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Fix GPU bugs (#3051)

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* Change uint to unsigned int

* Fix no root predictions bug

* Remove redundant splitting due to numerical instability
This commit is contained in:
Rory Mitchell
2018-01-23 13:14:15 +13:00
committed by GitHub
parent 8b2f4e2d39
commit f87802f00c
2 changed files with 16 additions and 12 deletions
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22
src/tree/updater_gpu_hist.cu
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@@ -12,8 +12,8 @@
#include <vector>
#include "../common/compressed_iterator.h"
#include "../common/device_helpers.cuh"
#include "../common/host_device_vector.h"
#include "../common/hist_util.h"
#include "../common/host_device_vector.h"
#include "../common/timer.h"
#include "param.h"
#include "updater_gpu_common.cuh"
@@ -361,8 +361,7 @@ struct DeviceShard {
std::fill(ridx_segments.begin(), ridx_segments.end(), Segment(0, 0));
ridx_segments.front() = Segment(0, ridx.size());
this->gpair.copy(begin + row_begin_idx,
begin + row_end_idx);
this->gpair.copy(begin + row_begin_idx, begin + row_end_idx);
subsample_gpair(&gpair, param.subsample, row_begin_idx);
hist.Reset();
}
@@ -527,7 +526,7 @@ class GPUHistMaker : public TreeUpdater {
private:
void UpdateHelper(HostDeviceVector<bst_gpair>* gpair, DMatrix* dmat,
const std::vector<RegTree*>& trees) {
const std::vector<RegTree*>& trees) {
GradStats::CheckInfo(dmat->info());
// rescale learning rate according to size of trees
float lr = param.learning_rate;
@@ -607,7 +606,8 @@ class GPUHistMaker : public TreeUpdater {
monitor.Start("InitDataReset", dList);
omp_set_num_threads(shards.size());
// TODO(canonizer): make it parallel again once HostDeviceVector is thread-safe
// TODO(canonizer): make it parallel again once HostDeviceVector is
// thread-safe
for (int shard = 0; shard < shards.size(); ++shard)
shards[shard]->Reset(gpair, param.gpu_id);
monitor.Stop("InitDataReset", dList);
@@ -722,7 +722,7 @@ class GPUHistMaker : public TreeUpdater {
shards[cpu_thread_id]->gpair.tend());
}
auto sum_gradient =
std::accumulate(tmp_sums.begin(), tmp_sums.end(), bst_gpair());
std::accumulate(tmp_sums.begin(), tmp_sums.end(), bst_gpair_precise());
// Generate root histogram
for (auto& shard : shards) {
@@ -733,7 +733,9 @@ class GPUHistMaker : public TreeUpdater {
// Remember root stats
p_tree->stat(root_nidx).sum_hess = sum_gradient.GetHess();
p_tree->stat(root_nidx).base_weight = CalcWeight(param, sum_gradient);
auto weight = CalcWeight(param, sum_gradient);
p_tree->stat(root_nidx).base_weight = weight;
(*p_tree)[root_nidx].set_leaf(param.learning_rate * weight);
// Store sum gradients
for (auto& shard : shards) {
@@ -879,8 +881,8 @@ class GPUHistMaker : public TreeUpdater {
return false;
}
bool UpdatePredictionCache(const DMatrix* data,
HostDeviceVector<bst_float>* p_out_preds) override {
bool UpdatePredictionCache(
const DMatrix* data, HostDeviceVector<bst_float>* p_out_preds) override {
return false;
}
@@ -894,6 +896,8 @@ class GPUHistMaker : public TreeUpdater {
: nid(nid), depth(depth), split(split), timestamp(timestamp) {}
bool IsValid(const TrainParam& param, int num_leaves) const {
if (split.loss_chg <= rt_eps) return false;
if (split.left_sum.GetHess() == 0 || split.right_sum.GetHess() == 0)
return false;
if (param.max_depth > 0 && depth == param.max_depth) return false;
if (param.max_leaves > 0 && num_leaves == param.max_leaves) return false;
return true;