Add cpu affinity option to supervised node config

scripts/base/frameworks/supervisor/api.zeek

@@ -24,6 +24,7 @@ export {
 		interface: string &optional;
 		directory: string &optional;
 		scripts: vector of string &default = vector();
+		cpu_affinity: int &optional;
 		cluster: table[string] of ClusterEndpoint &default=table();
 
 		# TODO: separate node config fields from status fields ?

src/CMakeLists.txt

@@ -204,6 +204,7 @@ set(MAIN_SRCS
     net_util.cc
     util.cc
     module_util.cc
+    zeek-affinity.cc
     Anon.cc
     Attr.cc
     Base64.cc

src/Supervisor.cc

@@ -732,6 +732,11 @@ Supervisor::Node Supervisor::Node::FromRecord(const RecordVal* node)
 	if ( directory_val )
 		rval.directory = directory_val->AsString()->CheckString();
 
+	auto affinity_val = node->Lookup("cpu_affinity");
+
+	if ( affinity_val )
+		rval.cpu_affinity = affinity_val->AsInt();
+
 	auto scripts_val = node->Lookup("scripts")->AsVectorVal();
 
 	for ( auto i = 0; i < scripts_val->Size(); ++i )
@@ -779,7 +784,10 @@ Supervisor::Node Supervisor::Node::FromJSON(std::string_view json)
 		rval.interface = *it;
 
 	if ( auto it = j.find("directory"); it != j.end() )
-		rval.directory= *it;
+		rval.directory = *it;
+
+	if ( auto it = j.find("cpu_affinity"); it != j.end() )
+		rval.cpu_affinity = *it;
 
 	auto scripts = j["scripts"];
 
@@ -833,6 +841,9 @@ IntrusivePtr<RecordVal> Supervisor::Node::ToRecord() const
 	if ( directory )
 		rval->Assign(rt->FieldOffset("directory"), new StringVal(*directory));
 
+	if ( cpu_affinity )
+		rval->Assign(rt->FieldOffset("cpu_affinity"), val_mgr->GetInt(*cpu_affinity));
+
 	auto st = BifType::Record::Supervisor::Node->FieldType("scripts");
 	auto scripts_val = new VectorVal(st->AsVectorType());
 	rval->Assign(rt->FieldOffset("scripts"), scripts_val);

src/Supervisor.h

@@ -47,6 +47,7 @@ public:
 		std::string name;
 		std::optional<std::string> interface;
 		std::optional<std::string> directory;
+		std::optional<int> cpu_affinity;
 		std::vector<std::string> scripts;
 		std::map<std::string, ClusterEndpoint> cluster;
 

src/main.cc

@@ -78,6 +78,8 @@ extern "C" {
 #include "setsignal.h"
 };
 
+#include "zeek-affinity.h"
+
 #ifdef USE_PERFTOOLS_DEBUG
 HeapLeakChecker* heap_checker = 0;
 int perftools_leaks = 0;
@@ -944,7 +946,7 @@ int main(int argc, char** argv)
 			{
 			if ( setenv("CLUSTER_NODE", node_name.data(), true) == -1 )
 				{
-				fprintf(stderr, "cluster node %s failed to setenv: %s\n",
+				fprintf(stderr, "node '%s' failed to setenv: %s\n",
 				        node_name.data(), strerror(errno));
 				exit(1);
 				}
@@ -954,7 +956,7 @@ int main(int argc, char** argv)
 			{
 			if ( chdir(zeek::supervised_node->directory->data()) )
 				{
-				fprintf(stderr, "supervised node %s failed to chdir to %s: %s\n",
+				fprintf(stderr, "node '%s' failed to chdir to %s: %s\n",
 				        node_name.data(),
 				        zeek::supervised_node->directory->data(),
 				        strerror(errno));
@@ -962,6 +964,15 @@ int main(int argc, char** argv)
 				}
 			}
 
+		if ( zeek::supervised_node->cpu_affinity )
+			{
+			auto res = zeek::set_affinity(*zeek::supervised_node->cpu_affinity);
+
+			if ( ! res )
+				fprintf(stderr, "node '%s' failed to set CPU affinity: %s\n",
+				        node_name.data(), strerror(errno));
+			}
+
 		for ( const auto& s : zeek::supervised_node->scripts )
 			options.scripts_to_load.emplace_back(s);
 		}

src/zeek-affinity.cc

@@ -0,0 +1,51 @@
+// See the file "COPYING" in the main distribution directory for copyright.
+
+#if defined(__linux__)
+
+#if !defined(_GNU_SOURCE)
+#define _GNU_SOURCE
+#endif
+
+#include <sched.h>
+
+namespace zeek {
+bool set_affinity(int core_number)
+	{
+	cpu_set_t cpus;
+	CPU_ZERO(&cpus);
+	CPU_SET(core_number, &cpus);
+	auto res = sched_setaffinity(0, sizeof(cpus), &cpus);
+	return res == 0;
+	}
+} // namespace zeek
+
+#elif defined(__FreeBSD__)
+
+#include <sys/param.h>
+#include <sys/cpuset.h>
+
+namespace zeek {
+bool set_affinity(int core_number)
+	{
+	cpuset_t cpus;
+	CPU_ZERO(&cpus);
+	CPU_SET(core_number, &cpus);
+	auto res = cpuset_setaffinity(CPU_LEVEL_WHICH, CPU_WHICH_PID, -1,
+	                              sizeof(cpus), &cpus);
+	return res == 0;
+	}
+} // namespace zeek
+
+#else
+
+#include <cerrno>
+
+namespace zeek {
+bool set_affinity(int core_number)
+	{
+	errno = ENOTSUP;
+	return false;
+	}
+} // namespace zeek
+
+#endif

src/zeek-affinity.h

@@ -0,0 +1,15 @@
+// See the file "COPYING" in the main distribution directory for copyright.
+
+namespace zeek {
+
+/**
+ * Set the process affinity to a given CPU.  Currently only supported on
+ * Linux and FreeBSD.
+ * @param core_number  the core to which this process should set its affinity.
+ * Cores are typically numbered 0..N.
+ * @return true if the affinity is successfully set and false if not with
+ * errno additionally being set to indicate the reason.
+ */
+bool set_affinity(int core_number);
+
+} // namespace zeek