Commit 538aaf9b authored by Joanne Koong's avatar Joanne Koong Committed by Jakub Kicinski
Browse files

selftests: Add test for timing a bind request to a port with a populated bhash entry 



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: default avatarJoanne Koong <joannelkoong@gmail.com>
Signed-off-by: default avatarJakub Kicinski <kuba@kernel.org>
parent d5a42de8

tools/testing/selftests/net/.gitignore

+1 −0
Original line number Diff line number Diff line
@@ -36,3 +36,4 @@ gro 
ioam6_parser

toeplitz

cmsg_sender

bind_bhash_test

tools/testing/selftests/net/Makefile

+2 −0
Original line number Diff line number Diff line
@@ -59,6 +59,7 @@ TEST_GEN_FILES += toeplitz 
TEST_GEN_FILES += cmsg_sender

TEST_GEN_FILES += stress_reuseport_listen

TEST_PROGS += test_vxlan_vnifiltering.sh

TEST_GEN_FILES += bind_bhash_test



TEST_FILES := settings
@@ -69,4 +70,5 @@ include bpf/Makefile 


$(OUTPUT)/reuseport_bpf_numa: LDLIBS += -lnuma

$(OUTPUT)/tcp_mmap: LDLIBS += -lpthread

$(OUTPUT)/bind_bhash_test: LDLIBS += -lpthread

$(OUTPUT)/tcp_inq: LDLIBS += -lpthread

tools/testing/selftests/net/bind_bhash_test.c

0 → 100644
+119 −0
Original line number Diff line number Diff line 
// 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;

}