selftests: cgroup: memcontrol: add basic test for socket accounting
diff mbox

Message ID 1526470089-27010-1-git-send-email-rppt@linux.vnet.ibm.com
State Superseded
Headers show

Commit Message

Mike Rapoport May 16, 2018, 11:28 a.m. UTC
The test verifies that with active TCP traffic memory.current and
memory.stat.sock have similar values.

Signed-off-by: Mike Rapoport <rppt@linux.vnet.ibm.com>
---
 tools/testing/selftests/cgroup/test_memcontrol.c | 184 +++++++++++++++++++++++
 1 file changed, 184 insertions(+)

Comments

Roman Gushchin May 16, 2018, 2:04 p.m. UTC | #1
Hi Mike!

On Wed, May 16, 2018 at 02:28:09PM +0300, Mike Rapoport wrote:
> The test verifies that with active TCP traffic memory.current and
> memory.stat.sock have similar values.
> 
> Signed-off-by: Mike Rapoport <rppt@linux.vnet.ibm.com>
> ---
>  tools/testing/selftests/cgroup/test_memcontrol.c | 184 +++++++++++++++++++++++
>  1 file changed, 184 insertions(+)
> 
> diff --git a/tools/testing/selftests/cgroup/test_memcontrol.c b/tools/testing/selftests/cgroup/test_memcontrol.c
> index beae06c9c899..0efdb1009175 100644
> --- a/tools/testing/selftests/cgroup/test_memcontrol.c
> +++ b/tools/testing/selftests/cgroup/test_memcontrol.c
> @@ -9,6 +9,12 @@
>  #include <sys/stat.h>
>  #include <sys/types.h>
>  #include <unistd.h>
> +#include <sys/socket.h>
> +#include <sys/wait.h>
> +#include <arpa/inet.h>
> +#include <netinet/in.h>
> +#include <netdb.h>
> +#include <errno.h>
>  
>  #include "../kselftest.h"
>  #include "cgroup_util.h"
> @@ -772,6 +778,183 @@ static int test_memcg_oom_events(const char *root)
>  	return ret;
>  }
>  
> +struct tcp_server_args {
> +	unsigned short port;
> +	int ctl[2];
> +};
> +
> +static int tcp_server(const char *cgroup, void *arg)
> +{
> +	struct tcp_server_args *srv_args = arg;
> +	struct sockaddr_in6 saddr = { 0 };
> +	socklen_t slen = sizeof(saddr);
> +	int sk, client_sk, ctl_fd, yes = 1, ret = -1;
> +
> +	close(srv_args->ctl[0]);
> +	ctl_fd = srv_args->ctl[1];
> +
> +	saddr.sin6_family = AF_INET6;
> +	saddr.sin6_addr = in6addr_any;
> +	saddr.sin6_port = htons(srv_args->port);
> +
> +	sk = socket(AF_INET6, SOCK_STREAM, 0);
> +	if (sk < 0)
> +		return ret;
> +
> +	if (setsockopt(sk, SOL_SOCKET, SO_REUSEADDR, &yes, sizeof(yes)) < 0)
> +		goto cleanup;
> +
> +	if (bind(sk, (struct sockaddr *)&saddr, slen)) {
> +		write(ctl_fd, &errno, sizeof(errno));
> +		goto cleanup;
> +	}
> +
> +	if (listen(sk, 1))
> +		goto cleanup;
> +
> +	ret = 0;
> +	if (write(ctl_fd, &ret, sizeof(ret)) != sizeof(ret)) {
> +		ret = -1;
> +		goto cleanup;
> +	}
> +
> +	client_sk = accept(sk, NULL, NULL);
> +	if (client_sk < 0)
> +		goto cleanup;
> +
> +	ret = -1;
> +	for (;;) {
> +		uint8_t buf[0x100000];
> +
> +		if (write(client_sk, buf, sizeof(buf)) <= 0) {
> +			if (errno == ECONNRESET)
> +				ret = 0;
> +			break;
> +		}
> +	}
> +
> +	close(client_sk);
> +
> +cleanup:
> +	close(sk);
> +	return ret;
> +}
> +
> +static int tcp_client(const char *cgroup, unsigned short port)
> +{
> +	const char server[] = "localhost";
> +	struct addrinfo *ai;
> +	char servport[6];
> +	int retries = 0x10; /* nice round number */
> +	int sk, ret;
> +
> +	snprintf(servport, sizeof(servport), "%hd", port);
> +	ret = getaddrinfo(server, servport, NULL, &ai);
> +	if (ret)
> +		return ret;
> +
> +	sk = socket(ai->ai_family, ai->ai_socktype, ai->ai_protocol);
> +	if (sk < 0)
> +		goto free_ainfo;
> +
> +	ret = connect(sk, ai->ai_addr, ai->ai_addrlen);
> +	if (ret < 0)
> +		goto close_sk;
> +
> +	ret = KSFT_FAIL;
> +	while (retries--) {
> +		uint8_t buf[0x100000];
> +		long current, sock;
> +
> +		if (read(sk, buf, sizeof(buf)) <= 0)
> +			goto close_sk;
> +
> +		current = cg_read_long(cgroup, "memory.current");
> +		if (current < 0)
> +			goto close_sk;
> +
> +		sock = cg_read_key_long(cgroup, "memory.stat", "sock ");
> +		if (sock < 0)
> +			goto close_sk;
> +
> +		if (values_close(current, sock, 3)) {
> +			ret = KSFT_PASS;
> +			break;
> +		}

The test is flapping (at least on my dev machine) because of this condition.

I believe it's because of the batching we're using on the page charge path.
So, in theory, it should be possible to calculate the maximum difference
like num_cpus * PAGE_SIZE * batch_size.

Alternatively, just bump allowed error percentage :)

> +	}
> +
> +close_sk:
> +	close(sk);

It would be great to check that sock and current are getting 0 values
after we're closing the socket.


Thanks!
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Mike Rapoport May 16, 2018, 2:48 p.m. UTC | #2
On Wed, May 16, 2018 at 03:04:08PM +0100, Roman Gushchin wrote:
> Hi Mike!
> 
> On Wed, May 16, 2018 at 02:28:09PM +0300, Mike Rapoport wrote:
> > The test verifies that with active TCP traffic memory.current and
> > memory.stat.sock have similar values.
> > 
> > Signed-off-by: Mike Rapoport <rppt@linux.vnet.ibm.com>
> > ---
> >  tools/testing/selftests/cgroup/test_memcontrol.c | 184 +++++++++++++++++++++++
> >  1 file changed, 184 insertions(+)
> > 
> > diff --git a/tools/testing/selftests/cgroup/test_memcontrol.c b/tools/testing/selftests/cgroup/test_memcontrol.c
> > index beae06c9c899..0efdb1009175 100644
> > --- a/tools/testing/selftests/cgroup/test_memcontrol.c
> > +++ b/tools/testing/selftests/cgroup/test_memcontrol.c
> > @@ -9,6 +9,12 @@
> >  #include <sys/stat.h>
> >  #include <sys/types.h>
> >  #include <unistd.h>
> > +#include <sys/socket.h>
> > +#include <sys/wait.h>
> > +#include <arpa/inet.h>
> > +#include <netinet/in.h>
> > +#include <netdb.h>
> > +#include <errno.h>
> >  
> >  #include "../kselftest.h"
> >  #include "cgroup_util.h"
> > @@ -772,6 +778,183 @@ static int test_memcg_oom_events(const char *root)
> >  	return ret;
> >  }
> >  
> > +struct tcp_server_args {
> > +	unsigned short port;
> > +	int ctl[2];
> > +};
> > +
> > +static int tcp_server(const char *cgroup, void *arg)
> > +{
> > +	struct tcp_server_args *srv_args = arg;
> > +	struct sockaddr_in6 saddr = { 0 };
> > +	socklen_t slen = sizeof(saddr);
> > +	int sk, client_sk, ctl_fd, yes = 1, ret = -1;
> > +
> > +	close(srv_args->ctl[0]);
> > +	ctl_fd = srv_args->ctl[1];
> > +
> > +	saddr.sin6_family = AF_INET6;
> > +	saddr.sin6_addr = in6addr_any;
> > +	saddr.sin6_port = htons(srv_args->port);
> > +
> > +	sk = socket(AF_INET6, SOCK_STREAM, 0);
> > +	if (sk < 0)
> > +		return ret;
> > +
> > +	if (setsockopt(sk, SOL_SOCKET, SO_REUSEADDR, &yes, sizeof(yes)) < 0)
> > +		goto cleanup;
> > +
> > +	if (bind(sk, (struct sockaddr *)&saddr, slen)) {
> > +		write(ctl_fd, &errno, sizeof(errno));
> > +		goto cleanup;
> > +	}
> > +
> > +	if (listen(sk, 1))
> > +		goto cleanup;
> > +
> > +	ret = 0;
> > +	if (write(ctl_fd, &ret, sizeof(ret)) != sizeof(ret)) {
> > +		ret = -1;
> > +		goto cleanup;
> > +	}
> > +
> > +	client_sk = accept(sk, NULL, NULL);
> > +	if (client_sk < 0)
> > +		goto cleanup;
> > +
> > +	ret = -1;
> > +	for (;;) {
> > +		uint8_t buf[0x100000];
> > +
> > +		if (write(client_sk, buf, sizeof(buf)) <= 0) {
> > +			if (errno == ECONNRESET)
> > +				ret = 0;
> > +			break;
> > +		}
> > +	}
> > +
> > +	close(client_sk);
> > +
> > +cleanup:
> > +	close(sk);
> > +	return ret;
> > +}
> > +
> > +static int tcp_client(const char *cgroup, unsigned short port)
> > +{
> > +	const char server[] = "localhost";
> > +	struct addrinfo *ai;
> > +	char servport[6];
> > +	int retries = 0x10; /* nice round number */
> > +	int sk, ret;
> > +
> > +	snprintf(servport, sizeof(servport), "%hd", port);
> > +	ret = getaddrinfo(server, servport, NULL, &ai);
> > +	if (ret)
> > +		return ret;
> > +
> > +	sk = socket(ai->ai_family, ai->ai_socktype, ai->ai_protocol);
> > +	if (sk < 0)
> > +		goto free_ainfo;
> > +
> > +	ret = connect(sk, ai->ai_addr, ai->ai_addrlen);
> > +	if (ret < 0)
> > +		goto close_sk;
> > +
> > +	ret = KSFT_FAIL;
> > +	while (retries--) {
> > +		uint8_t buf[0x100000];
> > +		long current, sock;
> > +
> > +		if (read(sk, buf, sizeof(buf)) <= 0)
> > +			goto close_sk;
> > +
> > +		current = cg_read_long(cgroup, "memory.current");
> > +		if (current < 0)
> > +			goto close_sk;
> > +
> > +		sock = cg_read_key_long(cgroup, "memory.stat", "sock ");
> > +		if (sock < 0)
> > +			goto close_sk;
> > +
> > +		if (values_close(current, sock, 3)) {
> > +			ret = KSFT_PASS;
> > +			break;
> > +		}
> 
> The test is flapping (at least on my dev machine) because of this condition.
> 
> I believe it's because of the batching we're using on the page charge path.
> So, in theory, it should be possible to calculate the maximum difference
> like num_cpus * PAGE_SIZE * batch_size.

I afraid it's more complex and timing sensitive
 
> Alternatively, just bump allowed error percentage :)

so I'll bump the error percentage :)
 
> > +	}
> > +
> > +close_sk:
> > +	close(sk);
> 
> It would be great to check that sock and current are getting 0 values
> after we're closing the socket.
 
Hmm, here it's also timing sensitive. I can see that sock is reliably
getting 0 if I check it after the server exits. But current usually remains
small but still !0.
 
> Thanks!
>
Roman Gushchin May 16, 2018, 4:04 p.m. UTC | #3
On Wed, May 16, 2018 at 05:48:26PM +0300, Mike Rapoport wrote:
> On Wed, May 16, 2018 at 03:04:08PM +0100, Roman Gushchin wrote:
> > Hi Mike!
> > 
> > On Wed, May 16, 2018 at 02:28:09PM +0300, Mike Rapoport wrote:
> > > The test verifies that with active TCP traffic memory.current and
> > > memory.stat.sock have similar values.
> > > 
> > > Signed-off-by: Mike Rapoport <rppt@linux.vnet.ibm.com>
> > > ---
> > >  tools/testing/selftests/cgroup/test_memcontrol.c | 184 +++++++++++++++++++++++
> > >  1 file changed, 184 insertions(+)
> > > 
> > > diff --git a/tools/testing/selftests/cgroup/test_memcontrol.c b/tools/testing/selftests/cgroup/test_memcontrol.c
> > > index beae06c9c899..0efdb1009175 100644
> > > --- a/tools/testing/selftests/cgroup/test_memcontrol.c
> > > +++ b/tools/testing/selftests/cgroup/test_memcontrol.c
> > > @@ -9,6 +9,12 @@
> > >  #include <sys/stat.h>
> > >  #include <sys/types.h>
> > >  #include <unistd.h>
> > > +#include <sys/socket.h>
> > > +#include <sys/wait.h>
> > > +#include <arpa/inet.h>
> > > +#include <netinet/in.h>
> > > +#include <netdb.h>
> > > +#include <errno.h>
> > >  
> > >  #include "../kselftest.h"
> > >  #include "cgroup_util.h"
> > > @@ -772,6 +778,183 @@ static int test_memcg_oom_events(const char *root)
> > >  	return ret;
> > >  }
> > >  
> > > +struct tcp_server_args {
> > > +	unsigned short port;
> > > +	int ctl[2];
> > > +};
> > > +
> > > +static int tcp_server(const char *cgroup, void *arg)
> > > +{
> > > +	struct tcp_server_args *srv_args = arg;
> > > +	struct sockaddr_in6 saddr = { 0 };
> > > +	socklen_t slen = sizeof(saddr);
> > > +	int sk, client_sk, ctl_fd, yes = 1, ret = -1;
> > > +
> > > +	close(srv_args->ctl[0]);
> > > +	ctl_fd = srv_args->ctl[1];
> > > +
> > > +	saddr.sin6_family = AF_INET6;
> > > +	saddr.sin6_addr = in6addr_any;
> > > +	saddr.sin6_port = htons(srv_args->port);
> > > +
> > > +	sk = socket(AF_INET6, SOCK_STREAM, 0);
> > > +	if (sk < 0)
> > > +		return ret;
> > > +
> > > +	if (setsockopt(sk, SOL_SOCKET, SO_REUSEADDR, &yes, sizeof(yes)) < 0)
> > > +		goto cleanup;
> > > +
> > > +	if (bind(sk, (struct sockaddr *)&saddr, slen)) {
> > > +		write(ctl_fd, &errno, sizeof(errno));
> > > +		goto cleanup;
> > > +	}
> > > +
> > > +	if (listen(sk, 1))
> > > +		goto cleanup;
> > > +
> > > +	ret = 0;
> > > +	if (write(ctl_fd, &ret, sizeof(ret)) != sizeof(ret)) {
> > > +		ret = -1;
> > > +		goto cleanup;
> > > +	}
> > > +
> > > +	client_sk = accept(sk, NULL, NULL);
> > > +	if (client_sk < 0)
> > > +		goto cleanup;
> > > +
> > > +	ret = -1;
> > > +	for (;;) {
> > > +		uint8_t buf[0x100000];
> > > +
> > > +		if (write(client_sk, buf, sizeof(buf)) <= 0) {
> > > +			if (errno == ECONNRESET)
> > > +				ret = 0;
> > > +			break;
> > > +		}
> > > +	}
> > > +
> > > +	close(client_sk);
> > > +
> > > +cleanup:
> > > +	close(sk);
> > > +	return ret;
> > > +}
> > > +
> > > +static int tcp_client(const char *cgroup, unsigned short port)
> > > +{
> > > +	const char server[] = "localhost";
> > > +	struct addrinfo *ai;
> > > +	char servport[6];
> > > +	int retries = 0x10; /* nice round number */
> > > +	int sk, ret;
> > > +
> > > +	snprintf(servport, sizeof(servport), "%hd", port);
> > > +	ret = getaddrinfo(server, servport, NULL, &ai);
> > > +	if (ret)
> > > +		return ret;
> > > +
> > > +	sk = socket(ai->ai_family, ai->ai_socktype, ai->ai_protocol);
> > > +	if (sk < 0)
> > > +		goto free_ainfo;
> > > +
> > > +	ret = connect(sk, ai->ai_addr, ai->ai_addrlen);
> > > +	if (ret < 0)
> > > +		goto close_sk;
> > > +
> > > +	ret = KSFT_FAIL;
> > > +	while (retries--) {
> > > +		uint8_t buf[0x100000];
> > > +		long current, sock;
> > > +
> > > +		if (read(sk, buf, sizeof(buf)) <= 0)
> > > +			goto close_sk;
> > > +
> > > +		current = cg_read_long(cgroup, "memory.current");
> > > +		if (current < 0)
> > > +			goto close_sk;
> > > +
> > > +		sock = cg_read_key_long(cgroup, "memory.stat", "sock ");
> > > +		if (sock < 0)
> > > +			goto close_sk;
> > > +
> > > +		if (values_close(current, sock, 3)) {
> > > +			ret = KSFT_PASS;
> > > +			break;
> > > +		}
> > 
> > The test is flapping (at least on my dev machine) because of this condition.
> > 
> > I believe it's because of the batching we're using on the page charge path.
> > So, in theory, it should be possible to calculate the maximum difference
> > like num_cpus * PAGE_SIZE * batch_size.
> 
> I afraid it's more complex and timing sensitive
>  
> > Alternatively, just bump allowed error percentage :)
> 
> so I'll bump the error percentage :)

Ok.
Please, add then a check that current >= sock.
It should be always true, right?

>  
> > > +	}
> > > +
> > > +close_sk:
> > > +	close(sk);
> > 
> > It would be great to check that sock and current are getting 0 values
> > after we're closing the socket.
>  
> Hmm, here it's also timing sensitive. I can see that sock is reliably
> getting 0 if I check it after the server exits. But current usually remains
> small but still !0.

Ok, then I'd check that sock == 0 and current >= 0.
That will catch some refcounter underrun issues we had in the past.

Other than that (and assuming the test isn't flapping):
Acked-by: Roman Gushchin <guro@fb.com>

Thanks!
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Patch
diff mbox

diff --git a/tools/testing/selftests/cgroup/test_memcontrol.c b/tools/testing/selftests/cgroup/test_memcontrol.c
index beae06c9c899..0efdb1009175 100644
--- a/tools/testing/selftests/cgroup/test_memcontrol.c
+++ b/tools/testing/selftests/cgroup/test_memcontrol.c
@@ -9,6 +9,12 @@ 
 #include <sys/stat.h>
 #include <sys/types.h>
 #include <unistd.h>
+#include <sys/socket.h>
+#include <sys/wait.h>
+#include <arpa/inet.h>
+#include <netinet/in.h>
+#include <netdb.h>
+#include <errno.h>
 
 #include "../kselftest.h"
 #include "cgroup_util.h"
@@ -772,6 +778,183 @@  static int test_memcg_oom_events(const char *root)
 	return ret;
 }
 
+struct tcp_server_args {
+	unsigned short port;
+	int ctl[2];
+};
+
+static int tcp_server(const char *cgroup, void *arg)
+{
+	struct tcp_server_args *srv_args = arg;
+	struct sockaddr_in6 saddr = { 0 };
+	socklen_t slen = sizeof(saddr);
+	int sk, client_sk, ctl_fd, yes = 1, ret = -1;
+
+	close(srv_args->ctl[0]);
+	ctl_fd = srv_args->ctl[1];
+
+	saddr.sin6_family = AF_INET6;
+	saddr.sin6_addr = in6addr_any;
+	saddr.sin6_port = htons(srv_args->port);
+
+	sk = socket(AF_INET6, SOCK_STREAM, 0);
+	if (sk < 0)
+		return ret;
+
+	if (setsockopt(sk, SOL_SOCKET, SO_REUSEADDR, &yes, sizeof(yes)) < 0)
+		goto cleanup;
+
+	if (bind(sk, (struct sockaddr *)&saddr, slen)) {
+		write(ctl_fd, &errno, sizeof(errno));
+		goto cleanup;
+	}
+
+	if (listen(sk, 1))
+		goto cleanup;
+
+	ret = 0;
+	if (write(ctl_fd, &ret, sizeof(ret)) != sizeof(ret)) {
+		ret = -1;
+		goto cleanup;
+	}
+
+	client_sk = accept(sk, NULL, NULL);
+	if (client_sk < 0)
+		goto cleanup;
+
+	ret = -1;
+	for (;;) {
+		uint8_t buf[0x100000];
+
+		if (write(client_sk, buf, sizeof(buf)) <= 0) {
+			if (errno == ECONNRESET)
+				ret = 0;
+			break;
+		}
+	}
+
+	close(client_sk);
+
+cleanup:
+	close(sk);
+	return ret;
+}
+
+static int tcp_client(const char *cgroup, unsigned short port)
+{
+	const char server[] = "localhost";
+	struct addrinfo *ai;
+	char servport[6];
+	int retries = 0x10; /* nice round number */
+	int sk, ret;
+
+	snprintf(servport, sizeof(servport), "%hd", port);
+	ret = getaddrinfo(server, servport, NULL, &ai);
+	if (ret)
+		return ret;
+
+	sk = socket(ai->ai_family, ai->ai_socktype, ai->ai_protocol);
+	if (sk < 0)
+		goto free_ainfo;
+
+	ret = connect(sk, ai->ai_addr, ai->ai_addrlen);
+	if (ret < 0)
+		goto close_sk;
+
+	ret = KSFT_FAIL;
+	while (retries--) {
+		uint8_t buf[0x100000];
+		long current, sock;
+
+		if (read(sk, buf, sizeof(buf)) <= 0)
+			goto close_sk;
+
+		current = cg_read_long(cgroup, "memory.current");
+		if (current < 0)
+			goto close_sk;
+
+		sock = cg_read_key_long(cgroup, "memory.stat", "sock ");
+		if (sock < 0)
+			goto close_sk;
+
+		if (values_close(current, sock, 3)) {
+			ret = KSFT_PASS;
+			break;
+		}
+	}
+
+close_sk:
+	close(sk);
+free_ainfo:
+	freeaddrinfo(ai);
+	return ret;
+}
+
+/*
+ * This test checks socket memory accounting.
+ * The test forks a TCP server listens on a random port between 1000
+ * and 61000. Once it gets a client connection, it starts writing to
+ * its socket.
+ * The TCP client interleaves reads from the socket with check whether
+ * memory.current and memory.stat.sock are similar.
+ */
+static int test_memcg_sock(const char *root)
+{
+	int bind_retries = 5, ret = KSFT_FAIL, pid, status;
+	unsigned short port;
+	char *memcg;
+
+	memcg = cg_name(root, "memcg_test");
+	if (!memcg)
+		goto cleanup;
+
+	if (cg_create(memcg))
+		goto cleanup;
+
+	while (bind_retries--) {
+		struct tcp_server_args args;
+
+		if (pipe(args.ctl))
+			goto cleanup;
+
+		port = args.port = 1000 + rand() % 60000;
+
+		pid = cg_run_nowait(memcg, tcp_server, &args);
+		if (pid < 0)
+			goto cleanup;
+
+		close(args.ctl[1]);
+		if (read(args.ctl[0], &ret, sizeof(ret)) != sizeof(ret))
+			goto cleanup;
+		close(args.ctl[0]);
+
+		if (!ret)
+			break;
+		if (ret != EADDRINUSE)
+			goto cleanup;
+
+		waitpid(pid, NULL, 0);
+	}
+
+	if (!ret) {
+		ret = tcp_client(memcg, port);
+
+		waitpid(pid, &status, 0);
+		if (WEXITSTATUS(status))
+			ret = KSFT_FAIL;
+	} else if (ret == EADDRINUSE) {
+		ret = KSFT_SKIP;
+	} else {
+		ret = KSFT_FAIL;
+	}
+
+cleanup:
+	cg_destroy(memcg);
+	free(memcg);
+
+	return ret;
+}
+
 #define T(x) { x, #x }
 struct memcg_test {
 	int (*fn)(const char *root);
@@ -785,6 +968,7 @@  struct memcg_test {
 	T(test_memcg_max),
 	T(test_memcg_oom_events),
 	T(test_memcg_swap_max),
+	T(test_memcg_sock),
 };
 #undef T