Re: [Starpu-devel] StarPU: questions about performance model

[Samuel Thibault <samuel.thibault@ens-lyon.org>]

Hello,

Leo Li, le Fri 17 Jun 2011 11:43:20 +0200, a écrit :
> 1) There is one API(starpu_load_history_debug) which can be used to
> load history-based performance model. If the performance model have
> multiple entries for cpu, and given the size and layout of parameters
> I need to find the right entry. Does anybody know how to find the
> right entry according to size and layout of parameters? Which APIs
> should I use?
> 
> 2) Could someone send me more information or an example about
> regression model? How does it work?

I have just added these yesterday to the documentation:

“For instance, @code{tests/perfmodels/regression_based.c} uses a
regression-based performance model for the @code{memset} operation”

“The application can request time estimations from the StarPU performance
models by filling a task structure as usual without actually submitting
it. The data handles can be created by calling @code{starpu_data_register}
functions with a @code{NULL} pointer (and need to be unregistered as usual)
and the desired data sizes. The @code{starpu_task_expected_length} and
@code{starpu_task_expected_power} functions can then be called to get an
estimation of the task duration on a given arch. @code{starpu_task_destroy}
needs to be called to destroy the dummy task afterwards.”

Samuel