gmon.h

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/*-
 * Copyright (c) 1982, 1986, 1992, 1993
 *  The Regents of the University of California.  All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 * 3. All advertising materials mentioning features or use of this software
 *    must display the following acknowledgement:
 *  This product includes software developed by the University of
 *  California, Berkeley and its contributors.
 * 4. Neither the name of the University nor the names of its contributors
 *    may be used to endorse or promote products derived from this software
 *    without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 * SUCH DAMAGE.
 *
 *  @(#)gmon.h  8.2 (Berkeley) 1/4/94
 * $FreeBSD: src/sys/sys/gmon.h,v 1.15 1999/08/28 00:51:45 peter Exp $
 */
 
#ifndef _SYS_GMON_H_
#define _SYS_GMON_H_
 
//#include <machine/profile.h>
typedef u_int fptrint_t;
typedef int fptrdiff_t;
typedef u_int uintfptr_t;
 
/*
 * Getkerninfo clock information structure
 */
struct clockinfo {
    int hz;     /* clock frequency */
    int tick;       /* micro-seconds per hz tick */
    int tickadj;    /* clock skew rate for adjtime() */
    int stathz;     /* statistics clock frequency */
    int profhz;     /* profiling clock frequency */
};
 
/*
 * Config generates something to tell the compiler to align functions on 16
 * byte boundaries.  A strict alignment is good for keeping the tables small.
 */
#define FUNCTION_ALIGNMENT  16
 
/*
 * Structure prepended to gmon.out profiling data file.
 */
struct gmonhdr {
    u_long  lpc;        /* base pc address of sample buffer */
    u_long  hpc;        /* max pc address of sampled buffer */
    int ncnt;       /* size of sample buffer (plus this header) */
    int version;    /* version number */
    int profrate;   /* profiling clock rate */
    int spare[3];   /* reserved */
    /* XXX should record counter size and density */
};
#define GMONVERSION 0x00051879
 
/*
 * Type of histogram counters used in the kernel.
 */
#ifdef GPROF4
#define HISTCOUNTER int64_t
#else
#define HISTCOUNTER unsigned short
#endif
 
/*
 * Fraction of text space to allocate for histogram counters.
 * We allocate counters at the same or higher density as function
 * addresses, so that each counter belongs to a unique function.
 * A lower density of counters would give less resolution but a
 * higher density would be wasted.
 */
#define HISTFRACTION    (FUNCTION_ALIGNMENT / sizeof(HISTCOUNTER) == 0 \
             ? 1 : FUNCTION_ALIGNMENT / sizeof(HISTCOUNTER))
 
/*
 * Fraction of text space to allocate for from hash buckets.
 * The value of HASHFRACTION is based on the minimum number of bytes
 * of separation between two subroutine call points in the object code.
 * Given MIN_SUBR_SEPARATION bytes of separation the value of
 * HASHFRACTION is calculated as:
 *
 *  HASHFRACTION = MIN_SUBR_SEPARATION / (2 * sizeof(short) - 1);
 *
 * For example, on the VAX, the shortest two call sequence is:
 *
 *  calls   $0,(r0)
 *  calls   $0,(r0)
 *
 * which is separated by only three bytes, thus HASHFRACTION is
 * calculated as:
 *
 *  HASHFRACTION = 3 / (2 * 2 - 1) = 1
 *
 * Note that the division above rounds down, thus if MIN_SUBR_FRACTION
 * is less than three, this algorithm will not work!
 *
 * In practice, however, call instructions are rarely at a minimal
 * distance.  Hence, we will define HASHFRACTION to be 2 across all
 * architectures.  This saves a reasonable amount of space for
 * profiling data structures without (in practice) sacrificing
 * any granularity.
 */
/*
 * XXX I think the above analysis completely misses the point.  I think
 * the point is that addresses in different functions must hash to
 * different values.  Since the hash is essentially division by
 * sizeof(unsigned short), the correct formula is:
 *
 *  HASHFRACTION = MIN_FUNCTION_ALIGNMENT / sizeof(unsigned short)
 *
 * Note that he unsigned short here has nothing to do with the one for
 * HISTFRACTION.
 *
 * Hash collisions from a two call sequence don't matter.  They get
 * handled like collisions for calls to different addresses from the
 * same address through a function pointer.
 */
#define HASHFRACTION    (FUNCTION_ALIGNMENT / sizeof(unsigned short) == 0 \
             ? 1 : FUNCTION_ALIGNMENT / sizeof(unsigned short))
 
/*
 * percent of text space to allocate for tostructs with a minimum.
 */
#define ARCDENSITY  2
#define MINARCS     50
 
/*
 * Limit on the number of arcs to so that arc numbers can be stored in
 * `*froms' and stored and incremented without overflow in links.
 */
#define MAXARCS     (((u_long)1 << (8 * sizeof(u_short))) - 2)
 
struct tostruct {
    u_long  selfpc;
    long    count;
    u_short link;
    u_short pad;
};
 
/*
 * a raw arc, with pointers to the calling site and
 * the called site and a count.
 */
struct rawarc {
    u_long  raw_frompc;
    u_long  raw_selfpc;
    long    raw_count;
};
 
/*
 * general rounding functions.
 */
#define ROUNDDOWN(x,y)  (((x)/(y))*(y))
#define ROUNDUP(x,y)    ((((x)+(y)-1)/(y))*(y))
 
/*
 * The profiling data structures are housed in this structure.
 */
struct gmonparam {
    int     state;
    HISTCOUNTER *kcount;
    u_long      kcountsize;
    u_short     *froms;
    u_long      fromssize;
    struct tostruct *tos;
    u_long      tossize;
    long        tolimit;
    uintfptr_t  lowpc;
    uintfptr_t  highpc;
    u_long      textsize;
    u_long      hashfraction;
    int     profrate;   /* XXX wrong type to match gmonhdr */
    HISTCOUNTER *cputime_count;
    int     cputime_overhead;
    HISTCOUNTER *mcount_count;
    int     mcount_overhead;
    int     mcount_post_overhead;
    int     mcount_pre_overhead;
    HISTCOUNTER *mexitcount_count;
    int     mexitcount_overhead;
    int     mexitcount_post_overhead;
    int     mexitcount_pre_overhead;
};
extern struct gmonparam _gmonparam;
 
/*
 * Possible states of profiling.
 */
#define GMON_PROF_ON    0
#define GMON_PROF_BUSY  1
#define GMON_PROF_ERROR 2
#define GMON_PROF_OFF   3
#define GMON_PROF_HIRES 4
 
/*
 * Sysctl definitions for extracting profiling information from the kernel.
 */
#define GPROF_STATE 0   /* int: profiling enabling variable */
#define GPROF_COUNT 1   /* struct: profile tick count buffer */
#define GPROF_FROMS 2   /* struct: from location hash bucket */
#define GPROF_TOS   3   /* struct: destination/count structure */
#define GPROF_GMONPARAM 4   /* struct: profiling parameters (see above) */
 
#define CALIB_SCALE 1000
#define KCOUNT(p,index) ((p)->kcount[(index) \
             / (HISTFRACTION * sizeof(HISTCOUNTER))])
 
#endif /* !_SYS_GMON_H_ */