proc.c

   1 #define _GNU_SOURCE
   2 #include <sched.h>
   3 #include <sys/types.h>
   4 #include <sys/resource.h>
   5 #include <unistd.h>
   6 #include <string.h>
   7 #include <errno.h>
   8
   9 #include "proc.h"
  10 #include "die.h"
  11
  12 void cpu_affinity(int cpu)
  13 {
  14         int ret;
  15         cpu_set_t cpu_bitmask;
  16
  17         CPU_ZERO(&cpu_bitmask);
  18         CPU_SET(cpu, &cpu_bitmask);
  19
  20         ret = sched_setaffinity(getpid(), sizeof(cpu_bitmask),
  21                                 &cpu_bitmask);
  22         if (ret)
  23                 panic("Can't set this cpu affinity!\n");
  24 }
  25
  26 int set_proc_prio(int priority)
  27 {
  28         int ret = setpriority(PRIO_PROCESS, getpid(), priority);
  29         if (ret)
  30                 panic("Can't set nice val to %i!\n", priority);
  31
  32         return 0;
  33 }
  34
  35 int set_sched_status(int policy, int priority)
  36 {
  37         int ret, min_prio, max_prio;
  38         struct sched_param sp;
  39
  40         max_prio = sched_get_priority_max(policy);
  41         min_prio = sched_get_priority_min(policy);
  42
  43         if (max_prio == -1 || min_prio == -1)
  44                 printf("Cannot determine scheduler prio limits!\n");
  45         else if (priority < min_prio)
  46                 priority = min_prio;
  47         else if (priority > max_prio)
  48                 priority = max_prio;
  49
  50         memset(&sp, 0, sizeof(sp));
  51         sp.sched_priority = priority;
  52
  53         ret = sched_setscheduler(getpid(), policy, &sp);
  54         if (ret) {
  55                 printf("Cannot set scheduler policy!\n");
  56                 return -EINVAL;
  57         }
  58
  59         ret = sched_setparam(getpid(), &sp);
  60         if (ret) {
  61                 printf("Cannot set scheduler prio!\n");
  62                 return -EINVAL;
  63         }
  64
  65         return 0;
  66 }
  67
  68 ssize_t proc_get_cmdline(unsigned int pid, char *cmdline, size_t len)
  69 {
  70         ssize_t ret;
  71         char path[1024];
  72
  73         snprintf(path, sizeof(path), "/proc/%u/exe", pid);
  74         ret = readlink(path, cmdline, len - 1);
  75         if (ret < 0)
  76                 cmdline[0] = '\0';
  77         else
  78                 cmdline[ret] = '\0';
  79
  80         return ret;
  81 }