tools/perf/util/cpumap.c

   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 static int read_all_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
  61 int read_cpu_map(const char *cpu_list)
  62 {
  63         unsigned long start_cpu, end_cpu = 0;
  64         char *p = NULL;
  65         int i, nr_cpus = 0;
  66
  67         if (!cpu_list)
  68                 return read_all_cpu_map();
  69
  70         if (!isdigit(*cpu_list))
  71                 goto invalid;
  72
  73         while (isdigit(*cpu_list)) {
  74                 p = NULL;
  75                 start_cpu = strtoul(cpu_list, &p, 0);
  76                 if (start_cpu >= INT_MAX
  77                     || (*p != '\0' && *p != ',' && *p != '-'))
  78                         goto invalid;
  79
  80                 if (*p == '-') {
  81                         cpu_list = ++p;
  82                         p = NULL;
  83                         end_cpu = strtoul(cpu_list, &p, 0);
  84
  85                         if (end_cpu >= INT_MAX || (*p != '\0' && *p != ','))
  86                                 goto invalid;
  87
  88                         if (end_cpu < start_cpu)
  89                                 goto invalid;
  90                 } else {
  91                         end_cpu = start_cpu;
  92                 }
  93
  94                 for (; start_cpu <= end_cpu; start_cpu++) {
  95                         /* check for duplicates */
  96                         for (i = 0; i < nr_cpus; i++)
  97                                 if (cpumap[i] == (int)start_cpu)
  98                                         goto invalid;
  99
 100                         assert(nr_cpus < MAX_NR_CPUS);
 101                         cpumap[nr_cpus++] = (int)start_cpu;
 102                 }
 103                 if (*p)
 104                         ++p;
 105
 106                 cpu_list = p;
 107         }
 108         if (nr_cpus > 0)
 109                 return nr_cpus;
 110
 111         return default_cpu_map();
 112 invalid:
 113         return -1;
 114 }