void OpenMP::partition_master( F const& f
, int num_partitions
, int partition_size
)
{
if (omp_get_nested()) {
using Exec = Impl::OpenMPExec;
Exec * prev_instance = Impl::t_openmp_instance;
Exec::validate_partition( prev_instance->m_pool_size, num_partitions, partition_size );
OpenMP::memory_space space;
#pragma omp parallel num_threads(num_partitions)
{
void * const ptr = space.allocate( sizeof(Exec) );
Impl::t_openmp_instance = new (ptr) Exec( partition_size );
size_t pool_reduce_bytes = 32 * partition_size ;
size_t team_reduce_bytes = 32 * partition_size ;
size_t team_shared_bytes = 1024 * partition_size ;
size_t thread_local_bytes = 1024 ;
Impl::t_openmp_instance->resize_thread_data( pool_reduce_bytes
, team_reduce_bytes
, team_shared_bytes
, thread_local_bytes
);
omp_set_num_threads(partition_size);
f( omp_get_thread_num(), omp_get_num_threads() );
Impl::t_openmp_instance->~Exec();
space.deallocate( Impl::t_openmp_instance, sizeof(Exec) );
Impl::t_openmp_instance = nullptr;
}
Impl::t_openmp_instance = prev_instance;
}
else {
// nested openmp not enabled
f(0,1);
}
}
void OpenMP::impl_initialize( int thread_count )
#endif
{
if ( omp_in_parallel() ) {
std::string msg("Kokkos::OpenMP::initialize ERROR : in parallel");
Kokkos::Impl::throw_runtime_exception(msg);
}
if ( Impl::t_openmp_instance )
{
finalize();
}
{
if ( Kokkos::show_warnings() && nullptr == std::getenv("OMP_PROC_BIND") ) {
printf("Kokkos::OpenMP::initialize WARNING: OMP_PROC_BIND environment variable not set\n");
printf(" In general, for best performance with OpenMP 4.0 or better set OMP_PROC_BIND=spread and OMP_PLACES=threads\n");
printf(" For best performance with OpenMP 3.1 set OMP_PROC_BIND=true\n");
printf(" For unit testing set OMP_PROC_BIND=false\n");
}
OpenMP::memory_space space ;
// Before any other call to OMP query the maximum number of threads
// and save the value for re-initialization unit testing.
#ifdef KOKKOS_ENABLE_DEPRECATED_CODE
Impl::g_openmp_hardware_max_threads = get_current_max_threads();
#else
Impl::g_openmp_hardware_max_threads = impl_get_current_max_threads();
#endif
int process_num_threads = Impl::g_openmp_hardware_max_threads;
if ( Kokkos::hwloc::available() ) {
process_num_threads = Kokkos::hwloc::get_available_numa_count()
* Kokkos::hwloc::get_available_cores_per_numa()
* Kokkos::hwloc::get_available_threads_per_core();
}
// if thread_count < 0, use g_openmp_hardware_max_threads;
// if thread_count == 0, set g_openmp_hardware_max_threads to process_num_threads
// if thread_count > 0, set g_openmp_hardware_max_threads to thread_count
if (thread_count < 0 ) {
thread_count = Impl::g_openmp_hardware_max_threads;
}
else if( thread_count == 0 && Impl::g_openmp_hardware_max_threads != process_num_threads ) {
Impl::g_openmp_hardware_max_threads = process_num_threads;
omp_set_num_threads(Impl::g_openmp_hardware_max_threads);
}
else {
if( Kokkos::show_warnings() && thread_count > process_num_threads ) {
printf( "Kokkos::OpenMP::initialize WARNING: You are likely oversubscribing your CPU cores.\n");
printf( " process threads available : %3d, requested thread : %3d\n", process_num_threads, thread_count );
}
Impl::g_openmp_hardware_max_threads = thread_count;
omp_set_num_threads(Impl::g_openmp_hardware_max_threads);
}
// setup thread local
#pragma omp parallel num_threads(Impl::g_openmp_hardware_max_threads)
{
Impl::t_openmp_instance = nullptr;
Impl::t_openmp_hardware_id = omp_get_thread_num();
Impl::SharedAllocationRecord< void, void >::tracking_enable();
}
void * const ptr = space.allocate( sizeof(Impl::OpenMPExec) );
Impl::t_openmp_instance = new (ptr) Impl::OpenMPExec( Impl::g_openmp_hardware_max_threads );
// New, unified host thread team data:
{
size_t pool_reduce_bytes = 32 * thread_count ;
size_t team_reduce_bytes = 32 * thread_count ;
size_t team_shared_bytes = 1024 * thread_count ;
size_t thread_local_bytes = 1024 ;
Impl::t_openmp_instance->resize_thread_data( pool_reduce_bytes
, team_reduce_bytes
, team_shared_bytes
, thread_local_bytes
);
}
}
// Check for over-subscription
if( Kokkos::show_warnings() && (Impl::mpi_ranks_per_node() * long(thread_count) > Impl::processors_per_node()) ) {
std::cerr << "Kokkos::OpenMP::initialize WARNING: You are likely oversubscribing your CPU cores." << std::endl;
std::cerr << " Detected: " << Impl::processors_per_node() << " cores per node." << std::endl;
std::cerr << " Detected: " << Impl::mpi_ranks_per_node() << " MPI_ranks per node." << std::endl;
std::cerr << " Requested: " << thread_count << " threads per process." << std::endl;
}
// Init the array for used for arbitrarily sized atomics
Impl::init_lock_array_host_space();
#if defined(KOKKOS_ENABLE_DEPRECATED_CODE) && defined(KOKKOS_ENABLE_PROFILING)
Kokkos::Profiling::initialize();
#endif
}
void OpenMPExec::resize_thread_data( size_t pool_reduce_bytes
, size_t team_reduce_bytes
, size_t team_shared_bytes
, size_t thread_local_bytes )
{
const size_t member_bytes =
sizeof(int64_t) *
HostThreadTeamData::align_to_int64( sizeof(HostThreadTeamData) );
HostThreadTeamData * root = m_pool[0] ;
const size_t old_pool_reduce = root ? root->pool_reduce_bytes() : 0 ;
const size_t old_team_reduce = root ? root->team_reduce_bytes() : 0 ;
const size_t old_team_shared = root ? root->team_shared_bytes() : 0 ;
const size_t old_thread_local = root ? root->thread_local_bytes() : 0 ;
const size_t old_alloc_bytes = root ? ( member_bytes + root->scratch_bytes() ) : 0 ;
// Allocate if any of the old allocation is tool small:
const bool allocate = ( old_pool_reduce < pool_reduce_bytes ) ||
( old_team_reduce < team_reduce_bytes ) ||
( old_team_shared < team_shared_bytes ) ||
( old_thread_local < thread_local_bytes );
if ( allocate ) {
if ( pool_reduce_bytes < old_pool_reduce ) { pool_reduce_bytes = old_pool_reduce ; }
if ( team_reduce_bytes < old_team_reduce ) { team_reduce_bytes = old_team_reduce ; }
if ( team_shared_bytes < old_team_shared ) { team_shared_bytes = old_team_shared ; }
if ( thread_local_bytes < old_thread_local ) { thread_local_bytes = old_thread_local ; }
const size_t alloc_bytes =
member_bytes +
HostThreadTeamData::scratch_size( pool_reduce_bytes
, team_reduce_bytes
, team_shared_bytes
, thread_local_bytes );
OpenMP::memory_space space ;
memory_fence();
#pragma omp parallel num_threads(m_pool_size)
{
const int rank = omp_get_thread_num();
if ( 0 != m_pool[rank] ) {
m_pool[rank]->disband_pool();
space.deallocate( m_pool[rank] , old_alloc_bytes );
}
void * const ptr = space.allocate( alloc_bytes );
m_pool[ rank ] = new( ptr ) HostThreadTeamData();
m_pool[ rank ]->
scratch_assign( ((char *)ptr) + member_bytes
, alloc_bytes
, pool_reduce_bytes
, team_reduce_bytes
, team_shared_bytes
, thread_local_bytes
);
memory_fence();
}
/* END #pragma omp parallel */
HostThreadTeamData::organize_pool( m_pool , m_pool_size );
}
}