pc(1) NAME pc - perturbance compensation for an AIMS Trace file SYNOPSIS pc [ -options ] [ tracefile [ new tracefile ] ] DESCRIPTION pc tries to remove monitoring overhead from a trace file. Two kinds of intrusions are considered: the CPU overhead due to the execution of instrumentation software and file-system usage for storing trace data (trace flushing) during program execution. Currently, the user has to supply the overhead values via a parameter file. pc maintains the consistency of send-receive-block relation- ships across nodes and preserves barrier-synchronization patterns. The message routing time between nodes is determined for two possible scenarios: a) a communication model with empirical values to estimate the transmit time, or b) "measured" com- munication time for the case where the receiving request started before the sending occurred. pc allows user to test both cases. Several communication models (LAN, MODEL, SP2, LOWER) are built into the current implementation of pc and can be selected from command line options. OPTIONS -file pfile gives a file that contains overhead experimental data or parameter file names. -b indicates that broadcasts should be output as broad- casts. -comm Model defines a communication model. Possible Model values are: LAN (local area network), MODEL (modeling by "latency+speed*size"), SP2 (IBM SP2), and LOWER (for a lower bound). -latency value defines latency for MODEL. -sfactor factor defines speed factor (per byte) for MODEL. -mtime uses measured communication time if receiving request occurred before sending. -nsort do not post-sort new trace file (default is to sort). -help if present, a brief help message is printed. The default input trace file name is TRACE.SORT, and the default output trace file name is TRACE.PC.UNSORT (unsorted, if [-nsort] option is selected) or TRACE.PC.SORT (sorted). File names may also be specified in a file via [-file name], using the format "<file type> <filename>" on each line, where <file type> is one of TRACE_FILE input trace file, NEW_TRACE_FILE new output trace file, COMM_PARAM_FILE communication parameter file (not yet functioning), OH_PARAM_FILE overhead parameter file. The data format of this file is "<event-type> <overhead-1> <overhead-2>" on each line. Please refer to AIMS' Reference Manual for the values of <event-type>. <overhead-1> and <overhead-2> are overhead values (in seconds) of the first and second clock measurements for a given event type. SEE ALSO AIMS(1), xinstrument(1), tracesort(1), VK(1), tally(1) The AIMS Reference Manual AIMS Release 3.7 Last change: 2 July 1997