Dtrace script trying to inspect return values for getaddrinfo

gistfile1.txt

#!/usr/sbin/dtrace -s

#pragma D option quiet

dtrace:::BEGIN
{
    printf("%-20s  %-12s %s\n", "TIME", "LATENCY(ms)", "HOST");
}

pid$target::getaddrinfo:entry
{
    self->host = copyinstr(arg0);
    self->start = timestamp;
}

pid$target::getaddrinfo:return
/self->start/
{
    printf("%d %d %d", arg0, arg1, arg2);
    this->delta = (timestamp - self->start) / 1000000;
    printf("%-20Y  %-12d %s\n", walltimestamp, this->delta, self->host);
    self->host = 0;
    self->start = 0;
    @ = quantize((int32_t)arg1);
}

arg1 distribution:

       value  ------------- Distribution ------------- count    
          -1 |                                         0        
           0 |@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@  283      
           1 |                                         0        
           2 |                                         0        
           4 |                                         0        
           8 |@                                        5        
          16 |                                         0        

difference in return values

335 0 10172962014 Apr 25 10:35:11  1            data-proxy
335 0 10127522014 Apr 25 10:35:11  0            data-proxy
335 8 43720655562014 Apr 25 10:35:11  0            data-proxy
335 8 43709924042014 Apr 25 10:35:11  0            data-proxy

from netdb.h

#define EAI_NONAME   8  /* hostname nor servname provided, or not known */