dtrace(1M) System Administration Commands dtrace(1M)
NAME
dtrace - DTrace dynamic tracing compiler and tracing utility
SYNOPSIS
dtrace [-32 | -64] [-aACeFGHhlqSvVwZ] [-b bufsz] [-c cmd]
[-D name [=value]] [-I path] [-L path] [-o output]
[-s script] [-U name] [-x arg [=val]]
[-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 for the Solaris Operating System. DTrace provides a powerful infrastructure that per-
mits administrators, developers, and service personnel to concisely answer arbitrary questions about the behavior of the operating system
and user programs.
The Solaris Dynamic Tracing Guide describes how to use DTrace to observe, debug, and tune system behavior. Refer to this book for a
detailed description of DTrace features, including the bundled DTrace observability tools, instrumentation providers, and the D programming
language.
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 #! declaration to create an interpreter file. You can also use dtrace to attempt to
compile D programs and determine their properties without actually enabling tracing using the -e option. See OPTIONS. See the for detailed
examples of how to use the dtrace utility to perform these tasks.
OPTIONS
The arguments accepted by the -P, -m, -f, -n, and -i options can include an optional D language predicate enclosed in slashes // and
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. You can use the isainfo -b command to
determine the current operating system data model. 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 the D compiler to compile a D program using the 64-bit data
model. These options are typically not required as dtrace selects the native data model as the default. The data model affects the
sizes of integer types and other language properties. D programs compiled for either data model can be executed on both 32-bit and
64-bit kernels. The -32 and -64 options also determine the ELF file format (ELF32 or ELF64) produced by the -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. See the Solaris Dynamic Tracing
Guide for more information about anonymous tracing.
-A
Generate driver.conf(4) directives for anonymous tracing. This option constructs a set of dtrace(7D) 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 /ker-
nel/drv/dtrace.conf. You can modify this behavior if you use the -o option to specify an alternate output file.
-b bufsz
Set principal trace buffer size (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. Refer to
the for more information on macro variables.
-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 name [=value]
Define name when invoking cpp(1) (enabled using the -C option). If you specify the equals sign (=) and additional value, the name is
assigned the corresponding value. This option passes the -D option to each cpp 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 corresponding argument can include any of the probe description forms
provider:module:function, module:function, or function. Unspecified probe description fields are left blank and match any probes
regardless of the values in those fields. If no qualifiers other than function are specified in the description, all probes with the
corresponding function are matched. The -f argument can be suffixed with an optional D probe clause. You 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 relocat-
able ELF object which can be linked into another program. If the -o option is present, the ELF file is saved using the pathname speci-
fied 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
Print the pathnames of included files when invoking cpp(1) (enabled using the -C option). This option passes the -H option to each cpp
invocation, causing it to display the list of pathnames, one for each line, to stderr.
-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 with a file whose name is filename.d, then the header file is saved using the name filename.h.
-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 invocation. The specified path is inserted into the search path ahead of the default directory list.
-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 specified path is added after the default library search path.
-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.
-m [[provider:] module: [[predicate] action]]
Specify module name to trace or list (-l option). The corresponding argument can include any of the probe description forms
provider:module or module. Unspecified probe description fields are left blank and match any probes regardless of 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, -h, 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 /kernel/drv/dtrace.conf. 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.
Refer to the for more information on macro variables.
-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 state-
ments such as trace() and printf() is displayed to stdout.
-s
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 report of the intermediate code generated for each D program to stderr.
-U name
Undefine the specified name when invoking cpp(1) (enabled using the -C option). This option passes the -U option to each cpp invoca-
tion.
-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. DTrace stability levels are explained in further detail in the .
-V
Report the highest D programming interface version supported by dtrace. The version information is printed to stdout and the dtrace
command exits. Refer to the for more information about DTrace versioning features.
-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 [=val]
Enable or modify a DTrace runtime option or D compiler option. The list of options is found in the . Boolean options are enabled by
specifying their name. Options with values are set by separating the option name and value with an equals sign (=).
-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 letter.
The -X option supports the following arguments:
a Default. ISO C plus K&R compatibility extensions, with semantic changes required by ISO C. This is the default mode if -X is not
specified. The predefined macro __STDC__ has a value of 0 when cpp 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 is invoked in conjunction with the -Xc option.
s K&R C only. The macro __STDC__ is not defined when cpp 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 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 perspec-
tive 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, __SunOS_5_10)
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. Refer to the for more information about DTrace versioning.
-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.
OPERANDS
You can specify zero or more additional arguments on the dtrace command line to define a set of macro variables ($1, $2, and so forth). The
additional arguments can be used in D programs specified using the -s option or on the command line. The use of macro variables is
described further in the .
EXIT STATUS
The following exit values 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 sat-
isfied.
2 Invalid command line options or arguments were specified.
ATTRIBUTES
See attributes(5) for descriptions of the following attributes:
+-----------------------------+-----------------------------+
| ATTRIBUTE TYPE | ATTRIBUTE VALUE |
+-----------------------------+-----------------------------+
|Availability |SUNWdtrc |
+-----------------------------+-----------------------------+
|Interface Stability |See below. |
+-----------------------------+-----------------------------+
The command-line syntax is Committed. The human-readable output is Uncommitted.
SEE ALSO
cpp(1), isainfo(1), ssh(1), libdtrace(3LIB), driver.conf(4), attributes(5), dtrace(7D)
Solaris Dynamic Tracing Guide
USAGE
When using the -p flag, dtrace stops the target processes while it is inspecting them and reporting results. A process can do nothing while
it is stopped. This means that, if , for example, the X server is inspected by dtrace running in a window under the X server's control, the
whole window system can become deadlocked, because the proc tool would be attempting to display its results to a window that cannot be
refreshed. In such a case, logging in from another system using ssh(1) and killing the offending proc tool clears the deadlock.
SunOS 5.11 3 Feb 2009 dtrace(1M)