src/basic/cpu-set-util.c

   1 /* SPDX-License-Identifier: LGPL-2.1+ */
   2
   3 #include <errno.h>
   4 #include <stddef.h>
   5 #include <syslog.h>
   6
   7 #include "alloc-util.h"
   8 #include "cpu-set-util.h"
   9 #include "extract-word.h"
  10 #include "log.h"
  11 #include "macro.h"
  12 #include "parse-util.h"
  13 #include "string-util.h"
  14
  15 cpu_set_t* cpu_set_malloc(unsigned *ncpus) {
  16         cpu_set_t *c;
  17         unsigned n = 1024;
  18
  19         /* Allocates the cpuset in the right size */
  20
  21         for (;;) {
  22                 c = CPU_ALLOC(n);
  23                 if (!c)
  24                         return NULL;
  25
  26                 if (sched_getaffinity(0, CPU_ALLOC_SIZE(n), c) >= 0) {
  27                         CPU_ZERO_S(CPU_ALLOC_SIZE(n), c);
  28
  29                         if (ncpus)
  30                                 *ncpus = n;
  31
  32                         return c;
  33                 }
  34
  35                 CPU_FREE(c);
  36
  37                 if (errno != EINVAL)
  38                         return NULL;
  39
  40                 n *= 2;
  41         }
  42 }
  43
  44 int parse_cpu_set_internal(
  45                 const char *rvalue,
  46                 cpu_set_t **cpu_set,
  47                 bool warn,
  48                 const char *unit,
  49                 const char *filename,
  50                 unsigned line,
  51                 const char *lvalue) {
  52
  53         _cleanup_cpu_free_ cpu_set_t *c = NULL;
  54         const char *p = rvalue;
  55         unsigned ncpus = 0;
  56
  57         assert(rvalue);
  58
  59         for (;;) {
  60                 _cleanup_free_ char *word = NULL;
  61                 unsigned cpu, cpu_lower, cpu_upper;
  62                 int r;
  63
  64                 r = extract_first_word(&p, &word, WHITESPACE ",", EXTRACT_QUOTES);
  65                 if (r == -ENOMEM)
  66                         return warn ? log_oom() : -ENOMEM;
  67                 if (r < 0)
  68                         return warn ? log_syntax(unit, LOG_ERR, filename, line, r, "Invalid value for %s: %s", lvalue, rvalue) : r;
  69                 if (r == 0)
  70                         break;
  71
  72                 if (!c) {
  73                         c = cpu_set_malloc(&ncpus);
  74                         if (!c)
  75                                 return warn ? log_oom() : -ENOMEM;
  76                 }
  77
  78                 r = parse_range(word, &cpu_lower, &cpu_upper);
  79                 if (r < 0)
  80                         return warn ? log_syntax(unit, LOG_ERR, filename, line, r, "Failed to parse CPU affinity '%s'", word) : r;
  81                 if (cpu_lower >= ncpus || cpu_upper >= ncpus)
  82                         return warn ? log_syntax(unit, LOG_ERR, filename, line, EINVAL, "CPU out of range '%s' ncpus is %u", word, ncpus) : -EINVAL;
  83
  84                 if (cpu_lower > cpu_upper) {
  85                         if (warn)
  86                                 log_syntax(unit, LOG_WARNING, filename, line, 0, "Range '%s' is invalid, %u > %u, ignoring", word, cpu_lower, cpu_upper);
  87                         continue;
  88                 }
  89
  90                 for (cpu = cpu_lower; cpu <= cpu_upper; cpu++)
  91                         CPU_SET_S(cpu, CPU_ALLOC_SIZE(ncpus), c);
  92         }
  93
  94         /* On success, sets *cpu_set and returns ncpus for the system. */
  95         if (c)
  96                 *cpu_set = TAKE_PTR(c);
  97
  98         return (int) ncpus;
  99 }