src/basic/cpu-set-util.c

   1 /***
   2   This file is part of systemd.
   3
   4   Copyright 2010-2015 Lennart Poettering
   5   Copyright 2015 Filipe Brandenburger
   6
   7   systemd is free software; you can redistribute it and/or modify it
   8   under the terms of the GNU Lesser General Public License as published by
   9   the Free Software Foundation; either version 2.1 of the License, or
  10   (at your option) any later version.
  11
  12   systemd is distributed in the hope that it will be useful, but
  13   WITHOUT ANY WARRANTY; without even the implied warranty of
  14   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
  15   Lesser General Public License for more details.
  16
  17   You should have received a copy of the GNU Lesser General Public License
  18   along with systemd; If not, see <http://www.gnu.org/licenses/>.
  19 ***/
  20
  21 #include <errno.h>
  22 #include <stddef.h>
  23 #include <syslog.h>
  24
  25 #include "alloc-util.h"
  26 #include "cpu-set-util.h"
  27 #include "extract-word.h"
  28 #include "log.h"
  29 #include "macro.h"
  30 #include "parse-util.h"
  31 #include "string-util.h"
  32
  33 cpu_set_t* cpu_set_malloc(unsigned *ncpus) {
  34         cpu_set_t *c;
  35         unsigned n = 1024;
  36
  37         /* Allocates the cpuset in the right size */
  38
  39         for (;;) {
  40                 c = CPU_ALLOC(n);
  41                 if (!c)
  42                         return NULL;
  43
  44                 if (sched_getaffinity(0, CPU_ALLOC_SIZE(n), c) >= 0) {
  45                         CPU_ZERO_S(CPU_ALLOC_SIZE(n), c);
  46
  47                         if (ncpus)
  48                                 *ncpus = n;
  49
  50                         return c;
  51                 }
  52
  53                 CPU_FREE(c);
  54
  55                 if (errno != EINVAL)
  56                         return NULL;
  57
  58                 n *= 2;
  59         }
  60 }
  61
  62 int parse_cpu_set_and_warn(
  63                 const char *rvalue,
  64                 cpu_set_t **cpu_set,
  65                 const char *unit,
  66                 const char *filename,
  67                 unsigned line,
  68                 const char *lvalue) {
  69
  70         const char *whole_rvalue = rvalue;
  71         _cleanup_cpu_free_ cpu_set_t *c = NULL;
  72         unsigned ncpus = 0;
  73
  74         assert(lvalue);
  75         assert(rvalue);
  76
  77         for (;;) {
  78                 _cleanup_free_ char *word = NULL;
  79                 unsigned cpu, cpu_lower, cpu_upper;
  80                 int r;
  81
  82                 r = extract_first_word(&rvalue, &word, WHITESPACE ",", EXTRACT_QUOTES);
  83                 if (r < 0)
  84                         return log_syntax(unit, LOG_ERR, filename, line, r, "Invalid value for %s: %s", lvalue, whole_rvalue);
  85                 if (r == 0)
  86                         break;
  87
  88                 if (!c) {
  89                         c = cpu_set_malloc(&ncpus);
  90                         if (!c)
  91                                 return log_oom();
  92                 }
  93
  94                 r = parse_range(word, &cpu_lower, &cpu_upper);
  95                 if (r < 0)
  96                         return log_syntax(unit, LOG_ERR, filename, line, r, "Failed to parse CPU affinity '%s'", word);
  97                 if (cpu_lower >= ncpus || cpu_upper >= ncpus)
  98                         return log_syntax(unit, LOG_ERR, filename, line, EINVAL, "CPU out of range '%s' ncpus is %u", word, ncpus);
  99
 100                 if (cpu_lower > cpu_upper)
 101                         log_syntax(unit, LOG_WARNING, filename, line, 0, "Range '%s' is invalid, %u > %u", word, cpu_lower, cpu_upper);
 102                 else
 103                         for (cpu = cpu_lower; cpu <= cpu_upper; cpu++)
 104                                 CPU_SET_S(cpu, CPU_ALLOC_SIZE(ncpus), c);
 105         }
 106
 107         /* On success, sets *cpu_set and returns ncpus for the system. */
 108         if (c) {
 109                 *cpu_set = c;
 110                 c = NULL;
 111         }
 112
 113         return (int) ncpus;
 114 }