mdw@git.distorted.org.uk Git - collect-bench/blob - benchspt.c

   1 #include <errno.h>
   2 #include <stdlib.h>
   3 #include <time.h>
   4
   5 #if defined(__GNUC__) && (defined(__i386__) || defined (__x86_64__))
   6
   7 struct cycle_counter {
   8   char dummy;
   9 };
  10
  11 static int init_counter(struct cycle_counter *cy) { return (0); }
  12 static void teardown_counter(struct cycle_counter *cy) { ; }
  13
  14 int cycles(struct cycle_counter *cy, unsigned long long *t_out)
  15 {
  16   unsigned lo, hi;
  17
  18   __asm__("rdtsc" : "=a"(lo), "=d"(hi));
  19   *t_out = lo | ((unsigned long long)hi << 32);
  20   return (0);
  21 }
  22
  23 #elif defined(__linux__)
  24
  25 #include <unistd.h>
  26 #include <linux/perf_event.h>
  27 #include <asm/unistd.h>
  28
  29 struct cycle_counter {
  30   int fd;
  31 };
  32
  33 static int init_counter(struct cycle_counter *cy)
  34 {
  35   struct perf_event_attr attr = { 0 };
  36
  37   attr.type = PERF_TYPE_HARDWARE;
  38   attr.size = sizeof(attr);
  39   attr.config = PERF_COUNT_HW_CPU_CYCLES;
  40   attr.disabled = 0;
  41   attr.exclude_kernel = 1;
  42   attr.exclude_hv = 1;
  43
  44   cy->fd = syscall(__NR_perf_event_open, &attr, 0, -1, -1, 0);
  45   if (cy->fd < 0) return (-1);
  46   return (0);
  47 }
  48
  49 static void teardown_counter(struct cycle_counter *cy)
  50   { if (cy->fd >= 0) close(cy->fd); }
  51
  52 int cycles(struct cycle_counter *cy, unsigned long long *t_out)
  53 {
  54   ssize_t n;
  55
  56   if (cy->fd < 0) { errno = EBADF; return (-1); }
  57   n = read(cy->fd, t_out, sizeof(*t_out));
  58   if (n < sizeof(*t_out)) {
  59     if (n >= 0) errno = ENODATA;
  60     close(cy->fd); cy->fd = -1;
  61     return (-1);
  62   }
  63   return (0);
  64 }
  65
  66 #else
  67
  68 struct cycle_counter {
  69   char dummy;
  70 };
  71
  72 static int init_counter(struct cycle_counter *cy)
  73   { errno = ENOSYS; return (-1); }
  74 static void teardown_counter(struct cycle_counter *cy) { ; }
  75 int cycles(struct cycle_counter *cy, unsigned long long *t_out)
  76   { return (-1); }
  77
  78 #endif
  79
  80 struct cycle_counter *open_cycle_counter(void)
  81 {
  82   struct cycle_counter *cy = 0, *cy_ret = 0;
  83
  84   cy = malloc(sizeof(*cy)); if (!cy) goto end;
  85   if (init_counter(cy)) goto end;
  86   cy_ret = cy; cy = 0;
  87 end:
  88   free(cy);
  89   return (cy_ret);
  90 }
  91
  92 void close_cycle_counter(struct cycle_counter *cy)
  93   { teardown_counter(cy); free(cy); }
  94
  95 struct clock {
  96   long long sec;
  97   unsigned nsec;
  98 };
  99
 100 int thread_clock(struct clock *clk_out)
 101 {
 102   struct timespec tv;
 103
 104   if (clock_gettime(CLOCK_THREAD_CPUTIME_ID, &tv)) return (-1);
 105   clk_out->sec = tv.tv_sec; clk_out->nsec = tv.tv_nsec;
 106   return (0);
 107 }
 108
 109 int get_errno(void) { return (errno); }