Finite-slice EXT tasks need the periodic scheduler tick to expire their slices even when nohz_full is enabled. Add a regression test that selects a nohz_full CPU and exercises both infinite-to-finite and finite-to-finite slice transitions across an idle interval. For each finite task, verify that its ops.tick() callback is invoked. Skip the test when an allowed nohz_full CPU and a separate housekeeping CPU are not available. Signed-off-by: Andrea Righi <arighi@nvidia.com> Signed-off-by: Tejun Heo <tj@kernel.org>