1#!/usr/sbin/dtrace -s
2/*
3 * hotspot.d - plot disk event by location, look for hotspots.
4 *             Written in DTrace (Solaris 10 3/05).
5 *
6 * This simple DTrace script determines if disk activity is occuring in
7 * the one place - a "hotspot". This helps us understand the system's usage
8 * of a disk, it does not imply that the existance or not of a hotspot is
9 * good or bad (often may be good, less seeking).
10 *
11 * $Id: hotspot.d 3 2007-08-01 10:50:08Z brendan $
12 *
13 * USAGE:       hotspot.d       # hit Ctrl-C to end
14 *
15 * FIELDS:
16 *              Disk            disk instance name
17 *              Major           driver major number
18 *              Minor           driver minor number
19 *              value           location, by megabyte
20 *              count           number of I/O operations
21 *
22 * COPYRIGHT: Copyright (c) 2005, 2006 Brendan Gregg.
23 *
24 * CDDL HEADER START
25 *
26 *  The contents of this file are subject to the terms of the
27 *  Common Development and Distribution License, Version 1.0 only
28 *  (the "License").  You may not use this file except in compliance
29 *  with the License.
30 *
31 *  You can obtain a copy of the license at Docs/cddl1.txt
32 *  or http://www.opensolaris.org/os/licensing.
33 *  See the License for the specific language governing permissions
34 *  and limitations under the License.
35 *
36 * CDDL HEADER END
37 *
38 * 07-May-2005	Brendan Gregg	Created this.
39 * 20-Apr-2006	   "      "	Last update.
40 */
41
42#pragma D option quiet
43
44inline int DISK_MB_MAX = 1000000;	/* max size of a single disk */
45inline int REPORT_SCALE_MB = 1000;	/* output step size for report */
46
47/*
48 * Print header
49 */
50dtrace:::BEGIN
51{
52	printf("Tracing... Hit Ctrl-C to end.\n");
53}
54
55/*
56 * Process disk event
57 */
58io:::start
59{
60	this->mb = args[0]->b_blkno / 2048;
61	@Block[args[1]->dev_statname, args[1]->dev_major, args[1]->dev_minor] =
62	    lquantize(this->mb, 0, DISK_MB_MAX, REPORT_SCALE_MB);
63}
64
65/*
66 * Print final report
67 */
68dtrace:::END
69{
70	printa("Disk: %s   Major,Minor: %d,%d\n%@d\n", @Block);
71}
72