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Dmatrix refactor stage 1 (#3301)

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* Use sparse page as singular CSR matrix representation

* Simplify dmatrix methods

* Reduce statefullness of batch iterators

* BREAKING CHANGE: Remove prob_buffer_row parameter. Users are instead recommended to sample their dataset as a preprocessing step before using XGBoost.
This commit is contained in:
Rory Mitchell
2018-06-07 10:25:58 +12:00
committed by GitHub
parent 286dccb8e8
commit a96039141a
47 changed files with 650 additions and 1036 deletions
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26
src/predictor/cpu_predictor.cc
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@@ -14,7 +14,7 @@ DMLC_REGISTRY_FILE_TAG(cpu_predictor);
class CPUPredictor : public Predictor {
protected:
static bst_float PredValue(const RowBatch::Inst& inst,
static bst_float PredValue(const SparsePage::Inst& inst,
const std::vector<std::unique_ptr<RegTree>>& trees,
const std::vector<int>& tree_info, int bst_group,
unsigned root_index, RegTree::FVec* p_feats,
@@ -53,20 +53,20 @@ class CPUPredictor : public Predictor {
<< "size_leaf_vector is enforced to 0 so far";
CHECK_EQ(preds.size(), p_fmat->Info().num_row_ * num_group);
// start collecting the prediction
dmlc::DataIter<RowBatch>* iter = p_fmat->RowIterator();
auto iter = p_fmat->RowIterator();
iter->BeforeFirst();
while (iter->Next()) {
const RowBatch& batch = iter->Value();
const auto& batch = iter->Value();
// parallel over local batch
constexpr int kUnroll = 8;
const auto nsize = static_cast<bst_omp_uint>(batch.size);
const auto nsize = static_cast<bst_omp_uint>(batch.Size());
const bst_omp_uint rest = nsize % kUnroll;
#pragma omp parallel for schedule(static)
for (bst_omp_uint i = 0; i < nsize - rest; i += kUnroll) {
const int tid = omp_get_thread_num();
RegTree::FVec& feats = thread_temp[tid];
int64_t ridx[kUnroll];
RowBatch::Inst inst[kUnroll];
SparsePage::Inst inst[kUnroll];
for (int k = 0; k < kUnroll; ++k) {
ridx[k] = static_cast<int64_t>(batch.base_rowid + i + k);
}
@@ -85,7 +85,7 @@ class CPUPredictor : public Predictor {
for (bst_omp_uint i = nsize - rest; i < nsize; ++i) {
RegTree::FVec& feats = thread_temp[0];
const auto ridx = static_cast<int64_t>(batch.base_rowid + i);
const RowBatch::Inst inst = batch[i];
auto inst = batch[i];
for (int gid = 0; gid < num_group; ++gid) {
const size_t offset = ridx * num_group + gid;
preds[offset] +=
@@ -183,7 +183,7 @@ class CPUPredictor : public Predictor {
}
}
void PredictInstance(const SparseBatch::Inst& inst,
void PredictInstance(const SparsePage::Inst& inst,
std::vector<bst_float>* out_preds,
const gbm::GBTreeModel& model, unsigned ntree_limit,
unsigned root_index) override {
@@ -218,12 +218,12 @@ class CPUPredictor : public Predictor {
std::vector<bst_float>& preds = *out_preds;
preds.resize(info.num_row_ * ntree_limit);
// start collecting the prediction
dmlc::DataIter<RowBatch>* iter = p_fmat->RowIterator();
auto iter = p_fmat->RowIterator();
iter->BeforeFirst();
while (iter->Next()) {
const RowBatch& batch = iter->Value();
auto batch = iter->Value();
// parallel over local batch
const auto nsize = static_cast<bst_omp_uint>(batch.size);
const auto nsize = static_cast<bst_omp_uint>(batch.Size());
#pragma omp parallel for schedule(static)
for (bst_omp_uint i = 0; i < nsize; ++i) {
const int tid = omp_get_thread_num();
@@ -266,13 +266,13 @@ class CPUPredictor : public Predictor {
model.trees[i]->FillNodeMeanValues();
}
// start collecting the contributions
dmlc::DataIter<RowBatch>* iter = p_fmat->RowIterator();
auto iter = p_fmat->RowIterator();
const std::vector<bst_float>& base_margin = info.base_margin_;
iter->BeforeFirst();
while (iter->Next()) {
const RowBatch& batch = iter->Value();
auto batch = iter->Value();
// parallel over local batch
const auto nsize = static_cast<bst_omp_uint>(batch.size);
const auto nsize = static_cast<bst_omp_uint>(batch.Size());
#pragma omp parallel for schedule(static)
for (bst_omp_uint i = 0; i < nsize; ++i) {
auto row_idx = static_cast<size_t>(batch.base_rowid + i);