@@ -36,3 +36,4 @@ gro
ioam6_parser
toeplitz
cmsg_sender
+bind_bhash_test
@@ -56,6 +56,7 @@ TEST_GEN_PROGS += reuseport_dualstack reuseaddr_conflict tls
TEST_GEN_FILES += toeplitz
TEST_GEN_FILES += cmsg_sender
TEST_PROGS += test_vxlan_vnifiltering.sh
+TEST_GEN_FILES += bind_bhash_test
TEST_FILES := settings
@@ -64,4 +65,5 @@ include ../lib.mk
$(OUTPUT)/reuseport_bpf_numa: LDLIBS += -lnuma
$(OUTPUT)/tcp_mmap: LDLIBS += -lpthread
+$(OUTPUT)/bind_bhash_test: LDLIBS += -lpthread
$(OUTPUT)/tcp_inq: LDLIBS += -lpthread
new file mode 100644
@@ -0,0 +1,119 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * This times how long it takes to bind to a port when the port already
+ * has multiple sockets in its bhash table.
+ *
+ * In the setup(), we populate the port's bhash table with
+ * MAX_THREADS * MAX_CONNECTIONS number of entries.
+ */
+
+#include <unistd.h>
+#include <stdio.h>
+#include <netdb.h>
+#include <pthread.h>
+
+#define MAX_THREADS 600
+#define MAX_CONNECTIONS 40
+
+static const char *bind_addr = "::1";
+static const char *port;
+
+static int fd_array[MAX_THREADS][MAX_CONNECTIONS];
+
+static int bind_socket(int opt, const char *addr)
+{
+ struct addrinfo *res, hint = {};
+ int sock_fd, reuse = 1, err;
+
+ sock_fd = socket(AF_INET6, SOCK_STREAM, 0);
+ if (sock_fd < 0) {
+ perror("socket fd err");
+ return -1;
+ }
+
+ hint.ai_family = AF_INET6;
+ hint.ai_socktype = SOCK_STREAM;
+
+ err = getaddrinfo(addr, port, &hint, &res);
+ if (err) {
+ perror("getaddrinfo failed");
+ return -1;
+ }
+
+ if (opt) {
+ err = setsockopt(sock_fd, SOL_SOCKET, opt, &reuse, sizeof(reuse));
+ if (err) {
+ perror("setsockopt failed");
+ return -1;
+ }
+ }
+
+ err = bind(sock_fd, res->ai_addr, res->ai_addrlen);
+ if (err) {
+ perror("failed to bind to port");
+ return -1;
+ }
+
+ return sock_fd;
+}
+
+static void *setup(void *arg)
+{
+ int sock_fd, i;
+ int *array = (int *)arg;
+
+ for (i = 0; i < MAX_CONNECTIONS; i++) {
+ sock_fd = bind_socket(SO_REUSEADDR | SO_REUSEPORT, bind_addr);
+ if (sock_fd < 0)
+ return NULL;
+ array[i] = sock_fd;
+ }
+
+ return NULL;
+}
+
+int main(int argc, const char *argv[])
+{
+ int listener_fd, sock_fd, i, j;
+ pthread_t tid[MAX_THREADS];
+ clock_t begin, end;
+
+ if (argc != 2) {
+ printf("Usage: listener <port>\n");
+ return -1;
+ }
+
+ port = argv[1];
+
+ listener_fd = bind_socket(SO_REUSEADDR | SO_REUSEPORT, bind_addr);
+ if (listen(listener_fd, 100) < 0) {
+ perror("listen failed");
+ return -1;
+ }
+
+ /* Set up threads to populate the bhash table entry for the port */
+ for (i = 0; i < MAX_THREADS; i++)
+ pthread_create(&tid[i], NULL, setup, fd_array[i]);
+
+ for (i = 0; i < MAX_THREADS; i++)
+ pthread_join(tid[i], NULL);
+
+ begin = clock();
+
+ /* Bind to the same port on a different address */
+ sock_fd = bind_socket(0, "2001:0db8:0:f101::1");
+
+ end = clock();
+
+ printf("time spent = %f\n", (double)(end - begin) / CLOCKS_PER_SEC);
+
+ /* clean up */
+ close(sock_fd);
+ close(listener_fd);
+ for (i = 0; i < MAX_THREADS; i++) {
+ for (j = 0; i < MAX_THREADS; i++)
+ close(fd_array[i][j]);
+ }
+
+ return 0;
+}
This test populates the bhash table for a given port with MAX_THREADS * MAX_CONNECTIONS sockets, and then times how long a bind request on the port takes. When populating the bhash table, we create the sockets and then bind the sockets to the same address and port (SO_REUSEADDR and SO_REUSEPORT are set). When timing how long a bind on the port takes, we bind on a different address without SO_REUSEPORT set. We do not set SO_REUSEPORT because we are interested in the case where the bind request does not go through the tb->fastreuseport path, which is fragile (eg tb->fastreuseport path does not work if binding with a different uid). To run the test locally, I did: * ulimit -n 65535000 * ip addr add 2001:0db8:0:f101::1 dev eth0 * ./bind_bhash_test 443 Signed-off-by: Joanne Koong <joannelkoong@gmail.com> --- tools/testing/selftests/net/.gitignore | 1 + tools/testing/selftests/net/Makefile | 2 + tools/testing/selftests/net/bind_bhash_test.c | 119 ++++++++++++++++++ 3 files changed, 122 insertions(+) create mode 100644 tools/testing/selftests/net/bind_bhash_test.c