gettime.c

   1 /*
   2  * Clock functions
   3  */
   4
   5 #include <unistd.h>
   6 #include <sys/time.h>
   7
   8 #include "fio.h"
   9
  10 #include "hash.h"
  11
  12 static int clock_gettime_works = 0;
  13
  14 #ifdef FIO_DEBUG_TIME
  15
  16 #define HASH_BITS       8
  17 #define HASH_SIZE       (1 << HASH_BITS)
  18
  19 static struct list_head hash[HASH_SIZE];
  20 static int gtod_inited;
  21
  22 struct gtod_log {
  23         struct list_head list;
  24         void *caller;
  25         unsigned long calls;
  26 };
  27
  28 static struct gtod_log *find_hash(void *caller)
  29 {
  30         unsigned long h = hash_ptr(caller, HASH_BITS);
  31         struct list_head *entry;
  32
  33         list_for_each(entry, &hash[h]) {
  34                 struct gtod_log *log = list_entry(entry, struct gtod_log, list);
  35
  36                 if (log->caller == caller)
  37                         return log;
  38         }
  39
  40         return NULL;
  41 }
  42
  43 static struct gtod_log *find_log(void *caller)
  44 {
  45         struct gtod_log *log = find_hash(caller);
  46
  47         if (!log) {
  48                 unsigned long h;
  49
  50                 log = malloc(sizeof(*log));
  51                 INIT_LIST_HEAD(&log->list);
  52                 log->caller = caller;
  53                 log->calls = 0;
  54
  55                 h = hash_ptr(caller, HASH_BITS);
  56                 list_add_tail(&log->list, &hash[h]);
  57         }
  58
  59         return log;
  60 }
  61
  62 static void gtod_log_caller(void *caller)
  63 {
  64         if (gtod_inited) {
  65                 struct gtod_log *log = find_log(caller);
  66
  67                 log->calls++;
  68         }
  69 }
  70
  71 static void fio_exit fio_dump_gtod(void)
  72 {
  73         unsigned long total_calls = 0;
  74         int i;
  75
  76         for (i = 0; i < HASH_SIZE; i++) {
  77                 struct list_head *entry;
  78                 struct gtod_log *log;
  79
  80                 list_for_each(entry, &hash[i]) {
  81                         log = list_entry(entry, struct gtod_log, list);
  82
  83                         printf("function %p, calls %lu\n", log->caller, log->calls);
  84                         total_calls += log->calls;
  85                 }
  86         }
  87
  88         printf("Total %lu gettimeofday\n", total_calls);
  89 }
  90
  91 static void fio_init gtod_init(void)
  92 {
  93         int i;
  94
  95         for (i = 0; i < HASH_SIZE; i++)
  96                 INIT_LIST_HEAD(&hash[i]);
  97
  98         gtod_inited = 1;
  99 }
 100
 101 #endif /* FIO_DEBUG_TIME */
 102
 103 #ifdef FIO_DEBUG_TIME
 104 void fio_gettime(struct timeval *tp, void *caller)
 105 #else
 106 void fio_gettime(struct timeval *tp, void fio_unused *caller)
 107 #endif
 108 {
 109 #ifdef FIO_DEBUG_TIME
 110         if (!caller)
 111                 caller = __builtin_return_address(0);
 112
 113         gtod_log_caller(caller);
 114 #endif
 115         if (!clock_gettime_works) {
 116 gtod:
 117                 gettimeofday(tp, NULL);
 118         } else {
 119                 struct timespec ts;
 120
 121                 if (clock_gettime(CLOCK_MONOTONIC, &ts) < 0) {
 122                         clock_gettime_works = 0;
 123                         goto gtod;
 124                 }
 125
 126                 tp->tv_sec = ts.tv_sec;
 127                 tp->tv_usec = ts.tv_nsec / 1000;
 128         }
 129 }