src/kernel/resource/models/network_ib.cpp

   1 /* Copyright (c) 2014-2023. The SimGrid Team. All rights reserved.          */
   2
   3 /* This program is free software; you can redistribute it and/or modify it
   4  * under the terms of the license (GNU LGPL) which comes with this package. */
   5
   6 #include <simgrid/kernel/routing/NetPoint.hpp>
   7
   8 #include "simgrid/sg_config.hpp"
   9 #include "src/kernel/EngineImpl.hpp"
  10 #include "src/kernel/activity/CommImpl.hpp"
  11 #include "src/kernel/resource/HostImpl.hpp"
  12 #include "src/kernel/resource/models/network_ib.hpp"
  13
  14 #include <boost/algorithm/string/classification.hpp>
  15 #include <boost/algorithm/string/split.hpp>
  16
  17 XBT_LOG_EXTERNAL_DEFAULT_CATEGORY(res_network);
  18
  19 /*********
  20  * Model *
  21  *********/
  22
  23 /************************************************************************/
  24 /* New model based on MPI contention model for Infiniband platforms */
  25 /************************************************************************/
  26 /* @Inproceedings{mescal_vienne_phd, */
  27 /*  author={Jérôme Vienne}, */
  28 /*  title={prédiction de performances d’applications de calcul haute performance sur réseau Infiniband}, */
  29 /*  address={Grenoble FRANCE}, */
  30 /*  month=june, */
  31 /*  year={2010} */
  32 /*  } */
  33 SIMGRID_REGISTER_NETWORK_MODEL(
  34     IB,
  35     "Realistic network model specifically tailored for HPC settings, with Infiniband contention model as described in "
  36     "http://mescal.imag.fr/membres/jean-marc.vincent/index.html/PhD/Vienne.pdf",
  37     []() {
  38       using simgrid::kernel::resource::NetworkIBModel;
  39
  40       auto net_model = std::make_shared<NetworkIBModel>("Network_IB");
  41       auto* engine   = simgrid::kernel::EngineImpl::get_instance();
  42       engine->add_model(net_model);
  43       engine->get_netzone_root()->set_network_model(net_model);
  44
  45       simgrid::s4u::Link::on_communication_state_change_cb(NetworkIBModel::IB_action_state_changed_callback);
  46       simgrid::kernel::activity::CommImpl::on_start.connect(NetworkIBModel::IB_comm_start_callback);
  47       simgrid::s4u::Host::on_creation_cb(NetworkIBModel::IB_create_host_callback);
  48       simgrid::config::set_default<double>("network/weight-S", 8775);
  49     });
  50
  51 namespace simgrid::kernel::resource {
  52
  53 void NetworkIBModel::IB_create_host_callback(s4u::Host const& host)
  54 {
  55   static int id = 0;
  56   auto* ibModel = static_cast<NetworkIBModel*>(host.get_netpoint()->get_englobing_zone()->get_network_model().get());
  57   ibModel->active_nodes.try_emplace(host.get_name(), id);
  58   id++;
  59 }
  60
  61 void NetworkIBModel::IB_action_state_changed_callback(NetworkAction& action, Action::State /*previous*/)
  62 {
  63   if (action.get_state() != Action::State::FINISHED)
  64     return;
  65   auto* ibModel   = static_cast<NetworkIBModel*>(action.get_model());
  66   auto [src, dst] = ibModel->active_comms[&action];
  67
  68   XBT_DEBUG("IB callback - action %p finished", &action);
  69   ibModel->update_IB_factors(&action, src, dst, 1);
  70   ibModel->active_comms.erase(&action);
  71 }
  72
  73 void NetworkIBModel::IB_comm_start_callback(const activity::CommImpl& comm)
  74 {
  75   auto* action  = static_cast<NetworkAction*>(comm.model_action_);
  76   auto* ibModel = static_cast<NetworkIBModel*>(action->get_model());
  77   auto* act_src = &ibModel->active_nodes.at(action->get_src().get_name());
  78   auto* act_dst = &ibModel->active_nodes.at(action->get_dst().get_name());
  79
  80   ibModel->active_comms[action] = std::make_pair(act_src, act_dst);
  81   ibModel->update_IB_factors(action, act_src, act_dst, 0);
  82 }
  83
  84 NetworkIBModel::NetworkIBModel(const std::string& name) : NetworkCm02Model(name)
  85 {
  86   std::string IB_factors_string = config::get_value<std::string>("smpi/IB-penalty-factors");
  87   std::vector<std::string> radical_elements;
  88   boost::split(radical_elements, IB_factors_string, boost::is_any_of(";"));
  89
  90   xbt_assert(radical_elements.size() == 3, "smpi/IB-penalty-factors should be provided and contain 3 "
  91                                            "elements, semi-colon separated. Example: 0.965;0.925;1.35");
  92
  93   try {
  94     Be_ = std::stod(radical_elements.front());
  95   } catch (const std::invalid_argument& ia) {
  96     throw std::invalid_argument(std::string("First part of smpi/IB-penalty-factors is not numerical:") + ia.what());
  97   }
  98
  99   try {
 100     Bs_ = std::stod(radical_elements.at(1));
 101   } catch (const std::invalid_argument& ia) {
 102     throw std::invalid_argument(std::string("Second part of smpi/IB-penalty-factors is not numerical:") + ia.what());
 103   }
 104
 105   try {
 106     ys_ = std::stod(radical_elements.back());
 107   } catch (const std::invalid_argument& ia) {
 108     throw std::invalid_argument(std::string("Third part of smpi/IB-penalty-factors is not numerical:") + ia.what());
 109   }
 110 }
 111
 112 void NetworkIBModel::compute_IB_factors(IBNode* root) const
 113 {
 114   size_t num_comm_out    = root->active_comms_up_.size();
 115   double max_penalty_out = 0.0;
 116   // first, compute all outbound penalties to get their max
 117   for (ActiveComm const* comm : root->active_comms_up_) {
 118     double my_penalty_out = 1.0;
 119
 120     if (num_comm_out != 1) {
 121       if (comm->destination->nb_active_comms_down_ > 2) // number of comms sent to the receiving node
 122         my_penalty_out = num_comm_out * Bs_ * ys_;
 123       else
 124         my_penalty_out = num_comm_out * Bs_;
 125     }
 126
 127     max_penalty_out = std::max(max_penalty_out, my_penalty_out);
 128   }
 129
 130   for (ActiveComm* comm : root->active_comms_up_) {
 131     // compute inbound penalty
 132     double my_penalty_in = 1.0;
 133     if (comm->destination->nb_active_comms_down_ != 1)                      // total number of incoming comms
 134       my_penalty_in = (comm->destination->active_comms_down_)[root]         // number of comm sent to dest by root node
 135                       * Be_ * comm->destination->active_comms_down_.size(); // number of different nodes sending to dest
 136
 137     double penalty = std::max(my_penalty_in, max_penalty_out);
 138
 139     double rate_before_update = comm->action->get_bound();
 140     // save initial rate of the action
 141     if (comm->init_rate == -1)
 142       comm->init_rate = rate_before_update;
 143
 144     double penalized_bw = num_comm_out ? comm->init_rate / penalty : comm->init_rate;
 145
 146     if (not double_equals(penalized_bw, rate_before_update, sg_precision_timing)) {
 147       XBT_DEBUG("%d->%d action %p penalty updated : bw now %f, before %f , initial rate %f", root->id_,
 148                 comm->destination->id_, comm->action, penalized_bw, comm->action->get_bound(), comm->init_rate);
 149       get_maxmin_system()->update_variable_bound(comm->action->get_variable(), penalized_bw);
 150     } else {
 151       XBT_DEBUG("%d->%d action %p penalty not updated : bw %f, initial rate %f", root->id_, comm->destination->id_,
 152                 comm->action, penalized_bw, comm->init_rate);
 153     }
 154   }
 155   XBT_DEBUG("Finished computing IB penalties");
 156 }
 157
 158 void NetworkIBModel::update_IB_factors_rec(IBNode* root, std::vector<bool>& updatedlist) const
 159 {
 160   if (not updatedlist[root->id_]) {
 161     XBT_DEBUG("IB - Updating rec %d", root->id_);
 162     compute_IB_factors(root);
 163     updatedlist[root->id_] = true;
 164     for (ActiveComm const* comm : root->active_comms_up_) {
 165       if (not updatedlist[comm->destination->id_])
 166         update_IB_factors_rec(comm->destination, updatedlist);
 167     }
 168     for (auto const& [comm, _] : root->active_comms_down_) {
 169       if (not updatedlist[comm->id_])
 170         update_IB_factors_rec(comm, updatedlist);
 171     }
 172   }
 173 }
 174
 175 void NetworkIBModel::update_IB_factors(NetworkAction* action, IBNode* from, IBNode* to, int remove) const
 176 {
 177   if (from == to) // disregard local comms (should use loopback)
 178     return;
 179
 180   if (remove) {
 181     if (to->active_comms_down_[from] == 1)
 182       to->active_comms_down_.erase(from);
 183     else
 184       to->active_comms_down_[from] -= 1;
 185
 186     to->nb_active_comms_down_--;
 187     if (auto it = std::find_if(begin(from->active_comms_up_), end(from->active_comms_up_),
 188                                [action](const ActiveComm* comm) { return comm->action == action; });
 189         it != std::end(from->active_comms_up_)) {
 190       delete *it;
 191       from->active_comms_up_.erase(it);
 192     }
 193     action->unref();
 194   } else {
 195     action->ref();
 196     auto* comm        = new ActiveComm();
 197     comm->action      = action;
 198     comm->destination = to;
 199     from->active_comms_up_.push_back(comm);
 200
 201     to->active_comms_down_[from] += 1;
 202     to->nb_active_comms_down_++;
 203   }
 204   XBT_DEBUG("IB - Updating %d", from->id_);
 205   std::vector<bool> updated(active_nodes.size(), false);
 206   update_IB_factors_rec(from, updated);
 207   XBT_DEBUG("IB - Finished updating %d", from->id_);
 208 }
 209 } // namespace simgrid::kernel::resource