1. Computer Architecture Group U.S.C.
PPC: Performance prediction for selected application kernels Task 2.3.2
Computer Architecture Group
U.S.C.

2. Introduction
The global purpose of the tool is to provide performance information about some important computational MPI kernels when they are executed in a Grid.
Two main works:
To establish analytical models for:
Basic simple kernels.
Kernels from applications.
A friendly to use Java GUI integrated in the M.D.

3. Establishing the models
Monitoring information is needed
X# monitoring not yet available for our needs
Latency, bandwidth between any pair of nodes at any time
In this meeting, we have contacted to Task 3.3 to adapt X# monitoring system to our needs
More collaboration with Task 2.3 (GridBench) started to solve common problems
NWS: installed in some sites as a temporary solution
NWS allows us to sensor monitoring information between sites and also inside of them.
Configurable to obtain data in any moment to know the current status of the Grid.

4. Establishing the models
To take measures of execution time for the kernel: K measurements, Tk.
At the same time, to get instant information from monitoring: M monitoring tests
Measures of latency, Li, and bandwidth, Wi.
We define a test cube in a three-dimensional space {L, W, T}
This test cube is limited by the maximum and the minimum values of these parameters.

5. Establishing the models
Monitoring measures must show enough homogeneity for the correlation search.
In each test cube
The meant point
Representative value
The size of the cube
Dispersion of the data

6. Establishing the models
Tests with different monitoring conditions and different kernel situations (size of the problem, etc.) determine several cube of tests.
To obtain the correlation
To establish the models

7. Analytical models for kernels
Vertlq (from Task 1.4, air pollution task)
Communications: is done
Computations: is in progress
Code was modified in order to use the size of the problem as a input parameter
To take measurements for different scenarios
PETSc (from Task 1.2, to solve linear systems)
Communications and computations: characterized for same cases. Generalization is in progress.

9. Current status and future work
We use NWS monitoring system, as a temporary solution, to obtain the analytical models.
To try to use a X# monitoring system.
We have models of some kernels in homogeneous systems.
We are adding more functionalities to the GUI.
We are completing models for some application kernels:
Vertlq, PETSc, ...
When done, to include them in the GUI.