From patchwork Thu Jan 16 04:36:12 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Suren Baghdasaryan X-Patchwork-Id: 208955 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-17.4 required=3.0 tests=DKIMWL_WL_MED, DKIM_SIGNED, DKIM_VALID, DKIM_VALID_AU, HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH, MAILING_LIST_MULTI, SIGNED_OFF_BY, SPF_HELO_NONE, SPF_PASS, USER_AGENT_GIT, USER_IN_DEF_DKIM_WL autolearn=unavailable autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id E9CB8C33CAF for ; Thu, 16 Jan 2020 04:36:25 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id B32AE2073A for ; Thu, 16 Jan 2020 04:36:25 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=google.com header.i=@google.com header.b="WStbr0MJ" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1730979AbgAPEgU (ORCPT ); Wed, 15 Jan 2020 23:36:20 -0500 Received: from mail-pl1-f201.google.com ([209.85.214.201]:54564 "EHLO mail-pl1-f201.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1730970AbgAPEgT (ORCPT ); Wed, 15 Jan 2020 23:36:19 -0500 Received: by mail-pl1-f201.google.com with SMTP id f10so8096647plr.21 for ; Wed, 15 Jan 2020 20:36:19 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20161025; h=date:in-reply-to:message-id:mime-version:references:subject:from:to :cc; bh=lOS4ewWznrG+/0jceSUIoLxZFs2qMA4l+9gH32rT8ZU=; b=WStbr0MJSOPJGqzN2iGhIkdauZViO9hiPHW8Uj0CQFi0U3cTaC+CtBLstGwqiu/okm HwJonDO4S20K4z1FseDh/ERI2uZPRo9aoKkZjNyJR4eLMsIuCWvGzCPrdTwlUbyFeq18 4aadRAQl8JLnnKuLbKXV8Kf5PuQGXgWmjRQGIXV6jLyRE55XPV46346RsbUI5pwP646F W7Zi4/hotQx4xNZHbfw2SyYexpMQ3MwhPt1at98Ah5V6RNdVvM3CwauYeM00GAr+WM2Y A8r1y2CyypILKIp6eJzku7HKEflikMjfc9K1prTtvGNz2mox+pXGPh+YGIgEKaDqqfYW KcnQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:date:in-reply-to:message-id:mime-version :references:subject:from:to:cc; bh=lOS4ewWznrG+/0jceSUIoLxZFs2qMA4l+9gH32rT8ZU=; b=qgOo9cq7YDi8N1NonbjHUiMIUxsgTlWE0VwghuC7v/oGa4sM9CJ8Qp7INkktLe1Qsz gszvhiUIlv18X4ZJ+HS31EMszsxzW6IVrVm0ScrmJ9ZP/sHvOy5ypJJT4rq4Qfg8gqEc nrL3F611NpJjltazEt9WmuRIgsMLqPFyp6AnckvlduWxfFbUOvCHPgFSMXHKp8Vyr53Z Y+YHXqR4oMKhz79xmuG2OLPKMqEQ3PMkWdmLJ4mAUg0N5jPeOg4+/yEMvh7aS/rF+weO zL4q2czkeNgvO7uJrZQ7dHm9r218ezsQ6AqpW0RDgay6AFSmqYAbNKcXSry+UEbLHz8w nr6g== X-Gm-Message-State: APjAAAUH1+pFUN3qa2+U/pFkBpBmtuB89NbCFqlOeqPUMx5TQvPHljLg pcMSTnrBNp1zTWOIP3uo1PffdRGavJE= X-Google-Smtp-Source: APXvYqzbKGjnpLecCWg4B+/ttVo20VzbmxlVS+5fmmSGkVQcYwu4EGAJJ4ZismsmxqM/zsKwRtOeqsmsDUk= X-Received: by 2002:a63:1f21:: with SMTP id f33mr37413032pgf.91.1579149378890; Wed, 15 Jan 2020 20:36:18 -0800 (PST) Date: Wed, 15 Jan 2020 20:36:12 -0800 In-Reply-To: <20200116043612.52782-1-surenb@google.com> Message-Id: <20200116043612.52782-2-surenb@google.com> Mime-Version: 1.0 References: <20200116043612.52782-1-surenb@google.com> X-Mailer: git-send-email 2.25.0.rc1.283.g88dfdc4193-goog Subject: [PATCH 2/2] kselftest/cgroup: add cgroup destruction test From: Suren Baghdasaryan To: surenb@google.com Cc: tj@kernel.org, lizefan@huawei.com, hannes@cmpxchg.org, matthias.bgg@gmail.com, cgroups@vger.kernel.org, linux-kernel@vger.kernel.org, linux-arm-kernel@lists.infradead.org, linux-mediatek@lists.infradead.org, shuah@kernel.org, guro@fb.com, alex.shi@linux.alibaba.com, mkoutny@suse.com, linux-kselftest@vger.kernel.org, linger.lee@mediatek.com, tomcherry@google.com, kernel-team@android.com Sender: linux-kselftest-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kselftest@vger.kernel.org Add new test to verify that a cgroup with dead processes can be destroyed. The test spawns a child process which allocates and touches 100MB of RAM to ensure prolonged exit. Subsequently it kills the child, waits until the cgroup containing the child is empty and destroys the cgroup. Signed-off-by: Suren Baghdasaryan --- tools/testing/selftests/cgroup/test_core.c | 113 +++++++++++++++++++++ 1 file changed, 113 insertions(+) diff --git a/tools/testing/selftests/cgroup/test_core.c b/tools/testing/selftests/cgroup/test_core.c index c5ca669feb2b..2a5242ec1a49 100644 --- a/tools/testing/selftests/cgroup/test_core.c +++ b/tools/testing/selftests/cgroup/test_core.c @@ -2,7 +2,10 @@ #include #include +#include +#include #include +#include #include #include #include @@ -12,6 +15,115 @@ #include "../kselftest.h" #include "cgroup_util.h" +static int touch_anon(char *buf, size_t size) +{ + int fd; + char *pos = buf; + + fd = open("/dev/urandom", O_RDONLY); + if (fd < 0) + return -1; + + while (size > 0) { + ssize_t ret = read(fd, pos, size); + + if (ret < 0) { + if (errno != EINTR) { + close(fd); + return -1; + } + } else { + pos += ret; + size -= ret; + } + } + close(fd); + + return 0; +} + +static int alloc_and_touch_anon_noexit(const char *cgroup, void *arg) +{ + int ppid = getppid(); + size_t size = (size_t)arg; + void *buf; + + buf = mmap(NULL, size, PROT_READ | PROT_WRITE, MAP_PRIVATE | MAP_ANON, + 0, 0); + if (buf == MAP_FAILED) + return -1; + + if (touch_anon((char *)buf, size)) { + munmap(buf, size); + return -1; + } + + while (getppid() == ppid) + sleep(1); + + munmap(buf, size); + return 0; +} + +/* + * Create a child process that allocates and touches 100MB, then waits to be + * killed. Wait until the child is attached to the cgroup, kill all processes + * in that cgroup and wait until "cgroup.events" is empty. At this point try to + * destroy the empty cgroup. The test helps detect race conditions between + * dying processes leaving the cgroup and cgroup destruction path. + */ +static int test_cgcore_destroy(const char *root) +{ + int ret = KSFT_FAIL; + char *cg_test = NULL; + int child_pid; + char buf[PAGE_SIZE]; + + cg_test = cg_name(root, "cg_test"); + + if (!cg_test) + goto cleanup; + + for (int i = 0; i < 10; i++) { + if (cg_create(cg_test)) + goto cleanup; + + child_pid = cg_run_nowait(cg_test, alloc_and_touch_anon_noexit, + (void *) MB(100)); + + if (child_pid < 0) + goto cleanup; + + /* wait for the child to enter cgroup */ + if (cg_wait_for_proc_count(cg_test, 1)) + goto cleanup; + + if (cg_killall(cg_test)) + goto cleanup; + + /* wait for cgroup to be empty */ + while (1) { + if (cg_read(cg_test, "cgroup.procs", buf, sizeof(buf))) + goto cleanup; + if (buf[0] == '\0') + break; + usleep(1000); + } + + if (rmdir(cg_test)) + goto cleanup; + + if (waitpid(child_pid, NULL, 0) < 0) + goto cleanup; + } + ret = KSFT_PASS; +cleanup: + if (cg_test) + cg_destroy(cg_test); + free(cg_test); + return ret; +} + /* * A(0) - B(0) - C(1) * \ D(0) @@ -512,6 +624,7 @@ struct corecg_test { T(test_cgcore_populated), T(test_cgcore_proc_migration), T(test_cgcore_thread_migration), + T(test_cgcore_destroy), }; #undef T