Profiling Configuration | ||
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Launching A Profile | OProfile View |
OProfile has many configuration options, the amount of which can be overwhelming. For more information about these options, refer to http://oprofile.sourceforge.net/doc/controlling-daemon.html. The Profile Configurations menu provided by the OProfile plug-in aims to make relevant, commonly-used OProfile configuration options easily accessible to users of all experience levels. Currently, the Profile Configurations menu provides two configuration tabs to the standard CDT launch configuration: Global Settings and Event Configuration.
Since Linux Tools 2.1, the Oprofile plug-in supports opcontrol and operf as profiling tools. Both of them are explained as follows.
Legacy OProfile consists of the opcontrol shell script for configuring, starting, and stopping a profiling session. To this purpose, a kernel driver (usually built as a kernel module) is used for collecting samples, which are recorded into sample files. A disadvantage of this mode is the necessity of elevated user privileges to run opcontrol.
Operf was designed to be used in place of opcontrol for profiling. It uses the Linux Performance Events Subsystem, and therefore, does not require the use of the opcontrol daemon or any elevated privileges. The use of operf and opcontrol are mutually exclusive.
The Global Settings tab configures which profiling binary is going to be used (operf or opcontrol) and how the OProfile daemon gathers profiling information. Each option is described below.
vmlinux
file. A kernel's
vmlinux
file contains debugging information required by OProfile. Note that the compressed
vmlinux file, often named
vmlinuz
, cannot be used for this purpose.
vmlinux
file is specified, the profile will include details of the specific kernel modules in use. Otherwise, kernel samples will be grouped under the name no-vmlinux
. Operf by default separates kernel samples per application.
The differences between the options are illustrated in the following OProfile view screenshot:
incl_library
was run with only the
Include dependent shared libraries
checked
incl_vmlinux
was run with the
vmlinux
file specified; both
Include dependent shared libraries
and
Include dependent kernel modules
checked
no_vmlinux
was run without any
vmlinux
file specified; both
Include dependent shared libraries
and
Include dependent kernel modules
checked
novmlinux_noseparate
was run with none of the options checkedYour system processor's hardware profiling registers often contain a large number of options. The Event Configuration tab condenses these options to a more manageable amount.
If your processor (or kernel) does not support the hardware profiling registers OProfile uses, OProfile will run in timer-interrupt mode. This mode has no user-configurable events. For more information about timer-interrupt mode, refer to http://oprofile.sourceforge.net/doc/detailed-parameters.html#timer.
The event configuration tab will then look like the screenshot below:
If your processor (or kernel) supports hardware profiling registers, there are several configuration options available to you. The availability of these configuration options depend on your processor model or kernel version. With proper support, the Events configuration tab will look like the following screenshot:
In regular mode, the Events configuration tab can contain any of the following options:
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Launching A Profile | OProfile View |