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. 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_ */