* [PATCH 1/4] selftests: cgroup_util: Add helpers for testing named v1 hierarchies
2025-06-17 13:36 [PATCH 0/4] selftests: cgroup: Add support for named v1 hierarchies in test_core Michal Koutný
@ 2025-06-17 13:36 ` Michal Koutný
2025-06-17 13:36 ` [PATCH 2/4] selftests: cgroup: Add support for named v1 hierarchies in test_core Michal Koutný
` (3 subsequent siblings)
4 siblings, 0 replies; 6+ messages in thread
From: Michal Koutný @ 2025-06-17 13:36 UTC (permalink / raw)
To: cgroups, linux-kselftest, linux-kernel
Cc: Michal Koutný, Tejun Heo, Johannes Weiner, Shuah Khan
Non-functional change, the control variable will be wired in a separate
commit.
Signed-off-by: Michal Koutný <mkoutny@suse.com>
---
tools/testing/selftests/cgroup/lib/cgroup_util.c | 4 +++-
tools/testing/selftests/cgroup/lib/include/cgroup_util.h | 5 +++++
tools/testing/selftests/cgroup/test_core.c | 6 +++---
3 files changed, 11 insertions(+), 4 deletions(-)
diff --git a/tools/testing/selftests/cgroup/lib/cgroup_util.c b/tools/testing/selftests/cgroup/lib/cgroup_util.c
index 8832f3d1cb614..0e89fcff4d05d 100644
--- a/tools/testing/selftests/cgroup/lib/cgroup_util.c
+++ b/tools/testing/selftests/cgroup/lib/cgroup_util.c
@@ -19,6 +19,8 @@
#include "cgroup_util.h"
#include "../../clone3/clone3_selftests.h"
+bool cg_test_v1_named;
+
/* Returns read len on success, or -errno on failure. */
ssize_t read_text(const char *path, char *buf, size_t max_len)
{
@@ -361,7 +363,7 @@ int cg_enter_current(const char *cgroup)
int cg_enter_current_thread(const char *cgroup)
{
- return cg_write(cgroup, "cgroup.threads", "0");
+ return cg_write(cgroup, CG_THREADS_FILE, "0");
}
int cg_run(const char *cgroup,
diff --git a/tools/testing/selftests/cgroup/lib/include/cgroup_util.h b/tools/testing/selftests/cgroup/lib/include/cgroup_util.h
index adb2bc1931839..c69cab66254b4 100644
--- a/tools/testing/selftests/cgroup/lib/include/cgroup_util.h
+++ b/tools/testing/selftests/cgroup/lib/include/cgroup_util.h
@@ -13,6 +13,10 @@
#define TEST_UID 65534 /* usually nobody, any !root is fine */
+#define CG_THREADS_FILE (!cg_test_v1_named ? "cgroup.threads" : "tasks")
+#define CG_NAMED_NAME "selftest"
+#define CG_PATH_FORMAT (!cg_test_v1_named ? "0::%s" : (":name=" CG_NAMED_NAME ":%s"))
+
/*
* Checks if two given values differ by less than err% of their sum.
*/
@@ -65,3 +69,4 @@ extern int dirfd_open_opath(const char *dir);
extern int cg_prepare_for_wait(const char *cgroup);
extern int memcg_prepare_for_wait(const char *cgroup);
extern int cg_wait_for(int fd);
+extern bool cg_test_v1_named;
diff --git a/tools/testing/selftests/cgroup/test_core.c b/tools/testing/selftests/cgroup/test_core.c
index a5672a91d273c..0c4cc4e5fc8c2 100644
--- a/tools/testing/selftests/cgroup/test_core.c
+++ b/tools/testing/selftests/cgroup/test_core.c
@@ -573,7 +573,7 @@ static int test_cgcore_proc_migration(const char *root)
}
cg_enter_current(dst);
- if (cg_read_lc(dst, "cgroup.threads") != n_threads + 1)
+ if (cg_read_lc(dst, CG_THREADS_FILE) != n_threads + 1)
goto cleanup;
ret = KSFT_PASS;
@@ -605,7 +605,7 @@ static void *migrating_thread_fn(void *arg)
char lines[3][PATH_MAX];
for (g = 1; g < 3; ++g)
- snprintf(lines[g], sizeof(lines[g]), "0::%s", grps[g] + strlen(grps[0]));
+ snprintf(lines[g], sizeof(lines[g]), CG_PATH_FORMAT, grps[g] + strlen(grps[0]));
for (i = 0; i < n_iterations; ++i) {
cg_enter_current_thread(grps[(i % 2) + 1]);
@@ -659,7 +659,7 @@ static int test_cgcore_thread_migration(const char *root)
if (retval)
goto cleanup;
- snprintf(line, sizeof(line), "0::%s", grps[1] + strlen(grps[0]));
+ snprintf(line, sizeof(line), CG_PATH_FORMAT, grps[1] + strlen(grps[0]));
if (proc_read_strstr(0, 1, "cgroup", line))
goto cleanup;
--
2.49.0
^ permalink raw reply related [flat|nested] 6+ messages in thread* [PATCH 2/4] selftests: cgroup: Add support for named v1 hierarchies in test_core
2025-06-17 13:36 [PATCH 0/4] selftests: cgroup: Add support for named v1 hierarchies in test_core Michal Koutný
2025-06-17 13:36 ` [PATCH 1/4] selftests: cgroup_util: Add helpers for testing named v1 hierarchies Michal Koutný
@ 2025-06-17 13:36 ` Michal Koutný
2025-06-17 13:36 ` [PATCH 3/4] selftests: cgroup: Optionally set up v1 environment Michal Koutný
` (2 subsequent siblings)
4 siblings, 0 replies; 6+ messages in thread
From: Michal Koutný @ 2025-06-17 13:36 UTC (permalink / raw)
To: cgroups, linux-kselftest, linux-kernel
Cc: Michal Koutný, Tejun Heo, Johannes Weiner, Shuah Khan
This comes useful when using selftests from mainline on older
kernels/setups that still rely on cgroup v1.
The core tests that rely on v2 specific features are skipped, the
remaining ones are adjusted to work with a v1 hierarchy.
The expected output on v1 system:
ok 1 # SKIP test_cgcore_internal_process_constraint
ok 2 # SKIP test_cgcore_top_down_constraint_enable
ok 3 # SKIP test_cgcore_top_down_constraint_disable
ok 4 # SKIP test_cgcore_no_internal_process_constraint_on_threads
ok 5 # SKIP test_cgcore_parent_becomes_threaded
ok 6 # SKIP test_cgcore_invalid_domain
ok 7 # SKIP test_cgcore_populated
ok 8 test_cgcore_proc_migration
ok 9 test_cgcore_thread_migration
ok 10 test_cgcore_destroy
ok 11 test_cgcore_lesser_euid_open
ok 12 # SKIP test_cgcore_lesser_ns_open
Signed-off-by: Michal Koutný <mkoutny@suse.com>
---
tools/testing/selftests/cgroup/test_core.c | 31 ++++++++++++++++++----
1 file changed, 26 insertions(+), 5 deletions(-)
diff --git a/tools/testing/selftests/cgroup/test_core.c b/tools/testing/selftests/cgroup/test_core.c
index 0c4cc4e5fc8c2..338e276aae5da 100644
--- a/tools/testing/selftests/cgroup/test_core.c
+++ b/tools/testing/selftests/cgroup/test_core.c
@@ -148,6 +148,9 @@ static int test_cgcore_populated(const char *root)
int cgroup_fd = -EBADF;
pid_t pid;
+ if (cg_test_v1_named)
+ return KSFT_SKIP;
+
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");
@@ -277,6 +280,9 @@ static int test_cgcore_invalid_domain(const char *root)
int ret = KSFT_FAIL;
char *grandparent = NULL, *parent = NULL, *child = NULL;
+ if (cg_test_v1_named)
+ return KSFT_SKIP;
+
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");
@@ -339,6 +345,9 @@ static int test_cgcore_parent_becomes_threaded(const char *root)
int ret = KSFT_FAIL;
char *parent = NULL, *child = NULL;
+ if (cg_test_v1_named)
+ return KSFT_SKIP;
+
parent = cg_name(root, "cg_test_parent");
child = cg_name(root, "cg_test_parent/cg_test_child");
if (!parent || !child)
@@ -378,7 +387,8 @@ static int test_cgcore_no_internal_process_constraint_on_threads(const char *roo
int ret = KSFT_FAIL;
char *parent = NULL, *child = NULL;
- if (cg_read_strstr(root, "cgroup.controllers", "cpu") ||
+ if (cg_test_v1_named ||
+ cg_read_strstr(root, "cgroup.controllers", "cpu") ||
cg_write(root, "cgroup.subtree_control", "+cpu")) {
ret = KSFT_SKIP;
goto cleanup;
@@ -430,6 +440,9 @@ static int test_cgcore_top_down_constraint_enable(const char *root)
int ret = KSFT_FAIL;
char *parent = NULL, *child = NULL;
+ if (cg_test_v1_named)
+ return KSFT_SKIP;
+
parent = cg_name(root, "cg_test_parent");
child = cg_name(root, "cg_test_parent/cg_test_child");
if (!parent || !child)
@@ -465,6 +478,9 @@ static int test_cgcore_top_down_constraint_disable(const char *root)
int ret = KSFT_FAIL;
char *parent = NULL, *child = NULL;
+ if (cg_test_v1_named)
+ return KSFT_SKIP;
+
parent = cg_name(root, "cg_test_parent");
child = cg_name(root, "cg_test_parent/cg_test_child");
if (!parent || !child)
@@ -506,6 +522,9 @@ static int test_cgcore_internal_process_constraint(const char *root)
int ret = KSFT_FAIL;
char *parent = NULL, *child = NULL;
+ if (cg_test_v1_named)
+ return KSFT_SKIP;
+
parent = cg_name(root, "cg_test_parent");
child = cg_name(root, "cg_test_parent/cg_test_child");
if (!parent || !child)
@@ -642,10 +661,12 @@ static int test_cgcore_thread_migration(const char *root)
if (cg_create(grps[2]))
goto cleanup;
- if (cg_write(grps[1], "cgroup.type", "threaded"))
- goto cleanup;
- if (cg_write(grps[2], "cgroup.type", "threaded"))
- goto cleanup;
+ if (!cg_test_v1_named) {
+ if (cg_write(grps[1], "cgroup.type", "threaded"))
+ goto cleanup;
+ if (cg_write(grps[2], "cgroup.type", "threaded"))
+ goto cleanup;
+ }
if (cg_enter_current(grps[1]))
goto cleanup;
--
2.49.0
^ permalink raw reply related [flat|nested] 6+ messages in thread* [PATCH 3/4] selftests: cgroup: Optionally set up v1 environment
2025-06-17 13:36 [PATCH 0/4] selftests: cgroup: Add support for named v1 hierarchies in test_core Michal Koutný
2025-06-17 13:36 ` [PATCH 1/4] selftests: cgroup_util: Add helpers for testing named v1 hierarchies Michal Koutný
2025-06-17 13:36 ` [PATCH 2/4] selftests: cgroup: Add support for named v1 hierarchies in test_core Michal Koutný
@ 2025-06-17 13:36 ` Michal Koutný
2025-06-17 13:36 ` [PATCH 4/4] selftests: cgroup: Fix compilation on pre-cgroupns kernels Michal Koutný
2025-06-17 18:13 ` [PATCH 0/4] selftests: cgroup: Add support for named v1 hierarchies in test_core Tejun Heo
4 siblings, 0 replies; 6+ messages in thread
From: Michal Koutný @ 2025-06-17 13:36 UTC (permalink / raw)
To: cgroups, linux-kselftest, linux-kernel
Cc: Michal Koutný, Tejun Heo, Johannes Weiner, Shuah Khan
Use the missing mount of the unifier hierarchy as a hint of legacy
system and prepare our own named v1 hierarchy for tests.
The code is only in test_core.c and not cgroup_util.c because other
selftests are related to controllers which will be exposed on v2
hierarchy but named hierarchies are only v1 thing.
Signed-off-by: Michal Koutný <mkoutny@suse.com>
---
tools/testing/selftests/cgroup/test_core.c | 44 +++++++++++++++++++++-
1 file changed, 42 insertions(+), 2 deletions(-)
diff --git a/tools/testing/selftests/cgroup/test_core.c b/tools/testing/selftests/cgroup/test_core.c
index 338e276aae5da..452c2abf9794e 100644
--- a/tools/testing/selftests/cgroup/test_core.c
+++ b/tools/testing/selftests/cgroup/test_core.c
@@ -5,6 +5,8 @@
#include <linux/sched.h>
#include <sys/types.h>
#include <sys/mman.h>
+#include <sys/mount.h>
+#include <sys/stat.h>
#include <sys/wait.h>
#include <unistd.h>
#include <fcntl.h>
@@ -863,6 +865,38 @@ static int test_cgcore_lesser_ns_open(const char *root)
return ret;
}
+static int setup_named_v1_root(char *root, size_t len, const char *name)
+{
+ char options[PATH_MAX];
+ int r;
+
+ r = snprintf(root, len, "/mnt/cg_selftest");
+ if (r < 0)
+ return r;
+
+ r = snprintf(options, sizeof(options), "none,name=%s", name);
+ if (r < 0)
+ return r;
+
+ r = mkdir(root, 0755);
+ if (r < 0 && errno != EEXIST)
+ return r;
+
+ r = mount("none", root, "cgroup", 0, options);
+ if (r < 0)
+ return r;
+
+ return 0;
+}
+
+static void cleanup_named_v1_root(char *root)
+{
+ if (!cg_test_v1_named)
+ return;
+ umount(root);
+ rmdir(root);
+}
+
#define T(x) { x, #x }
struct corecg_test {
int (*fn)(const char *root);
@@ -888,13 +922,18 @@ int main(int argc, char *argv[])
char root[PATH_MAX];
int i, ret = EXIT_SUCCESS;
- if (cg_find_unified_root(root, sizeof(root), &nsdelegate))
- ksft_exit_skip("cgroup v2 isn't mounted\n");
+ if (cg_find_unified_root(root, sizeof(root), &nsdelegate)) {
+ if (setup_named_v1_root(root, sizeof(root), CG_NAMED_NAME))
+ ksft_exit_skip("cgroup v2 isn't mounted and could not setup named v1 hierarchy\n");
+ cg_test_v1_named = true;
+ goto post_v2_setup;
+ }
if (cg_read_strstr(root, "cgroup.subtree_control", "memory"))
if (cg_write(root, "cgroup.subtree_control", "+memory"))
ksft_exit_skip("Failed to set memory controller\n");
+post_v2_setup:
for (i = 0; i < ARRAY_SIZE(tests); i++) {
switch (tests[i].fn(root)) {
case KSFT_PASS:
@@ -910,5 +949,6 @@ int main(int argc, char *argv[])
}
}
+ cleanup_named_v1_root(root);
return ret;
}
--
2.49.0
^ permalink raw reply related [flat|nested] 6+ messages in thread* [PATCH 4/4] selftests: cgroup: Fix compilation on pre-cgroupns kernels
2025-06-17 13:36 [PATCH 0/4] selftests: cgroup: Add support for named v1 hierarchies in test_core Michal Koutný
` (2 preceding siblings ...)
2025-06-17 13:36 ` [PATCH 3/4] selftests: cgroup: Optionally set up v1 environment Michal Koutný
@ 2025-06-17 13:36 ` Michal Koutný
2025-06-17 18:13 ` [PATCH 0/4] selftests: cgroup: Add support for named v1 hierarchies in test_core Tejun Heo
4 siblings, 0 replies; 6+ messages in thread
From: Michal Koutný @ 2025-06-17 13:36 UTC (permalink / raw)
To: cgroups, linux-kselftest, linux-kernel
Cc: Michal Koutný, Tejun Heo, Johannes Weiner, Shuah Khan
The test would be skipped because of nsdelegate, so the defined value is
not used (0 is always acceptable).
Signed-off-by: Michal Koutný <mkoutny@suse.com>
---
tools/testing/selftests/cgroup/test_core.c | 3 +++
1 file changed, 3 insertions(+)
diff --git a/tools/testing/selftests/cgroup/test_core.c b/tools/testing/selftests/cgroup/test_core.c
index 452c2abf9794e..a360e2eb2eefd 100644
--- a/tools/testing/selftests/cgroup/test_core.c
+++ b/tools/testing/selftests/cgroup/test_core.c
@@ -21,6 +21,9 @@
#include "cgroup_util.h"
static bool nsdelegate;
+#ifndef CLONE_NEWCGROUP
+#define CLONE_NEWCGROUP 0
+#endif
static int touch_anon(char *buf, size_t size)
{
--
2.49.0
^ permalink raw reply related [flat|nested] 6+ messages in thread* Re: [PATCH 0/4] selftests: cgroup: Add support for named v1 hierarchies in test_core
2025-06-17 13:36 [PATCH 0/4] selftests: cgroup: Add support for named v1 hierarchies in test_core Michal Koutný
` (3 preceding siblings ...)
2025-06-17 13:36 ` [PATCH 4/4] selftests: cgroup: Fix compilation on pre-cgroupns kernels Michal Koutný
@ 2025-06-17 18:13 ` Tejun Heo
4 siblings, 0 replies; 6+ messages in thread
From: Tejun Heo @ 2025-06-17 18:13 UTC (permalink / raw)
To: Michal Koutný
Cc: linux-kernel, cgroups, linux-kselftest, Johannes Weiner,
Shuah Khan
On Tue, Jun 17, 2025 at 03:36:52PM +0200, Michal Koutný wrote:
> Michal Koutný (4):
> selftests: cgroup_util: Add helpers for testing named v1 hierarchies
> selftests: cgroup: Add support for named v1 hierarchies in test_core
> selftests: cgroup: Optionally set up v1 environment
> selftests: cgroup: Fix compilation on pre-cgroupns kernels
Applied to cgroup/for-6.17.
Thanks.
--
tejun
^ permalink raw reply [flat|nested] 6+ messages in thread