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[dragonfly.git] / sys / sys / gmon.h
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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 * $FreeBSD: src/sys/sys/gmon.h,v 1.15 1999/08/28 00:51:45 peter 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_ */