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Kokkos_Cuda_Impl.cu
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Kokkos_Cuda_Impl.cu

/*
//@HEADER
// ************************************************************************
//
// Kokkos: Manycore Performance-Portable Multidimensional Arrays
// Copyright (2012) Sandia Corporation
//
// Under the terms of Contract DE-AC04-94AL85000 with Sandia Corporation,
// the U.S. Government retains certain rights in this software.
//
// Redistribution and use in source and binary forms, with or without
// modification, are permitted provided that the following conditions are
// met:
//
// 1. Redistributions of source code must retain the above copyright
// notice, this list of conditions and the following disclaimer.
//
// 2. Redistributions in binary form must reproduce the above copyright
// notice, this list of conditions and the following disclaimer in the
// documentation and/or other materials provided with the distribution.
//
// 3. Neither the name of the Corporation nor the names of the
// contributors may be used to endorse or promote products derived from
// this software without specific prior written permission.
//
// THIS SOFTWARE IS PROVIDED BY SANDIA CORPORATION "AS IS" AND ANY
// EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
// IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
// PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL SANDIA CORPORATION OR THE
// CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
// EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
// PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
// PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
// LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
// NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
// SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
//
// Questions? Contact H. Carter Edwards (hcedwar@sandia.gov)
//
// ************************************************************************
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*/
/*--------------------------------------------------------------------------*/
/* Kokkos interfaces */
#include <Kokkos_Cuda.hpp>
#include <Cuda/Kokkos_Cuda_Internal.hpp>
#include <impl/Kokkos_Error.hpp>
/*--------------------------------------------------------------------------*/
/* Standard 'C' libraries */
#include <stdlib.h>
/* Standard 'C++' libraries */
#include <vector>
#include <iostream>
#include <sstream>
#include <string>
#ifdef KOKKOS_CUDA_USE_RELOCATABLE_DEVICE_CODE
__device__ __constant__
Kokkos::Impl::CudaTraits::ConstantGlobalBufferType
kokkos_impl_cuda_constant_memory_buffer ;
#endif
/*--------------------------------------------------------------------------*/
namespace Kokkos {
namespace Impl {
namespace {
__global__
void query_cuda_kernel_arch( int * d_arch )
{
#if defined( __CUDA_ARCH__ )
*d_arch = __CUDA_ARCH__ ;
#else
*d_arch = 0 ;
#endif
}
/** Query what compute capability is actually launched to the device: */
int cuda_kernel_arch()
{
int * d_arch = 0 ;
cudaMalloc( (void **) & d_arch , sizeof(int) );
query_cuda_kernel_arch<<<1,1>>>( d_arch );
int arch = 0 ;
cudaMemcpy( & arch , d_arch , sizeof(int) , cudaMemcpyDefault );
cudaFree( d_arch );
return arch ;
}
bool cuda_launch_blocking()
{
const char * env = getenv("CUDA_LAUNCH_BLOCKING");
if (env == 0) return false;
return atoi(env);
}
}
void cuda_device_synchronize()
{
static const bool launch_blocking = cuda_launch_blocking();
if (!launch_blocking) {
CUDA_SAFE_CALL( cudaDeviceSynchronize() );
}
}
void cuda_internal_error_throw( cudaError e , const char * name, const char * file, const int line )
{
std::ostringstream out ;
out << name << " error: " << cudaGetErrorString(e);
if (file) {
out << " " << file << ":" << line;
}
throw_runtime_exception( out.str() );
}
//----------------------------------------------------------------------------
// Some significant cuda device properties:
//
// cudaDeviceProp::name : Text label for device
// cudaDeviceProp::major : Device major number
// cudaDeviceProp::minor : Device minor number
// cudaDeviceProp::warpSize : number of threads per warp
// cudaDeviceProp::multiProcessorCount : number of multiprocessors
// cudaDeviceProp::sharedMemPerBlock : capacity of shared memory per block
// cudaDeviceProp::totalConstMem : capacity of constant memory
// cudaDeviceProp::totalGlobalMem : capacity of global memory
// cudaDeviceProp::maxGridSize[3] : maximum grid size
//
// Section 4.4.2.4 of the CUDA Toolkit Reference Manual
//
// struct cudaDeviceProp {
// char name[256];
// size_t totalGlobalMem;
// size_t sharedMemPerBlock;
// int regsPerBlock;
// int warpSize;
// size_t memPitch;
// int maxThreadsPerBlock;
// int maxThreadsDim[3];
// int maxGridSize[3];
// size_t totalConstMem;
// int major;
// int minor;
// int clockRate;
// size_t textureAlignment;
// int deviceOverlap;
// int multiProcessorCount;
// int kernelExecTimeoutEnabled;
// int integrated;
// int canMapHostMemory;
// int computeMode;
// int concurrentKernels;
// int ECCEnabled;
// int pciBusID;
// int pciDeviceID;
// int tccDriver;
// int asyncEngineCount;
// int unifiedAddressing;
// int memoryClockRate;
// int memoryBusWidth;
// int l2CacheSize;
// int maxThreadsPerMultiProcessor;
// };
namespace {
class CudaInternalDevices {
public:
enum { MAXIMUM_DEVICE_COUNT = 8 };
struct cudaDeviceProp m_cudaProp[ MAXIMUM_DEVICE_COUNT ] ;
int m_cudaDevCount ;
CudaInternalDevices();
static const CudaInternalDevices & singleton();
};
CudaInternalDevices::CudaInternalDevices()
{
// See 'cudaSetDeviceFlags' for host-device thread interaction
// Section 4.4.2.6 of the CUDA Toolkit Reference Manual
CUDA_SAFE_CALL (cudaGetDeviceCount( & m_cudaDevCount ) );
for ( int i = 0 ; i < m_cudaDevCount ; ++i ) {
CUDA_SAFE_CALL( cudaGetDeviceProperties( m_cudaProp + i , i ) );
}
}
const CudaInternalDevices & CudaInternalDevices::singleton()
{
static CudaInternalDevices self ; return self ;
}
}
//----------------------------------------------------------------------------
class CudaInternal {
private:
CudaInternal( const CudaInternal & );
CudaInternal & operator = ( const CudaInternal & );
public:
typedef Cuda::size_type size_type ;
int m_cudaDev ;
int m_cudaArch ;
unsigned m_maxWarpCount ;
unsigned m_maxBlock ;
unsigned m_maxSharedWords ;
size_type m_scratchSpaceCount ;
size_type m_scratchFlagsCount ;
size_type m_scratchUnifiedCount ;
size_type m_scratchUnifiedSupported ;
size_type * m_scratchSpace ;
size_type * m_scratchFlags ;
size_type * m_scratchUnified ;
static CudaInternal & singleton();
int verify_is_initialized( const char * const label ) const ;
int is_initialized() const
{ return 0 != m_scratchSpace && 0 != m_scratchFlags ; }
void initialize( int cuda_device_id );
void finalize();
void print_configuration( std::ostream & ) const ;
~CudaInternal();
CudaInternal()
: m_cudaDev( -1 )
, m_cudaArch( -1 )
, m_maxWarpCount( 0 )
, m_maxBlock( 0 )
, m_maxSharedWords( 0 )
, m_scratchSpaceCount( 0 )
, m_scratchFlagsCount( 0 )
, m_scratchUnifiedCount( 0 )
, m_scratchUnifiedSupported( 0 )
, m_scratchSpace( 0 )
, m_scratchFlags( 0 )
, m_scratchUnified( 0 )
{}
size_type * scratch_space( const size_type size );
size_type * scratch_flags( const size_type size );
size_type * scratch_unified( const size_type size );
};
//----------------------------------------------------------------------------
void CudaInternal::print_configuration( std::ostream & s ) const
{
const CudaInternalDevices & dev_info = CudaInternalDevices::singleton();
#if defined( KOKKOS_HAVE_CUDA )
s << "macro KOKKOS_HAVE_CUDA : defined" << std::endl ;
#endif
#if defined( CUDA_VERSION )
s << "macro CUDA_VERSION = " << CUDA_VERSION
<< " = version " << CUDA_VERSION / 1000
<< "." << ( CUDA_VERSION % 1000 ) / 10
<< std::endl ;
#endif
for ( int i = 0 ; i < dev_info.m_cudaDevCount ; ++i ) {
s << "Kokkos::Cuda[ " << i << " ] "
<< dev_info.m_cudaProp[i].name
<< " capability " << dev_info.m_cudaProp[i].major << "." << dev_info.m_cudaProp[i].minor
<< ", Total Global Memory: " << human_memory_size(dev_info.m_cudaProp[i].totalGlobalMem)
<< ", Shared Memory per Block: " << human_memory_size(dev_info.m_cudaProp[i].sharedMemPerBlock);
if ( m_cudaDev == i ) s << " : Selected" ;
s << std::endl ;
}
}
//----------------------------------------------------------------------------
CudaInternal::~CudaInternal()
{
if ( m_scratchSpace ||
m_scratchFlags ||
m_scratchUnified ) {
std::cerr << "Kokkos::Cuda ERROR: Failed to call Kokkos::Cuda::finalize()"
<< std::endl ;
std::cerr.flush();
}
m_cudaDev = -1 ;
m_cudaArch = -1 ;
m_maxWarpCount = 0 ;
m_maxBlock = 0 ;
m_maxSharedWords = 0 ;
m_scratchSpaceCount = 0 ;
m_scratchFlagsCount = 0 ;
m_scratchUnifiedCount = 0 ;
m_scratchUnifiedSupported = 0 ;
m_scratchSpace = 0 ;
m_scratchFlags = 0 ;
m_scratchUnified = 0 ;
}
int CudaInternal::verify_is_initialized( const char * const label ) const
{
if ( m_cudaDev < 0 ) {
std::cerr << "Kokkos::Cuda::" << label << " : ERROR device not initialized" << std::endl ;
}
return 0 <= m_cudaDev ;
}
CudaInternal & CudaInternal::singleton()
{
static CudaInternal self ;
return self ;
}
void CudaInternal::initialize( int cuda_device_id )
{
enum { WordSize = sizeof(size_type) };
if ( ! Cuda::host_mirror_device_type::is_initialized() ) {
const std::string msg("Cuda::initialize ERROR : Cuda::host_mirror_device_type is not initialized");
throw_runtime_exception( msg );
}
const CudaInternalDevices & dev_info = CudaInternalDevices::singleton();
const bool ok_init = 0 == m_scratchSpace || 0 == m_scratchFlags ;
const bool ok_id = 0 <= cuda_device_id &&
cuda_device_id < dev_info.m_cudaDevCount ;
// Need device capability 2.0 or better
const bool ok_dev = ok_id &&
( 2 <= dev_info.m_cudaProp[ cuda_device_id ].major &&
0 <= dev_info.m_cudaProp[ cuda_device_id ].minor );
if ( ok_init && ok_dev ) {
const struct cudaDeviceProp & cudaProp =
dev_info.m_cudaProp[ cuda_device_id ];
m_cudaDev = cuda_device_id ;
CUDA_SAFE_CALL( cudaSetDevice( m_cudaDev ) );
CUDA_SAFE_CALL( cudaDeviceReset() );
Kokkos::Impl::cuda_device_synchronize();
// Query what compute capability architecture a kernel executes:
m_cudaArch = cuda_kernel_arch();
if ( m_cudaArch != cudaProp.major * 100 + cudaProp.minor * 10 ) {
std::cerr << "Kokkos::Cuda::initialize WARNING: running kernels compiled for compute capability "
<< ( m_cudaArch / 100 ) << "." << ( ( m_cudaArch % 100 ) / 10 )
<< " on device with compute capability "
<< cudaProp.major << "." << cudaProp.minor
<< " , this will likely reduce potential performance."
<< std::endl ;
}
//----------------------------------
// Maximum number of warps,
// at most one warp per thread in a warp for reduction.
// HCE 2012-February :
// Found bug in CUDA 4.1 that sometimes a kernel launch would fail
// if the thread count == 1024 and a functor is passed to the kernel.
// Copying the kernel to constant memory and then launching with
// thread count == 1024 would work fine.
//
// HCE 2012-October :
// All compute capabilities support at least 16 warps (512 threads).
// However, we have found that 8 warps typically gives better performance.
m_maxWarpCount = 8 ;
// m_maxWarpCount = cudaProp.maxThreadsPerBlock / Impl::CudaTraits::WarpSize ;
if ( Impl::CudaTraits::WarpSize < m_maxWarpCount ) {
m_maxWarpCount = Impl::CudaTraits::WarpSize ;
}
m_maxSharedWords = cudaProp.sharedMemPerBlock / WordSize ;
//----------------------------------
// Maximum number of blocks:
m_maxBlock = m_cudaArch < 300 ? 65535 : cudaProp.maxGridSize[0] ;
//----------------------------------
m_scratchUnifiedSupported = cudaProp.unifiedAddressing ;
if ( ! m_scratchUnifiedSupported ) {
std::cout << "Kokkos::Cuda device "
<< cudaProp.name << " capability "
<< cudaProp.major << "." << cudaProp.minor
<< " does not support unified virtual address space"
<< std::endl ;
}
//----------------------------------
// Multiblock reduction uses scratch flags for counters
// and scratch space for partial reduction values.
// Allocate some initial space. This will grow as needed.
{
const unsigned reduce_block_count = m_maxWarpCount * Impl::CudaTraits::WarpSize ;
(void) scratch_unified( 16 * sizeof(size_type) );
(void) scratch_flags( reduce_block_count * 2 * sizeof(size_type) );
(void) scratch_space( reduce_block_count * 16 * sizeof(size_type) );
}
}
else {
std::ostringstream msg ;
msg << "Kokkos::Cuda::initialize(" << cuda_device_id << ") FAILED" ;
if ( ! ok_init ) {
msg << " : Already initialized" ;
}
if ( ! ok_id ) {
msg << " : Device identifier out of range "
<< "[0.." << dev_info.m_cudaDevCount << "]" ;
}
else if ( ! ok_dev ) {
msg << " : Device " ;
msg << dev_info.m_cudaProp[ cuda_device_id ].major ;
msg << "." ;
msg << dev_info.m_cudaProp[ cuda_device_id ].minor ;
msg << " has insufficient capability, required 2.0 or better" ;
}
Kokkos::Impl::throw_runtime_exception( msg.str() );
}
}
//----------------------------------------------------------------------------
typedef Cuda::size_type ScratchGrain[ Impl::CudaTraits::WarpSize ] ;
enum { sizeScratchGrain = sizeof(ScratchGrain) };
Cuda::size_type *
CudaInternal::scratch_flags( const Cuda::size_type size )
{
if ( verify_is_initialized("scratch_flags") && m_scratchFlagsCount * sizeScratchGrain < size ) {
Cuda::memory_space::decrement( m_scratchFlags );
m_scratchFlagsCount = ( size + sizeScratchGrain - 1 ) / sizeScratchGrain ;
m_scratchFlags = (size_type *)
Cuda::memory_space::allocate(
std::string("InternalScratchFlags") ,
typeid( ScratchGrain ),
sizeof( ScratchGrain ),
m_scratchFlagsCount );
CUDA_SAFE_CALL( cudaMemset( m_scratchFlags , 0 , m_scratchFlagsCount * sizeScratchGrain ) );
}
return m_scratchFlags ;
}
Cuda::size_type *
CudaInternal::scratch_space( const Cuda::size_type size )
{
if ( verify_is_initialized("scratch_space") && m_scratchSpaceCount * sizeScratchGrain < size ) {
Cuda::memory_space::decrement( m_scratchSpace );
m_scratchSpaceCount = ( size + sizeScratchGrain - 1 ) / sizeScratchGrain ;
m_scratchSpace = (size_type *)
Cuda::memory_space::allocate(
std::string("InternalScratchSpace") ,
typeid( ScratchGrain ),
sizeof( ScratchGrain ),
m_scratchSpaceCount );
}
return m_scratchSpace ;
}
Cuda::size_type *
CudaInternal::scratch_unified( const Cuda::size_type size )
{
if ( verify_is_initialized("scratch_unified") && m_scratchUnifiedSupported ) {
const bool allocate = m_scratchUnifiedCount * sizeScratchGrain < size ;
const bool deallocate = m_scratchUnified && ( 0 == size || allocate );
if ( allocate || deallocate ) {
Kokkos::Impl::cuda_device_synchronize();
}
if ( deallocate ) {
CUDA_SAFE_CALL( cudaFreeHost( m_scratchUnified ) );
m_scratchUnified = 0 ;
m_scratchUnifiedCount = 0 ;
}
if ( allocate ) {
m_scratchUnifiedCount = ( size + sizeScratchGrain - 1 ) / sizeScratchGrain ;
CUDA_SAFE_CALL( cudaHostAlloc( (void **)( & m_scratchUnified ) ,
m_scratchUnifiedCount * sizeScratchGrain ,
cudaHostAllocDefault ) );
}
}
return m_scratchUnified ;
}
//----------------------------------------------------------------------------
void CudaInternal::finalize()
{
if ( 0 != m_scratchSpace || 0 != m_scratchFlags ) {
Cuda::memory_space::decrement( m_scratchSpace );
Cuda::memory_space::decrement( m_scratchFlags );
(void) scratch_unified( 0 );
m_cudaDev = -1 ;
m_maxWarpCount = 0 ;
m_maxBlock = 0 ;
m_maxSharedWords = 0 ;
m_scratchSpaceCount = 0 ;
m_scratchFlagsCount = 0 ;
m_scratchSpace = 0 ;
m_scratchFlags = 0 ;
}
}
//----------------------------------------------------------------------------
Cuda::size_type cuda_internal_maximum_warp_count()
{ return CudaInternal::singleton().m_maxWarpCount ; }
Cuda::size_type cuda_internal_maximum_grid_count()
{ return CudaInternal::singleton().m_maxBlock ; }
Cuda::size_type cuda_internal_maximum_shared_words()
{ return CudaInternal::singleton().m_maxSharedWords ; }
Cuda::size_type * cuda_internal_scratch_space( const Cuda::size_type size )
{ return CudaInternal::singleton().scratch_space( size ); }
Cuda::size_type * cuda_internal_scratch_flags( const Cuda::size_type size )
{ return CudaInternal::singleton().scratch_flags( size ); }
Cuda::size_type * cuda_internal_scratch_unified( const Cuda::size_type size )
{ return CudaInternal::singleton().scratch_unified( size ); }
} // namespace Impl
} // namespace Kokkos
//----------------------------------------------------------------------------
namespace Kokkos {
Cuda::size_type Cuda::detect_device_count()
{ return Impl::CudaInternalDevices::singleton().m_cudaDevCount ; }
int Cuda::is_initialized()
{ return Impl::CudaInternal::singleton().is_initialized(); }
void Cuda::initialize( const Cuda::SelectDevice config )
{ Impl::CudaInternal::singleton().initialize( config.cuda_device_id ); }
void Cuda::initialize( const int device )
{ initialize( SelectDevice(device) ); }
void Cuda::initialize( const int device , const int )
{ initialize( device ); }
std::vector<unsigned>
Cuda::detect_device_arch()
{
const Impl::CudaInternalDevices & s = Impl::CudaInternalDevices::singleton();
std::vector<unsigned> output( s.m_cudaDevCount );
for ( int i = 0 ; i < s.m_cudaDevCount ; ++i ) {
output[i] = s.m_cudaProp[i].major * 100 + s.m_cudaProp[i].minor ;
}
return output ;
}
Cuda::size_type Cuda::device_arch()
{
const int dev_id = Impl::CudaInternal::singleton().m_cudaDev ;
int dev_arch = 0 ;
if ( 0 <= dev_id ) {
const struct cudaDeviceProp & cudaProp =
Impl::CudaInternalDevices::singleton().m_cudaProp[ dev_id ] ;
dev_arch = cudaProp.major * 100 + cudaProp.minor ;
}
return dev_arch ;
}
void Cuda::finalize()
{ Impl::CudaInternal::singleton().finalize(); }
void Cuda::print_configuration( std::ostream & s , const bool )
{ Impl::CudaInternal::singleton().print_configuration( s ); }
bool Cuda::sleep() { return false ; }
bool Cuda::wake() { return true ; }
void Cuda::fence()
{
Kokkos::Impl::cuda_device_synchronize();
}
unsigned Cuda::team_max()
{
return Impl::CudaInternal::singleton().m_maxWarpCount << Impl::CudaTraits::WarpIndexShift ;
}
unsigned Cuda::team_recommended()
{
// Recommend 8 warps to hide latency and be a power of two
return unsigned(8) << Impl::CudaTraits::WarpIndexShift ;
}
} // namespace Kokkos
//----------------------------------------------------------------------------

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