Current cpu.max tests (both the normal one and the nested one) are broken.
They setup cpu.max with 1000 us quota and the default period (100,000 us).
A cpu hog is run for a duration of 1s as per wall clock time. This corresponds
to 10 periods, hence an expected usage of 10,000 us. We want the measured
usage (as per cpu.stat) to be close to 10,000 us.
Previously, this approximate equality test was done by
`!values_close(usage_usec, expected_usage_usec, 95)`: if the absolute
difference between usage_usec and expected_usage_usec is greater than 95% of
their sum, then we pass. And expected_usage_usec was set to 1,000,000 us.
Mathematically, this translates to the following being true for pass:
|usage - expected_usage| > (usage + expected_usage)*0.95
If usage > expected_usage:
usage - expected_usage > (usage + expected_usage)*0.95
0.05*usage > 1.95*expected_usage
usage > 39*expected_usage = 39s
If usage < expected_usage:
expected_usage - usage > (usage + expected_usage)*0.95
0.05*expected_usage > 1.95*usage
usage < 0.0256*expected_usage = 25,600 us
Combined,
Pass if usage < 25,600 us or > 39 s,
which makes no sense given that all we need is for usage_usec to be close to
10,000 us.
Fix this by explicitly calcuating the expected usage duration based on the
configured quota, default period, and the duration, and compare usage_usec
and expected_usage_usec using values_close() with a 10% error margin.
Also, use snprintf to get the quota string to write to cpu.max instead of
hardcoding the quota, ensuring a single source of truth.
Remove the check comparing user_usec and expected_usage_usec, since on running
this test modified with printfs, it's seen that user_usec and usage_usec can
regularly exceed the theoretical expected_usage_usec:
$ sudo ./test_cpu
user: 10485, usage: 10485, expected: 10000
ok 1 test_cpucg_max
user: 11127, usage: 11127, expected: 10000
ok 2 test_cpucg_max_nested
$ sudo ./test_cpu
user: 10286, usage: 10286, expected: 10000
ok 1 test_cpucg_max
user: 10404, usage: 11271, expected: 10000
ok 2 test_cpucg_max_nested
Hence, a values_close() check of usage_usec and expected_usage_usec is
sufficient.
Fixes: a79906570f ("cgroup: Add test_cpucg_max_nested() testcase")
Fixes: 889ab8113e ("cgroup: Add test_cpucg_max() testcase")
Acked-by: Michal Koutný <mkoutny@suse.com>
Signed-off-by: Shashank Balaji <shashank.mahadasyam@sony.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
When compiling the cgroup selftests with the following command:
make -C tools/testing/selftests/cgroup/
the compiler complains as below:
test_cpu.c: In function ‘test_cpucg_nice’:
test_cpu.c:284:39: error: incompatible type for argument 2 of ‘hog_cpus_timed’
284 | hog_cpus_timed(cpucg, param);
| ^~~~~
| |
| struct cpu_hog_func_param
test_cpu.c:132:53: note: expected ‘void *’ but argument is of type ‘struct cpu_hog_func_param’
132 | static int hog_cpus_timed(const char *cgroup, void *arg)
| ~~~~~~^~~
Fix it by passing the address of param to hog_cpus_timed().
Fixes: 2e82c0d456 ("cgroup/rstat: Selftests for niced CPU statistics")
Signed-off-by: Xiu Jianfeng <xiujianfeng@huawei.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
Creates a cgroup with a single nice CPU hog process running.
fork() is called to generate the nice process because un-nicing is
not possible (see man nice(3)). If fork() was not used to generate
the CPU hog, we would run the rest of the cgroup selftest suite as a
nice process.
Signed-off-by: Joshua Hahn <joshua.hahnjy@gmail.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
This reverts commit c1457d9aad.
The framework change to add D_GNU_SOURCE to KHDR_INCLUDES
to Makefile, lib.mk, and kselftest_harness.h is reverted
as it is causing build failures and warnings.
Revert this change as this change depends on the framework
change.
Reported-by: Mark Brown <broonie@kernel.org>
Signed-off-by: Shuah Khan <skhan@linuxfoundation.org>
_GNU_SOURCE is provided by lib.mk, so it should be dropped to prevent
redefinition warnings.
Signed-off-by: Edward Liaw <edliaw@google.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
First of all, in order to build with clang at all, one must first apply
Valentin Obst's build fix for LLVM [1]. Once that is done, then when
building with clang, via:
make LLVM=1 -C tools/testing/selftests
...clang generates warning here, because struct cpu_hogger has multiple
fields, and the code is initializing an array of these structs, and it
is incorrect to specify a single NULL value as the initializer.
Fix this by initializing with {}, so that the compiler knows to use
default initializer values for all fields in each array entry.
[1] https://lore.kernel.org/all/20240329-selftests-libmk-llvm-rfc-v1-1-2f9ed7d1c49f@valentinobst.de/
Signed-off-by: John Hubbard <jhubbard@nvidia.com>
Reviewed-by: Roman Gushchin <roman.gushchin@linux.dev>
Signed-off-by: Tejun Heo <tj@kernel.org>
The test case test_cgcore_lesser_ns_open only tasks effect when cgroup2
is mounted with "nsdelegate" mount option. If it misses this option, or
is remounted without "nsdelegate", the test case will fail. For example,
running bpf/test_cgroup_storage first, and then run cgroup/test_core will
fail on test_cgcore_lesser_ns_open. Skip it if "nsdelegate" is not
detected in cgroup2 mount options.
Fixes: bf35a7879f ("selftests: cgroup: Test open-time cgroup namespace usage for migration checks")
Signed-off-by: Tianchen Ding <dtcccc@linux.alibaba.com>
Reviewed-by: Muhammad Usama Anjum <usama.anjum@collabora.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
The cgroup cpu controller selftests have a test_cpucg_max() testcase
that validates the behavior of the cpu.max knob. Let's also add a
testcase that verifies that the behavior works correctly when set on a
nested cgroup.
Signed-off-by: David Vernet <void@manifault.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
The cgroup cpu controller test suite has a number of testcases that
validate the expected behavior of the cpu.weight knob, but none for
cpu.max. This testcase fixes that by adding a testcase for cpu.max as well.
Signed-off-by: David Vernet <void@manifault.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
The cgroup cpu controller test suite currently contains a testcase called
test_cpucg_nested_weight_underprovisioned() which verifies the expected
behavior of cpu.weight when applied to nested cgroups. That first testcase
validated the expected behavior when the processes in the leaf cgroups
overcommitted the system. This patch adds a complementary
test_cpucg_nested_weight_underprovisioned() testcase which validates
behavior when those leaf cgroups undercommit the system.
Signed-off-by: David Vernet <void@manifault.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
The cgroup cpu controller tests in
tools/testing/selftests/cgroup/test_cpu.c have some testcases that validate
the expected behavior of setting cpu.weight on cgroups, and then hogging
CPUs. What is still missing from the suite is a testcase that validates
nested cgroups. This patch adds test_cpucg_nested_weight_overprovisioned(),
which validates that a parent's cpu.weight will override its children if
they overcommit a host, and properly protect any sibling groups of that
parent.
Signed-off-by: David Vernet <void@manifault.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
test_cpu.c includes testcases that validate the cgroup cpu controller.
This patch adds a new testcase called test_cpucg_weight_underprovisioned()
that verifies that processes with different cpu.weight that are all running
on an underprovisioned system, still get roughly the same amount of cpu
time.
Because test_cpucg_weight_underprovisioned() is very similar to
test_cpucg_weight_overprovisioned(), this patch also pulls the common logic
into a separate helper function that is invoked from both testcases, and
which uses function pointers to invoke the unique portions of the
testcases.
Signed-off-by: David Vernet <void@manifault.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
test_cpu.c includes testcases that validate the cgroup cpu controller.
This patch adds a new testcase called test_cpucg_weight_overprovisioned()
that verifies the expected behavior of creating multiple processes with
different cpu.weight, on a system that is overprovisioned.
So as to avoid code duplication, this patch also updates cpu_hog_func_param
to take a new hog_clock_type enum which informs how time is counted in
hog_cpus_timed() (either process time or wall clock time).
Signed-off-by: David Vernet <void@manifault.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
test_cpu.c includes testcases that validate the cgroup cpu controller.
This patch adds a new testcase called test_cpucg_stats() that verifies the
expected behavior of the cpu.stat interface. In doing so, we define a
new hog_cpus_timed() function which takes a cpu_hog_func_param struct
that configures how many CPUs it uses, and how long it runs. Future
patches will also spawn threads that hog CPUs, so this function will
eventually serve those use-cases as well.
Signed-off-by: David Vernet <void@manifault.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
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>
