sys/sys/gmon.h

   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. Neither the name of the University nor the names of its contributors
  14  *    may be used to endorse or promote products derived from this software
  15  *    without specific prior written permission.
  16  *
  17  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
  18  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  19  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  20  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
  21  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  22  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  23  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  24  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  25  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  26  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  27  * SUCH DAMAGE.
  28  *
  29  *      @(#)gmon.h      8.2 (Berkeley) 1/4/94
  30  * $FreeBSD: src/sys/sys/gmon.h,v 1.15 1999/08/28 00:51:45 peter Exp $
  31  */
  32
  33 #ifndef _SYS_GMON_H_
  34 #define _SYS_GMON_H_
  35
  36 #include <machine/profile.h>
  37
  38 /*
  39  * Structure prepended to gmon.out profiling data file.
  40  */
  41 struct gmonhdr {
  42         u_long  lpc;            /* base pc address of sample buffer */
  43         u_long  hpc;            /* max pc address of sampled buffer */
  44         int     ncnt;           /* size of sample buffer (plus this header) */
  45         int     version;        /* version number */
  46         int     profrate;       /* profiling clock rate */
  47         int     spare[3];       /* reserved */
  48         /* XXX should record counter size and density */
  49 };
  50 #define GMONVERSION     0x00051879
  51
  52 /*
  53  * Type of histogram counters used in the kernel.
  54  */
  55 #ifdef GPROF4
  56 #define HISTCOUNTER     int64_t
  57 #else
  58 #define HISTCOUNTER     unsigned short
  59 #endif
  60
  61 /*
  62  * Fraction of text space to allocate for histogram counters.
  63  * We allocate counters at the same or higher density as function
  64  * addresses, so that each counter belongs to a unique function.
  65  * A lower density of counters would give less resolution but a
  66  * higher density would be wasted.
  67  */
  68 #define HISTFRACTION    (FUNCTION_ALIGNMENT / sizeof(HISTCOUNTER) == 0 \
  69                          ? 1 : FUNCTION_ALIGNMENT / sizeof(HISTCOUNTER))
  70
  71 /*
  72  * Fraction of text space to allocate for from hash buckets.
  73  * The value of HASHFRACTION is based on the minimum number of bytes
  74  * of separation between two subroutine call points in the object code.
  75  * Given MIN_SUBR_SEPARATION bytes of separation the value of
  76  * HASHFRACTION is calculated as:
  77  *
  78  *      HASHFRACTION = MIN_SUBR_SEPARATION / (2 * sizeof(short) - 1);
  79  *
  80  * For example, on the VAX, the shortest two call sequence is:
  81  *
  82  *      calls   $0,(r0)
  83  *      calls   $0,(r0)
  84  *
  85  * which is separated by only three bytes, thus HASHFRACTION is
  86  * calculated as:
  87  *
  88  *      HASHFRACTION = 3 / (2 * 2 - 1) = 1
  89  *
  90  * Note that the division above rounds down, thus if MIN_SUBR_FRACTION
  91  * is less than three, this algorithm will not work!
  92  *
  93  * In practice, however, call instructions are rarely at a minimal
  94  * distance.  Hence, we will define HASHFRACTION to be 2 across all
  95  * architectures.  This saves a reasonable amount of space for
  96  * profiling data structures without (in practice) sacrificing
  97  * any granularity.
  98  */
  99 /*
 100  * XXX I think the above analysis completely misses the point.  I think
 101  * the point is that addresses in different functions must hash to
 102  * different values.  Since the hash is essentially division by
 103  * sizeof(unsigned short), the correct formula is:
 104  *
 105  *      HASHFRACTION = MIN_FUNCTION_ALIGNMENT / sizeof(unsigned short)
 106  *
 107  * Note that he unsigned short here has nothing to do with the one for
 108  * HISTFRACTION.
 109  *
 110  * Hash collisions from a two call sequence don't matter.  They get
 111  * handled like collisions for calls to different addresses from the
 112  * same address through a function pointer.
 113  */
 114 #define HASHFRACTION    (FUNCTION_ALIGNMENT / sizeof(unsigned short) == 0 \
 115                          ? 1 : FUNCTION_ALIGNMENT / sizeof(unsigned short))
 116
 117 /*
 118  * percent of text space to allocate for tostructs with a minimum.
 119  */
 120 #define ARCDENSITY      2
 121 #define MINARCS         50
 122
 123 /*
 124  * Limit on the number of arcs to so that arc numbers can be stored in
 125  * `*froms' and stored and incremented without overflow in links.
 126  */
 127 #define MAXARCS         (((u_long)1 << (8 * sizeof(u_short))) - 2)
 128
 129 struct tostruct {
 130         u_long  selfpc;
 131         long    count;
 132         u_short link;
 133         u_short pad;
 134 };
 135
 136 /*
 137  * a raw arc, with pointers to the calling site and
 138  * the called site and a count.
 139  */
 140 struct rawarc {
 141         u_long  raw_frompc;
 142         u_long  raw_selfpc;
 143         long    raw_count;
 144 };
 145
 146 /*
 147  * general rounding functions.
 148  */
 149 #define ROUNDDOWN(x,y)  rounddown(x,y)
 150 #define ROUNDUP(x,y)    roundup(x,y)
 151
 152 /*
 153  * The profiling data structures are housed in this structure.
 154  */
 155 struct gmonparam {
 156         int             state;
 157         HISTCOUNTER     *kcount;
 158         u_long          kcountsize;
 159         u_short         *froms;
 160         u_long          fromssize;
 161         struct tostruct *tos;
 162         u_long          tossize;
 163         long            tolimit;
 164         uintfptr_t      lowpc;
 165         uintfptr_t      highpc;
 166         u_long          textsize;
 167         u_long          hashfraction;
 168         int             profrate;       /* XXX wrong type to match gmonhdr */
 169         HISTCOUNTER     *cputime_count;
 170         int             cputime_overhead;
 171         HISTCOUNTER     *mcount_count;
 172         int             mcount_overhead;
 173         int             mcount_post_overhead;
 174         int             mcount_pre_overhead;
 175         HISTCOUNTER     *mexitcount_count;
 176         int             mexitcount_overhead;
 177         int             mexitcount_post_overhead;
 178         int             mexitcount_pre_overhead;
 179 };
 180 extern struct gmonparam _gmonparam;
 181
 182 /*
 183  * Possible states of profiling.
 184  */
 185 #define GMON_PROF_ON    0
 186 #define GMON_PROF_BUSY  1
 187 #define GMON_PROF_ERROR 2
 188 #define GMON_PROF_OFF   3
 189 #define GMON_PROF_HIRES 4
 190
 191 /*
 192  * Sysctl definitions for extracting profiling information from the kernel.
 193  */
 194 #define GPROF_STATE     0       /* int: profiling enabling variable */
 195 #define GPROF_COUNT     1       /* struct: profile tick count buffer */
 196 #define GPROF_FROMS     2       /* struct: from location hash bucket */
 197 #define GPROF_TOS       3       /* struct: destination/count structure */
 198 #define GPROF_GMONPARAM 4       /* struct: profiling parameters (see above) */
 199
 200 #ifndef _KERNEL
 201
 202 #include <sys/cdefs.h>
 203
 204 __BEGIN_DECLS
 205 void    moncontrol(int);
 206 void    monstartup(u_long, u_long);
 207 __END_DECLS
 208
 209 #endif /* !_KERNEL */
 210
 211 #endif /* !_SYS_GMON_H_ */