Execution policy creator for Kokkos (or "polk" for short) is a header-only library that proposes a class to build an execution policy step by step.

This library is a proof of concept.

The best way is to use CMake.

Get the library in your project:

git clone https://github.com/cexa-project/polk.git path/to/polk

In your main CMake file:

add_subdirectory(path/to/polk)

target_link_libraries(
    my-lib
    PRIVATE
        Polk::polk
)

In your main CMake file:

include(FetchContent)
FetchContent_Declare(
    polk
    GIT_REPOSITORY https://github.com/CExA-project/polk.git
    GIT_TAG master
)
FetchContent_MakeAvailable(polk)

target_link_libraries(
    my-lib
    PRIVATE
        Polk::polk
)

Get, then install the project:

git clone https://github.com/cexa-project/polk.git
cd polk
cmake -B build -DCMAKE_INSTALL_PREFIX=path/to/install -DCMAKE_BUILD_TYPE=Release # other Kokkos options here if needed
cmake --install build

In your main CMake file:

find_package(Polk REQUIRED)

target_link_libraries(
    my-lib
    PRIVATE
        Polk::polk
)

Alternatively, you can also copy include/polk in your project and start using it.

You can build tests with the CMake option POLK_ENABLE_TESTS, and run them with ctest.

If you don't have a GPU available when compiling, you have to disable the CMake option POLK_ENABLE_GTEST_DISCOVER_TESTS.

You can build examples with the CMake option POLK_ENABLE_EXAMPLES. They should be run individually.

Benchmarks are built with the CMake option POLK_ENABLE_BENCHMARKS. They should be run individually.

The library provides a ExecutionPolicyCreator class that is created without arguments, and where execution policy parameters are added successively with the with method. Finally, the execution policy is retrieved with the getPolicy method:

#include <Kokkos_Core.hpp>
#include <polk/execution_policy_creator.hpp>

void doSomething() {
    Kokkos::parallel_for(
        "do something",
        polk::ExecutionPolicyCreator()
            .with(polk::Range<2>({0, 0}, {100, 100}))
            .with(polk::Tiling<2>({10, 10}))
            .with(Kokkos::DefaultHostExecutionSpace())
            .getPolicy(),
        KOKKOS_LAMBDA (int const i, int const j) {
            /* ... */
        }
    );
}

The with method can be called at different times:

#include <Kokkos_Core.hpp>
#include <polk/execution_policy_creator.hpp>

template <typename ExecutionPolicyCreator, typename Kernel>
void doSomething(ExecutionPolicyCreator const& policy, Kernel const& kernel) {
    Kokkos::parallel_for(
        "do something",
        policy
            .with(Kokkos::DefaultHostExecutionSpace())
            .getPolicy(),
        kernel
    );
}

void prepareSomething() {
    doSomething(
        polk::ExecutionPolicyCreator()
            .with(polk::Range<2>({0, 0}, {100, 100}))
            .with(polk::Tiling<2>({10, 10})),
        KOKKOS_LAMBDA (int const i, int const j) {
            /* ... */
        }
    );
}