About this task
Sessions store and organize the results of several performance
tuning Activities. A Session must be created before any Activities
are created.
- Make sure the Performance Tuning perspective
is open.
- Right click the Sessions node in
the Performance Explorer view and select New
Session.
The New Performance Tuning Session
Wizard will open.
- Enter a name for the new Session.
- Select a remote C/C++ project.
- Select a remote context for the project, consisting of
the build host and project location. This should be the context that
is used to build the application, and is where the application's
source code can be found (if available).
- If the build host will also be used to run the application
then leave Same as build host checked. If the
application will be run on a different host then uncheck the box and
select the runtime host. If the desired runtime host is not listed
then cancel the wizard, create
a connection to the runtime host, and then open the New
Performance Tuning Session Wizard again.
Note: On
Linux, runtime data collection must run as the root user, so if you
choose a remote Linux connection it must be connected as root.
- Select a folder on the runtime host where temporary files
will be stored during the performance run. These files
will be automatically deleted after the performance run completes.
- Click the Use Default button
to select the default location for the user account on the runtime
machine.
- Click the Browse button to select
a specific location.
- Click Next.

- If your runtime system is a local Linux system, you
will be asked to select a root access command. On Linux, runtime data
collection must be run as the root user. Choose or enter a graphical
command that can authenticate that you have root privileges and run
a command as root; different Linux distributions and desktops have
different commands. A terminal command such as su or sudo is
not sufficient, since the data collection is not performed in a terminal.
If no other commands are available, you may be able to run sudo in
a graphical terminal, for example by entering xterm -x
sudo as your root access command, but the terminal command
must wait for the command it runs to complete before it exits;gnome-terminal is
not a suitable terminal command for this reason.
- Click Next

The second page of the wizard is used
to enter the executables and shared libraries that make up the application.
This page is optional, however it is strongly recommended to enter
this information because it will help produce useful feedback on how
to increase the application's performance.
- Add executables by clicking the Add button
next to the Executables list, or click Scan to
search the project area for executables.
Many applications
consist of a single executable, however if your application consists
of multiple executables then please enter them all.
- Add shared libraries by clicking the Add button
next to the Shared Libraries list.
Enter
the shared libraries that are built along with the application for
which you would like to collect performance data. It is not necessary
to list 3rd party or system libraries.
- Click Next.
If your application contains a mixture of C/C++ and Java
code this page allows you to specify the percentage of time that the
application usually spends executing Java code. This information will
allow Performance Advisor to provide feedback on the Java portion
of your application.
If your application does not contain
any Java code then click Next to skip to the
next page.
If your application does contain some Java code
then either enter the percentage of Java in the text box or use the
slider to select a value between 1 and 100.
Enter the path
to one or more JREs on the runtime system that may be used by the
application. You can click the Scan button
to automatically scan the system for JREs installed in typical locations.
Alternatively you can add each JRE by clicking the Add... button
and browsing to the folder on the remote host that contains the JRE.
Feedback on the installed JREs can be found in the System Scorecard
view after running an Activity.
If you wish to performance
analyze your Java code, a Java5 or newer IBM JRE is required. If you
select a single IBM JRE here, Performance Advisor may be able to perform
this analysis automatically, see Creating a Hotspot Detection Activity for
more information.
- Click Next.
It is recommended to begin performance tuning by running
a System Scorecard Activity. This Activity will: 1) validate the runtime
host by checking for the required system tools and 2) provide suggestions
for configuration changes that can increase the application's performance.
- On Power systems only, select the minimum platform on which
the application is expected to run. Select Auto if
you are not sure what the minimum platform should be.
- On Power systems only, select the ideal platform. Recommendations
will focus on performance tuning for this platform. Select Auto if
you are not sure what the ideal platform should be.
- Click Finish. The newly
created Session will appear in the Performance Explorer