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  * $DragonFly: src/sys/sys/gmon.h,v 1.3 2006/05/21 03:43:47 dillon Exp $
  36  */
  37
  38 #ifndef _SYS_GMON_H_
  39 #define _SYS_GMON_H_
  40
  41 #ifndef _MACHINE_PROFILE_H_
  42 #include <machine/profile.h>
  43 #endif
  44
  45 /*
  46  * Structure prepended to gmon.out profiling data file.
  47  */
  48 struct gmonhdr {
  49         u_long  lpc;            /* base pc address of sample buffer */
  50         u_long  hpc;            /* max pc address of sampled buffer */
  51         int     ncnt;           /* size of sample buffer (plus this header) */
  52         int     version;        /* version number */
  53         int     profrate;       /* profiling clock rate */
  54         int     spare[3];       /* reserved */
  55         /* XXX should record counter size and density */
  56 };
  57 #define GMONVERSION     0x00051879
  58
  59 /*
  60  * Type of histogram counters used in the kernel.
  61  */
  62 #ifdef GPROF4
  63 #define HISTCOUNTER     int64_t
  64 #else
  65 #define HISTCOUNTER     unsigned short
  66 #endif
  67
  68 /*
  69  * Fraction of text space to allocate for histogram counters.
  70  * We allocate counters at the same or higher density as function
  71  * addresses, so that each counter belongs to a unique function.
  72  * A lower density of counters would give less resolution but a
  73  * higher density would be wasted.
  74  */
  75 #define HISTFRACTION    (FUNCTION_ALIGNMENT / sizeof(HISTCOUNTER) == 0 \
  76                          ? 1 : FUNCTION_ALIGNMENT / sizeof(HISTCOUNTER))
  77
  78 /*
  79  * Fraction of text space to allocate for from hash buckets.
  80  * The value of HASHFRACTION is based on the minimum number of bytes
  81  * of separation between two subroutine call points in the object code.
  82  * Given MIN_SUBR_SEPARATION bytes of separation the value of
  83  * HASHFRACTION is calculated as:
  84  *
  85  *      HASHFRACTION = MIN_SUBR_SEPARATION / (2 * sizeof(short) - 1);
  86  *
  87  * For example, on the VAX, the shortest two call sequence is:
  88  *
  89  *      calls   $0,(r0)
  90  *      calls   $0,(r0)
  91  *
  92  * which is separated by only three bytes, thus HASHFRACTION is
  93  * calculated as:
  94  *
  95  *      HASHFRACTION = 3 / (2 * 2 - 1) = 1
  96  *
  97  * Note that the division above rounds down, thus if MIN_SUBR_FRACTION
  98  * is less than three, this algorithm will not work!
  99  *
 100  * In practice, however, call instructions are rarely at a minimal
 101  * distance.  Hence, we will define HASHFRACTION to be 2 across all
 102  * architectures.  This saves a reasonable amount of space for
 103  * profiling data structures without (in practice) sacrificing
 104  * any granularity.
 105  */
 106 /*
 107  * XXX I think the above analysis completely misses the point.  I think
 108  * the point is that addresses in different functions must hash to
 109  * different values.  Since the hash is essentially division by
 110  * sizeof(unsigned short), the correct formula is:
 111  *
 112  *      HASHFRACTION = MIN_FUNCTION_ALIGNMENT / sizeof(unsigned short)
 113  *
 114  * Note that he unsigned short here has nothing to do with the one for
 115  * HISTFRACTION.
 116  *
 117  * Hash collisions from a two call sequence don't matter.  They get
 118  * handled like collisions for calls to different addresses from the
 119  * same address through a function pointer.
 120  */
 121 #define HASHFRACTION    (FUNCTION_ALIGNMENT / sizeof(unsigned short) == 0 \
 122                          ? 1 : FUNCTION_ALIGNMENT / sizeof(unsigned short))
 123
 124 /*
 125  * percent of text space to allocate for tostructs with a minimum.
 126  */
 127 #define ARCDENSITY      2
 128 #define MINARCS         50
 129
 130 /*
 131  * Limit on the number of arcs to so that arc numbers can be stored in
 132  * `*froms' and stored and incremented without overflow in links.
 133  */
 134 #define MAXARCS         (((u_long)1 << (8 * sizeof(u_short))) - 2)
 135
 136 struct tostruct {
 137         u_long  selfpc;
 138         long    count;
 139         u_short link;
 140         u_short pad;
 141 };
 142
 143 /*
 144  * a raw arc, with pointers to the calling site and
 145  * the called site and a count.
 146  */
 147 struct rawarc {
 148         u_long  raw_frompc;
 149         u_long  raw_selfpc;
 150         long    raw_count;
 151 };
 152
 153 /*
 154  * general rounding functions.
 155  */
 156 #define ROUNDDOWN(x,y)  rounddown(x,y)
 157 #define ROUNDUP(x,y)    roundup(x,y)
 158
 159 /*
 160  * The profiling data structures are housed in this structure.
 161  */
 162 struct gmonparam {
 163         int             state;
 164         HISTCOUNTER     *kcount;
 165         u_long          kcountsize;
 166         u_short         *froms;
 167         u_long          fromssize;
 168         struct tostruct *tos;
 169         u_long          tossize;
 170         long            tolimit;
 171         uintfptr_t      lowpc;
 172         uintfptr_t      highpc;
 173         u_long          textsize;
 174         u_long          hashfraction;
 175         int             profrate;       /* XXX wrong type to match gmonhdr */
 176         HISTCOUNTER     *cputime_count;
 177         int             cputime_overhead;
 178         HISTCOUNTER     *mcount_count;
 179         int             mcount_overhead;
 180         int             mcount_post_overhead;
 181         int             mcount_pre_overhead;
 182         HISTCOUNTER     *mexitcount_count;
 183         int             mexitcount_overhead;
 184         int             mexitcount_post_overhead;
 185         int             mexitcount_pre_overhead;
 186 };
 187 extern struct gmonparam _gmonparam;
 188
 189 /*
 190  * Possible states of profiling.
 191  */
 192 #define GMON_PROF_ON    0
 193 #define GMON_PROF_BUSY  1
 194 #define GMON_PROF_ERROR 2
 195 #define GMON_PROF_OFF   3
 196 #define GMON_PROF_HIRES 4
 197
 198 /*
 199  * Sysctl definitions for extracting profiling information from the kernel.
 200  */
 201 #define GPROF_STATE     0       /* int: profiling enabling variable */
 202 #define GPROF_COUNT     1       /* struct: profile tick count buffer */
 203 #define GPROF_FROMS     2       /* struct: from location hash bucket */
 204 #define GPROF_TOS       3       /* struct: destination/count structure */
 205 #define GPROF_GMONPARAM 4       /* struct: profiling parameters (see above) */
 206
 207 #endif /* !_SYS_GMON_H_ */