Reduce data access type whenever possible

This PR aims at reducing the data access type to enable more cases with the allocation on the fly.

For example, with a gemm: alpha A *B + beta * C, and beta = 0. C is used only as output, and not as inout. This changes all the codelets to STARPU_VARIABLE_NBUFFERS.

changed milestone to %Chameleon 1.1.0

added Feature StarPU labels

@all and more specifically to the StarPU guys. What is the best ?

• Use STARPU_VARIABLE_NBUFFERS everywhere as it does not change anything
• Set the number of buffers as before whenever it's possible, and change it to variable only for the codelets which need it.

I'm wondering, because either I simplify the macro to declare the codelet by removing an argument everywhere, or I change the parameter in this macro only where it is necessary.

There is no real performance hit in using VARIABLE_NBUFFERS, so if it makes the code simpler that's fine :)

Perfect. So I'll simplify this :).

added 1 commit

• ea4026f2 - Remove the nbuffer parameter from the codelet declaration

Compare with previous version

I just checked on one node of bora with potrf, and indeed it's in the noise :). So unless anyone complains today, I'll merge this one tonight, in order to apply it to other runtimes too.

merged

mentioned in commit e428d838

mentioned in merge request !216 (merged)