tools/perf/util/clockid.c

   1 // SPDX-License-Identifier: GPL-2.0
   2
   3 #include <subcmd/parse-options.h>
   4 #include <stdio.h>
   5 #include <time.h>
   6 #include <strings.h>
   7 #include <linux/time64.h>
   8 #include "debug.h"
   9 #include "clockid.h"
  10 #include "record.h"
  11
  12 struct clockid_map {
  13         const char *name;
  14         int clockid;
  15 };
  16
  17 #define CLOCKID_MAP(n, c)       \
  18         { .name = n, .clockid = (c), }
  19
  20 #define CLOCKID_END     { .name = NULL, }
  21
  22
  23 /*
  24  * Add the missing ones, we need to build on many distros...
  25  */
  26 #ifndef CLOCK_MONOTONIC_RAW
  27 #define CLOCK_MONOTONIC_RAW 4
  28 #endif
  29 #ifndef CLOCK_BOOTTIME
  30 #define CLOCK_BOOTTIME 7
  31 #endif
  32 #ifndef CLOCK_TAI
  33 #define CLOCK_TAI 11
  34 #endif
  35
  36 static const struct clockid_map clockids[] = {
  37         /* available for all events, NMI safe */
  38         CLOCKID_MAP("monotonic", CLOCK_MONOTONIC),
  39         CLOCKID_MAP("monotonic_raw", CLOCK_MONOTONIC_RAW),
  40
  41         /* available for some events */
  42         CLOCKID_MAP("realtime", CLOCK_REALTIME),
  43         CLOCKID_MAP("boottime", CLOCK_BOOTTIME),
  44         CLOCKID_MAP("tai", CLOCK_TAI),
  45
  46         /* available for the lazy */
  47         CLOCKID_MAP("mono", CLOCK_MONOTONIC),
  48         CLOCKID_MAP("raw", CLOCK_MONOTONIC_RAW),
  49         CLOCKID_MAP("real", CLOCK_REALTIME),
  50         CLOCKID_MAP("boot", CLOCK_BOOTTIME),
  51
  52         CLOCKID_END,
  53 };
  54
  55 static int get_clockid_res(clockid_t clk_id, u64 *res_ns)
  56 {
  57         struct timespec res;
  58
  59         *res_ns = 0;
  60         if (!clock_getres(clk_id, &res))
  61                 *res_ns = res.tv_nsec + res.tv_sec * NSEC_PER_SEC;
  62         else
  63                 pr_warning("WARNING: Failed to determine specified clock resolution.\n");
  64
  65         return 0;
  66 }
  67
  68 int parse_clockid(const struct option *opt, const char *str, int unset)
  69 {
  70         struct record_opts *opts = (struct record_opts *)opt->value;
  71         const struct clockid_map *cm;
  72         const char *ostr = str;
  73
  74         if (unset) {
  75                 opts->use_clockid = 0;
  76                 return 0;
  77         }
  78
  79         /* no arg passed */
  80         if (!str)
  81                 return 0;
  82
  83         /* no setting it twice */
  84         if (opts->use_clockid)
  85                 return -1;
  86
  87         opts->use_clockid = true;
  88
  89         /* if its a number, we're done */
  90         if (sscanf(str, "%d", &opts->clockid) == 1)
  91                 return get_clockid_res(opts->clockid, &opts->clockid_res_ns);
  92
  93         /* allow a "CLOCK_" prefix to the name */
  94         if (!strncasecmp(str, "CLOCK_", 6))
  95                 str += 6;
  96
  97         for (cm = clockids; cm->name; cm++) {
  98                 if (!strcasecmp(str, cm->name)) {
  99                         opts->clockid = cm->clockid;
 100                         return get_clockid_res(opts->clockid,
 101                                                &opts->clockid_res_ns);
 102                 }
 103         }
 104
 105         opts->use_clockid = false;
 106         ui__warning("unknown clockid %s, check man page\n", ostr);
 107         return -1;
 108 }
 109
 110 const char *clockid_name(clockid_t clk_id)
 111 {
 112         const struct clockid_map *cm;
 113
 114         for (cm = clockids; cm->name; cm++) {
 115                 if (cm->clockid == clk_id)
 116                         return cm->name;
 117         }
 118         return "(not found)";
 119 }