cgroup: Add new test_cpu.c test suite in cgroup selftests

The cgroup selftests suite currently contains tests that validate various
aspects of cgroup, such as validating the expected behavior for memory
controllers, the expected behavior of cgroup.procs, etc. There are no tests
that validate the expected behavior of the cgroup cpu controller.

This patch therefore adds a new test_cpu.c file that will contain cpu
controller testcases. The file currently only contains a single testcase
that validates creating nested cgroups with cgroup.subtree_control
including cpu. Future patches will add more sophisticated testcases that
validate functional aspects of the cpu controller.

Signed-off-by: David Vernet <void@manifault.com>
Signed-off-by: Tejun Heo <tj@kernel.org>

diff --git a/tools/testing/selftests/cgroup/.gitignore b/tools/testing/selftests/cgroup/.gitignore
index be9643ef62852bf28a32abafdfe404822b42b91e..306ee1b01e72f4abb2af8a501c830fb4c87dd9e9 100644 (file)
--- a/tools/testing/selftests/cgroup/.gitignore
+++ b/tools/testing/selftests/cgroup/.gitignore
@@ -4,3 +4,4 @@ test_core
 test_freezer
 test_kmem
 test_kill
+test_cpu

diff --git a/tools/testing/selftests/cgroup/Makefile b/tools/testing/selftests/cgroup/Makefile
index 745fe25fa0b9316658da20c2eed6dd76c123476a..478217cc1371469302ebb049cf6efdb01869cc6a 100644 (file)
--- a/tools/testing/selftests/cgroup/Makefile
+++ b/tools/testing/selftests/cgroup/Makefile
@@ -10,6 +10,7 @@ TEST_GEN_PROGS += test_kmem
 TEST_GEN_PROGS += test_core
 TEST_GEN_PROGS += test_freezer
 TEST_GEN_PROGS += test_kill
+TEST_GEN_PROGS += test_cpu
 
 LOCAL_HDRS += $(selfdir)/clone3/clone3_selftests.h $(selfdir)/pidfd/pidfd.h
 
@@ -20,3 +21,4 @@ $(OUTPUT)/test_kmem: cgroup_util.c
 $(OUTPUT)/test_core: cgroup_util.c
 $(OUTPUT)/test_freezer: cgroup_util.c
 $(OUTPUT)/test_kill: cgroup_util.c
+$(OUTPUT)/test_cpu: cgroup_util.c

diff --git a/tools/testing/selftests/cgroup/test_cpu.c b/tools/testing/selftests/cgroup/test_cpu.c
new file mode 100644 (file)
index 0000000..a724bff
--- /dev/null
+++ b/tools/testing/selftests/cgroup/test_cpu.c
@@ -0,0 +1,110 @@
+// SPDX-License-Identifier: GPL-2.0
+
+#define _GNU_SOURCE
+#include <linux/limits.h>
+#include <stdio.h>
+
+#include "../kselftest.h"
+#include "cgroup_util.h"
+
+/*
+ * This test creates two nested cgroups with and without enabling
+ * the cpu controller.
+ */
+static int test_cpucg_subtree_control(const char *root)
+{
+       char *parent = NULL, *child = NULL, *parent2 = NULL, *child2 = NULL;
+       int ret = KSFT_FAIL;
+
+       // Create two nested cgroups with the cpu controller enabled.
+       parent = cg_name(root, "cpucg_test_0");
+       if (!parent)
+               goto cleanup;
+
+       if (cg_create(parent))
+               goto cleanup;
+
+       if (cg_write(parent, "cgroup.subtree_control", "+cpu"))
+               goto cleanup;
+
+       child = cg_name(parent, "cpucg_test_child");
+       if (!child)
+               goto cleanup;
+
+       if (cg_create(child))
+               goto cleanup;
+
+       if (cg_read_strstr(child, "cgroup.controllers", "cpu"))
+               goto cleanup;
+
+       // Create two nested cgroups without enabling the cpu controller.
+       parent2 = cg_name(root, "cpucg_test_1");
+       if (!parent2)
+               goto cleanup;
+
+       if (cg_create(parent2))
+               goto cleanup;
+
+       child2 = cg_name(parent2, "cpucg_test_child");
+       if (!child2)
+               goto cleanup;
+
+       if (cg_create(child2))
+               goto cleanup;
+
+       if (!cg_read_strstr(child2, "cgroup.controllers", "cpu"))
+               goto cleanup;
+
+       ret = KSFT_PASS;
+
+cleanup:
+       cg_destroy(child);
+       free(child);
+       cg_destroy(child2);
+       free(child2);
+       cg_destroy(parent);
+       free(parent);
+       cg_destroy(parent2);
+       free(parent2);
+
+       return ret;
+}
+
+#define T(x) { x, #x }
+struct cpucg_test {
+       int (*fn)(const char *root);
+       const char *name;
+} tests[] = {
+       T(test_cpucg_subtree_control),
+};
+#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");
+
+       if (cg_read_strstr(root, "cgroup.subtree_control", "cpu"))
+               if (cg_write(root, "cgroup.subtree_control", "+cpu"))
+                       ksft_exit_skip("Failed to set cpu controller\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;
+}