forked from bartvdbraak/blender
fd25e883e2
Remove prefix of filenames that is the same as the folder name. This used to help when #includes were using individual files, but now they are always relative to the cycles root directory and so the prefixes are redundant. For patches and branches, git merge and rebase should be able to detect the renames and move over code to the right file.
100 lines
3.1 KiB
C++
100 lines
3.1 KiB
C++
/*
|
|
* Copyright 2011-2021 Blender Foundation
|
|
*
|
|
* Licensed under the Apache License, Version 2.0 (the "License");
|
|
* you may not use this file except in compliance with the License.
|
|
* You may obtain a copy of the License at
|
|
*
|
|
* http://www.apache.org/licenses/LICENSE-2.0
|
|
*
|
|
* Unless required by applicable law or agreed to in writing, software
|
|
* distributed under the License is distributed on an "AS IS" BASIS,
|
|
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
|
|
* See the License for the specific language governing permissions and
|
|
* limitations under the License.
|
|
*/
|
|
|
|
#include "integrator/work_balancer.h"
|
|
|
|
#include "util/math.h"
|
|
|
|
#include "util/log.h"
|
|
|
|
CCL_NAMESPACE_BEGIN
|
|
|
|
void work_balance_do_initial(vector<WorkBalanceInfo> &work_balance_infos)
|
|
{
|
|
const int num_infos = work_balance_infos.size();
|
|
|
|
if (num_infos == 1) {
|
|
work_balance_infos[0].weight = 1.0;
|
|
return;
|
|
}
|
|
|
|
/* There is no statistics available, so start with an equal distribution. */
|
|
const double weight = 1.0 / num_infos;
|
|
for (WorkBalanceInfo &balance_info : work_balance_infos) {
|
|
balance_info.weight = weight;
|
|
}
|
|
}
|
|
|
|
static double calculate_total_time(const vector<WorkBalanceInfo> &work_balance_infos)
|
|
{
|
|
double total_time = 0;
|
|
for (const WorkBalanceInfo &info : work_balance_infos) {
|
|
total_time += info.time_spent;
|
|
}
|
|
return total_time;
|
|
}
|
|
|
|
/* The balance is based on equalizing time which devices spent performing a task. Assume that
|
|
* average of the observed times is usable for estimating whether more or less work is to be
|
|
* scheduled, and how difference in the work scheduling is needed. */
|
|
|
|
bool work_balance_do_rebalance(vector<WorkBalanceInfo> &work_balance_infos)
|
|
{
|
|
const int num_infos = work_balance_infos.size();
|
|
|
|
const double total_time = calculate_total_time(work_balance_infos);
|
|
const double time_average = total_time / num_infos;
|
|
|
|
double total_weight = 0;
|
|
vector<double> new_weights;
|
|
new_weights.reserve(num_infos);
|
|
|
|
/* Equalize the overall average time. This means that we don't make it so every work will perform
|
|
* amount of work based on the current average, but that after the weights changes the time will
|
|
* equalize.
|
|
* Can think of it that if one of the devices is 10% faster than another, then one device needs
|
|
* to do 5% less of the current work, and another needs to do 5% more. */
|
|
const double lerp_weight = 1.0 / num_infos;
|
|
|
|
bool has_big_difference = false;
|
|
|
|
for (const WorkBalanceInfo &info : work_balance_infos) {
|
|
const double time_target = lerp(info.time_spent, time_average, lerp_weight);
|
|
const double new_weight = info.weight * time_target / info.time_spent;
|
|
new_weights.push_back(new_weight);
|
|
total_weight += new_weight;
|
|
|
|
if (std::fabs(1.0 - time_target / time_average) > 0.02) {
|
|
has_big_difference = true;
|
|
}
|
|
}
|
|
|
|
if (!has_big_difference) {
|
|
return false;
|
|
}
|
|
|
|
const double total_weight_inv = 1.0 / total_weight;
|
|
for (int i = 0; i < num_infos; ++i) {
|
|
WorkBalanceInfo &info = work_balance_infos[i];
|
|
info.weight = new_weights[i] * total_weight_inv;
|
|
info.time_spent = 0;
|
|
}
|
|
|
|
return true;
|
|
}
|
|
|
|
CCL_NAMESPACE_END
|