1 #include "util.h" 2 #include "../perf.h" 3 #include "cpumap.h" 4 #include <assert.h> 5 #include <stdio.h> 6 7 int cpumap[MAX_NR_CPUS]; 8 9 static int default_cpu_map(void) 10 { 11 int nr_cpus, i; 12 13 nr_cpus = sysconf(_SC_NPROCESSORS_ONLN); 14 assert(nr_cpus <= MAX_NR_CPUS); 15 assert((int)nr_cpus >= 0); 16 17 for (i = 0; i < nr_cpus; ++i) 18 cpumap[i] = i; 19 20 return nr_cpus; 21 } 22 23 int read_cpu_map(void) 24 { 25 FILE *onlnf; 26 int nr_cpus = 0; 27 int n, cpu, prev; 28 char sep; 29 30 onlnf = fopen("/sys/devices/system/cpu/online", "r"); 31 if (!onlnf) 32 return default_cpu_map(); 33 34 sep = 0; 35 prev = -1; 36 for (;;) { 37 n = fscanf(onlnf, "%u%c", &cpu, &sep); 38 if (n <= 0) 39 break; 40 if (prev >= 0) { 41 assert(nr_cpus + cpu - prev - 1 < MAX_NR_CPUS); 42 while (++prev < cpu) 43 cpumap[nr_cpus++] = prev; 44 } 45 assert (nr_cpus < MAX_NR_CPUS); 46 cpumap[nr_cpus++] = cpu; 47 if (n == 2 && sep == '-') 48 prev = cpu; 49 else 50 prev = -1; 51 if (n == 1 || sep == '\n') 52 break; 53 } 54 fclose(onlnf); 55 if (nr_cpus > 0) 56 return nr_cpus; 57 58 return default_cpu_map(); 59 } 60