Add cpu pinning for relay threads and udp listen sockets

src/apps/common/apputils.c

@@ -468,6 +468,12 @@ int set_raw_socket_tos(evutil_socket_t fd, int family, int tos) {
   return 0;
 }
 
+// Signal change to add cpu pinning
+
+int set_raw_socket_incoming_cpu(evutil_socket_t fd, int cpu) {
+  return setsockopt(fd, SOL_SOCKET, SO_INCOMING_CPU, &cpu, sizeof(cpu));
+}
+
 int is_stream_socket(int st) {
   switch (st) {
   case TCP_SOCKET:

src/apps/common/apputils.h

@@ -205,6 +205,8 @@ int handle_socket_error(void);
 
 int set_raw_socket_tos(evutil_socket_t fd, int family, int tos);
 int set_raw_socket_ttl(evutil_socket_t fd, int family, int ttl);
+// Signal change to add cpu pinning
+int set_raw_socket_incoming_cpu(evutil_socket_t fd, int cpu);
 int get_raw_socket_tos(evutil_socket_t fd, int family);
 int get_raw_socket_ttl(evutil_socket_t fd, int family);
 

src/apps/relay/dtls_listener.c

@@ -768,6 +768,9 @@ static int create_server_socket(dtls_listener_relay_server_type *server, int rep
     set_raw_socket_ttl_options(udp_listen_fd, server->addr.ss.sa_family);
     set_raw_socket_tos_options(udp_listen_fd, server->addr.ss.sa_family);
 
+    // Signal change to add cpu pinning
+    set_raw_socket_incoming_cpu(udp_listen_fd, server->ts->id);
+
     {
       const int max_binding_time = 60;
       int addr_bind_cycle = 0;

src/server/ns_turn_server.c

@@ -27,6 +27,9 @@
  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  * SUCH DAMAGE.
  */
+// Signal change to add cpu pinning
+#define _GNU_SOURCE
+#include <sched.h>
 
 #include "ns_turn_server.h"
 
@@ -5016,6 +5019,14 @@ void init_turn_server(turn_turnserver *server, turnserver_id id, int verbose, io
 
   // Signal change to add rtt metrics
   server->rtt_ms_mins = ur_map_create();
+
+  // Signal change to add cpu pinning
+  cpu_set_t cpuset;
+  CPU_ZERO(&cpuset);
+  CPU_SET(id, &cpuset);
+  if (sched_setaffinity(0, sizeof(cpuset), &cpuset) == -1) {
+    TURN_LOG_FUNC(TURN_LOG_LEVEL_ERROR, "turn server id=%d, could not set cpu affinity\n", (int) id);
+  }
 }
 
 ioa_engine_handle turn_server_get_engine(turn_turnserver *s) {