From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1750935AbeEPOsg (ORCPT ); Wed, 16 May 2018 10:48:36 -0400 Received: from mx0a-001b2d01.pphosted.com ([148.163.156.1]:45492 "EHLO mx0a-001b2d01.pphosted.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750749AbeEPOsf (ORCPT ); Wed, 16 May 2018 10:48:35 -0400 Date: Wed, 16 May 2018 17:48:26 +0300 From: Mike Rapoport To: Roman Gushchin Cc: Shuah Khan , Tejun Heo , linux-kselftest@vger.kernel.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH] selftests: cgroup: memcontrol: add basic test for socket accounting References: <1526470089-27010-1-git-send-email-rppt@linux.vnet.ibm.com> <20180516140332.GA19754@castle.DHCP.thefacebook.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20180516140332.GA19754@castle.DHCP.thefacebook.com> User-Agent: Mutt/1.5.24 (2015-08-30) X-TM-AS-GCONF: 00 x-cbid: 18051614-0020-0000-0000-0000041DDAF4 X-IBM-AV-DETECTION: SAVI=unused REMOTE=unused XFE=unused x-cbparentid: 18051614-0021-0000-0000-000042B2F85E Message-Id: <20180516144826.GB23563@rapoport-lnx> X-Proofpoint-Virus-Version: vendor=fsecure engine=2.50.10434:,, definitions=2018-05-16_07:,, signatures=0 X-Proofpoint-Spam-Details: rule=outbound_notspam policy=outbound score=0 priorityscore=1501 malwarescore=0 suspectscore=2 phishscore=0 bulkscore=0 spamscore=0 clxscore=1015 lowpriorityscore=0 impostorscore=0 adultscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.0.1-1709140000 definitions=main-1805160150 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 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 > > --- > > 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 > > #include > > #include > > +#include > > +#include > > +#include > > +#include > > +#include > > +#include > > > > #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! > -- Sincerely yours, Mike.