gmon.h revision 37629
1/*-
2 * Copyright (c) 1982, 1986, 1992, 1993
3 *	The Regents of the University of California.  All rights reserved.
4 *
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions
7 * are met:
8 * 1. Redistributions of source code must retain the above copyright
9 *    notice, this list of conditions and the following disclaimer.
10 * 2. Redistributions in binary form must reproduce the above copyright
11 *    notice, this list of conditions and the following disclaimer in the
12 *    documentation and/or other materials provided with the distribution.
13 * 3. All advertising materials mentioning features or use of this software
14 *    must display the following acknowledgement:
15 *	This product includes software developed by the University of
16 *	California, Berkeley and its contributors.
17 * 4. Neither the name of the University nor the names of its contributors
18 *    may be used to endorse or promote products derived from this software
19 *    without specific prior written permission.
20 *
21 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
22 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
23 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
24 * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
25 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
26 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
27 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
28 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
29 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
30 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
31 * SUCH DAMAGE.
32 *
33 *	@(#)gmon.h	8.2 (Berkeley) 1/4/94
34 * $Id: gmon.h,v 1.13 1997/07/13 16:38:31 bde Exp $
35 */
36
37#ifndef _SYS_GMON_H_
38#define _SYS_GMON_H_
39
40#include <machine/profile.h>
41
42/*
43 * Structure prepended to gmon.out profiling data file.
44 */
45struct gmonhdr {
46	u_long	lpc;		/* base pc address of sample buffer */
47	u_long	hpc;		/* max pc address of sampled buffer */
48	int	ncnt;		/* size of sample buffer (plus this header) */
49	int	version;	/* version number */
50	int	profrate;	/* profiling clock rate */
51	int	spare[3];	/* reserved */
52	/* XXX should record counter size and density */
53};
54#define GMONVERSION	0x00051879
55
56/*
57 * Type of histogram counters used in the kernel.
58 */
59#ifdef GPROF4
60#define	HISTCOUNTER	int64_t
61#else
62#define	HISTCOUNTER	unsigned short
63#endif
64
65/*
66 * Fraction of text space to allocate for histogram counters.
67 * We allocate counters at the same or higher density as function
68 * addresses, so that each counter belongs to a unique function.
69 * A lower density of counters would give less resolution but a
70 * higher density would be wasted.
71 */
72#define	HISTFRACTION	(FUNCTION_ALIGNMENT / sizeof(HISTCOUNTER) == 0 \
73			 ? 1 : FUNCTION_ALIGNMENT / sizeof(HISTCOUNTER))
74
75/*
76 * Fraction of text space to allocate for from hash buckets.
77 * The value of HASHFRACTION is based on the minimum number of bytes
78 * of separation between two subroutine call points in the object code.
79 * Given MIN_SUBR_SEPARATION bytes of separation the value of
80 * HASHFRACTION is calculated as:
81 *
82 *	HASHFRACTION = MIN_SUBR_SEPARATION / (2 * sizeof(short) - 1);
83 *
84 * For example, on the VAX, the shortest two call sequence is:
85 *
86 *	calls	$0,(r0)
87 *	calls	$0,(r0)
88 *
89 * which is separated by only three bytes, thus HASHFRACTION is
90 * calculated as:
91 *
92 *	HASHFRACTION = 3 / (2 * 2 - 1) = 1
93 *
94 * Note that the division above rounds down, thus if MIN_SUBR_FRACTION
95 * is less than three, this algorithm will not work!
96 *
97 * In practice, however, call instructions are rarely at a minimal
98 * distance.  Hence, we will define HASHFRACTION to be 2 across all
99 * architectures.  This saves a reasonable amount of space for
100 * profiling data structures without (in practice) sacrificing
101 * any granularity.
102 */
103/*
104 * XXX I think the above analysis completely misses the point.  I think
105 * the point is that addresses in different functions must hash to
106 * different values.  Since the hash is essentially division by
107 * sizeof(unsigned short), the correct formula is:
108 *
109 * 	HASHFRACTION = MIN_FUNCTION_ALIGNMENT / sizeof(unsigned short)
110 *
111 * Note that he unsigned short here has nothing to do with the one for
112 * HISTFRACTION.
113 *
114 * Hash collisions from a two call sequence don't matter.  They get
115 * handled like collisions for calls to different addresses from the
116 * same address through a function pointer.
117 */
118#define	HASHFRACTION	(FUNCTION_ALIGNMENT / sizeof(unsigned short) == 0 \
119			 ? 1 : FUNCTION_ALIGNMENT / sizeof(unsigned short))
120
121/*
122 * percent of text space to allocate for tostructs with a minimum.
123 */
124#define ARCDENSITY	2
125#define MINARCS		50
126
127/*
128 * Limit on the number of arcs to so that arc numbers can be stored in
129 * `*froms' and stored and incremented without overflow in links.
130 */
131#define MAXARCS		(((u_long)1 << (8 * sizeof(u_short))) - 2)
132
133struct tostruct {
134	u_long	selfpc;
135	long	count;
136	u_short	link;
137	u_short pad;
138};
139
140/*
141 * a raw arc, with pointers to the calling site and
142 * the called site and a count.
143 */
144struct rawarc {
145	u_long	raw_frompc;
146	u_long	raw_selfpc;
147	long	raw_count;
148};
149
150/*
151 * general rounding functions.
152 */
153#define ROUNDDOWN(x,y)	rounddown(x,y)
154#define ROUNDUP(x,y)	roundup(x,y)
155
156/*
157 * The profiling data structures are housed in this structure.
158 */
159struct gmonparam {
160	int		state;
161	HISTCOUNTER	*kcount;
162	u_long		kcountsize;
163	u_short		*froms;
164	u_long		fromssize;
165	struct tostruct	*tos;
166	u_long		tossize;
167	long		tolimit;
168	uintfptr_t	lowpc;
169	uintfptr_t	highpc;
170	u_long		textsize;
171	u_long		hashfraction;
172	int		profrate;	/* XXX wrong type to match gmonhdr */
173	HISTCOUNTER	*cputime_count;
174	int		cputime_overhead;
175	HISTCOUNTER	*mcount_count;
176	int		mcount_overhead;
177	int		mcount_post_overhead;
178	int		mcount_pre_overhead;
179	HISTCOUNTER	*mexitcount_count;
180	int		mexitcount_overhead;
181	int		mexitcount_post_overhead;
182	int		mexitcount_pre_overhead;
183};
184extern struct gmonparam _gmonparam;
185
186/*
187 * Possible states of profiling.
188 */
189#define	GMON_PROF_ON	0
190#define	GMON_PROF_BUSY	1
191#define	GMON_PROF_ERROR	2
192#define	GMON_PROF_OFF	3
193#define	GMON_PROF_HIRES	4
194
195/*
196 * Sysctl definitions for extracting profiling information from the kernel.
197 */
198#define	GPROF_STATE	0	/* int: profiling enabling variable */
199#define	GPROF_COUNT	1	/* struct: profile tick count buffer */
200#define	GPROF_FROMS	2	/* struct: from location hash bucket */
201#define	GPROF_TOS	3	/* struct: destination/count structure */
202#define	GPROF_GMONPARAM	4	/* struct: profiling parameters (see above) */
203
204#endif /* !_SYS_GMON_H_ */
205