gmon.h revision 19000
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 1.8 1995/12/29 15:29:26 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 int 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 * Assume that function addresses are at least 4-byte-aligned. 73 * It would be better to get the linker to align functions more 74 * strictly so that we could use smaller tables. 75 */ 76#define FUNCTION_ALIGNMENT 4 77#define HISTFRACTION (FUNCTION_ALIGNMENT / sizeof(HISTCOUNTER) == 0 \ 78 ? 1 : FUNCTION_ALIGNMENT / sizeof(HISTCOUNTER)) 79 80/* 81 * Fraction of text space to allocate for from hash buckets. 82 * The value of HASHFRACTION is based on the minimum number of bytes 83 * of separation between two subroutine call points in the object code. 84 * Given MIN_SUBR_SEPARATION bytes of separation the value of 85 * HASHFRACTION is calculated as: 86 * 87 * HASHFRACTION = MIN_SUBR_SEPARATION / (2 * sizeof(short) - 1); 88 * 89 * For example, on the VAX, the shortest two call sequence is: 90 * 91 * calls $0,(r0) 92 * calls $0,(r0) 93 * 94 * which is separated by only three bytes, thus HASHFRACTION is 95 * calculated as: 96 * 97 * HASHFRACTION = 3 / (2 * 2 - 1) = 1 98 * 99 * Note that the division above rounds down, thus if MIN_SUBR_FRACTION 100 * is less than three, this algorithm will not work! 101 * 102 * In practice, however, call instructions are rarely at a minimal 103 * distance. Hence, we will define HASHFRACTION to be 2 across all 104 * architectures. This saves a reasonable amount of space for 105 * profiling data structures without (in practice) sacrificing 106 * any granularity. 107 */ 108/* 109 * XXX I think the above analysis completely misses the point. I think 110 * the point is that addresses in different functions must hash to 111 * different values. Since the hash is essentially division by 112 * sizeof(unsigned short), the correct formula is: 113 * 114 * HASHFRACTION = MIN_FUNCTION_ALIGNMENT / sizeof(unsigned short) 115 * 116 * Note that he unsigned short here has nothing to do with the one for 117 * HISTFRACTION. 118 * 119 * Hash collisions from a two call sequence don't matter. They get 120 * handled like collisions for calls to different addresses from the 121 * same address through a function pointer. 122 */ 123#define HASHFRACTION (FUNCTION_ALIGNMENT / sizeof(unsigned short) == 0 \ 124 ? 1 : FUNCTION_ALIGNMENT / sizeof(unsigned short)) 125 126/* 127 * percent of text space to allocate for tostructs with a minimum. 128 */ 129#define ARCDENSITY 2 130#define MINARCS 50 131 132/* 133 * Limit on the number of arcs to so that arc numbers can be stored in 134 * `*froms' and stored and incremented without overflow in links. 135 */ 136#define MAXARCS (((u_long)1 << (8 * sizeof(u_short))) - 2) 137 138struct tostruct { 139 u_long selfpc; 140 long count; 141 u_short link; 142 u_short pad; 143}; 144 145/* 146 * a raw arc, with pointers to the calling site and 147 * the called site and a count. 148 */ 149struct rawarc { 150 u_long raw_frompc; 151 u_long raw_selfpc; 152 long raw_count; 153}; 154 155/* 156 * general rounding functions. 157 */ 158#define ROUNDDOWN(x,y) rounddown(x,y) 159#define ROUNDUP(x,y) roundup(x,y) 160 161/* 162 * The profiling data structures are housed in this structure. 163 */ 164struct gmonparam { 165 int state; 166 HISTCOUNTER *kcount; 167 u_long kcountsize; 168 u_short *froms; 169 u_long fromssize; 170 struct tostruct *tos; 171 u_long tossize; 172 long tolimit; 173 fptrint_t lowpc; 174 fptrint_t highpc; 175 u_long textsize; 176 u_long hashfraction; 177 int profrate; /* XXX wrong type to match gmonhdr */ 178 HISTCOUNTER *cputime_count; 179 int cputime_overhead; 180 HISTCOUNTER *mcount_count; 181 int mcount_overhead; 182 int mcount_post_overhead; 183 int mcount_pre_overhead; 184 HISTCOUNTER *mexitcount_count; 185 int mexitcount_overhead; 186 int mexitcount_post_overhead; 187 int mexitcount_pre_overhead; 188}; 189extern struct gmonparam _gmonparam; 190 191/* 192 * Possible states of profiling. 193 */ 194#define GMON_PROF_ON 0 195#define GMON_PROF_BUSY 1 196#define GMON_PROF_ERROR 2 197#define GMON_PROF_OFF 3 198#define GMON_PROF_HIRES 4 199 200/* 201 * Sysctl definitions for extracting profiling information from the kernel. 202 */ 203#define GPROF_STATE 0 /* int: profiling enabling variable */ 204#define GPROF_COUNT 1 /* struct: profile tick count buffer */ 205#define GPROF_FROMS 2 /* struct: from location hash bucket */ 206#define GPROF_TOS 3 /* struct: destination/count structure */ 207#define GPROF_GMONPARAM 4 /* struct: profiling parameters (see above) */ 208 209#endif /* !_SYS_GMON_H_ */ 210