2.2 PROJECTIONS Tracing Modules at Application Link Time

PROJECTIONS tracing modules dictate the type of performance data, data detail and data format each processor will record. They are also refered to as ``tracemodes''. There are currently 2 tracemodes available. Zero or more tracemodes may be specified at link-time. When no tracemodes are specified, no trace data is generated.

2.2.1 Tracemode projections

Link time option: -tracemode projections

This tracemode generates detailed event log files that contain information about all CHARM++ events like entry method calls and message packing during the execution of the program. The data will be used by PROJECTIONS in visualization and analysis.

This tracemode will generate a single symbol table file and ASCII log files for processors. The names of the log files will be NAME.#.log where NAME is the name of your executable and # is the processor #. The name of the symbol table file is NAME.sts where NAME is the name of your executable.

This is the main source of data expected by the performance visualizer. Certain tools like timeline will not work without the detailed data from this tracemode.

The following is a list of runtime options available under this tracemode:

• +logsize NUM: keep only NUM log entries in the memory of each processor. The logs are emptied and flushed to disk when filled.
• +binary-trace: generate projections log in binary form.
• +gz-trace: generated gzip (if available) compressed log files.
• +checknested: a debug option. Checks if events are improperly nested while recorded and issue a warning immediately.

2.2.2 Tracemode summary

Compile option: -tracemode summary

In this tracemode, execution time across all entry points for each processor is partitioned into a fixed number of equally sized time-interval bins. These bins are globally resized whenever they are all filled in order to accomodate longer execution times while keeping the amount of space used constant.

Additional data like the total number of calls made to each entry point is summarised within each processor.

This tracemode will generate a single symbol table file and ASCII summary files for processors. The names of the summary files will be NAME.#.sum where NAME is the name of your executable and # is the processor #. The name of the symbol table file is NAME.sum.sts where NAME is the name of your executable.

This tracemode can be used to control the amount of output generated in a run. It is typically used in scenarios where a quick look at the overall utilization graph of the application is desired to identify smaller regions of time for more detailed study. Attempting to generate the same graph using the detailed logs of the prior tracemode may be unnecessarily time consuming or impossible.

The following is a list of runtime options available under this tracemode:

• +bincount NUM: use NUM time-interval bins. The bins are resized and compacted when filled.
• +binsize TIME: sets the initial time quantum each bin represents.
• +version: set summary version to generate.
• +sumDetail: Generates a additional set of files, one per processor, that stores the time spent by each entry method associated with each time-bin. The names of ``summary detail'' files will be NAME.#.sumd where NAME is the name of your executable and # is the processor #.
• +sumOnly: Generates an additional file that stores a single utilization value per time-bin, averaged across all processors. This file bears the name NAME.sum where NAME is the name of your executable. This runtime option currently overrides the +sumDetail option.