src/basic/cpu-set-util.c

   1 /*-*- Mode: C; c-basic-offset: 8; indent-tabs-mode: nil -*-*/
   2
   3 /***
   4   This file is part of systemd.
   5
   6   Copyright 2010-2015 Lennart Poettering
   7   Copyright 2015 Filipe Brandenburger
   8
   9   systemd is free software; you can redistribute it and/or modify it
  10   under the terms of the GNU Lesser General Public License as published by
  11   the Free Software Foundation; either version 2.1 of the License, or
  12   (at your option) any later version.
  13
  14   systemd is distributed in the hope that it will be useful, but
  15   WITHOUT ANY WARRANTY; without even the implied warranty of
  16   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
  17   Lesser General Public License for more details.
  18
  19   You should have received a copy of the GNU Lesser General Public License
  20   along with systemd; If not, see <http://www.gnu.org/licenses/>.
  21 ***/
  22
  23 #include <errno.h>
  24 #include <stddef.h>
  25 #include <syslog.h>
  26
  27 #include "alloc-util.h"
  28 #include "cpu-set-util.h"
  29 #include "extract-word.h"
  30 #include "parse-util.h"
  31 #include "log.h"
  32 #include "macro.h"
  33 #include "string-util.h"
  34
  35 cpu_set_t* cpu_set_malloc(unsigned *ncpus) {
  36         cpu_set_t *c;
  37         unsigned n = 1024;
  38
  39         /* Allocates the cpuset in the right size */
  40
  41         for (;;) {
  42                 c = CPU_ALLOC(n);
  43                 if (!c)
  44                         return NULL;
  45
  46                 if (sched_getaffinity(0, CPU_ALLOC_SIZE(n), c) >= 0) {
  47                         CPU_ZERO_S(CPU_ALLOC_SIZE(n), c);
  48
  49                         if (ncpus)
  50                                 *ncpus = n;
  51
  52                         return c;
  53                 }
  54
  55                 CPU_FREE(c);
  56
  57                 if (errno != EINVAL)
  58                         return NULL;
  59
  60                 n *= 2;
  61         }
  62 }
  63
  64 int parse_cpu_set_and_warn(
  65                 const char *rvalue,
  66                 cpu_set_t **cpu_set,
  67                 const char *unit,
  68                 const char *filename,
  69                 unsigned line,
  70                 const char *lvalue) {
  71
  72         const char *whole_rvalue = rvalue;
  73         _cleanup_cpu_free_ cpu_set_t *c = NULL;
  74         unsigned ncpus = 0;
  75
  76         assert(lvalue);
  77         assert(rvalue);
  78
  79         for (;;) {
  80                 _cleanup_free_ char *word = NULL;
  81                 unsigned cpu, cpu_lower, cpu_upper;
  82                 int r;
  83
  84                 r = extract_first_word(&rvalue, &word, WHITESPACE ",", EXTRACT_QUOTES);
  85                 if (r < 0)
  86                         return log_syntax(unit, LOG_ERR, filename, line, r, "Invalid value for %s: %s", lvalue, whole_rvalue);
  87                 if (r == 0)
  88                         break;
  89
  90                 if (!c) {
  91                         c = cpu_set_malloc(&ncpus);
  92                         if (!c)
  93                                 return log_oom();
  94                 }
  95
  96                 r = parse_range(word, &cpu_lower, &cpu_upper);
  97                 if (r < 0)
  98                         return log_syntax(unit, LOG_ERR, filename, line, r, "Failed to parse CPU affinity '%s'", word);
  99                 if (cpu_lower >= ncpus || cpu_upper >= ncpus)
 100                         return log_syntax(unit, LOG_ERR, filename, line, EINVAL, "CPU out of range '%s' ncpus is %u", word, ncpus);
 101
 102                 if (cpu_lower > cpu_upper)
 103                         log_syntax(unit, LOG_WARNING, filename, line, 0, "Range '%s' is invalid, %u > %u", word, cpu_lower, cpu_upper);
 104                 else
 105                         for (cpu = cpu_lower; cpu <= cpu_upper; cpu++)
 106                                 CPU_SET_S(cpu, CPU_ALLOC_SIZE(ncpus), c);
 107         }
 108
 109         /* On success, sets *cpu_set and returns ncpus for the system. */
 110         if (c) {
 111                 *cpu_set = c;
 112                 c = NULL;
 113         }
 114
 115         return (int) ncpus;
 116 }