Some cgroup selftests, such as test_cpu, occasionally fail by a very
small margin and if run in the CI context, it is useful to have detailed
diagnostic output to understand the deviation.
Introduce a values_close_report() helper which performs the same
comparison as values_close(), but prints detailed information when the
values differ beyond the allowed tolerance.
Signed-off-by: Sebastian Chlad <sebastian.chlad@suse.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
The predicates in test expect event counting from 73e75e6fc352b
("cgroup/pids: Separate semantics of pids.events related to pids.max")
and the test would fail on older kernels. We want to have one version of
tests for all, so detect the feature and skip the test on old kernels.
(The test could even switch to check v1 semantics based on the flag but
keep it simple for now.)
Fixes: 9f34c566027b6 ("selftests: cgroup: Add basic tests for pids controller")
Signed-off-by: Michal Koutný <mkoutny@suse.com>
Tested-by: Sebastian Chlad <sebastian.chlad@suse.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
Non-functional change, the control variable will be wired in a separate
commit.
Signed-off-by: Michal Koutný <mkoutny@suse.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
Add an API in the cgroups library to find the root of a specific
controller. KVM selftests will use the API to find the memory controller.
Search for the controller on both v1 and v2 mounts, as KVM selftests'
usage will be completely oblivious of v1 versus v2.
Signed-off-by: James Houghton <jthoughton@google.com>
Link: https://lore.kernel.org/r/20250508184649.2576210-6-jthoughton@google.com
Signed-off-by: Sean Christopherson <seanjc@google.com>
KVM selftests will soon need to use some of the cgroup creation and
deletion functionality from cgroup_util.
Suggested-by: David Matlack <dmatlack@google.com>
Signed-off-by: James Houghton <jthoughton@google.com>
Acked-by: Tejun Heo <tj@kernel.org>
Link: https://lore.kernel.org/r/20250508184649.2576210-5-jthoughton@google.com
Signed-off-by: Sean Christopherson <seanjc@google.com>
