This commit adds tests for some of the core functionalities of cgroups v2.

The commit adds tests for some core principles of croup V2 API:

- test_cgcore_internal_process_constraint

Tests internal process constraint. You can't add a pid to a domain parent if a controller is enabled.

- test_cgcore_top_down_constraint_enable

Tests that you can't enable a controller on a child if it's not enabled on the parent.

- test_cgcore_top_down_constraint_disable

Tests that you can't disable a controller on a parent if it's enabled in a child.

- test_cgcore_no_internal_process_constraint_on_threads

Tests that there's no internal process constrain on threaded cgroups. You can add threads/processes on a parent with a controller enabled.

- test_cgcore_parent_becomes_threaded

Tests that when a child becomes threaded the parent type becomes domain threaded.

- test_cgcore_invalid_domain

In a situation like:

A (domain threaded) - B (threaded) - C (domain)

it tests that C can't be used until it is turned into a threaded cgroup. The "cgroup.type" file will report "domain (invalid)" in these cases. Operations which fail due to invalid topology use EOPNOTSUPP as the errno.

- test_cgcore_populated

In a situation like:

A(0) - B(0) - C(1) \ D(0)

It tests that A, B and C's "populated" fields would be 1 while D's 0. It tests that after the one process in C is moved to root, A,B and C's "populated" fields would flip to "0" and file modified events will be generated on the "cgroup.events" files of both cgroups.

Signed-off-by: Claudio Zumbo claudioz@fb.com Cc: Shuah Khan shuah@kernel.org Cc: Roman Gushchin guro@fb.com Cc: Tejun Heo tj@kernel.org Cc: kernel-team@fb.com --- tools/testing/selftests/cgroup/Makefile | 2 + tools/testing/selftests/cgroup/cgroup_util.c | 8 + tools/testing/selftests/cgroup/cgroup_util.h | 1 + tools/testing/selftests/cgroup/test_core.c | 395 +++++++++++++++++++++++++++ 4 files changed, 406 insertions(+) create mode 100644 tools/testing/selftests/cgroup/test_core.c

diff --git a/tools/testing/selftests/cgroup/Makefile b/tools/testing/selftests/cgroup/Makefile index f7a31392eb2f..23fbaa4a9630 100644 --- a/tools/testing/selftests/cgroup/Makefile +++ b/tools/testing/selftests/cgroup/Makefile @@ -4,7 +4,9 @@ CFLAGS += -Wall all:

TEST_GEN_PROGS = test_memcontrol +TEST_GEN_PROGS += test_core

include ../lib.mk

$(OUTPUT)/test_memcontrol: cgroup_util.c +$(OUTPUT)/test_core: cgroup_util.c diff --git a/tools/testing/selftests/cgroup/cgroup_util.c b/tools/testing/selftests/cgroup/cgroup_util.c index 1e9e3c470561..1c5d2b2a583b 100644 --- a/tools/testing/selftests/cgroup/cgroup_util.c +++ b/tools/testing/selftests/cgroup/cgroup_util.c @@ -229,6 +229,14 @@ int cg_destroy(const char *cgroup) return ret; }

+int cg_enter_current(const char *cgroup) +{ + char pidbuf[64]; + + snprintf(pidbuf, sizeof(pidbuf), "%d", getpid()); + return cg_write(cgroup, "cgroup.procs", pidbuf); +} + int cg_run(const char *cgroup, int (*fn)(const char *cgroup, void *arg), void *arg) diff --git a/tools/testing/selftests/cgroup/cgroup_util.h b/tools/testing/selftests/cgroup/cgroup_util.h index fe82a297d4e0..1ff6f9f1abdc 100644 --- a/tools/testing/selftests/cgroup/cgroup_util.h +++ b/tools/testing/selftests/cgroup/cgroup_util.h @@ -32,6 +32,7 @@ extern int cg_write(const char *cgroup, const char *control, char *buf); extern int cg_run(const char *cgroup, int (*fn)(const char *cgroup, void *arg), void *arg); +extern int cg_enter_current(const char *cgroup); extern int cg_run_nowait(const char *cgroup, int (*fn)(const char *cgroup, void *arg), void *arg); diff --git a/tools/testing/selftests/cgroup/test_core.c b/tools/testing/selftests/cgroup/test_core.c new file mode 100644 index 000000000000..be59f9c34ea2 --- /dev/null +++ b/tools/testing/selftests/cgroup/test_core.c @@ -0,0 +1,395 @@ +/* SPDX-License-Identifier: GPL-2.0 */ + +#include <linux/limits.h> +#include <sys/types.h> +#include <unistd.h> +#include <stdio.h> +#include <errno.h> + +#include "../kselftest.h" +#include "cgroup_util.h" + +/* + * A(0) - B(0) - C(1) + * \ D(0) + * + * A, B and C's "populated" fields would be 1 while D's 0. + * test that after the one process in C is moved to root, + * A,B and C's "populated" fields would flip to "0" and file + * modified events will be generated on the + * "cgroup.events" files of both cgroups. + */ +static int test_cgcore_populated(const char *root) +{ + int ret = KSFT_FAIL; + char *cg_test_a = NULL, *cg_test_b = NULL; + char *cg_test_c = NULL, *cg_test_d = NULL; + + cg_test_a = cg_name(root, "cg_test_a"); + cg_test_b = cg_name(root, "cg_test_a/cg_test_b"); + cg_test_c = cg_name(root, "cg_test_a/cg_test_b/cg_test_c"); + cg_test_d = cg_name(root, "cg_test_a/cg_test_b/cg_test_d"); + + if (!cg_test_a || !cg_test_b || !cg_test_c || !cg_test_d) + goto cleanup; + + if (cg_create(cg_test_a)) + goto cleanup; + + if (cg_create(cg_test_b)) + goto cleanup; + + if (cg_create(cg_test_c)) + goto cleanup; + + if (cg_create(cg_test_d)) + goto cleanup; + + if (cg_enter_current(cg_test_c)) + goto cleanup; + + if (cg_read_strcmp(cg_test_a, "cgroup.events", "populated 1\n")) + goto cleanup; + + if (cg_read_strcmp(cg_test_b, "cgroup.events", "populated 1\n")) + goto cleanup; + + if (cg_read_strcmp(cg_test_c, "cgroup.events", "populated 1\n")) + goto cleanup; + + if (cg_read_strcmp(cg_test_d, "cgroup.events", "populated 0\n")) + goto cleanup; + + if (cg_enter_current(root)) + goto cleanup; + + if (cg_read_strcmp(cg_test_a, "cgroup.events", "populated 0\n")) + goto cleanup; + + if (cg_read_strcmp(cg_test_b, "cgroup.events", "populated 0\n")) + goto cleanup; + + if (cg_read_strcmp(cg_test_c, "cgroup.events", "populated 0\n")) + goto cleanup; + + if (cg_read_strcmp(cg_test_d, "cgroup.events", "populated 0\n")) + goto cleanup; + + ret = KSFT_PASS; + +cleanup: + if (cg_test_d) + cg_destroy(cg_test_d); + if (cg_test_c) + cg_destroy(cg_test_c); + if (cg_test_b) + cg_destroy(cg_test_b); + if (cg_test_a) + cg_destroy(cg_test_a); + free(cg_test_d); + free(cg_test_c); + free(cg_test_b); + free(cg_test_a); + return ret; +} + +/* + * A (domain threaded) - B (threaded) - C (domain) + * + * test that C can't be used until it is turned into a + * threaded cgroup. "cgroup.type" file will report "domain (invalid)" in + * these cases. Operations which fail due to invalid topology use + * EOPNOTSUPP as the errno. + */ +static int test_cgcore_invalid_domain(const char *root) +{ + int ret = KSFT_FAIL; + char *grandparent = NULL, *parent = NULL, *child = NULL; + + grandparent = cg_name(root, "cg_test_grandparent"); + parent = cg_name(root, "cg_test_grandparent/cg_test_parent"); + child = cg_name(root, "cg_test_grandparent/cg_test_parent/cg_test_child"); + if (!parent || !child || !grandparent) + goto cleanup; + + if (cg_create(grandparent)) + goto cleanup; + + if (cg_create(parent)) + goto cleanup; + + if (cg_create(child)) + goto cleanup; + + if (cg_write(parent, "cgroup.type", "threaded")) + goto cleanup; + + if (cg_read_strcmp(child, "cgroup.type", "domain invalid\n")) + goto cleanup; + + if (!cg_enter_current(child)) + goto cleanup; + + if (errno != EOPNOTSUPP) + goto cleanup; + + ret = KSFT_PASS; + +cleanup: + cg_enter_current(root); + if (child) + cg_destroy(child); + if (parent) + cg_destroy(parent); + if (grandparent) + cg_destroy(grandparent); + free(child); + free(parent); + free(grandparent); + return ret; +} + +/* + * Test that when a child becomes threaded + * the parent type becomes domain threaded. + */ +static int test_cgcore_parent_becomes_threaded(const char *root) +{ + int ret = KSFT_FAIL; + char *parent = NULL, *child = NULL; + + parent = cg_name(root, "cg_test_parent"); + child = cg_name(root, "cg_test_parent/cg_test_child"); + if (!parent || !child) + goto cleanup; + + if (cg_create(parent)) + goto cleanup; + + if (cg_create(child)) + goto cleanup; + + if (cg_write(child, "cgroup.type", "threaded")) + goto cleanup; + + if (cg_read_strcmp(parent, "cgroup.type", "domain threaded\n")) + goto cleanup; + + ret = KSFT_PASS; + +cleanup: + if (child) + cg_destroy(child); + if (parent) + cg_destroy(parent); + free(child); + free(parent); + return ret; + +} + +/* + * Test that there's no internal process constrain on threaded cgroups. + * You can add threads/processes on a parent with a controller enabled. + */ +static int test_cgcore_no_internal_process_constraint_on_threads(const char *root) +{ + int ret = KSFT_FAIL; + char *parent = NULL, *child = NULL; + + if (cg_read_strstr(root, "cgroup.controllers", "cpu") || + cg_read_strstr(root, "cgroup.subtree_control", "cpu")) { + ret = KSFT_SKIP; + goto cleanup; + } + + parent = cg_name(root, "cg_test_parent"); + child = cg_name(root, "cg_test_parent/cg_test_child"); + if (!parent || !child) + goto cleanup; + + if (cg_create(parent)) + goto cleanup; + + if (cg_create(child)) + goto cleanup; + + if (cg_write(parent, "cgroup.type", "threaded")) + goto cleanup; + + if (cg_write(child, "cgroup.type", "threaded")) + goto cleanup; + + if (cg_write(parent, "cgroup.subtree_control", "+cpu")) + goto cleanup; + + if (cg_enter_current(parent)) + goto cleanup; + + ret = KSFT_PASS; + +cleanup: + cg_enter_current(root); + cg_enter_current(root); + if (child) + cg_destroy(child); + if (parent) + cg_destroy(parent); + free(child); + free(parent); + return ret; +} + +/* + * Test that you can't enable a controller on a child if it's not enabled + * on the parent. + */ +static int test_cgcore_top_down_constraint_enable(const char *root) +{ + int ret = KSFT_FAIL; + char *parent = NULL, *child = NULL; + + parent = cg_name(root, "cg_test_parent"); + child = cg_name(root, "cg_test_parent/cg_test_child"); + if (!parent || !child) + goto cleanup; + + if (cg_create(parent)) + goto cleanup; + + if (cg_create(child)) + goto cleanup; + + if (!cg_write(child, "cgroup.subtree_control", "+memory")) + goto cleanup; + + ret = KSFT_PASS; + +cleanup: + if (child) + cg_destroy(child); + if (parent) + cg_destroy(parent); + free(child); + free(parent); + return ret; +} + +/* + * Test that you can't disable a controller on a parent + * if it's enabled in a child. + */ +static int test_cgcore_top_down_constraint_disable(const char *root) +{ + int ret = KSFT_FAIL; + char *parent = NULL, *child = NULL; + + parent = cg_name(root, "cg_test_parent"); + child = cg_name(root, "cg_test_parent/cg_test_child"); + if (!parent || !child) + goto cleanup; + + if (cg_create(parent)) + goto cleanup; + + if (cg_create(child)) + goto cleanup; + + if (cg_write(parent, "cgroup.subtree_control", "+memory")) + goto cleanup; + + if (cg_write(child, "cgroup.subtree_control", "+memory")) + goto cleanup; + + if (!cg_write(parent, "cgroup.subtree_control", "-memory")) + goto cleanup; + + ret = KSFT_PASS; + +cleanup: + if (child) + cg_destroy(child); + if (parent) + cg_destroy(parent); + free(child); + free(parent); + return ret; +} + +/* + * Test internal process constraint. + * You can't add a pid to a domain parent if a controller is enabled. + */ +static int test_cgcore_internal_process_constraint(const char *root) +{ + int ret = KSFT_FAIL; + char *parent = NULL, *child = NULL; + + parent = cg_name(root, "cg_test_parent"); + child = cg_name(root, "cg_test_parent/cg_test_child"); + if (!parent || !child) + goto cleanup; + + if (cg_create(parent)) + goto cleanup; + + if (cg_create(child)) + goto cleanup; + + if (cg_write(parent, "cgroup.subtree_control", "+memory")) + goto cleanup; + + if (!cg_enter_current(parent)) + goto cleanup; + + ret = KSFT_PASS; + +cleanup: + if (child) + cg_destroy(child); + if (parent) + cg_destroy(parent); + free(child); + free(parent); + return ret; +} + +#define T(x) { x, #x } +struct corecg_test { + int (*fn)(const char *root); + const char *name; +} tests[] = { + T(test_cgcore_internal_process_constraint), + T(test_cgcore_top_down_constraint_enable), + T(test_cgcore_top_down_constraint_disable), + T(test_cgcore_no_internal_process_constraint_on_threads), + T(test_cgcore_parent_becomes_threaded), + T(test_cgcore_invalid_domain), + T(test_cgcore_populated), +}; +#undef T + +int main(int argc, char *argv[]) +{ + char root[PATH_MAX]; + int i, ret = EXIT_SUCCESS; + + if (cg_find_unified_root(root, sizeof(root))) + ksft_exit_skip("cgroup v2 isn't mounted\n"); + for (i = 0; i < ARRAY_SIZE(tests); i++) { + switch (tests[i].fn(root)) { + case KSFT_PASS: + ksft_test_result_pass("%s\n", tests[i].name); + break; + case KSFT_SKIP: + ksft_test_result_skip("%s\n", tests[i].name); + break; + default: + ret = EXIT_FAILURE; + ksft_test_result_fail("%s\n", tests[i].name); + break; + } + } + + return ret; +}