2.4. Battery Life Tool Kit

Red Hat Enterprise Linux 6 introduces the Battery Life Tool Kit (BLTK), a test suite that simulates and analyzes battery life and performance. BLTK achieves this by performing sets of tasks that simulate specific user groups and reporting on the results. Although developed specifically to test notebook performance, BLTK can also report on the performance of desktop computers when started with the -a.

BLTK allows you to generate very reproducible workloads that are comparable to real use of a machine. For example, the office workload writes a text, corrects things in it, and does the same for a spreadsheet. Running BLTK combined with PowerTOP or any of the other auditing or analysis tool allows you to test if the optimizations you performed have an effect when the machine is actively in use instead of only idling. Because you can run the exact same workload multiple times for different settings, you can compare results for different settings.

Install BLTK with the command:

yum install bltk

Run BLTK with the command:

bltk workload options

For example, to run the idle workload for 120 seconds:

bltk -I -T 120

The workloads available by default are:

-I, --idle: system is idle, to use as a baseline for comparison with other workloads
-R, --reader: simulates reading documents (by default, with Firefox)
-P, --player: simulates watching multimedia files from a CD or DVD drive (by default, with mplayer)
-O, --office: simulates editing documents with the OpenOffice.org suite

Other options allow you to specify:

-a, --ac-ignore: ignore whether AC power is available (necessary for desktop use)
-T number_of_seconds, --time number_of_seconds: the time (in seconds) over which to run the test; use this option with the idle workload
-F filename, --file filename: specifies a file to be used by a particular workload, for example, a file for the player workload to play instead of accessing the CD or DVD drive
-W application, --prog application: specifies an application to be used by a particular workload, for example, a browser other than Firefox for the reader workload

BLTK supports a large number of more specialized options. For details, refer to the bltk man page.

BLTK saves the results that it generates in a directory specified in the /etc/bltk.conf configuration file — by default, ~/.bltk/workload.results.number/. For example, the ~/.bltk/reader.results.002/ directory holds the results of the third test with the reader workload (the first test is not numbered). The results are spread across several text files. To condense these results into a format that is easy to read, run:

bltk_report path_to_results_directory

The results now appear in a text file named Report in the results directory. To view the results in a terminal emulator instead, use the -o option:

bltk_report -o path_to_results_directory