Hi all, This small series adds practical test coverage for the dmem cgroup controller.
The motivation came from following the recent dmem API discussion in thread [1]. That discussion considered changing the dmem API and adding a new knob. Currently there are no dedicated tests covering dmem behaviour, which makes such changes riskier. Adding selftests has an additional challenge: dmem charging paths are driver-driven today, so regression testing harder unless a suitable driver is present in the test environment. This series addresses that by adding: - a kernel-side selftest helper module to trigger charge/uncharge from userspace in a controlled way, - cgroup selftests covering dmem accounting and protection semantics (including dmem.max enforcement and byte-granularity checks), - a virtme-based VM runner for repeatable execution of the dmem tests. The goal is to make dmem behavior easier to validate when evolving the API and implementation, while keeping tests deterministic and driver-independent. Thanks. [1] - https://lore.kernel.org/all/aZoHfloupKvF2oSu@fedora/ Signed-off-by: Albert Esteve <[email protected]> --- Albert Esteve (3): cgroup: Add dmem_selftest module selftests: cgroup: Add dmem selftest coverage selftests: cgroup: Add vmtest-dmem runner based on hid vmtest init/Kconfig | 12 + kernel/cgroup/Makefile | 1 + kernel/cgroup/dmem_selftest.c | 192 ++++++++++ tools/testing/selftests/cgroup/.gitignore | 1 + tools/testing/selftests/cgroup/Makefile | 2 + tools/testing/selftests/cgroup/test_dmem.c | 487 ++++++++++++++++++++++++++ tools/testing/selftests/cgroup/vmtest-dmem.sh | 189 ++++++++++ 7 files changed, 884 insertions(+) --- base-commit: 80234b5ab240f52fa45d201e899e207b9265ef91 change-id: 20260318-kunit_cgroups-7fb0b9e64017 Best regards, -- Albert Esteve <[email protected]>
