The software described in this documentation is either in Extended Support or Sustaining Support. See https://www.oracle.com/us/support/library/enterprise-linux-support-policies-069172.pdf for more information.
Oracle recommends that you upgrade the software described by this documentation as soon as possible.
Use the modprobe command to load the modules
that support the DTrace probes that you want to use. For
example, if you wanted to use the probes that the
proc
provider publishes, you would load the
sdt
module.
# modprobe sdt
The fasttrap
, profile
,
sdt
, and systrace
modules automatically load the dtrace
module, and the dtrace
module automatically
loads the ctf
module.
To list the probes that a specific provider publishes, use the following command:
# dtrace -l -P provider
To verify that a probe is available:
# dtrace -l -n probe_name
To display the probes that are available for a specific module:
# dtrace -l -m module_name
For example, display the probes that are provided by the
libphp5.so
and mysqld
modules for DTrace-enabled PHP and MySQL:
# dtrace -l -m libphp5.so -m mysqld
ID PROVIDER MODULE FUNCTION NAME
4 php3566 libphp5.so dtrace_compile_file compile-file-entry
5 php3566 libphp5.so dtrace_compile_file compile-file-return
6 php3566 libphp5.so zend_error error
7 php3566 libphp5.so ZEND_CATCH_SPEC_CONST_CV_HANDLER exception-caught
8 php3566 libphp5.so zend_throw_exception_internal exception-thrown
9 php3566 libphp5.so dtrace_execute_ex execute-entry
10 php3566 libphp5.so dtrace_execute_internal execute-entry
11 php3566 libphp5.so dtrace_execute_ex execute-return
12 php3566 libphp5.so dtrace_execute_internal execute-return
13 php3566 libphp5.so dtrace_execute_ex function-entry
14 php3566 libphp5.so dtrace_execute_ex function-return
15 php3566 libphp5.so php_request_shutdown request-shutdown
16 php3566 libphp5.so php_request_startup request-startup
...
121 mysql3684 mysqld _Z16dispatch_command19enum_server_commandP3THDPcj
command-done
122 mysql3684 mysqld _Z16dispatch_command19enum_server_commandP3THDPcj
command-start
123 mysql3684 mysqld _Z16close_connectionP3THDj connection-done
124 mysql3684 mysqld _Z22thd_prepare_connectionP3THD connection-start
125 mysql3684 mysqld _Z21mysql_execute_commandP3THD delete-done
126 mysql3684 mysqld _ZN7handler13ha_delete_rowEPKh delete-row-done
127 mysql3684 mysqld _ZN7handler13ha_delete_rowEPKh delete-row-start
128 mysql3684 mysqld _Z21mysql_execute_commandP3THD delete-start
129 mysql3684 mysqld _Z8filesortP3THDP5TABLEP8FilesortbPyS5_
filesort-done
130 mysql3684 mysqld _Z8filesortP3THDP5TABLEP8FilesortbPyS5_
filesort-start
...
For DTrace-enabled, user-space programs, this command requires
the fasttrap
module to have been loaded
before the program was started, and it does not return any
probes if no instance of the program is running.
dtrace appends the PID of the process to
the DTrace provider name that was defined for the program when
it was built.