stats_timing.d revision 293493 
1#!/usr/sbin/dtrace -qs
2
3/*-
4 * Copyright (c) 2008-2012 Alexander Leidinger <netchild@FreeBSD.org>
5 * All rights reserved.
6 *
7 * Redistribution and use in source and binary forms, with or without
8 * modification, are permitted provided that the following conditions
9 * are met:
10 * 1. Redistributions of source code must retain the above copyright
11 *    notice, this list of conditions and the following disclaimer
12 *    in this position and unchanged.
13 * 2. Redistributions in binary form must reproduce the above copyright
14 *    notice, this list of conditions and the following disclaimer in the
15 *    documentation and/or other materials provided with the distribution.
16 *
17 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
18 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
19 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
20 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
21 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
22 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
23 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
24 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
25 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
26 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
27 *
28 * $FreeBSD: stable/10/sys/compat/linux/stats_timing.d 293493 2016-01-09 15:16:13Z dchagin $
29 */
30
31/**
32 * Some statistics (all per provider):
33 *  - number of calls to a function per executable binary (not per PID!)
34 *    - allows to see where an optimization would be beneficial for a given
35 *      application
36 *  - graph of CPU time spend in functions per executable binary
37 *    - together with the number of calls to this function this allows
38 *      to determine if a kernel optimization would be beneficial / is
39 *      possible for a given application
40 *  - graph of longest running (CPU-time!) function in total
41 *    - may help finding problem cases in the kernel code
42 * - graph of longest held (CPU-time!) locks
43 */
44
45#pragma D option dynvarsize=32m
46
47linuxulator*:::entry
48{
49	self->time[probefunc] = vtimestamp;
50	@calls[probeprov, execname, probefunc] = count();
51}
52
53linuxulator*:::return
54/self->time[probefunc] != 0/
55{
56	this->timediff = self->time[probefunc] - vtimestamp;
57
58	@stats[probeprov, execname, probefunc] = quantize(this->timediff);
59	@longest[probeprov, probefunc] = max(this->timediff);
60
61	self->time[probefunc] = 0;
62}
63
64linuxulator*:::locked
65{
66	self->lock[arg0] = vtimestamp;
67}
68
69linuxulator*:::unlock
70/self->lock[arg0] != 0/
71{
72	this->timediff = self->lock[arg0] - vtimestamp;
73
74	@lockstats[probefunc] = quantize(this->timediff);
75	@longlock[probefunc] = max(this->timediff);
76
77	self->lock[arg0] = 0;
78}
79
80END
81{
82	printf("Number of calls per provider/application/kernel function:");
83	printa(@calls);
84	printf("CPU-timing statistics per provider/application/kernel function (in ns):");
85	printa(@stats);
86	printf("Longest running (CPU-time!) functions per provider (in ns):");
87	printa(@longest);
88	printf("Lock CPU-timing statistics:");
89	printa(@lockstats);
90	printf("Longest running (CPU-time!) locks:");
91	printa(@longlock);
92}
93
94