mac_rx to freemsg latency (RX IP stack latency)

gistfile1.txt

[root@headnode /var/tmp/brendan]# cat rxstacklat.d 
#!/usr/sbin/dtrace -s

fbt::mac_rx:entry
{
	ts[arg2] = timestamp;
}

fbt::freemsg:entry,
fbt::freeb:entry
/this->t = ts[arg0]/
{
	@["ns"] = quantize(timestamp - this->t);
	ts[arg0] = 0;
}
[root@headnode /var/tmp/brendan]# ./rxstacklat.d 
dtrace: script './rxstacklat.d' matched 3 probes
^C

  ns                                                
           value  ------------- Distribution ------------- count    
            2048 |                                         0        
            4096 |                                         121      
            8192 |@@@                                      1332     
           16384 |@@@@@@@@@@@@@@@@@@@@@@@@@                12291    
           32768 |@@@@@@@@@                                4283     
           65536 |@@                                       1137     
          131072 |                                         139      
          262144 |                                         37       
          524288 |                                         3        
         1048576 |                                         0