/usr/sbin/dtrace -q -Z -32 -n '
/*
# Program: Request Size Distribution <requestsize.d>
#
# Author: Matty <matty91 at gmail dot com>
#
# Current Version: 0.1a
#
# Revision History:
#  Version 0.1a
#
# Last Updated: 11-25-2005
#
# Purpose: Prints a frequency distribution with request sizes.
#
# Installation:
#   Copy the shell script to a suitable location
#
# CDDL HEADER START
#  The contents of this file are subject to the terms of the
#  Common Development and Distribution License, Version 1.0 only
#  (the "License").  You may not use this file except in compliance
#  with the License.
#
#  You can obtain a copy of the license at Docs/cddl1.txt
#  or http://www.opensolaris.org/os/licensing.
#  See the License for the specific language governing permissions
#  and limitations under the License.
# CDDL HEADER END
#
# Example:
# $ requestsize.d
# dtrace: script 'requestsize.d' matched 1 probe
#^C
#
#  httpd                                                  5549
#           value  ------------- Distribution ------------- count    
#              -1 |                                         0        
#               0 |@@@@@@@@@@@@@@@@@@@@@@@@                 43       
#               1 |                                         0        
#               2 |                                         0        
#               4 |                                         0        
#               8 |                                         0        
#              16 |                                         0        
#              32 |                                         0        
#              64 |                                         0        
#             128 |                                         0        
#             256 |@@@@                                     8        
#             512 |                                         0        
#            1024 |                                         0        
#            2048 |@@@@@@@@@@@@                             22       
#            4096 |                                         0        
*/

dtrace:::BEGIN
{
    printf("Sampling request size data (Control-C to stop and print)\n");
}

::apache_log_request:log-request
{
    this->request_size = (int)*(uintptr_t *)copyin(arg0 + 100, sizeof(int));
    @size[execname,pid]  = quantize(this->request_size);
}'