gettime.c

   1 /*
   2  * Clock functions
   3  */
   4
   5 #include <unistd.h>
   6 #include <sys/time.h>
   7
   8 #include "fio.h"
   9 #include "os.h"
  10
  11 #include "hash.h"
  12
  13 static int clock_gettime_works = 1;
  14
  15 #ifdef FIO_DEBUG_TIME
  16
  17 #define HASH_BITS       8
  18 #define HASH_SIZE       (1 << HASH_BITS)
  19
  20 static struct list_head hash[HASH_SIZE];
  21 static int gtod_inited;
  22
  23 struct gtod_log {
  24         struct list_head list;
  25         void *caller;
  26         unsigned long calls;
  27 };
  28
  29 static struct gtod_log *find_hash(void *caller)
  30 {
  31         unsigned long h = hash_ptr(caller, HASH_BITS);
  32         struct list_head *entry;
  33
  34         list_for_each(entry, &hash[h]) {
  35                 struct gtod_log *log = list_entry(entry, struct gtod_log, list);
  36
  37                 if (log->caller == caller)
  38                         return log;
  39         }
  40
  41         return NULL;
  42 }
  43
  44 static struct gtod_log *find_log(void *caller)
  45 {
  46         struct gtod_log *log = find_hash(caller);
  47
  48         if (!log) {
  49                 unsigned long h;
  50
  51                 log = malloc(sizeof(*log));
  52                 INIT_LIST_HEAD(&log->list);
  53                 log->caller = caller;
  54                 log->calls = 0;
  55
  56                 h = hash_ptr(caller, HASH_BITS);
  57                 list_add_tail(&log->list, &hash[h]);
  58         }
  59
  60         return log;
  61 }
  62
  63 static void gtod_log_caller(void *caller)
  64 {
  65         if (gtod_inited) {
  66                 struct gtod_log *log = find_log(caller);
  67
  68                 log->calls++;
  69         }
  70 }
  71
  72 static void fio_exit fio_dump_gtod(void)
  73 {
  74         unsigned long total_calls = 0;
  75         int i;
  76
  77         for (i = 0; i < HASH_SIZE; i++) {
  78                 struct list_head *entry;
  79                 struct gtod_log *log;
  80
  81                 list_for_each(entry, &hash[i]) {
  82                         log = list_entry(entry, struct gtod_log, list);
  83
  84                         printf("function %p, calls %lu\n", log->caller, log->calls);
  85                         total_calls += log->calls;
  86                 }
  87         }
  88
  89         printf("Total %lu gettimeofday\n", total_calls);
  90 }
  91
  92 static void fio_init gtod_init(void)
  93 {
  94         int i;
  95
  96         for (i = 0; i < HASH_SIZE; i++)
  97                 INIT_LIST_HEAD(&hash[i]);
  98
  99         gtod_inited = 1;
 100 }
 101
 102 #endif /* FIO_DEBUG_TIME */
 103
 104 void fio_gettime(struct timeval *tp, void *caller)
 105 {
 106 #ifdef FIO_DEBUG_TIME
 107         if (!caller)
 108                 caller = __builtin_return_address(0);
 109
 110         gtod_log_caller(caller);
 111 #else
 112         caller = NULL;
 113 #endif
 114 repeat:
 115         if (!clock_gettime_works)
 116                 gettimeofday(tp, NULL);
 117         else {
 118                 struct timespec ts;
 119
 120                 if (clock_gettime(CLOCK_MONOTONIC, &ts) < 0) {
 121                         clock_gettime_works = 0;
 122                         goto repeat;
 123                 }
 124
 125                 tp->tv_sec = ts.tv_sec;
 126                 tp->tv_usec = ts.tv_nsec / 1000;
 127         }
 128 }
 129
 130 static void fio_init check_clock(void)
 131 {
 132         struct timespec ts;
 133
 134         if (clock_getres(CLOCK_MONOTONIC, &ts) < 0)
 135                 clock_gettime_works = 0;
 136 }