X-Git-Url: http://info.iut-bm.univ-fcomte.fr/pub/gitweb/simgrid.git/blobdiff_plain/0ebbe45d4b9227f6ac08b04c57eaeb684a1d9201..3e9453209f1da7deb92fe629428e49f3528217bd:/src/kernel/lmm/bmf.cpp diff --git a/src/kernel/lmm/bmf.cpp b/src/kernel/lmm/bmf.cpp index 7ec03e87b5..a754fd5dec 100644 --- a/src/kernel/lmm/bmf.cpp +++ b/src/kernel/lmm/bmf.cpp @@ -1,10 +1,10 @@ -/* Copyright (c) 2007-2022. The SimGrid Team. All rights reserved. */ +/* Copyright (c) 2007-2023. The SimGrid Team. All rights reserved. */ /* This program is free software; you can redistribute it and/or modify it * under the terms of the license (GNU LGPL) which comes with this package. */ #include "src/kernel/lmm/bmf.hpp" -#include "xbt/config.hpp" +#include "src/simgrid/math_utils.h" #include #include @@ -13,17 +13,7 @@ XBT_LOG_NEW_DEFAULT_SUBCATEGORY(ker_bmf, kernel, "Kernel BMF solver"); -simgrid::config::Flag - cfg_bmf_max_iteration("bmf/max-iterations", - "Maximum number of steps to be performed while searching for a BMF allocation", 1000); - -simgrid::config::Flag cfg_bmf_selective_update{ - "bmf/selective-update", "Update the constraint set propagating recursively to others constraints (off by default)", - false}; - -namespace simgrid { -namespace kernel { -namespace lmm { +namespace simgrid::kernel::lmm { AllocationGenerator::AllocationGenerator(Eigen::MatrixXd A) : A_(std::move(A)), alloc_(A_.cols(), 0) { @@ -74,7 +64,6 @@ BmfSolver::BmfSolver(Eigen::MatrixXd A, Eigen::MatrixXd maxA, Eigen::VectorXd C, , C_shared_(std::move(shared)) , phi_(std::move(phi)) , gen_(A_) - , max_iteration_(cfg_bmf_max_iteration) { xbt_assert(max_iteration_ > 0, @@ -103,8 +92,8 @@ template std::string BmfSolver::debug_vector(const C& container) co std::string BmfSolver::debug_alloc(const allocation_map_t& alloc) const { std::stringstream debug; - for (const auto& e : alloc) { - debug << "{" + std::to_string(e.first) + ": [" + debug_vector(e.second) + "]}, "; + for (const auto& [resource, players] : alloc) { + debug << "{" + std::to_string(resource) + ": [" + debug_vector(players) + "]}, "; } return debug.str(); } @@ -121,12 +110,21 @@ double BmfSolver::get_resource_capacity(int resource, const std::vector& bo return std::max(0.0, capacity); } +double BmfSolver::get_maxmin_share(int resource, const std::vector& bounded_players) const +{ + auto n_players = (A_.row(resource).array() > 0).count() - bounded_players.size(); + double capacity = get_resource_capacity(resource, bounded_players); + if (n_players > 0) + capacity /= n_players; + return capacity; +} + std::vector BmfSolver::alloc_map_to_vector(const allocation_map_t& alloc) const { std::vector alloc_by_player(A_.cols(), -1); - for (const auto& it : alloc) { - for (auto p : it.second) { - alloc_by_player[p] = it.first; + for (const auto& [resource, players] : alloc) { + for (auto p : players) { + alloc_by_player[p] = resource; } } return alloc_by_player; @@ -135,9 +133,9 @@ std::vector BmfSolver::alloc_map_to_vector(const allocation_map_t& alloc) c std::vector BmfSolver::get_bounded_players(const allocation_map_t& alloc) const { std::vector bounded_players; - for (const auto& e : alloc) { - if (e.first == NO_RESOURCE) { - bounded_players.insert(bounded_players.end(), e.second.begin(), e.second.end()); + for (const auto& [resource, players] : alloc) { + if (resource == NO_RESOURCE) { + bounded_players.insert(bounded_players.end(), players.begin(), players.end()); } } return bounded_players; @@ -151,38 +149,37 @@ Eigen::VectorXd BmfSolver::equilibrium(const allocation_map_t& alloc) const int row = 0; auto bounded_players = get_bounded_players(alloc); - for (const auto& e : alloc) { + for (const auto& [resource, players] : alloc) { // add one row for the resource with A[r,] - int cur_resource = e.first; /* bounded players, nothing to do */ - if (cur_resource == NO_RESOURCE) + if (resource == NO_RESOURCE) continue; /* not shared resource, each player can receive the full capacity of the resource */ - if (not C_shared_[cur_resource]) { - for (int i : e.second) { - C_p[row] = get_resource_capacity(cur_resource, bounded_players); - A_p(row, i) = A_(cur_resource, i); + if (not C_shared_[resource]) { + for (int i : players) { + C_p[row] = get_resource_capacity(resource, bounded_players); + A_p(row, i) = A_(resource, i); row++; } continue; } /* shared resource: fairly share it between players */ - A_p.row(row) = A_.row(cur_resource); - C_p[row] = get_resource_capacity(cur_resource, bounded_players); + A_p.row(row) = A_.row(resource); + C_p[row] = get_resource_capacity(resource, bounded_players); row++; - if (e.second.size() > 1) { + if (players.size() > 1) { // if 2 players have chosen the same resource // they must have a fair sharing of this resource, adjust A_p and C_p accordingly - auto it = e.second.begin(); + auto it = players.begin(); int i = *it; // first player /* for each other player sharing this resource */ - for (++it; it != e.second.end(); ++it) { + for (++it; it != players.end(); ++it) { /* player i and k on this resource j: so maxA_ji*rho_i - maxA_jk*rho_k = 0 */ int k = *it; C_p[row] = 0; - A_p(row, i) = maxA_(cur_resource, i); - A_p(row, k) = -maxA_(cur_resource, k); + A_p(row, i) = maxA_(resource, i); + A_p(row, k) = -maxA_(resource, k); row++; } } @@ -238,28 +235,36 @@ bool BmfSolver::get_alloc(const Eigen::VectorXd& fair_sharing, const allocation_ alloc.clear(); for (int player_idx = 0; player_idx < A_.cols(); player_idx++) { int selected_resource = NO_RESOURCE; - double bound = phi_[player_idx]; - double min_share = (bound <= 0 || initial) ? -1 : bound; + + /* the player's maximal rate is the minimum among all resources */ + double min_rate = -1; for (int cnst_idx = 0; cnst_idx < A_.rows(); cnst_idx++) { if (A_(cnst_idx, player_idx) <= 0.0) continue; - double share = fair_sharing[cnst_idx] / A_(cnst_idx, player_idx); - if (min_share == -1 || share < min_share) { + /* Note: the max_ may artificially increase the rate if priority < 0 + * The equilibrium sets a rho which respects the C_ though */ + if (double rate = fair_sharing[cnst_idx] / maxA_(cnst_idx, player_idx); + min_rate == -1 || double_positive(min_rate - rate, cfg_bmf_precision)) { selected_resource = cnst_idx; - min_share = share; + min_rate = rate; + } + /* Given that the priority may artificially increase the rate, + * we need to check that the bound given by user respects the resource capacity C_ */ + if (double bound = initial ? -1 : phi_[player_idx]; bound > 0 && + bound * A_(cnst_idx, player_idx) < C_[cnst_idx] && + double_positive(min_rate - bound, cfg_bmf_precision)) { + selected_resource = NO_RESOURCE; + min_rate = bound; } } alloc[selected_resource].insert(player_idx); } - bool is_stable = (alloc == last_alloc); - if (is_stable) + if (alloc == last_alloc) // considered stable return true; - std::vector alloc_by_player = alloc_map_to_vector(alloc); - auto ret = allocations_.insert(alloc_by_player); - /* oops, allocation already tried, let's pertube it a bit */ - if (not ret.second) { + if (auto alloc_by_player = alloc_map_to_vector(alloc); not allocations_.insert(alloc_by_player).second) { + /* oops, allocation already tried, let's pertube it a bit */ XBT_DEBUG("Allocation already tried: %s", debug_alloc(alloc).c_str()); return disturb_allocation(alloc, alloc_by_player); } @@ -273,19 +278,21 @@ void BmfSolver::set_fair_sharing(const allocation_map_t& alloc, const Eigen::Vec for (int r = 0; r < fair_sharing.size(); r++) { auto it = alloc.find(r); - if (it != alloc.end()) { // resource selected by some player, fair share depends on rho - int player = *(it->second.begin()); // equilibrium assures that every player receives the same, use one of them to - // calculate the fair sharing for resource r - fair_sharing[r] = A_(r, player) * rho[player]; + if (it != alloc.end()) { // resource selected by some player, fair share depends on rho + double min_share = std::numeric_limits::max(); + for (int p : it->second) { + double share = A_(r, p) * rho[p]; + min_share = std::min(min_share, share); + } + fair_sharing[r] = min_share; } else { // nobody selects this resource, fair_sharing depends on resource saturation // resource r is saturated (A[r,*] * rho > C), divide it among players double consumption_r = A_.row(r) * rho; - double_update(&consumption_r, C_[r], sg_maxmin_precision); + double_update(&consumption_r, C_[r], cfg_bmf_precision); if (consumption_r > 0.0) { - auto n_players = (A_.row(r).array() > 0).count(); - fair_sharing[r] = C_[r] / n_players; + fair_sharing[r] = get_maxmin_share(r, bounded_players); } else { - fair_sharing[r] = get_resource_capacity(r, bounded_players); + fair_sharing[r] = C_[r]; } } } @@ -303,7 +310,7 @@ bool BmfSolver::is_bmf(const Eigen::VectorXd& rho) const Eigen::VectorXd remaining = (A_ * rho) - C_; remaining = remaining.array() * shared.array(); // ignore non shared resources bmf = bmf && (not std::any_of(remaining.data(), remaining.data() + remaining.size(), - [](double v) { return double_positive(v, sg_maxmin_precision); })); + [](double v) { return double_positive(v, sg_precision_workamount); })); // 3) every player receives maximum share in at least 1 saturated resource // due to subflows, compare with the maximum consumption and not the A matrix @@ -315,15 +322,15 @@ bool BmfSolver::is_bmf(const Eigen::VectorXd& rho) const // matrix_ji: boolean indicating player p has the maximum share at resource j Eigen::MatrixXi player_max_share = - ((usage.array().colwise() - max_share.array()).abs() <= sg_maxmin_precision).cast(); + ((usage.array().colwise() - max_share.array()).abs() <= sg_precision_workamount).cast(); // but only saturated resources must be considered - Eigen::VectorXi saturated = (remaining.array().abs() <= sg_maxmin_precision).cast(); + Eigen::VectorXi saturated = (remaining.array().abs() <= sg_precision_workamount).cast(); XBT_DEBUG("Saturated_j resources:\n%s", debug_eigen(saturated).c_str()); player_max_share.array().colwise() *= saturated.array(); // just check if it has received at least it's bound for (int p = 0; p < rho.size(); p++) { - if (double_equals(rho[p], phi_[p], sg_maxmin_precision)) { + if (double_equals(rho[p], phi_[p], sg_precision_workamount)) { player_max_share(0, p) = 1; // it doesn't really matter, just to say that it's a bmf saturated[0] = 1; } @@ -345,6 +352,7 @@ Eigen::VectorXd BmfSolver::solve() XBT_DEBUG("A:\n%s", debug_eigen(A_).c_str()); XBT_DEBUG("maxA:\n%s", debug_eigen(maxA_).c_str()); XBT_DEBUG("C:\n%s", debug_eigen(C_).c_str()); + XBT_DEBUG("phi:\n%s", debug_eigen(phi_).c_str()); /* no flows to share, just returns */ if (A_.cols() == 0) @@ -380,7 +388,7 @@ Eigen::VectorXd BmfSolver::solve() fprintf(stderr, "Unable to find a BMF allocation for your system.\n" "You may try to increase the maximum number of iterations performed by BMF solver " "(\"--cfg=bmf/max-iterations\").\n" - "Additionally, you could decrease numerical precision (\"--cfg=surf/precision\").\n"); + "Additionally, you could adjust numerical precision (\"--cfg=bmf/precision\").\n"); fprintf(stderr, "Internal states (after %d iterations):\n", it); fprintf(stderr, "A:\n%s\n", debug_eigen(A_).c_str()); fprintf(stderr, "maxA:\n%s\n", debug_eigen(maxA_).c_str()); @@ -413,10 +421,9 @@ void BmfSystem::get_flows_data(Eigen::Index number_cnsts, Eigen::MatrixXd& A, Ei bool active = false; bool linked = false; // variable is linked to some constraint (specially for selective_update) for (const Element& elem : var.cnsts_) { - const boost::intrusive::list_member_hook<>& cnst_hook = selective_update_active - ? elem.constraint->modified_constraint_set_hook_ - : elem.constraint->active_constraint_set_hook_; - if (not cnst_hook.is_linked()) + if (const auto& cnst_hook = selective_update_active ? elem.constraint->modified_constraint_set_hook_ + : elem.constraint->active_constraint_set_hook_; + not cnst_hook.is_linked()) continue; /* active and linked variable, lets check its consumption */ linked = true; @@ -457,13 +464,6 @@ void BmfSystem::get_constraint_data(const CnstList& cnst_list, Eigen::VectorXd& C(cnst_idx) = cnst.bound_; if (cnst.get_sharing_policy() == Constraint::SharingPolicy::NONLINEAR && cnst.dyn_constraint_cb_) { C(cnst_idx) = cnst.dyn_constraint_cb_(cnst.bound_, cnst.concurrency_current_); - if (not warned_nonlinear_) { - XBT_WARN("You are using dynamic constraint bound with parallel tasks and BMF model." - " The BMF solver assumes that all flows (and subflows) are always active and executing." - " This is quite pessimist, specially considering parallel tasks with small subflows." - " Analyze your results with caution."); - warned_nonlinear_ = true; - } } cnst2idx_[&cnst] = cnst_idx; // FATPIPE links aren't really shared @@ -482,7 +482,6 @@ void BmfSystem::do_solve() template void BmfSystem::bmf_solve(const CnstList& cnst_list) { - /* initialize players' weight and constraint matrices */ idx2Var_.clear(); cnst2idx_.clear(); Eigen::MatrixXd A; @@ -505,6 +504,4 @@ template void BmfSystem::bmf_solve(const CnstList& cnst_list) } } -} // namespace lmm -} // namespace kernel -} // namespace simgrid +} // namespace simgrid::kernel::lmm