Fixed bug when numa.h functions are not available.

src/system_info/system_info.hpp

@@ -13,6 +13,7 @@
 
 #include <linux/sched.h>
 #include <numa.h>
+#include <numeric>
 #include <sys/sysinfo.h>
 #include <unistd.h>
 
@@ -153,47 +154,88 @@ namespace system_info {
 
 			return proc.unpin(print);
 		}
-	} // namespace auxiliary_functions
 
-	bool detect_system() {
-		details::node_cpu_map = std::vector<std::vector<cpu_t>>(details::NUM_OF_MEMORIES);
-		for (node_t node = 0; node < details::NUM_OF_MEMORIES; node++) {
-			details::node_cpu_map[node] = auxiliary_functions::cpus_from_node(node);
-			if (details::node_cpu_map[node].empty()) {
-				return false;
+		bool detect_system_NUMA() {
+			details::node_cpu_map.resize(details::NUM_OF_MEMORIES);
+			for (node_t node = 0; node < details::NUM_OF_MEMORIES; node++) {
+				details::node_cpu_map[node] = auxiliary_functions::cpus_from_node(node);
+				if (details::node_cpu_map[node].empty()) {
+					return false;
+				}
 			}
-		}
 
-		details::cpu_node_map = std::vector<node_t>(details::NUM_OF_CPUS);
+			details::cpu_node_map = std::vector<node_t>(details::NUM_OF_CPUS);
 
-		details::cpu_tid_map.resize(details::NUM_OF_CPUS);
-		details::node_tid_map.resize(details::NUM_OF_MEMORIES);
+			details::cpu_tid_map.resize(details::NUM_OF_CPUS);
+			details::node_tid_map.resize(details::NUM_OF_MEMORIES);
 
-		// For each CPU, reads topology file to get package (node) id
-		for (size_t cpu = 0; cpu < details::NUM_OF_CPUS; cpu++) {
-			details::cpu_node_map[cpu] = numa_node_of_cpu(cpu);
-		}
+			// For each CPU, reads topology file to get package (node) id
+			for (size_t cpu = 0; cpu < details::NUM_OF_CPUS; cpu++) {
+				details::cpu_node_map[cpu] = numa_node_of_cpu(cpu);
+			}
 
-		// Compute the lists of nodes sorted by distance from a given node...
-		for (node_t node = 0; node < details::NUM_OF_MEMORIES; node++) {
-			std::multimap<int, node_t> distance_nodes_map{};
-			for (size_t node2 = 0; node2 < details::NUM_OF_MEMORIES; node2++) {
-				distance_nodes_map.insert(std::pair(numa_distance(node, node2), node2));
+			// Compute the lists of nodes sorted by distance from a given node...
+			for (node_t node = 0; node < details::NUM_OF_MEMORIES; node++) {
+				std::multimap<int, node_t> distance_nodes_map{};
+				for (size_t node2 = 0; node2 < details::NUM_OF_MEMORIES; node2++) {
+					distance_nodes_map.insert(std::pair(numa_distance(node, node2), node2));
+				}
+				std::vector<node_t> nodes_by_distance;
+				for (const auto & [distance, node2] : distance_nodes_map) {
+					nodes_by_distance.push_back(node2);
+				}
+				details::nodes_by_distance[node] = nodes_by_distance;
 			}
-			std::vector<node_t> nodes_by_distance;
-			for (const auto & [distance, node2] : distance_nodes_map) {
-				nodes_by_distance.push_back(node2);
+
+			if (VERBOSE_LVL >= DEFAULT_VERB) {
+				for (const auto & [node, nodes] : details::nodes_by_distance) {
+					std::cout << "Node " << node << ":" << '\n';
+					for (const auto & node2 : nodes) {
+						std::cout << "\tNode " << node2 << " (distance " << numa_distance(node, node2) << ")" << '\n';
+					}
+				}
 			}
-			details::nodes_by_distance[node] = nodes_by_distance;
+
+			return true;
 		}
 
-		if (VERBOSE_LVL >= DEFAULT_VERB) {
-			for (const auto & [node, nodes] : details::nodes_by_distance) {
-				std::cout << "Node " << node << ":" << '\n';
-				for (const auto & node2 : nodes) {
-					std::cout << "\tNode " << node2 << " (distance " << numa_distance(node, node2) << ")" << '\n';
-				}
+		bool detect_system_UMA() {
+			details::NUM_OF_MEMORIES = 1;
+			details::CPUS_PER_MEMORY = details::NUM_OF_CPUS / details::NUM_OF_MEMORIES;
+
+			std::vector<cpu_t> cpus(details::NUM_OF_CPUS);
+			std::iota(cpus.begin(), cpus.end(), 0);
+
+			details::node_cpu_map.resize(details::NUM_OF_MEMORIES);
+			details::node_cpu_map[0] = cpus;
+
+			details::cpu_node_map = std::vector<node_t>(details::NUM_OF_CPUS, 0);
+
+			details::cpu_tid_map.resize(details::NUM_OF_CPUS);
+			details::node_tid_map.resize(details::NUM_OF_MEMORIES);
+
+			// For each CPU, reads topology file to get package (node) id
+			for (size_t cpu = 0; cpu < details::NUM_OF_CPUS; cpu++) {
+				details::cpu_node_map[cpu] = 0;
 			}
+
+			// Compute the lists of nodes sorted by distance from a given node...
+			details::nodes_by_distance[0] = { 0 };
+
+			return true;
+		}
+	} // namespace auxiliary_functions
+
+	bool detect_system() {
+		bool ret_value;
+
+		if (numa_available() == -1) {
+			std::cerr << "NUMA support not available. Assuming you are using a UMA machine. Trying to survive..."
+			          << '\n';
+
+			ret_value = auxiliary_functions::detect_system_UMA();
+		} else {
+			ret_value = auxiliary_functions::detect_system_NUMA();
 		}
 
 		if (VERBOSE_LVL >= DEFAULT_VERB) {
@@ -201,7 +243,7 @@ namespace system_info {
 			          << " memory nodes, " << details::CPUS_PER_MEMORY << " CPUs per node." << '\n';
 		}
 
-		return true;
+		return ret_value;
 	}
 
 	void scan_dir(const char * dirname, process * parent = nullptr, bool scan_children = true);