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Kokkos_QthreadExec.hpp
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/*
//@HEADER
// ************************************************************************
//
// Kokkos v. 2.0
// Copyright (2014) 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)
//
// ************************************************************************
//@HEADER
*/
#ifndef KOKKOS_QTHREADEXEC_HPP
#define KOKKOS_QTHREADEXEC_HPP
#include <impl/Kokkos_spinwait.hpp>
//----------------------------------------------------------------------------
namespace Kokkos {
namespace Impl {
//----------------------------------------------------------------------------
class QthreadExec ;
typedef void (*QthreadExecFunctionPointer)( QthreadExec & , const void * );
class QthreadExec {
private:
enum { Inactive = 0 , Active = 1 };
const QthreadExec * const * m_worker_base ;
const QthreadExec * const * m_shepherd_base ;
void * m_scratch_alloc ; ///< Scratch memory [ reduce , team , shared ]
int m_reduce_end ; ///< End of scratch reduction memory
int m_shepherd_rank ;
int m_shepherd_size ;
int m_shepherd_worker_rank ;
int m_shepherd_worker_size ;
/*
* m_worker_rank = m_shepherd_rank * m_shepherd_worker_size + m_shepherd_worker_rank
* m_worker_size = m_shepherd_size * m_shepherd_worker_size
*/
int m_worker_rank ;
int m_worker_size ;
int mutable volatile m_worker_state ;
friend class Kokkos::Qthread ;
~QthreadExec();
QthreadExec( const QthreadExec & );
QthreadExec & operator = ( const QthreadExec & );
public:
QthreadExec();
/** Execute the input function on all available Qthread workers */
static void exec_all( Qthread & , QthreadExecFunctionPointer , const void * );
//----------------------------------------
/** Barrier across all workers participating in the 'exec_all' */
void exec_all_barrier() const
{
const int rev_rank = m_worker_size - ( m_worker_rank + 1 );
int n , j ;
for ( n = 1 ; ( ! ( rev_rank & n ) ) && ( ( j = rev_rank + n ) < m_worker_size ) ; n <<= 1 ) {
Impl::spinwait( m_worker_base[j]->m_worker_state , QthreadExec::Active );
}
if ( rev_rank ) {
m_worker_state = QthreadExec::Inactive ;
Impl::spinwait( m_worker_state , QthreadExec::Inactive );
}
for ( n = 1 ; ( ! ( rev_rank & n ) ) && ( ( j = rev_rank + n ) < m_worker_size ) ; n <<= 1 ) {
m_worker_base[j]->m_worker_state = QthreadExec::Active ;
}
}
/** Barrier across workers within the shepherd with rank < team_rank */
void shepherd_barrier( const int team_size ) const
{
if ( m_shepherd_worker_rank < team_size ) {
const int rev_rank = team_size - ( m_shepherd_worker_rank + 1 );
int n , j ;
for ( n = 1 ; ( ! ( rev_rank & n ) ) && ( ( j = rev_rank + n ) < team_size ) ; n <<= 1 ) {
Impl::spinwait( m_shepherd_base[j]->m_worker_state , QthreadExec::Active );
}
if ( rev_rank ) {
m_worker_state = QthreadExec::Inactive ;
Impl::spinwait( m_worker_state , QthreadExec::Inactive );
}
for ( n = 1 ; ( ! ( rev_rank & n ) ) && ( ( j = rev_rank + n ) < team_size ) ; n <<= 1 ) {
m_shepherd_base[j]->m_worker_state = QthreadExec::Active ;
}
}
}
//----------------------------------------
/** Reduce across all workers participating in the 'exec_all' */
template< class FunctorType , class ArgTag >
inline
void exec_all_reduce( const FunctorType & func ) const
{
typedef Kokkos::Impl::FunctorValueJoin< FunctorType , ArgTag > ValueJoin ;
const int rev_rank = m_worker_size - ( m_worker_rank + 1 );
int n , j ;
for ( n = 1 ; ( ! ( rev_rank & n ) ) && ( ( j = rev_rank + n ) < m_worker_size ) ; n <<= 1 ) {
const QthreadExec & fan = *m_worker_base[j];
Impl::spinwait( fan.m_worker_state , QthreadExec::Active );
ValueJoin::join( func , m_scratch_alloc , fan.m_scratch_alloc );
}
if ( rev_rank ) {
m_worker_state = QthreadExec::Inactive ;
Impl::spinwait( m_worker_state , QthreadExec::Inactive );
}
for ( n = 1 ; ( ! ( rev_rank & n ) ) && ( ( j = rev_rank + n ) < m_worker_size ) ; n <<= 1 ) {
m_worker_base[j]->m_worker_state = QthreadExec::Active ;
}
}
//----------------------------------------
/** Scall across all workers participating in the 'exec_all' */
template< class FunctorType , class ArgTag >
inline
void exec_all_scan( const FunctorType & func ) const
{
typedef Kokkos::Impl::FunctorValueInit< FunctorType , ArgTag > ValueInit ;
typedef Kokkos::Impl::FunctorValueJoin< FunctorType , ArgTag > ValueJoin ;
typedef Kokkos::Impl::FunctorValueOps< FunctorType , ArgTag > ValueOps ;
const int rev_rank = m_worker_size - ( m_worker_rank + 1 );
int n , j ;
for ( n = 1 ; ( ! ( rev_rank & n ) ) && ( ( j = rev_rank + n ) < m_worker_size ) ; n <<= 1 ) {
Impl::spinwait( m_worker_base[j]->m_worker_state , QthreadExec::Active );
}
if ( rev_rank ) {
m_worker_state = QthreadExec::Inactive ;
Impl::spinwait( m_worker_state , QthreadExec::Inactive );
}
else {
// Root thread scans across values before releasing threads
// Worker data is in reverse order, so m_worker_base[0] is the
// highest ranking thread.
// Copy from lower ranking to higher ranking worker.
for ( int i = 1 ; i < m_worker_size ; ++i ) {
ValueOps::copy( func
, m_worker_base[i-1]->m_scratch_alloc
, m_worker_base[i]->m_scratch_alloc
);
}
ValueInit::init( func , m_worker_base[m_worker_size-1]->m_scratch_alloc );
// Join from lower ranking to higher ranking worker.
// Value at m_worker_base[n-1] is zero so skip adding it to m_worker_base[n-2].
for ( int i = m_worker_size - 1 ; --i ; ) {
ValueJoin::join( func , m_worker_base[i-1]->m_scratch_alloc , m_worker_base[i]->m_scratch_alloc );
}
}
for ( n = 1 ; ( ! ( rev_rank & n ) ) && ( ( j = rev_rank + n ) < m_worker_size ) ; n <<= 1 ) {
m_worker_base[j]->m_worker_state = QthreadExec::Active ;
}
}
//----------------------------------------
template< class Type>
inline
volatile Type * shepherd_team_scratch_value() const
{ return (volatile Type*)(((unsigned char *) m_scratch_alloc) + m_reduce_end); }
template< class Type >
inline
void shepherd_broadcast( Type & value , const int team_size , const int team_rank ) const
{
if ( m_shepherd_base ) {
Type * const shared_value = m_shepherd_base[0]->shepherd_team_scratch_value<Type>();
if ( m_shepherd_worker_rank == team_rank ) { *shared_value = value ; }
memory_fence();
shepherd_barrier( team_size );
value = *shared_value ;
}
}
template< class Type >
inline
Type shepherd_reduce( const int team_size , const Type & value ) const
{
*shepherd_team_scratch_value<Type>() = value ;
memory_fence();
const int rev_rank = team_size - ( m_shepherd_worker_rank + 1 );
int n , j ;
for ( n = 1 ; ( ! ( rev_rank & n ) ) && ( ( j = rev_rank + n ) < team_size ) ; n <<= 1 ) {
Impl::spinwait( m_shepherd_base[j]->m_worker_state , QthreadExec::Active );
}
if ( rev_rank ) {
m_worker_state = QthreadExec::Inactive ;
Impl::spinwait( m_worker_state , QthreadExec::Inactive );
}
else {
Type & accum = * m_shepherd_base[0]->shepherd_team_scratch_value<Type>();
for ( int i = 1 ; i < n ; ++i ) {
accum += * m_shepherd_base[i]->shepherd_team_scratch_value<Type>();
}
for ( int i = 1 ; i < n ; ++i ) {
* m_shepherd_base[i]->shepherd_team_scratch_value<Type>() = accum ;
}
memory_fence();
}
for ( n = 1 ; ( ! ( rev_rank & n ) ) && ( ( j = rev_rank + n ) < team_size ) ; n <<= 1 ) {
m_shepherd_base[j]->m_worker_state = QthreadExec::Active ;
}
return *shepherd_team_scratch_value<Type>();
}
template< class JoinOp >
inline
typename JoinOp::value_type
shepherd_reduce( const int team_size
, const typename JoinOp::value_type & value
, const JoinOp & op ) const
{
typedef typename JoinOp::value_type Type ;
*shepherd_team_scratch_value<Type>() = value ;
memory_fence();
const int rev_rank = team_size - ( m_shepherd_worker_rank + 1 );
int n , j ;
for ( n = 1 ; ( ! ( rev_rank & n ) ) && ( ( j = rev_rank + n ) < team_size ) ; n <<= 1 ) {
Impl::spinwait( m_shepherd_base[j]->m_worker_state , QthreadExec::Active );
}
if ( rev_rank ) {
m_worker_state = QthreadExec::Inactive ;
Impl::spinwait( m_worker_state , QthreadExec::Inactive );
}
else {
volatile Type & accum = * m_shepherd_base[0]->shepherd_team_scratch_value<Type>();
for ( int i = 1 ; i < team_size ; ++i ) {
op.join( accum , * m_shepherd_base[i]->shepherd_team_scratch_value<Type>() );
}
for ( int i = 1 ; i < team_size ; ++i ) {
* m_shepherd_base[i]->shepherd_team_scratch_value<Type>() = accum ;
}
memory_fence();
}
for ( n = 1 ; ( ! ( rev_rank & n ) ) && ( ( j = rev_rank + n ) < team_size ) ; n <<= 1 ) {
m_shepherd_base[j]->m_worker_state = QthreadExec::Active ;
}
return *shepherd_team_scratch_value<Type>();
}
template< class Type >
inline
Type shepherd_scan( const int team_size
, const Type & value
, Type * const global_value = 0 ) const
{
*shepherd_team_scratch_value<Type>() = value ;
memory_fence();
const int rev_rank = team_size - ( m_shepherd_worker_rank + 1 );
int n , j ;
for ( n = 1 ; ( ! ( rev_rank & n ) ) && ( ( j = rev_rank + n ) < team_size ) ; n <<= 1 ) {
Impl::spinwait( m_shepherd_base[j]->m_worker_state , QthreadExec::Active );
}
if ( rev_rank ) {
m_worker_state = QthreadExec::Inactive ;
Impl::spinwait( m_worker_state , QthreadExec::Inactive );
}
else {
// Root thread scans across values before releasing threads
// Worker data is in reverse order, so m_shepherd_base[0] is the
// highest ranking thread.
// Copy from lower ranking to higher ranking worker.
Type accum = * m_shepherd_base[0]->shepherd_team_scratch_value<Type>();
for ( int i = 1 ; i < team_size ; ++i ) {
const Type tmp = * m_shepherd_base[i]->shepherd_team_scratch_value<Type>();
accum += tmp ;
* m_shepherd_base[i-1]->shepherd_team_scratch_value<Type>() = tmp ;
}
* m_shepherd_base[team_size-1]->shepherd_team_scratch_value<Type>() =
global_value ? atomic_fetch_add( global_value , accum ) : 0 ;
// Join from lower ranking to higher ranking worker.
for ( int i = team_size ; --i ; ) {
* m_shepherd_base[i-1]->shepherd_team_scratch_value<Type>() += * m_shepherd_base[i]->shepherd_team_scratch_value<Type>();
}
memory_fence();
}
for ( n = 1 ; ( ! ( rev_rank & n ) ) && ( ( j = rev_rank + n ) < team_size ) ; n <<= 1 ) {
m_shepherd_base[j]->m_worker_state = QthreadExec::Active ;
}
return *shepherd_team_scratch_value<Type>();
}
//----------------------------------------
static inline
int align_alloc( int size )
{
enum { ALLOC_GRAIN = 1 << 6 /* power of two, 64bytes */};
enum { ALLOC_GRAIN_MASK = ALLOC_GRAIN - 1 };
return ( size + ALLOC_GRAIN_MASK ) & ~ALLOC_GRAIN_MASK ;
}
void shared_reset( Qthread::scratch_memory_space & );
void * exec_all_reduce_value() const { return m_scratch_alloc ; }
static void * exec_all_reduce_result();
static void resize_worker_scratch( const int reduce_size , const int shared_size );
static void clear_workers();
//----------------------------------------
inline int worker_rank() const { return m_worker_rank ; }
inline int worker_size() const { return m_worker_size ; }
inline int shepherd_worker_rank() const { return m_shepherd_worker_rank ; }
inline int shepherd_worker_size() const { return m_shepherd_worker_size ; }
inline int shepherd_rank() const { return m_shepherd_rank ; }
inline int shepherd_size() const { return m_shepherd_size ; }
static int worker_per_shepherd();
};
} /* namespace Impl */
} /* namespace Kokkos */
//----------------------------------------------------------------------------
namespace Kokkos {
namespace Impl {
class QthreadTeamPolicyMember {
private:
typedef Kokkos::Qthread execution_space ;
typedef execution_space::scratch_memory_space scratch_memory_space ;
Impl::QthreadExec & m_exec ;
scratch_memory_space m_team_shared ;
const int m_team_size ;
const int m_team_rank ;
const int m_league_size ;
const int m_league_end ;
int m_league_rank ;
public:
KOKKOS_INLINE_FUNCTION
const scratch_memory_space & team_shmem() const { return m_team_shared ; }
KOKKOS_INLINE_FUNCTION int league_rank() const { return m_league_rank ; }
KOKKOS_INLINE_FUNCTION int league_size() const { return m_league_size ; }
KOKKOS_INLINE_FUNCTION int team_rank() const { return m_team_rank ; }
KOKKOS_INLINE_FUNCTION int team_size() const { return m_team_size ; }
KOKKOS_INLINE_FUNCTION void team_barrier() const
#if ! defined( KOKKOS_ACTIVE_EXECUTION_MEMORY_SPACE_HOST )
{}
#else
{ m_exec.shepherd_barrier( m_team_size ); }
#endif
template< typename Type >
KOKKOS_INLINE_FUNCTION Type team_broadcast( const Type & value , int rank ) const
#if ! defined( KOKKOS_ACTIVE_EXECUTION_MEMORY_SPACE_HOST )
{ return Type(); }
#else
{ return m_exec.template shepherd_broadcast<Type>( value , m_team_size , rank ); }
#endif
template< typename Type >
KOKKOS_INLINE_FUNCTION Type team_reduce( const Type & value ) const
#if ! defined( KOKKOS_ACTIVE_EXECUTION_MEMORY_SPACE_HOST )
{ return Type(); }
#else
{ return m_exec.template shepherd_reduce<Type>( m_team_size , value ); }
#endif
template< typename JoinOp >
KOKKOS_INLINE_FUNCTION typename JoinOp::value_type
team_reduce( const typename JoinOp::value_type & value
, const JoinOp & op ) const
#if ! defined( KOKKOS_ACTIVE_EXECUTION_MEMORY_SPACE_HOST )
{ return typename JoinOp::value_type(); }
#else
{ return m_exec.template shepherd_reduce<JoinOp>( m_team_size , value , op ); }
#endif
/** \brief Intra-team exclusive prefix sum with team_rank() ordering.
*
* The highest rank thread can compute the reduction total as
* reduction_total = dev.team_scan( value ) + value ;
*/
template< typename Type >
KOKKOS_INLINE_FUNCTION Type team_scan( const Type & value ) const
#if ! defined( KOKKOS_ACTIVE_EXECUTION_MEMORY_SPACE_HOST )
{ return Type(); }
#else
{ return m_exec.template shepherd_scan<Type>( m_team_size , value ); }
#endif
/** \brief Intra-team exclusive prefix sum with team_rank() ordering
* with intra-team non-deterministic ordering accumulation.
*
* The global inter-team accumulation value will, at the end of the
* league's parallel execution, be the scan's total.
* Parallel execution ordering of the league's teams is non-deterministic.
* As such the base value for each team's scan operation is similarly
* non-deterministic.
*/
template< typename Type >
KOKKOS_INLINE_FUNCTION Type team_scan( const Type & value , Type * const global_accum ) const
#if ! defined( KOKKOS_ACTIVE_EXECUTION_MEMORY_SPACE_HOST )
{ return Type(); }
#else
{ return m_exec.template shepherd_scan<Type>( m_team_size , value , global_accum ); }
#endif
//----------------------------------------
// Private driver for task-team parallel
QthreadTeamPolicyMember();
//----------------------------------------
// Private for the driver ( for ( member_type i(exec,team); i ; i.next_team() ) { ... }
// Initialize
template< class Arg0 , class Arg1 >
QthreadTeamPolicyMember( Impl::QthreadExec & exec , const TeamPolicy<Arg0,Arg1,Qthread> & team )
: m_exec( exec )
, m_team_shared(0,0)
, m_team_size( team.m_team_size )
, m_team_rank( exec.shepherd_worker_rank() )
, m_league_size( team.m_league_size )
, m_league_end( team.m_league_size - team.m_shepherd_iter * ( exec.shepherd_size() - ( exec.shepherd_rank() + 1 ) ) )
, m_league_rank( m_league_end > team.m_shepherd_iter ? m_league_end - team.m_shepherd_iter : 0 )
{
m_exec.shared_reset( m_team_shared );
}
// Continue
operator bool () const { return m_league_rank < m_league_end ; }
// iterate
void next_team() { ++m_league_rank ; m_exec.shared_reset( m_team_shared ); }
};
} // namespace Impl
template< class Arg0 , class Arg1 >
class TeamPolicy< Arg0 , Arg1 , Kokkos::Qthread >
{
private:
const int m_league_size ;
const int m_team_size ;
const int m_shepherd_iter ;
public:
//! Tag this class as a kokkos execution policy
typedef TeamPolicy execution_policy ;
typedef Qthread execution_space ;
typedef typename
Impl::if_c< ! Impl::is_same< Kokkos::Qthread , Arg0 >::value , Arg0 , Arg1 >::type
work_tag ;
//----------------------------------------
template< class FunctorType >
inline static
int team_size_max( const FunctorType & )
{ return Qthread::instance().shepherd_worker_size(); }
template< class FunctorType >
static int team_size_recommended( const FunctorType & f )
{ return team_size_max( f ); }
template< class FunctorType >
inline static
int team_size_recommended( const FunctorType & f , const int& )
{ return team_size_max( f ); }
//----------------------------------------
inline int team_size() const { return m_team_size ; }
inline int league_size() const { return m_league_size ; }
// One active team per shepherd
TeamPolicy( Kokkos::Qthread & q
, const int league_size
, const int team_size
)
: m_league_size( league_size )
, m_team_size( team_size < q.shepherd_worker_size()
? team_size : q.shepherd_worker_size() )
, m_shepherd_iter( ( league_size + q.shepherd_size() - 1 ) / q.shepherd_size() )
{
}
// One active team per shepherd
TeamPolicy( const int league_size
, const int team_size
)
: m_league_size( league_size )
, m_team_size( team_size < Qthread::instance().shepherd_worker_size()
? team_size : Qthread::instance().shepherd_worker_size() )
, m_shepherd_iter( ( league_size + Qthread::instance().shepherd_size() - 1 ) / Qthread::instance().shepherd_size() )
{
}
typedef Impl::QthreadTeamPolicyMember member_type ;
friend class Impl::QthreadTeamPolicyMember ;
};
} /* namespace Kokkos */
//----------------------------------------------------------------------------
//----------------------------------------------------------------------------
#endif /* #define KOKKOS_QTHREADEXEC_HPP */
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