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   systemd is free software; you can redistribute it and/or modify it
   9   under the terms of the GNU Lesser General Public License as published by
  10   the Free Software Foundation; either version 2.1 of the License, or
  11   (at your option) any later version.
  12
  13   systemd is distributed in the hope that it will be useful, but
  14   WITHOUT ANY WARRANTY; without even the implied warranty of
  15   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
  16   Lesser General Public License for more details.
  17
  18   You should have received a copy of the GNU Lesser General Public License
  19   along with systemd; If not, see <http://www.gnu.org/licenses/>.
  20 ***/
  21
  22 #include <errno.h>
  23 #include <stddef.h>
  24 #include <syslog.h>
  25
  26 #include "alloc-util.h"
  27 #include "cpu-set-util.h"
  28 #include "extract-word.h"
  29 #include "log.h"
  30 #include "macro.h"
  31 #include "parse-util.h"
  32 #include "string-util.h"
  33
  34 cpu_set_t* cpu_set_malloc(unsigned *ncpus) {
  35         cpu_set_t *c;
  36         unsigned n = 1024;
  37
  38         /* Allocates the cpuset in the right size */
  39
  40         for (;;) {
  41                 c = CPU_ALLOC(n);
  42                 if (!c)
  43                         return NULL;
  44
  45                 if (sched_getaffinity(0, CPU_ALLOC_SIZE(n), c) >= 0) {
  46                         CPU_ZERO_S(CPU_ALLOC_SIZE(n), c);
  47
  48                         if (ncpus)
  49                                 *ncpus = n;
  50
  51                         return c;
  52                 }
  53
  54                 CPU_FREE(c);
  55
  56                 if (errno != EINVAL)
  57                         return NULL;
  58
  59                 n *= 2;
  60         }
  61 }
  62
  63 int parse_cpu_set_internal(
  64                 const char *rvalue,
  65                 cpu_set_t **cpu_set,
  66                 bool warn,
  67                 const char *unit,
  68                 const char *filename,
  69                 unsigned line,
  70                 const char *lvalue) {
  71
  72         _cleanup_cpu_free_ cpu_set_t *c = NULL;
  73         const char *p = rvalue;
  74         unsigned ncpus = 0;
  75
  76         assert(rvalue);
  77
  78         for (;;) {
  79                 _cleanup_free_ char *word = NULL;
  80                 unsigned cpu, cpu_lower, cpu_upper;
  81                 int r;
  82
  83                 r = extract_first_word(&p, &word, WHITESPACE ",", EXTRACT_QUOTES);
  84                 if (r == -ENOMEM)
  85                         return warn ? log_oom() : -ENOMEM;
  86                 if (r < 0)
  87                         return warn ? log_syntax(unit, LOG_ERR, filename, line, r, "Invalid value for %s: %s", lvalue, rvalue) : r;
  88                 if (r == 0)
  89                         break;
  90
  91                 if (!c) {
  92                         c = cpu_set_malloc(&ncpus);
  93                         if (!c)
  94                                 return warn ? log_oom() : -ENOMEM;
  95                 }
  96
  97                 r = parse_range(word, &cpu_lower, &cpu_upper);
  98                 if (r < 0)
  99                         return warn ? log_syntax(unit, LOG_ERR, filename, line, r, "Failed to parse CPU affinity '%s'", word) : r;
 100                 if (cpu_lower >= ncpus || cpu_upper >= ncpus)
 101                         return warn ? log_syntax(unit, LOG_ERR, filename, line, EINVAL, "CPU out of range '%s' ncpus is %u", word, ncpus) : -EINVAL;
 102
 103                 if (cpu_lower > cpu_upper) {
 104                         if (warn)
 105                                 log_syntax(unit, LOG_WARNING, filename, line, 0, "Range '%s' is invalid, %u > %u, ignoring", word, cpu_lower, cpu_upper);
 106                         continue;
 107                 }
 108
 109                 for (cpu = cpu_lower; cpu <= cpu_upper; cpu++)
 110                         CPU_SET_S(cpu, CPU_ALLOC_SIZE(ncpus), c);
 111         }
 112
 113         /* On success, sets *cpu_set and returns ncpus for the system. */
 114         if (c)
 115                 *cpu_set = TAKE_PTR(c);
 116
 117         return (int) ncpus;
 118 }