123 lines
3.7 KiB
Groff
123 lines
3.7 KiB
Groff
.\" Copyright (c) 1993
|
|
.\" The Regents of the University of California. All rights reserved.
|
|
.\"
|
|
.\" This code is derived from software contributed to Berkeley by
|
|
.\" Donn Seeley of BSDI.
|
|
.\"
|
|
.\" 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.
|
|
.\" 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.
|
|
.\"
|
|
.\" @(#)profil.2 8.1 (Berkeley) 6/4/93
|
|
.\" $FreeBSD$
|
|
.\"
|
|
.Dd June 4, 1993
|
|
.Dt PROFIL 2
|
|
.Os
|
|
.Sh NAME
|
|
.Nm profil
|
|
.Nd control process profiling
|
|
.Sh LIBRARY
|
|
.Lb libc
|
|
.Sh SYNOPSIS
|
|
.In unistd.h
|
|
.Ft int
|
|
.Fn profil "char *samples" "size_t size" "vm_offset_t offset" "int scale"
|
|
.Sh DESCRIPTION
|
|
The
|
|
.Fn profil
|
|
system call enables or disables
|
|
program counter profiling of the current process.
|
|
If profiling is enabled,
|
|
then at every profiling clock tick,
|
|
the kernel updates an appropriate count in the
|
|
.Fa samples
|
|
buffer.
|
|
The frequency of the profiling clock is recorded
|
|
in the header in the profiling output file.
|
|
.Pp
|
|
The buffer
|
|
.Fa samples
|
|
contains
|
|
.Fa size
|
|
bytes and is divided into
|
|
a series of 16-bit bins.
|
|
Each bin counts the number of times the program counter
|
|
was in a particular address range in the process
|
|
when a profiling clock tick occurred while profiling was enabled.
|
|
For a given program counter address,
|
|
the number of the corresponding bin is given
|
|
by the relation:
|
|
.Bd -literal -offset indent
|
|
[(pc - offset) / 2] * scale / 65536
|
|
.Ed
|
|
.Pp
|
|
The
|
|
.Fa offset
|
|
argument is the lowest address at which
|
|
the kernel takes program counter samples.
|
|
The
|
|
.Fa scale
|
|
argument ranges from 1 to 65536 and
|
|
can be used to change the span of the bins.
|
|
A scale of 65536 maps each bin to 2 bytes of address range;
|
|
a scale of 32768 gives 4 bytes, 16384 gives 8 bytes and so on.
|
|
Intermediate values provide approximate intermediate ranges.
|
|
A
|
|
.Fa scale
|
|
value of 0 disables profiling.
|
|
.Sh RETURN VALUES
|
|
.Rv -std profil
|
|
.Sh FILES
|
|
.Bl -tag -width /usr/lib/gcrt0.o -compact
|
|
.It Pa /usr/lib/gcrt0.o
|
|
profiling C run-time startup file
|
|
.It Pa gmon.out
|
|
conventional name for profiling output file
|
|
.El
|
|
.Sh ERRORS
|
|
The following error may be reported:
|
|
.Bl -tag -width Er
|
|
.It Bq Er EFAULT
|
|
The buffer
|
|
.Fa samples
|
|
contains an invalid address.
|
|
.El
|
|
.Sh SEE ALSO
|
|
.Xr gprof 1
|
|
.Sh HISTORY
|
|
The
|
|
.Fn profil
|
|
function appeared in
|
|
.At v7 .
|
|
.Sh BUGS
|
|
This routine should be named
|
|
.Fn profile .
|
|
.Pp
|
|
The
|
|
.Fa samples
|
|
argument should really be a vector of type
|
|
.Fa "unsigned short" .
|
|
.Pp
|
|
The format of the gmon.out file is undocumented.
|