src/basic/cpu-set-util.c

   1 /* SPDX-License-Identifier: LGPL-2.1+ */
   2 /***
   3   This file is part of systemd.
   4
   5   Copyright 2010-2015 Lennart Poettering
   6   Copyright 2015 Filipe Brandenburger
   7 ***/
   8
   9 #include <errno.h>
  10 #include <stddef.h>
  11 #include <syslog.h>
  12
  13 #include "alloc-util.h"
  14 #include "cpu-set-util.h"
  15 #include "extract-word.h"
  16 #include "log.h"
  17 #include "macro.h"
  18 #include "parse-util.h"
  19 #include "string-util.h"
  20
  21 cpu_set_t* cpu_set_malloc(unsigned *ncpus) {
  22         cpu_set_t *c;
  23         unsigned n = 1024;
  24
  25         /* Allocates the cpuset in the right size */
  26
  27         for (;;) {
  28                 c = CPU_ALLOC(n);
  29                 if (!c)
  30                         return NULL;
  31
  32                 if (sched_getaffinity(0, CPU_ALLOC_SIZE(n), c) >= 0) {
  33                         CPU_ZERO_S(CPU_ALLOC_SIZE(n), c);
  34
  35                         if (ncpus)
  36                                 *ncpus = n;
  37
  38                         return c;
  39                 }
  40
  41                 CPU_FREE(c);
  42
  43                 if (errno != EINVAL)
  44                         return NULL;
  45
  46                 n *= 2;
  47         }
  48 }
  49
  50 int parse_cpu_set_internal(
  51                 const char *rvalue,
  52                 cpu_set_t **cpu_set,
  53                 bool warn,
  54                 const char *unit,
  55                 const char *filename,
  56                 unsigned line,
  57                 const char *lvalue) {
  58
  59         _cleanup_cpu_free_ cpu_set_t *c = NULL;
  60         const char *p = rvalue;
  61         unsigned ncpus = 0;
  62
  63         assert(rvalue);
  64
  65         for (;;) {
  66                 _cleanup_free_ char *word = NULL;
  67                 unsigned cpu, cpu_lower, cpu_upper;
  68                 int r;
  69
  70                 r = extract_first_word(&p, &word, WHITESPACE ",", EXTRACT_QUOTES);
  71                 if (r == -ENOMEM)
  72                         return warn ? log_oom() : -ENOMEM;
  73                 if (r < 0)
  74                         return warn ? log_syntax(unit, LOG_ERR, filename, line, r, "Invalid value for %s: %s", lvalue, rvalue) : r;
  75                 if (r == 0)
  76                         break;
  77
  78                 if (!c) {
  79                         c = cpu_set_malloc(&ncpus);
  80                         if (!c)
  81                                 return warn ? log_oom() : -ENOMEM;
  82                 }
  83
  84                 r = parse_range(word, &cpu_lower, &cpu_upper);
  85                 if (r < 0)
  86                         return warn ? log_syntax(unit, LOG_ERR, filename, line, r, "Failed to parse CPU affinity '%s'", word) : r;
  87                 if (cpu_lower >= ncpus || cpu_upper >= ncpus)
  88                         return warn ? log_syntax(unit, LOG_ERR, filename, line, EINVAL, "CPU out of range '%s' ncpus is %u", word, ncpus) : -EINVAL;
  89
  90                 if (cpu_lower > cpu_upper) {
  91                         if (warn)
  92                                 log_syntax(unit, LOG_WARNING, filename, line, 0, "Range '%s' is invalid, %u > %u, ignoring", word, cpu_lower, cpu_upper);
  93                         continue;
  94                 }
  95
  96                 for (cpu = cpu_lower; cpu <= cpu_upper; cpu++)
  97                         CPU_SET_S(cpu, CPU_ALLOC_SIZE(ncpus), c);
  98         }
  99
 100         /* On success, sets *cpu_set and returns ncpus for the system. */
 101         if (c)
 102                 *cpu_set = TAKE_PTR(c);
 103
 104         return (int) ncpus;
 105 }