Trace control

When a PDT-enabled application starts, PDT reads its configuration from a file. The PDT configuration for DaCS is separate from the configuration for your job.

Environment variable

PDT supports an environment variable (PDT_CONFIG_FILE) which allows you to specify the relative or full path to a configuration file. DaCS will ship an example configuration file which lists all of the DaCS groups and events and allows you to turn selected items on or off as desired. This will be shipped as:

/usr/share/pdt/config/pdt_dacs_config_cell.xml

In order to see the trace events the application must be built with the trace-enabled libraries. To see SPE events the application's SPE code must be rebuilt with special compile settings (see the PDT User's Guide for specifics) and needs to be linked with /usr/spu/lib/dacs/trace/libdacs.a, the trace-enabled DaCS SPU library code. To see PPE events the application must use the trace-enabled DaCS PPU code. If the application is using the static PPU library then it must be re-linked with /usr/lib64/dacs/trace/libdacs.a, the trace-enabled DaCS PPU library code. If the application was built using the shared PPU library then no re-linking is needed. In that case the library path must be changed to point to the trace-enabled PPU code as well as the PDT trace library, by setting the environment before running the application:

LD_LIBRARY_PATH=/usr/lib64/dacs/trace:/usr/lib64/trace