src/basic/cpu-set-util.c

   1 /* SPDX-License-Identifier: LGPL-2.1+ */
   2 /***
   3   Copyright 2015 Filipe Brandenburger
   4 ***/
   5
   6 #include <errno.h>
   7 #include <stddef.h>
   8 #include <syslog.h>
   9
  10 #include "alloc-util.h"
  11 #include "cpu-set-util.h"
  12 #include "extract-word.h"
  13 #include "log.h"
  14 #include "macro.h"
  15 #include "parse-util.h"
  16 #include "string-util.h"
  17
  18 cpu_set_t* cpu_set_malloc(unsigned *ncpus) {
  19         cpu_set_t *c;
  20         unsigned n = 1024;
  21
  22         /* Allocates the cpuset in the right size */
  23
  24         for (;;) {
  25                 c = CPU_ALLOC(n);
  26                 if (!c)
  27                         return NULL;
  28
  29                 if (sched_getaffinity(0, CPU_ALLOC_SIZE(n), c) >= 0) {
  30                         CPU_ZERO_S(CPU_ALLOC_SIZE(n), c);
  31
  32                         if (ncpus)
  33                                 *ncpus = n;
  34
  35                         return c;
  36                 }
  37
  38                 CPU_FREE(c);
  39
  40                 if (errno != EINVAL)
  41                         return NULL;
  42
  43                 n *= 2;
  44         }
  45 }
  46
  47 int parse_cpu_set_internal(
  48                 const char *rvalue,
  49                 cpu_set_t **cpu_set,
  50                 bool warn,
  51                 const char *unit,
  52                 const char *filename,
  53                 unsigned line,
  54                 const char *lvalue) {
  55
  56         _cleanup_cpu_free_ cpu_set_t *c = NULL;
  57         const char *p = rvalue;
  58         unsigned ncpus = 0;
  59
  60         assert(rvalue);
  61
  62         for (;;) {
  63                 _cleanup_free_ char *word = NULL;
  64                 unsigned cpu, cpu_lower, cpu_upper;
  65                 int r;
  66
  67                 r = extract_first_word(&p, &word, WHITESPACE ",", EXTRACT_QUOTES);
  68                 if (r == -ENOMEM)
  69                         return warn ? log_oom() : -ENOMEM;
  70                 if (r < 0)
  71                         return warn ? log_syntax(unit, LOG_ERR, filename, line, r, "Invalid value for %s: %s", lvalue, rvalue) : r;
  72                 if (r == 0)
  73                         break;
  74
  75                 if (!c) {
  76                         c = cpu_set_malloc(&ncpus);
  77                         if (!c)
  78                                 return warn ? log_oom() : -ENOMEM;
  79                 }
  80
  81                 r = parse_range(word, &cpu_lower, &cpu_upper);
  82                 if (r < 0)
  83                         return warn ? log_syntax(unit, LOG_ERR, filename, line, r, "Failed to parse CPU affinity '%s'", word) : r;
  84                 if (cpu_lower >= ncpus || cpu_upper >= ncpus)
  85                         return warn ? log_syntax(unit, LOG_ERR, filename, line, EINVAL, "CPU out of range '%s' ncpus is %u", word, ncpus) : -EINVAL;
  86
  87                 if (cpu_lower > cpu_upper) {
  88                         if (warn)
  89                                 log_syntax(unit, LOG_WARNING, filename, line, 0, "Range '%s' is invalid, %u > %u, ignoring", word, cpu_lower, cpu_upper);
  90                         continue;
  91                 }
  92
  93                 for (cpu = cpu_lower; cpu <= cpu_upper; cpu++)
  94                         CPU_SET_S(cpu, CPU_ALLOC_SIZE(ncpus), c);
  95         }
  96
  97         /* On success, sets *cpu_set and returns ncpus for the system. */
  98         if (c)
  99                 *cpu_set = TAKE_PTR(c);
 100
 101         return (int) ncpus;
 102 }