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22 changes: 22 additions & 0 deletions include/osp/bsp/model/BspSchedule.hpp
Original file line number Diff line number Diff line change
Expand Up @@ -830,6 +830,28 @@ class BspSchedule : public IBspSchedule<Graph_t>, public IBspScheduleEval<Graph_
return num;
}

virtual void shrinkSchedule() {

std::vector<bool> comm_phase_empty(number_of_supersteps, true);
for (const auto& node : instance->vertices())
for (const auto &child : instance->getComputationalDag().children(node))
if(node_to_processor_assignment[node] != node_to_processor_assignment[child])
comm_phase_empty[node_to_superstep_assignment[child]-1] = false;

std::vector<unsigned> new_step_index(number_of_supersteps);
unsigned current_index = 0;
for(unsigned step = 0; step < number_of_supersteps; ++step)
{
new_step_index[step] = current_index;
if(!comm_phase_empty[step])
current_index++;
}
for (const auto& node : instance->vertices())
node_to_superstep_assignment[node] = new_step_index[node_to_superstep_assignment[node]];

setNumberOfSupersteps(current_index);
}

unsigned virtual getStaleness() const { return 1; }
};

Expand Down
120 changes: 120 additions & 0 deletions include/osp/bsp/model/BspScheduleCS.hpp
Original file line number Diff line number Diff line change
Expand Up @@ -467,6 +467,126 @@ class BspScheduleCS : public BspSchedule<Graph_t> {
}
}
}

virtual void shrinkSchedule() override {

std::vector<unsigned> comm_phase_latest_dependency(this->number_of_supersteps, 0);
std::vector<std::vector<unsigned> > first_at = getFirstPresence();

for (auto const &[key, val] : commSchedule)
if(this->assignedProcessor(std::get<0>(key)) != std::get<1>(key))
comm_phase_latest_dependency[val] = std::max(comm_phase_latest_dependency[val], first_at[std::get<0>(key)][std::get<1>(key)]);


for (const auto &node : BspSchedule<Graph_t>::instance->getComputationalDag().vertices())
for (const auto &child : BspSchedule<Graph_t>::instance->getComputationalDag().children(node))
if(this->assignedProcessor(node) != this->assignedProcessor(child))
comm_phase_latest_dependency[this->assignedSuperstep(child)] = std::max(comm_phase_latest_dependency[this->assignedSuperstep(child)], first_at[node][this->assignedProcessor(child)]);

std::vector<bool> comm_phase_deleted(this->number_of_supersteps, false);
for(unsigned step = this->number_of_supersteps-1; step < this->number_of_supersteps; --step)
{
unsigned limit = 0;
while(step > limit)
{
limit = std::max(limit, comm_phase_latest_dependency[step]);
if(step > limit)
{
comm_phase_deleted[step] = true;
--step;
}
}
}

std::vector<unsigned> new_step_index(this->number_of_supersteps);
unsigned current_index = std::numeric_limits<unsigned>::max();
for(unsigned step = 0; step < this->number_of_supersteps; ++step)
{
if(!comm_phase_deleted[step])
current_index++;

new_step_index[step] = current_index;
}
for (const auto& node : this->instance->vertices())
this->node_to_superstep_assignment[node] = new_step_index[this->node_to_superstep_assignment[node]];
for (auto &[key, val] : commSchedule)
val = new_step_index[val];

this->setNumberOfSupersteps(current_index+1);
}

std::vector<std::vector<unsigned> > getFirstPresence() const {

std::vector<std::vector<unsigned> > first_at(BspSchedule<Graph_t>::instance->numberOfVertices(),
std::vector<unsigned>(BspSchedule<Graph_t>::instance->numberOfProcessors(), std::numeric_limits<unsigned>::max()));

for (const auto &node : BspSchedule<Graph_t>::instance->getComputationalDag().vertices())
first_at[node][this->assignedProcessor(node)] = this->assignedSuperstep(node);

for (auto const &[key, val] : commSchedule)
first_at[std::get<0>(key)][std::get<2>(key)] =
std::min(first_at[std::get<0>(key)][std::get<2>(key)], val + 1); // TODO: replace by staleness after merge

return first_at;
}

// remove unneeded comm. schedule entries - these can happen in ILPs, partial ILPs, etc.
void cleanCommSchedule(){

// data that is already present before it arrives
std::vector<std::vector<std::multiset<unsigned> > > arrives_at(BspSchedule<Graph_t>::instance->numberOfVertices(),
std::vector<std::multiset<unsigned> >(BspSchedule<Graph_t>::instance->numberOfProcessors()));
for (const auto &node : BspSchedule<Graph_t>::instance->getComputationalDag().vertices())
arrives_at[node][this->assignedProcessor(node)].insert(this->assignedSuperstep(node));

for (auto const &[key, val] : commSchedule)
arrives_at[std::get<0>(key)][std::get<2>(key)].insert(val);

std::vector<KeyTriple> toErase;
for (auto const &[key, val] : commSchedule)
{
auto itr = arrives_at[std::get<0>(key)][std::get<2>(key)].begin();
if(*itr < val)
toErase.push_back(key);
else if(*itr == val && ++itr != arrives_at[std::get<0>(key)][std::get<2>(key)].end() && *itr == val)
{
toErase.push_back(key);
arrives_at[std::get<0>(key)][std::get<2>(key)].erase(itr);
}
}

for(const KeyTriple& key : toErase)
commSchedule.erase(key);

// data that is not used after being sent
std::vector<std::vector<std::multiset<unsigned> > > used_at(BspSchedule<Graph_t>::instance->numberOfVertices(),
std::vector<std::multiset<unsigned> >(BspSchedule<Graph_t>::instance->numberOfProcessors()));
for (const auto &node : BspSchedule<Graph_t>::instance->getComputationalDag().vertices())
for (const auto &child : BspSchedule<Graph_t>::instance->getComputationalDag().children(node))
used_at[node][this->assignedProcessor(child)].insert(this->assignedSuperstep(child));

for (auto const &[key, val] : commSchedule)
used_at[std::get<0>(key)][std::get<1>(key)].insert(val);

// (need to visit cs entries in reverse superstep order here)
std::vector<std::vector<KeyTriple> > entries(this->number_of_supersteps);
for (auto const &[key, val] : commSchedule)
entries[val].push_back(key);

toErase.clear();
for(unsigned step = this->number_of_supersteps-1; step < this->number_of_supersteps; --step)
for(const KeyTriple& key : entries[step])
if(used_at[std::get<0>(key)][std::get<2>(key)].empty() ||
*used_at[std::get<0>(key)][std::get<2>(key)].rbegin() <= step)
{
toErase.push_back(key);
auto itr = used_at[std::get<0>(key)][std::get<1>(key)].find(step);
used_at[std::get<0>(key)][std::get<1>(key)].erase(itr);
}

for(const KeyTriple& key : toErase)
commSchedule.erase(key);
}
};

} // namespace osp
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