xgboost/plugin/sycl/common/hist_util.cc
Dmitry Razdoburdin 6a7c6a8ae6
add sycl reaslisation of ghist builder (#10138)
Co-authored-by: Dmitry Razdoburdin <>
2024-03-23 12:55:25 +08:00

335 lines
15 KiB
C++

/*!
* Copyright 2017-2023 by Contributors
* \file hist_util.cc
*/
#include <vector>
#include <limits>
#include <algorithm>
#include "../data/gradient_index.h"
#include "hist_util.h"
#include <CL/sycl.hpp>
namespace xgboost {
namespace sycl {
namespace common {
/*!
* \brief Fill histogram with zeroes
*/
template<typename GradientSumT>
void InitHist(::sycl::queue qu, GHistRow<GradientSumT, MemoryType::on_device>* hist,
size_t size, ::sycl::event* event) {
*event = qu.fill(hist->Begin(),
xgboost::detail::GradientPairInternal<GradientSumT>(), size, *event);
}
template void InitHist(::sycl::queue qu,
GHistRow<float, MemoryType::on_device>* hist,
size_t size, ::sycl::event* event);
template void InitHist(::sycl::queue qu,
GHistRow<double, MemoryType::on_device>* hist,
size_t size, ::sycl::event* event);
/*!
* \brief Compute Subtraction: dst = src1 - src2
*/
template<typename GradientSumT>
::sycl::event SubtractionHist(::sycl::queue qu,
GHistRow<GradientSumT, MemoryType::on_device>* dst,
const GHistRow<GradientSumT, MemoryType::on_device>& src1,
const GHistRow<GradientSumT, MemoryType::on_device>& src2,
size_t size, ::sycl::event event_priv) {
GradientSumT* pdst = reinterpret_cast<GradientSumT*>(dst->Data());
const GradientSumT* psrc1 = reinterpret_cast<const GradientSumT*>(src1.DataConst());
const GradientSumT* psrc2 = reinterpret_cast<const GradientSumT*>(src2.DataConst());
auto event_final = qu.submit([&](::sycl::handler& cgh) {
cgh.depends_on(event_priv);
cgh.parallel_for<>(::sycl::range<1>(2 * size), [pdst, psrc1, psrc2](::sycl::item<1> pid) {
const size_t i = pid.get_id(0);
pdst[i] = psrc1[i] - psrc2[i];
});
});
return event_final;
}
template ::sycl::event SubtractionHist(::sycl::queue qu,
GHistRow<float, MemoryType::on_device>* dst,
const GHistRow<float, MemoryType::on_device>& src1,
const GHistRow<float, MemoryType::on_device>& src2,
size_t size, ::sycl::event event_priv);
template ::sycl::event SubtractionHist(::sycl::queue qu,
GHistRow<double, MemoryType::on_device>* dst,
const GHistRow<double, MemoryType::on_device>& src1,
const GHistRow<double, MemoryType::on_device>& src2,
size_t size, ::sycl::event event_priv);
// Kernel with buffer using
template<typename FPType, typename BinIdxType, bool isDense>
::sycl::event BuildHistKernel(::sycl::queue qu,
const USMVector<GradientPair, MemoryType::on_device>& gpair_device,
const RowSetCollection::Elem& row_indices,
const GHistIndexMatrix& gmat,
GHistRow<FPType, MemoryType::on_device>* hist,
GHistRow<FPType, MemoryType::on_device>* hist_buffer,
::sycl::event event_priv) {
const size_t size = row_indices.Size();
const size_t* rid = row_indices.begin;
const size_t n_columns = isDense ? gmat.nfeatures : gmat.row_stride;
const GradientPair::ValueT* pgh =
reinterpret_cast<const GradientPair::ValueT*>(gpair_device.DataConst());
const BinIdxType* gradient_index = gmat.index.data<BinIdxType>();
const uint32_t* offsets = gmat.index.Offset();
FPType* hist_data = reinterpret_cast<FPType*>(hist->Data());
const size_t nbins = gmat.nbins;
const size_t max_work_group_size =
qu.get_device().get_info<::sycl::info::device::max_work_group_size>();
const size_t work_group_size = n_columns < max_work_group_size ? n_columns : max_work_group_size;
const size_t max_nblocks = hist_buffer->Size() / (nbins * 2);
const size_t min_block_size = 128;
size_t nblocks = std::min(max_nblocks, size / min_block_size + !!(size % min_block_size));
const size_t block_size = size / nblocks + !!(size % nblocks);
FPType* hist_buffer_data = reinterpret_cast<FPType*>(hist_buffer->Data());
auto event_fill = qu.fill(hist_buffer_data, FPType(0), nblocks * nbins * 2, event_priv);
auto event_main = qu.submit([&](::sycl::handler& cgh) {
cgh.depends_on(event_fill);
cgh.parallel_for<>(::sycl::nd_range<2>(::sycl::range<2>(nblocks, work_group_size),
::sycl::range<2>(1, work_group_size)),
[=](::sycl::nd_item<2> pid) {
size_t block = pid.get_global_id(0);
size_t feat = pid.get_global_id(1);
FPType* hist_local = hist_buffer_data + block * nbins * 2;
for (size_t idx = 0; idx < block_size; ++idx) {
size_t i = block * block_size + idx;
if (i < size) {
const size_t icol_start = n_columns * rid[i];
const size_t idx_gh = rid[i];
pid.barrier(::sycl::access::fence_space::local_space);
const BinIdxType* gr_index_local = gradient_index + icol_start;
for (size_t j = feat; j < n_columns; j += work_group_size) {
uint32_t idx_bin = static_cast<uint32_t>(gr_index_local[j]);
if constexpr (isDense) {
idx_bin += offsets[j];
}
if (idx_bin < nbins) {
hist_local[2 * idx_bin] += pgh[2 * idx_gh];
hist_local[2 * idx_bin+1] += pgh[2 * idx_gh+1];
}
}
}
}
});
});
auto event_save = qu.submit([&](::sycl::handler& cgh) {
cgh.depends_on(event_main);
cgh.parallel_for<>(::sycl::range<1>(nbins), [=](::sycl::item<1> pid) {
size_t idx_bin = pid.get_id(0);
FPType gsum = 0.0f;
FPType hsum = 0.0f;
for (size_t j = 0; j < nblocks; ++j) {
gsum += hist_buffer_data[j * nbins * 2 + 2 * idx_bin];
hsum += hist_buffer_data[j * nbins * 2 + 2 * idx_bin + 1];
}
hist_data[2 * idx_bin] = gsum;
hist_data[2 * idx_bin + 1] = hsum;
});
});
return event_save;
}
// Kernel with atomic using
template<typename FPType, typename BinIdxType, bool isDense>
::sycl::event BuildHistKernel(::sycl::queue qu,
const USMVector<GradientPair, MemoryType::on_device>& gpair_device,
const RowSetCollection::Elem& row_indices,
const GHistIndexMatrix& gmat,
GHistRow<FPType, MemoryType::on_device>* hist,
::sycl::event event_priv) {
const size_t size = row_indices.Size();
const size_t* rid = row_indices.begin;
const size_t n_columns = isDense ? gmat.nfeatures : gmat.row_stride;
const GradientPair::ValueT* pgh =
reinterpret_cast<const GradientPair::ValueT*>(gpair_device.DataConst());
const BinIdxType* gradient_index = gmat.index.data<BinIdxType>();
const uint32_t* offsets = gmat.index.Offset();
FPType* hist_data = reinterpret_cast<FPType*>(hist->Data());
const size_t nbins = gmat.nbins;
const size_t max_work_group_size =
qu.get_device().get_info<::sycl::info::device::max_work_group_size>();
const size_t feat_local = n_columns < max_work_group_size ? n_columns : max_work_group_size;
auto event_fill = qu.fill(hist_data, FPType(0), nbins * 2, event_priv);
auto event_main = qu.submit([&](::sycl::handler& cgh) {
cgh.depends_on(event_fill);
cgh.parallel_for<>(::sycl::range<2>(size, feat_local),
[=](::sycl::item<2> pid) {
size_t i = pid.get_id(0);
size_t feat = pid.get_id(1);
const size_t icol_start = n_columns * rid[i];
const size_t idx_gh = rid[i];
const BinIdxType* gr_index_local = gradient_index + icol_start;
for (size_t j = feat; j < n_columns; j += feat_local) {
uint32_t idx_bin = static_cast<uint32_t>(gr_index_local[j]);
if constexpr (isDense) {
idx_bin += offsets[j];
}
if (idx_bin < nbins) {
AtomicRef<FPType> gsum(hist_data[2 * idx_bin]);
AtomicRef<FPType> hsum(hist_data[2 * idx_bin + 1]);
gsum.fetch_add(pgh[2 * idx_gh]);
hsum.fetch_add(pgh[2 * idx_gh + 1]);
}
}
});
});
return event_main;
}
template<typename FPType, typename BinIdxType>
::sycl::event BuildHistDispatchKernel(
::sycl::queue qu,
const USMVector<GradientPair, MemoryType::on_device>& gpair_device,
const RowSetCollection::Elem& row_indices,
const GHistIndexMatrix& gmat,
GHistRow<FPType, MemoryType::on_device>* hist,
bool isDense,
GHistRow<FPType, MemoryType::on_device>* hist_buffer,
::sycl::event events_priv,
bool force_atomic_use) {
const size_t size = row_indices.Size();
const size_t n_columns = isDense ? gmat.nfeatures : gmat.row_stride;
const size_t nbins = gmat.nbins;
// max cycle size, while atomics are still effective
const size_t max_cycle_size_atomics = nbins;
const size_t cycle_size = size;
// TODO(razdoburdin): replace the add-hock dispatching criteria by more sutable one
bool use_atomic = (size < nbins) || (gmat.max_num_bins == gmat.nbins / n_columns);
// force_atomic_use flag is used only for testing
use_atomic = use_atomic || force_atomic_use;
if (!use_atomic) {
if (isDense) {
return BuildHistKernel<FPType, BinIdxType, true>(qu, gpair_device, row_indices,
gmat, hist, hist_buffer,
events_priv);
} else {
return BuildHistKernel<FPType, uint32_t, false>(qu, gpair_device, row_indices,
gmat, hist, hist_buffer,
events_priv);
}
} else {
if (isDense) {
return BuildHistKernel<FPType, BinIdxType, true>(qu, gpair_device, row_indices,
gmat, hist, events_priv);
} else {
return BuildHistKernel<FPType, uint32_t, false>(qu, gpair_device, row_indices,
gmat, hist, events_priv);
}
}
}
template<typename FPType>
::sycl::event BuildHistKernel(::sycl::queue qu,
const USMVector<GradientPair, MemoryType::on_device>& gpair_device,
const RowSetCollection::Elem& row_indices,
const GHistIndexMatrix& gmat, const bool isDense,
GHistRow<FPType, MemoryType::on_device>* hist,
GHistRow<FPType, MemoryType::on_device>* hist_buffer,
::sycl::event event_priv,
bool force_atomic_use) {
const bool is_dense = isDense;
switch (gmat.index.GetBinTypeSize()) {
case BinTypeSize::kUint8BinsTypeSize:
return BuildHistDispatchKernel<FPType, uint8_t>(qu, gpair_device, row_indices,
gmat, hist, is_dense, hist_buffer,
event_priv, force_atomic_use);
break;
case BinTypeSize::kUint16BinsTypeSize:
return BuildHistDispatchKernel<FPType, uint16_t>(qu, gpair_device, row_indices,
gmat, hist, is_dense, hist_buffer,
event_priv, force_atomic_use);
break;
case BinTypeSize::kUint32BinsTypeSize:
return BuildHistDispatchKernel<FPType, uint32_t>(qu, gpair_device, row_indices,
gmat, hist, is_dense, hist_buffer,
event_priv, force_atomic_use);
break;
default:
CHECK(false); // no default behavior
}
}
template <typename GradientSumT>
::sycl::event GHistBuilder<GradientSumT>::BuildHist(
const USMVector<GradientPair, MemoryType::on_device>& gpair_device,
const RowSetCollection::Elem& row_indices,
const GHistIndexMatrix &gmat,
GHistRowT<MemoryType::on_device>* hist,
bool isDense,
GHistRowT<MemoryType::on_device>* hist_buffer,
::sycl::event event_priv,
bool force_atomic_use) {
return BuildHistKernel<GradientSumT>(qu_, gpair_device, row_indices, gmat,
isDense, hist, hist_buffer, event_priv,
force_atomic_use);
}
template
::sycl::event GHistBuilder<float>::BuildHist(
const USMVector<GradientPair, MemoryType::on_device>& gpair_device,
const RowSetCollection::Elem& row_indices,
const GHistIndexMatrix& gmat,
GHistRow<float, MemoryType::on_device>* hist,
bool isDense,
GHistRow<float, MemoryType::on_device>* hist_buffer,
::sycl::event event_priv,
bool force_atomic_use);
template
::sycl::event GHistBuilder<double>::BuildHist(
const USMVector<GradientPair, MemoryType::on_device>& gpair_device,
const RowSetCollection::Elem& row_indices,
const GHistIndexMatrix& gmat,
GHistRow<double, MemoryType::on_device>* hist,
bool isDense,
GHistRow<double, MemoryType::on_device>* hist_buffer,
::sycl::event event_priv,
bool force_atomic_use);
template<typename GradientSumT>
void GHistBuilder<GradientSumT>::SubtractionTrick(GHistRowT<MemoryType::on_device>* self,
const GHistRowT<MemoryType::on_device>& sibling,
const GHistRowT<MemoryType::on_device>& parent) {
const size_t size = self->Size();
CHECK_EQ(sibling.Size(), size);
CHECK_EQ(parent.Size(), size);
SubtractionHist(qu_, self, parent, sibling, size, ::sycl::event());
}
template
void GHistBuilder<float>::SubtractionTrick(GHistRow<float, MemoryType::on_device>* self,
const GHistRow<float, MemoryType::on_device>& sibling,
const GHistRow<float, MemoryType::on_device>& parent);
template
void GHistBuilder<double>::SubtractionTrick(GHistRow<double, MemoryType::on_device>* self,
const GHistRow<double, MemoryType::on_device>& sibling,
const GHistRow<double, MemoryType::on_device>& parent);
} // namespace common
} // namespace sycl
} // namespace xgboost