xref: /dragonfly/sys/sys/gmon.h (revision 0ca59c34)
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  */
45 struct 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 
133 struct 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  */
144 struct 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  */
159 struct 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 };
184 extern 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 #ifndef _KERNEL
205 
206 #include <sys/cdefs.h>
207 
208 __BEGIN_DECLS
209 void	moncontrol(int);
210 void	monstartup(u_long, u_long);
211 __END_DECLS
212 
213 #endif /* !_KERNEL */
214 
215 #endif /* !_SYS_GMON_H_ */
216