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Work Package 2 Identification and Formalization of Knowledge

“(The report proposes) a generic technique for defining programming model specific abstractions allowing a simple description of compound runtime events in the context of that programming model.” a technique for detecting the existence of behaviors that lead

to reduced performance General Idea:

A Compound Runtime Event (CRE) is built from primitive events (trace file entries) such as those associated with entering a program region or seinding a message.

A CRE can also be regarded as an event pattern that can be found by applying pattern matching algorithms

For these methods to work it is necessary for trace files to include timestamp and location of execution AND some information regarding what state the program is in. Ex. Send and Recv pair messages, Enter and Exit pair for

region

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Primitive Event Objects

Class “Event” is defined, and subclasses of events inherit from it

Events have data fields and pointers All object of class “Event” have a

“enterptr” which points back to the “Enter” “Receive” objects also have a “sendptr”

Define two state functions to represent state of execution R(l) l=location and M(s,d) s=sender

d=receiver. R(l) represents the region stack M(s, d) represents the message queue

At each event the two the state of the functions is updated according to transition rules. send, and enter add new messages to the

message queue, and regions to the region stack

recv, and exit remove messages from the queue, and pop region from region stack

Using these functions one can define pattern (CRE) to check for at event as the trace is traversed

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Compound Runtime Events

A Compound Runtime Event is then specified in terms of “partitions” of events (root, send_msg,enter_send, enter_send) using a simple search algorithm Ex. Late Sender

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Compound Runtime Events

It is possible to extend this concept to the APART Specification Language.

ASL data model Mainly concentrates on profiling data, i.e. summary information

Examples are given. This approach is based on EARL trace analysis language.

EXPERT tool is based on top of EARL EXPERT is a part of KOJAK, to be evaluated later this semester

Trace examination speedup may be gained by automating the process, and specifying significant CREs before the process begins.