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DTRACE(1) FreeBSD General Commands Manual DTRACE(1)
NAME
dtrace - dynamic tracing compiler and tracing utility
SYNOPSIS
dtrace [-32 | -64] [-aACdeFGhHlqSvVwZ] [-b bufsz] [-c cmd]
[-D name [=value]] [-I path] [-L path] [-o output] [-s script]
[-U name] [-x arg [=value]] [-X a | c | s | t] [-p pid]
[-P provider [[predicate] action]]
[-m [provider:] module [[predicate] action]]
[-f [[provider:] module:] function [[predicate] action]]
[-n [[[provider:] module:] function:] name [[predicate] action]]
[-i probe-id [[predicate] action]]
DESCRIPTION
DTrace is a comprehensive dynamic tracing framework ported from Solaris.
DTrace provides a powerful infrastructure that permits administrators,
developers, and service personnel to concisely answer arbitrary questions
about the behavior of the operating system and user programs.
The dtrace command provides a generic interface to the essential services
provided by the DTrace facility, including:
o Options that list the set of probes and providers currently
published by DTrace
o Options that enable probes directly using any of the probe
description specifiers (provider, module, function, name)
o Options that run the D compiler and compile one or more D
program files or programs written directly on the command line
o Options that generate anonymous tracing programs
o Options that generate program stability reports
o Options that modify DTrace tracing and buffering behavior and
enable additional D compiler features
You can use dtrace to create D scripts by using it in a shebang
declaration to create an interpreter file. You can also use dtrace to
attempt to compile D programs and determine their properties without
actually enabling traces using the -e option.
OPTIONS
The arguments accepted by the -P, -m, -f, -n, and -i options can include
an optional D language predicate enclosed in slashes and an optional D
language action statement list enclosed in braces. D program code
specified on the command line must be appropriately quoted to avoid
interpretation of meta-characters by the shell.
The following options are supported:
-32 | -64
The D compiler produces programs using the native data model of
the operating system kernel. If the -32 option is specified,
dtrace forces the D compiler to compile a D program using the
32-bit data model. If the -64 option is specified, dtrace forces
-G option.
-a Claim anonymous tracing state and display the traced data. You
can combine the -a option with the -e option to force dtrace to
exit immediately after consuming the anonymous tracing state
rather than continuing to wait for new data.
-A Generate directives for anonymous tracing and write them to
/boot/dtrace.dof. This option constructs a set of dtrace
configuration file directives to enable the specified probes for
anonymous tracing and then exits. By default, dtrace attempts to
store the directives to the file /boot/dtrace.dof. This behavior
can be modified using the -o option to specify an alternate
output file.
-b bufsz
Set the principal trace buffer size to bufsz. The trace buffer
size can include any of the size suffixes k, m, g, or t. If the
buffer space cannot be allocated, dtrace attempts to reduce the
buffer size or exit depending on the setting of the bufresize
property.
-c cmd Run the specified command cmd and exit upon its completion. If
more than one -c option is present on the command line, dtrace
exits when all commands have exited, reporting the exit status
for each child process as it terminates. The process ID of the
first command is made available to any D programs specified on
the command line or using the -s option through the $target macro
variable.
-C Run the C preprocessor cpp(1) over D programs before compiling
them. You can pass options to the C preprocessor using the -D,
-U, -I, and -H options. You can select the degree of C standard
conformance if you use the -X option. For a description of the
set of tokens defined by the D compiler when invoking the C
preprocessor, see -X.
-d Dump the D script to standard output, after syntactic
transformations have been applied. For example, if-statements in
D are implemented using such transformations: a conditional
clause in a probe body is replaced at compile-time by a separate
probe predicated on the original condition.
-D name [=value]
Define name when invoking cpp(1) (enabled using the -C option).
If you specify an additional value, the name is assigned the
corresponding value. This option passes the -D option to each
cpp(1) invocation.
-e Exit after compiling any requests and consuming anonymous tracing
state (-a option) but prior to enabling any probes. You can
combine this option with the -a option to print anonymous tracing
data and exit. You can also combine this option with D compiler
options. This combination verifies that the programs compile
without actually executing them and enabling the corresponding
instrumentation.
-f [[provider:] module:] function [[predicate] action]
Specify function name to trace or list (-l option). The
can specify more than one -f option on the command line at a
time.
-F Coalesce trace output by identifying function entry and return.
Function entry probe reports are indented and their output is
prefixed with `->'. Function return probe reports are unindented
and their output is prefixed with `<-'. System call entry probe
reports are indented and their output is prefixed with `=>'.
System call return probe reports are unindented and their output
is prefixed with `<='.
-G Generate an ELF file containing an embedded DTrace program. The
DTrace probes specified in the program are saved inside of a
relocatable ELF object which can be linked into another program.
If the -o option is present, the ELF file is saved using the
pathname specified as the argument for this operand. If the -o
option is not present and the DTrace program is contained with a
file whose name is filename.d, then the ELF file is saved using
the name filename.o. Otherwise the ELF file is saved using the
name d.out.
-h Generate a header file containing macros that correspond to
probes in the specified provider definitions. This option should
be used to generate a header file that is included by other
source files for later use with the -G option. If the -o option
is present, the header file is saved using the pathname specified
as the argument for that option. If the -o option is not present
and the DTrace program is contained within a file whose name is
filename.d, then the header file is saved using the name
filename.h.
-H Print the pathnames of included files when invoking cpp(1)
(enabled using the -C option). This option passes the -H option
to each cpp(1) invocation, causing it to display the list of
pathnames, one for each line, to standard error.
-i probe-id [[predicate] action]
Specify probe identifier (probe-id) to trace or list (l option).
You can specify probe IDs using decimal integers as shown by
`dtrace -l`. The -i argument can be suffixed with an optional D
probe clause. You can specify more than one -i option at a time.
-I path
Add the specified directory path to the search path for #include
files when invoking cpp(1) (enabled using the -C option). This
option passes the -I option to each cpp(1) invocation. The
specified path is inserted into the search path ahead of the
default directory list.
-l List probes instead of enabling them. If the -l option is
specified, dtrace produces a report of the probes matching the
descriptions given using the -P, -m, -f, -n, -i, and -s options.
If none of these options are specified, this option lists all
probes.
-L path
Add the specified directory path to the search path for DTrace
libraries. DTrace libraries are used to contain common
definitions that can be used when writing D programs. The
values in those fields. If no qualifiers other than module are
specified in the description, all probes with a corresponding
module are matched. The -m argument can be suffixed with an
optional D probe clause. More than one -m option can be
specified on the command line at a time.
-n [[[provider:] module:] function:] name [[predicate] action]
Specify probe name to trace or list (-l option). The
corresponding argument can include any of the probe description
forms provider:module:function:name, module:function:name,
function:name, or name. Unspecified probe description fields are
left blank and match any probes regardless of the values in those
fields. If no qualifiers other than name are specified in the
description, all probes with a corresponding name are matched.
The -n argument can be suffixed with an optional D probe clause.
More than one -n option can be specified on the command line at a
time.
-o output
Specify the output file for the -A, -G, and -l options, or for
the traced data itself. If the -A option is present and -o is
not present, the default output file is /boot/dtrace.dof. If the
-G option is present and the -s option's argument is of the form
filename.d and -o is not present, the default output file is
filename.o. Otherwise the default output file is d.out.
-p pid Grab the specified process-ID pid, cache its symbol tables, and
exit upon its completion. If more than one -p option is present
on the command line, dtrace exits when all commands have exited,
reporting the exit status for each process as it terminates. The
first process-ID is made available to any D programs specified on
the command line or using the -s option through the $target macro
variable.
-P provider [[predicate] action]
Specify provider name to trace or list (-l option). The
remaining probe description fields module, function, and name are
left blank and match any probes regardless of the values in those
fields. The -P argument can be suffixed with an optional D probe
clause. You can specify more than one -P option on the command
line at a time.
-q Set quiet mode. dtrace suppresses messages such as the number of
probes matched by the specified options and D programs and does
not print column headers, the CPU ID, the probe ID, or insert
newlines into the output. Only data traced and formatted by D
program statements such as `dtrace()' and `printf()' is displayed
to standard output.
-s script
Compile the specified D program source file. If the -e option is
present, the program is compiled but instrumentation is not
enabled. If the -l option is present, the program is compiled
and the set of probes matched by it is listed, but
instrumentation is not enabled. If none of -e, -l, -G, or -A are
present, the instrumentation specified by the D program is
enabled and tracing begins.
-S Show D compiler intermediate code. The D compiler produces a
-v Set verbose mode. If the -v option is specified, dtrace produces
a program stability report showing the minimum interface
stability and dependency level for the specified D programs.
-V Report the highest D programming interface version supported by
dtrace. The version information is printed to standard output
and the dtrace command exits.
-w Permit destructive actions in D programs specified using the -s,
-P, -m, -f, -n, or -i options. If the -w option is not
specified, dtrace does not permit the compilation or enabling of
a D program that contains destructive actions.
-x arg [=value]
Enable or modify a DTrace runtime option or D compiler option.
Boolean options are enabled by specifying their name. Options
with values are set by separating the option name and value with
an equals sign (=).
A size argument may be suffixed with one of K, M, G or T (either
upper or lower case) to indicate a multiple of Kilobytes,
Megabytes, Gigabytes or Terabytes respectively.
A time argument may be suffixed with one of ns, nsec, us, usec,
ms, msec, s, sec, m, min, h, hour, d, day, hz. If no suffix is
specified hz will be used as the unit.
aggrate=time
Rate of aggregation reading.
aggsize=size
Size of the aggregation buffer.
bufpolicy=fill|switch|ring
Specifies the buffer policy for the principal buffer.
bufresize=auto|manual
Buffer resizing policy.
bufsize=size
Size of the per-CPU principal buffer. Same as the -b
flag.
cleanrate=time
Cleaning rate. Must be specified in number-per-second
with the "hz" suffix.
cpu=scalar
Specifies the CPU on which to enable tracing.
cpp Run a C preprocessor over input files. Same as the -C
flag.
cpppath=path
Use the specified path for the C preprocessor rather than
searching for "cpp" in PATH.
defaultargs
flowindent
Turn on flow indentation. Same as the -F flag.
grabanon
Claim anonymous state. Same as the -a flag.
jstackframes=scalar
Number of default stack frames for jstack().
jstackstrsize=scalar
Default string space size for jstack().
ldpath=path
When -G is specified, use the specified path for a static
linker rather than searching for "ld" in PATH.
libdir=path
Add a directory to the system library path.
nspec=scalar
Number of speculations.
nolibs Do not load D system libraries.
quiet Set quiet mode. Same as the -q flag.
specsize=size
Size of the speculation buffer.
strsize=size
Maximum size of strings.
stackframes=scalar
Maximum number of kernelspace stack frames to unwind when
executing the stack() action.
stackindent=scalar
Number of whitespace characters to use when indenting
stack() and ustack() output.
statusrate=time
Rate of status checking.
switchrate=time
Rate of buffer switching.
syslibdir=path
Path to system libraries. Defaults to /usr/lib/dtrace.
ustackframes=scalar
Maximum number of userspace stack frames to unwind when
executing the ustack() action.
-X a | c | s | t
Specify the degree of conformance to the ISO C standard that
should be selected when invoking cpp(1) (enabled using the -C
option). The -X option argument affects the value and presence
of the __STDC__ macro depending upon the value of the argument
__STDC__ has a value of 0 when cpp(1) is invoked in
conjunction with the -Xa option.
c Conformance. Strictly conformant ISO C, without K&R C
compatibility extensions. The predefined macro __STDC__
has a value of 1 when cpp(1) is invoked in conjunction
with the -Xc option.
s K&R C only. The macro __STDC__ is not defined when
cpp(1) is invoked in conjunction with the -Xs option.
t Transition. ISO C plus K&R C compatibility extensions,
without semantic changes required by ISO C. The
predefined macro __STDC__ has a value of 0 when cpp(1) is
invoked in conjunction with the -Xt option.
As the -X option only affects how the D compiler invokes the C
preprocessor, the -Xa and -Xt options are equivalent from the
perspective of D and both are provided only to ease re-use of
settings from a C build environment.
Regardless of the -X mode, the following additional C
preprocessor definitions are always specified and valid in all
modes:
o __sun
o __unix
o __SVR4
o __sparc (on SPARC systems only)
o __sparcv9 (on SPARC systems only when 64-bit programs
are compiled)
o __i386 (on x86 systems only when 32-bit programs are
compiled)
o __amd64 (on x86 systems only when 64-bit programs are
compiled)
o __`uname -s`_`uname -r` (for example,
`FreeBSD_9.2-RELEASE'.
o __SUNW_D=1
o __SUNW_D_VERSION=0xMMmmmuuu
Where MM is the major release value in hexadecimal, mmm
is the minor release value in hexadecimal, and uuu is
the micro release value in hexadecimal.
-Z Permit probe descriptions that match zero probes. If the -Z
option is not specified, dtrace reports an error and exits if any
probe descriptions specified in D program files (-s option) or on
the command line (-P, -m, -f, -n, or -i options) contain
descriptions that do not match any known probes.
/boot/dtrace.dof File for anonymous tracing directives.
EXIT STATUS
The following exit statuses are returned:
0 Successful completion.
For D program requests, an exit status of 0 indicates that
programs were successfully compiled, probes were successfully
enabled, or anonymous state was successfully retrieved. dtrace
returns 0 even if the specified tracing requests encountered
errors or drops.
1 An error occurred.
For D program requests, an exit status of 1 indicates that
program compilation failed or that the specified request could
not be satisfied.
2 Invalid command line options or arguments were specified.
SEE ALSO
cpp(1), elf(5), SDT(9)
Solaris Dynamic Tracing Guide.
HISTORY
The dtrace utility first appeared in FreeBSD 7.1.
FreeBSD 14.0-RELEASE-p11 February 24, 2023 FreeBSD 14.0-RELEASE-p11