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@xxxxxxxxxxxxxxxxxx> > > > --- > > > 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@xxxxxx> Thanks! -- To unsubscribe from this list: send the line "unsubscribe linux-kselftest" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html