src/cpuset_parse.c

   1 /* SPDX-License-Identifier: LGPL-2.1+ */
   2
   3 #ifndef _GNU_SOURCE
   4 #define _GNU_SOURCE
   5 #endif
   6
   7 #ifndef FUSE_USE_VERSION
   8 #define FUSE_USE_VERSION 26
   9 #endif
  10
  11 #define _FILE_OFFSET_BITS 64
  12
  13 #define __STDC_FORMAT_MACROS
  14
  15 #include <stdio.h>
  16 #include <string.h>
  17 #include <stdbool.h>
  18 #include <stdlib.h>
  19
  20 #include "bindings.h"
  21 #include "cgroups/cgroup.h"
  22 #include "cgroups/cgroup_utils.h"
  23 #include "config.h"
  24 #include "memory_utils.h"
  25 #include "proc_loadavg.h"
  26 #include "utils.h"
  27
  28 /*
  29  * Helper functions for cpuset_in-set
  30  */
  31 static char *cpuset_nexttok(const char *c)
  32 {
  33         char *r;
  34
  35         r = strchr(c + 1, ',');
  36         return r ? (r + 1) : NULL;
  37 }
  38
  39 static int cpuset_getrange(const char *c, int *a, int *b)
  40 {
  41         int ret;
  42
  43         ret = sscanf(c, "%d-%d", a, b);
  44         return ret;
  45 }
  46
  47 /*
  48  * cpusets are in format "1,2-3,4"
  49  * iow, comma-delimited ranges
  50  */
  51 bool cpu_in_cpuset(int cpu, const char *cpuset)
  52 {
  53         for (const char *c = cpuset; c; c = cpuset_nexttok(c)) {
  54                 int a, b, ret;
  55
  56                 ret = cpuset_getrange(c, &a, &b);
  57                 if (ret == 1 && cpu == a) /* "1" or "1,6" */
  58                         return true;
  59                 else if (ret == 2 && cpu >= a && cpu <= b) /* range match */
  60                         return true;
  61         }
  62
  63         return false;
  64 }
  65
  66 /*
  67  * get cpu number in cpuset
  68  */
  69 int cpu_number_in_cpuset(const char *cpuset)
  70 {
  71         int cpu_number = 0;
  72
  73         for (const char *c = cpuset; c; c = cpuset_nexttok(c)) {
  74                 int a, b, ret;
  75
  76                 ret = cpuset_getrange(c, &a, &b);
  77                 if (ret == 1)
  78                         cpu_number++;
  79                 else if (ret == 2)
  80                         cpu_number += a > b ? a - b + 1 : b - a + 1;
  81         }
  82
  83         return cpu_number;
  84 }