkg) return 1; else if (top1->core < top2->core) return -1; else if (top1->core > top2->core) return 1; else if (top1->cpu < top2->cpu) return -1; else if (top1->cpu > top2->cpu) return 1; else return 0; } /* * Returns amount of cpus, negative on error, cpu_top must be * passed to cpu_topology_release to free resources * * Array is sorted after ->pkg, ->core, then ->cpu */ int get_cpu_topology(struct cpupower_topology *cpu_top) { int cpu, last_pkg, cpus = sysconf(_SC_NPROCESSORS_CONF); cpu_top->core_info = malloc(sizeof(struct cpuid_core_info) * cpus); if (cpu_top->core_info == NULL) return -ENOMEM; cpu_top->pkgs = cpu_top->cores = 0; for (cpu = 0; cpu < cpus; cpu++) { cpu_top->core_info[cpu].cpu = cpu; cpu_top->core_info[cpu].is_online = cpupower_is_cpu_online(cpu); if(sysfs_topology_read_file( cpu, "physical_package_id", &(cpu_top->core_info[cpu].pkg)) < 0) { cpu_top->core_info[cpu].pkg = -1; cpu_top->core_info[cpu].core = -1; continue; } if(sysfs_topology_read_file( cpu, "core_id", &(cpu_top->core_info[cpu].core)) < 0) { cpu_top->core_info[cpu].pkg = -1; cpu_top->core_info[cpu].core = -1; continue; } } qsort(cpu_top->core_info, cpus, sizeof(struct cpuid_core_info), __compare); /* Count the number of distinct pkgs values. This works because the primary sort of the core_info struct was just done by pkg value. */ last_pkg = cpu_top->core_info[0].pkg; for(cpu = 1; cpu < cpus; cpu++) { if (cpu_top->core_info[cpu].pkg != last_pkg && cpu_top->core_info[cpu].pkg != -1) { last_pkg = cpu_top->core_info[cpu].pkg; cpu_top->pkgs++; } } if (!(cpu_top->core_info[0].pkg == -1)) cpu_top->pkgs++; /* Intel's cores count is not consecutively numbered, there may * be a core_id of 3, but none of 2. Assume there always is 0 * Get amount of cores by counting duplicates in a package for (cpu = 0; cpu_top->core_info[cpu].pkg = 0 && cpu < cpus; cpu++) { if (cpu_top->core_info[cpu].core == 0) cpu_top->cores++; */ return cpus; } void cpu_topology_release(struct cpupower_topology cpu_top) { free(cpu_top.core_info); } |