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documentation/poky-ref-manual/development.xml: updates for YP terms

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I updated the profiling sections to reflect Yocto Project rather than
Poky.

(From yocto-docs rev: 4f2c3bc93d97a6a8676fdd14ff9061bb92bdf5c9)

Signed-off-by: Scott Rifenbark <scott.m.rifenbark@intel.com>
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>
This commit is contained in:
Scott Rifenbark
2011-08-18 10:45:23 -07:00
committed by Richard Purdie
parent 90d5834ad2
commit ed4caadd13
1 changed files with 186 additions and 216 deletions
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402
documentation/poky-ref-manual/development.xml
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@@ -325,20 +325,23 @@
</section>
<section id="platdev-gdb-remotedebug">
<title>Debugging with GDB Remotely</title>
<title>Debugging With the GNU Project Debugger (GDB) Remotely</title>
<para>
GNU Project Debugger (GDB)
allows you to examine running programs to understand and fix problems and
also to perform post-mortem style analysis of program crashes.
GDB is available as a package within Poky and by default is installed in sdk images.
See <ulink url="http://sourceware.org/gdb/"/> for the GDB source.
GDB allows you to examine running programs, which in turn help you to understand and fix problems.
It also allows you to perform post-mortem style analysis of program crashes.
GDB is available as a package within the Yocto Project and by default is
installed in sdk images.
See <xref linkend='ref-images'>Reference: Images</xref> for a description of these
images.
You can find information on GDB at <ulink url="http://sourceware.org/gdb/"/>.
</para>
<tip><para>
For best results install <filename>-dbg</filename> packages for the applications
<tip>
For best results, install <filename>-dbg</filename> packages for the applications
you are going to debug.
Doing so makes available extra debug symbols that will give you more meaningful output.
</para></tip>
Doing so makes available extra debug symbols that give you more meaningful output.
</tip>
<para>
Sometimes, due to memory or disk space constraints, it is not possible
@@ -351,58 +354,62 @@
These extra computations place more load on the target system and can alter the
characteristics of the program being debugged.
</para>
<para>
To help get past these constraints you can use GDBSERVER.
It runs on the remote target and does not load any debugging information
To help get past the previously mentioned constraints, you can use Gdbserver.
Gdbserver runs on the remote target and does not load any debugging information
from the debugged process.
Instead, a GDB instance processes the debugging information that is run on a
remote computer - the host GDB.
The host GDB then sends control commands to GDBSERVER to make it stop or start the debugged
program, as well as read or write memory regions of that debugged
program.
The host GDB then sends control commands to Gdbserver to make it stop or start the debugged
program, as well as read or write memory regions of that debugged program.
All the debugging information loaded and processed as well
as all the heavy debugging is done by the host GDB.
Offloading these processes gives the GDBSERVER running on the target a chance to remain
Offloading these processes gives the Gdbserver running on the target a chance to remain
small and fast.
</para>
<para>
Because the host GDB is responsible for loading the debugging information and
for doing the necessary processing to make actual debugging happen, the
user has to make sure the host can access the unstripped binaries complete
with their debugging information and also compiled with no optimizations.
with their debugging information and also be sure the target is compiled with no optimizations.
The host GDB must also have local access to all the libraries used by the
debugged program.
Because GDBSERVER does not need any local debugging information the binaries on
Because Gdbserver does not need any local debugging information, the binaries on
the remote target can remain stripped.
However, the binaries must also be compiled without optimization
so they match the host's binaries.
</para>
<para>
To remain consistent with GDB documentation and terminology the binary being debugged
on the remote target machine is referred to as the 'inferior' binary.
For documentation on GDB see the GDB site at
<ulink url="http://sourceware.org/gdb/documentation/">on their site</ulink>.
To remain consistent with GDB documentation and terminology, the binary being debugged
on the remote target machine is referred to as the "inferior" binary.
For documentation on GDB see the
<ulink url="http://sourceware.org/gdb/documentation/">GDB site</ulink>.
</para>
<section id="platdev-gdb-remotedebug-launch-gdbserver">
<title>Launching GDBSERVER on the Target</title>
<title>Launching Gdbserver on the Target</title>
<para>
First, make sure GDBSERVER is installed on the target. If not,
install the package <filename>gdbserver</filename>, which needs the
First, make sure Gdbserver is installed on the target.
If it is not, install the package <filename>gdbserver</filename>, which needs the
<filename>libthread-db1</filename> package.
</para>
<para>
As an example, to launch GDBSERVER on the target and make it ready to "debug" a
As an example, to launch Gdbserver on the target and make it ready to "debug" a
program located at <filename>/path/to/inferior</filename>, connect
to the target and launch:
<literallayout class='monospaced'>
$ gdbserver localhost:2345 /path/to/inferior
</literallayout>
GDBSERVER should now be listening on port 2345 for debugging
Gdbserver should now be listening on port 2345 for debugging
commands coming from a remote GDB process that is running on the host computer.
Communication between GDBSERVER and the host GDB are done using TCP.
To use other communication protocols please refer to the GDBSERVER documentation.
Communication between Gdbserver and the host GDB are done using TCP.
To use other communication protocols, please refer to the
<ulink url='http://www.gnu.org/software/gdb/'>Gdbserver documentation</ulink>.
</para>
</section>
@@ -419,28 +426,29 @@
<para>
A suitable GDB cross-binary is required that runs on your host computer but
also knows about the the ABI of the remote target.
You can get this binary from the the Poky toolchain - for example:
<programlisting>
/usr/local/poky/eabi-glibc/arm/bin/arm-poky-linux-gnueabi-gdb
</programlisting>
where "arm" is the target architecture and "linux-gnueabi" the target ABI.
You can get this binary from the the Yocto Project meta-toolchain.
Here is an example:
<literallayout class='monospaced'>
/usr/local/poky/eabi-glibc/arm/bin/arm-poky-linux-gnueabi-gdb
</literallayout>
where <filename>arm</filename> is the target architecture and
<filename>linux-gnueabi</filename> the target ABI.
</para>
<para>
Alternatively, Poky can build the <filename>gdb-cross</filename> binary.
For example, the following command builds it:
Alternatively, the Yocto Project can build the <filename>gdb-cross</filename> binary.
Here is an example:
<literallayout class='monospaced'>
$ bitbake gdb-cross
</literallayout>
Once the binary is built you can find it here:
<programlisting>
tmp/sysroots/&lt;host-arch&gt;/usr/bin/&lt;target-abi&gt;-gdb
</programlisting>
Once the binary is built, you can find it here:
<literallayout class='monospaced'>
tmp/sysroots/&lt;host-arch&gt;/usr/bin/&lt;target-abi&gt;-gdb
</literallayout>
</para>
</section>
<section id="platdev-gdb-remotedebug-launch-gdb-inferiorbins">
<section id="platdev-gdb-remotedebug-launch-gdb-inferiorbins">
<title>Making the Inferior Binaries Available</title>
<para>
@@ -451,56 +459,58 @@ tmp/sysroots/&lt;host-arch&gt;/usr/bin/&lt;target-abi&gt;-gdb
</para>
<para>
Perhaps the easiest is to have an 'sdk' image that corresponds to the plain
Perhaps the easiest way is to have an 'sdk' image that corresponds to the plain
image installed on the device.
In the case of 'core-image-sato', 'core-image-sdk' would contain suitable symbols.
Because the sdk images already have the debugging symbols installed it is just a
In the case of <filename>core-image-sato</filename>,
<filename>core-image-sdk</filename> would contain suitable symbols.
Because the sdk images already have the debugging symbols installed, it is just a
question of expanding the archive to some location and then informing GDB.
</para>
<para>
Alternatively, Poky can build a custom directory of files for a specific
Alternatively, Yocto Project can build a custom directory of files for a specific
debugging purpose by reusing its <filename>tmp/rootfs</filename> directory.
This directory contains the contents of the last built image.
This process assumes two things:
<itemizedlist>
<listitem><para>The image running on the target was the last image to
be built by Poky.</para></listitem>
be built by the Yocto Project.</para></listitem>
<listitem><para>The package (<filename>foo</filename> in the following
example) that contains the inferior binary to be debugged has been built
without optimization and has debugging information available.</para></listitem>
</itemizedlist>
</para>
<para>
These steps show how to build the custom directory of files:
The following steps show how to build the custom directory of files:
<orderedlist>
<listitem><para>Install the package (<filename>foo</filename> in this case) to
<filename>tmp/rootfs</filename>:
<literallayout class='monospaced'>
$ tmp/sysroots/i686-linux/usr/bin/opkg-cl -f \
tmp/work/&lt;target-abi&gt;/core-image-sato-1.0-r0/temp/opkg.conf -o \
tmp/rootfs/ update
</literallayout></para></listitem>
<listitem><para>Install the debugging information:
<literallayout class='monospaced'>
$ tmp/sysroots/i686-linux/usr/bin/opkg-cl -f \
tmp/work/&lt;target-abi&gt;/core-image-sato-1.0-r0/temp/opkg.conf \
-o tmp/rootfs install foo
$ tmp/sysroots/i686-linux/usr/bin/opkg-cl -f \
tmp/work/&lt;target-abi&gt;/core-image-sato-1.0-r0/temp/opkg.conf \
-o tmp/rootfs install foo-dbg
</literallayout></para></listitem>
</orderedlist>
</para>
<orderedlist>
<listitem><para>Install the package (<filename>foo</filename> in this case) to
<filename>tmp/rootfs</filename>:
<programlisting>
tmp/sysroots/i686-linux/usr/bin/opkg-cl -f \
tmp/work/&lt;target-abi&gt;/core-image-sato-1.0-r0/temp/opkg.conf -o \
tmp/rootfs/ update
</programlisting></para></listitem>
<listitem><para>Install the debugging information:
<programlisting>
tmp/sysroots/i686-linux/usr/bin/opkg-cl -f \
tmp/work/&lt;target-abi&gt;/core-image-sato-1.0-r0/temp/opkg.conf \
-o tmp/rootfs install foo
tmp/sysroots/i686-linux/usr/bin/opkg-cl -f \
tmp/work/&lt;target-abi&gt;/core-image-sato-1.0-r0/temp/opkg.conf \
-o tmp/rootfs install foo-dbg
</programlisting></para></listitem>
</orderedlist>
</section>
<section id="platdev-gdb-remotedebug-launch-gdb-launchhost">
<section id="platdev-gdb-remotedebug-launch-gdb-launchhost">
<title>Launch the Host GDB</title>
<para>
To launch the host GDB, you run the cross-gdb binary and provide the inferior
binary as part of the command line.
To launch the host GDB, you run the <filename>cross-gdb</filename> binary and provide
the inferior binary as part of the command line.
For example, the following command form continues with the example used in
the previous section.
This command form loads the <filename>foo</filename> binary
@@ -517,21 +527,22 @@ tmp/work/&lt;target-abi&gt;/core-image-sato-1.0-r0/temp/opkg.conf \
the absolute path to <filename>tmp/rootfs</filename> or the location at which
binaries with debugging information reside.
</para>
<para>
At this point you can have GDB connect to the GDBSERVER that is running
At this point you can have GDB connect to the Gdbserver that is running
on the remote target by using the following command form:
<literallayout class='monospaced'>
$ target remote remote-target-ip-address:2345
</literallayout>
The <filename>remote-target-ip-address</filename> is the IP address of the
remote target where the GDBSERVER is running.
remote target where the Gdbserver is running.
Port 2345 is the port on which the GDBSERVER is running.
</para>
</section>
<section id="platdev-gdb-remotedebug-launch-gdb-using">
<section id="platdev-gdb-remotedebug-launch-gdb-using">
<title>Using the Debugger</title>
<para>
You can now proceed with debugging as normal - as if you were debugging
on the local machine.
@@ -543,13 +554,13 @@ tmp/work/&lt;target-abi&gt;/core-image-sato-1.0-r0/temp/opkg.conf \
(gdb) continue
</literallayout>
</para>
<para>
For more information about using GDB, see the project's online documentation at
<ulink url="http://sourceware.org/gdb/download/onlinedocs/"/>.
</para>
</section>
</section>
</section>
<section id="platdev-oprofile">
@@ -561,32 +572,33 @@ tmp/work/&lt;target-abi&gt;/core-image-sato-1.0-r0/temp/opkg.conf \
bottlenecks in both userspace software and in the kernel.
This profiler provides answers to questions like "Which functions does my application spend
the most time in when doing X?"
Because Poky is well integrated with OProfile it makes profiling applications on target
Because the Yocto Project is well integrated with OProfile, it makes profiling applications on target
hardware straightforward.
</para>
<para>
To use OProfile you need an image that has OProfile installed.
The easiest way to do this is with "tools-profile" in
<glossterm><link linkend='var-IMAGE_FEATURES'>IMAGE_FEATURES</link></glossterm>.
To use OProfile, you need an image that has OProfile installed.
The easiest way to do this is with <filename>tools-profile</filename> in the
<filename><link linkend='var-IMAGE_FEATURES'>IMAGE_FEATURES</link></filename> variable.
You also need debugging symbols to be available on the system where the analysis
takes place.
You can gain access to the symbols by using "dbg-pkgs" in
<glossterm><link linkend='var-IMAGE_FEATURES'>IMAGE_FEATURES</link></glossterm> or by
You can gain access to the symbols by using <filename>dbg-pkgs</filename> in the
<filename>IMAGE_FEATURES</filename> variable or by
installing the appropriate <filename>-dbg</filename> packages.
</para>
<para>
For successful call graph analysis the binaries must preserve the frame
For successful call graph analysis, the binaries must preserve the frame
pointer register and should also be compiled with the
"-fno-omit-framepointer" flag.
In Poky you can achieve this by setting
<glossterm><link linkend='var-SELECTED_OPTIMIZATION'>SELECTED_OPTIMIZATION
</link></glossterm> to "-fexpensive-optimizations -fno-omit-framepointer
-frename-registers -O2".
You can also achieve it by setting
<glossterm><link linkend='var-DEBUG_BUILD'>DEBUG_BUILD</link></glossterm> to "1" in
<filename>local.conf</filename>.
If you use the DEBUG_BUILD variable you will also add extra debug information
<filename>-fno-omit-framepointer</filename> flag.
In the Yocto Project you can achieve this by setting the
<filename><link linkend='var-SELECTED_OPTIMIZATION'>SELECTED_OPTIMIZATION
</link></filename> variable to
<filename>-fexpensive-optimizations -fno-omit-framepointer -frename-registers -O2</filename>.
You can also achieve it by setting the
<filename><link linkend='var-DEBUG_BUILD'>DEBUG_BUILD</link></filename> variable to "1" in
the <filename>local.conf</filename> configuration file.
If you use the <filename>DEBUG_BUILD</filename> variable you will also add extra debug information
that can make the debug packages large.
</para>
@@ -600,46 +612,51 @@ tmp/work/&lt;target-abi&gt;/core-image-sato-1.0-r0/temp/opkg.conf \
<para>
<literallayout class='monospaced'>
# opcontrol --reset
# opcontrol --start --separate=lib --no-vmlinux -c 5
[do whatever is being profiled]
# opcontrol --stop
$ opreport -cl
# opcontrol --reset
# opcontrol --start --separate=lib --no-vmlinux -c 5
.
.
[do whatever is being profiled]
.
.
# opcontrol --stop
$ opreport -cl
</literallayout>
</para>
<para>
In this example, the reset command clears any previously profiled data.
In this example, the <filename>reset</filename> command clears any previously profiled data.
The next command starts OProfile.
The options used when starting the profiler separate dynamic library data
within applications, disable kernel profiling, and enable callgraphing up to
five levels deep.
<note>
To profile the kernel, you would specify the
<filename>--vmlinux=/path/to/vmlinux</filename> option.
The <filename>vmlinux</filename> file is usually in the Yocto Project file's
<filename>/boot/</filename> directory and must match the running kernel.
</note>
</para>
<note><para>
To profile the kernel, you would specify the
<parameter>--vmlinux=/path/to/vmlinux</parameter> option.
The vmlinux file is usually in <filename class="directory">/boot/</filename>
in Poky and must match the running kernel.
</para></note>
<para>
After you perform your profiling tasks, the next command stops the profiler.
After that you can view results with the "opreport" command with options
After that, you can view results with the <filename>opreport</filename> command with options
to see the separate library symbols and callgraph information.
</para>
<para>
Callgraphing logs information about time spent in functions and about a function's
calling function (parent) and called functions (children).
The higher the callgraphing depth,
the more accurate the results.
However, higher depths also increase the logging
overhead.
The higher the callgraphing depth, the more accurate the results.
However, higher depths also increase the logging overhead.
Consequently, you should take care when setting the callgraphing depth.
<note>
On ARM, binaries need to have the frame pointer enabled for callgraphing to work.
To accomplish this use the <filename>-fno-omit-framepointer</filename> option
with <filename>gcc</filename>.
</note>
</para>
<note><para>
On ARM, binaries need to have the frame pointer enabled for callgraphing to work.
To accomplish this use the <filename>-fno-omit-framepointer</filename> option
with <filename>gcc</filename>.
</para></note>
<para>
For more information on using OProfile, see the OProfile
online documentation at
@@ -652,35 +669,14 @@ $ opreport -cl
<para>
A graphical user interface for OProfile is also available.
You can download and build it from the Yocto Project at
You can download and build this interface from the Yocto Project at
<ulink url="http://git.yoctoproject.org/cgit.cgi/oprofileui/"></ulink>.
If the "tools-profile" image feature is selected, all necessary binaries
are installed onto the target device for OProfileUI interaction.
</para>
<!-- DISABLED, Need a more 'contextual' shot?
<screenshot>
<mediaobject>
<imageobject>
<imagedata fileref="screenshots/ss-oprofile-viewer.png" format="PNG"/>
</imageobject>
<caption>
<para>OProfileUI Viewer showing an application being profiled on a remote device</para>
</caption>
</mediaobject>
</screenshot>
<para>
In order to convert the data in the sample format from the target
to the host you need the <filename>opimport</filename> program.
This program is not included in standard Debian OProfile packages.
However, an OProfile package with this addition is available from the
<ulink url='http://debian.o-hand.com/'>OpenedHand repository</ulink>.
We recommend using OProfile 0.9.3 or greater.
</para>
-->
<para>
Even though Poky usually includes all needed patches on the target device, you
Even though the Yocto Project usually includes all needed patches on the target device, you
might find you need other OProfile patches for recent OProfileUI features.
If so, see the <ulink url='http://git.yoctoproject.org/cgit.cgi/oprofileui/tree/README'>
OProfileUI README</ulink> for the most recent information.
@@ -693,101 +689,74 @@ $ opreport -cl
Using OProfile in online mode assumes a working network connection with the target
hardware.
With this connection, you just need to run "oprofile-server" on the device.
By default OProfile listens on port 4224.
By default, OProfile listens on port 4224.
<note>
You can change the port using the <filename>--port</filename> command-line
option.
</note>
</para>
<note><para>
You can change the port using the <filename>--port</filename> command-line
option.
</para></note>
<para>
The client program is called "oprofile-viewer" and its UI is relatively
The client program is called <filename>oprofile-viewer</filename> and its UI is relatively
straightforward.
You access key functionality through the buttons on the toolbar, which
are duplicated in the menus.
The buttons are:
</para>
<itemizedlist>
<listitem>
<para>
Connect - Connects to the remote host.
You can also supply the IP address or hostname.
</para>
</listitem>
<listitem>
<para>
Disconnect - Disconnects from the target.
</para>
</listitem>
<listitem>
<para>
Start - Starts profiling on the device.
</para>
</listitem>
<listitem>
<para>
Stop - Stops profiling on the device and downloads the data to the local
host.
Here are the buttons:
<itemizedlist>
<listitem><para><emphasis>Connect:</emphasis> Connects to the remote host.
You can also supply the IP address or hostname.</para></listitem>
<listitem><para><emphasis>Disconnect:</emphasis> Disconnects from the target.
</para></listitem>
<listitem><para><emphasis>Start:</emphasis> Starts profiling on the device.
</para></listitem>
<listitem><para><emphasis>Stop:</emphasis> Stops profiling on the device and
downloads the data to the local host.
Stopping the profiler generates the profile and displays it in the viewer.
</para>
</listitem>
<listitem>
<para>
Download - Downloads the data from the target and generates the profile,
which appears in the viewer.
</para>
</listitem>
<listitem>
<para>
Reset - Resets the sample data on the device.
</para></listitem>
<listitem><para><emphasis>Download:</emphasis> Downloads the data from the
target and generates the profile, which appears in the viewer.</para></listitem>
<listitem><para><emphasis>Reset:</emphasis> Resets the sample data on the device.
Resetting the data removes sample information collected from previous
sampling runs.
Be sure you reset the data if you do not want to include old sample information.
</para>
</listitem>
<listitem>
<para>
Save - Saves the data downloaded from the target to another directory for later
examination.
</para>
</listitem>
<listitem>
<para>
Open - Loads previously saved data.
</para>
</listitem>
</itemizedlist>
</para></listitem>
<listitem><para><emphasis>Save:</emphasis> Saves the data downloaded from the
target to another directory for later examination.</para></listitem>
<listitem><para><emphasis>Open:</emphasis> Loads previously saved data.
</para></listitem>
</itemizedlist>
</para>
<para>
The client downloads the complete 'profile archive' from
the target to the host for processing.
This archive is a directory that contains the sample data, the object files
This archive is a directory that contains the sample data, the object files,
and the debug information for the object files.
The archive is then converted using the "oparchconv" script, which is
The archive is then converted using the <filename>oparchconv</filename> script, which is
included in this distribution.
The script uses "opimport" to convert the archive from
The script uses <filename>opimport</filename> to convert the archive from
the target to something that can be processed on the host.
</para>
<para>
Downloaded archives reside in <filename>/tmp</filename> and are cleared up
when they are no longer in use.
Downloaded archives reside in the Yocto Project's build directory in
<filename>/tmp</filename> and are cleared up when they are no longer in use.
</para>
<para>
If you wish to perform kernel profiling you need to be sure
a "vmlinux" file that matches the running kernel is available.
In Poky, that file is usually located in
<filename>/boot/vmlinux-KERNELVERSION</filename>, where KERNEL-version is the
version of the kernel.
Poky generates separate vmlinux packages for each kernel
it builds so it should be a question of just making sure a matching package is
installed - for example: <filename>opkg install kernel-vmlinux</filename>.
If you wish to perform kernel profiling, you need to be sure
a <filename>vmlinux</filename> file that matches the running kernel is available.
In the Yocto Project, that file is usually located in
<filename>/boot/vmlinux-KERNELVERSION</filename>, where
<filename>KERNEL-version</filename> is the version of the kernel.
The Yocto Project generates separate <filename>vmlinux</filename> packages for each kernel
it builds.
Thus, it should just be a question of making sure a matching package is
installed (e.g. <filename>opkg install kernel-vmlinux</filename>.
The files are automatically installed into development and profiling images
alongside OProfile.
There is a configuration option within the OProfileUI settings page where
you can enter the location of the vmlinux file.
A configuration option exists within the OProfileUI settings page that you can use to
enter the location of the <filename>vmlinux</filename> file.
</para>
<para>
@@ -795,9 +764,9 @@ $ opreport -cl
is not always necessary to actually have them on the device for OProfile use.
All that is needed is a copy of the filesystem with the debug symbols present
on the viewer system.
The "<link linkend='platdev-gdb-remotedebug-launch-gdb'>Launching GDB
on the Host Computer</link>" section covers how to create such a directory with Poky and
how to use the OProfileUI Settings dialog to specify the location.
The <link linkend='platdev-gdb-remotedebug-launch-gdb'>Launching GDB
on the Host Computer</link> section covers how to create such a directory with
the Yocto Project and how to use the OProfileUI Settings dialog to specify the location.
If you specify the directory, it will be used when the file checksums
match those on the system you are profiling.
</para>
@@ -808,24 +777,25 @@ $ opreport -cl
<para>
If network access to the target is unavailable, you can generate
an archive for processing in "oprofile-viewer" as follows:
</para>
<para>
an archive for processing in <filename>oprofile-viewer</filename> as follows:
<literallayout class='monospaced'>
# opcontrol --reset
# opcontrol --start --separate=lib --no-vmlinux -c 5
.
.
[do whatever is being profiled]
.
.
# opcontrol --stop
# oparchive -o my_archive
</literallayout>
</para>
<para>
In the above example <filename>my_archive</filename> is the name of the
In the above example, <filename>my_archive</filename> is the name of the
archive directory where you would like the profile archive to be kept.
After the directory is created, you can copy it to another host and load it
using "oprofile-viewer" open functionality.
using <filename>oprofile-viewer</filename> open functionality.
If necessary, the archive is converted.
</para>
</section>