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

[Cédric Augonnet <cedric.augonnet@inria.fr>]

Hi,

Did you include <starpu_scheduler.h> in your code?

Best,
Cédric

On 20/06/2011 11:01, Leo Li wrote:
> Hi, Sameul
>
> I want to ask a silly question.
>
> When I use @code{starpu_task_expected_length} from external
> application, I have link error  undefined reference to
> `starpu_task_expected_length(starpu_task*, starpu_perf_archtype)'.
> Could you tell me how to use this function from an external
> application?
>
> Thanks in advance.
>
>
> On Fri, Jun 17, 2011 at 11:51 AM, Samuel Thibault
> <samuel.thibault@ens-lyon.org>  wrote:
> > 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