Add cgroup core selftests

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
Acked-by: Tejun Heo <tj@kernel.org>
Reviewed-by: Roman Gushchin <guro@fb.com>
Signed-off-by: Shuah Khan (Samsung OSG) <shuah@kernel.org>
This commit is contained in:
Claudio 2018-07-18 19:33:58 +02:00 committed by Shuah Khan (Samsung OSG)
parent d2d49495b5
commit d863cb03fc
4 changed files with 406 additions and 0 deletions

View File

@ -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

View File

@ -229,6 +229,14 @@ retry:
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)

View File

@ -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);

View File

@ -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;
}