Later commits will change CFS bandwidth control throttling from a per-cfs_rq basis to a per-task basis. This means special care needs to be taken around any transition a task can have into and out of a cfs_rq.
To ease reviewing, the transitions are patched with dummy-helpers that are implemented later on. Add helpers to task_change_group_fair() to cover CPU cgroup migration. If changing to a throttled taskgroup/cfs_rq, the task needs to be throttled. Conversely, if the task is already throttled but changing to a taskgroup/cfs_rq that still has some runtime, the task must be unthrottled. Signed-off-by: Valentin Schneider <[email protected]> --- kernel/sched/fair.c | 8 ++++++++ 1 file changed, 8 insertions(+) diff --git a/kernel/sched/fair.c b/kernel/sched/fair.c index acac0829c71f3..ec4cf7308a586 100644 --- a/kernel/sched/fair.c +++ b/kernel/sched/fair.c @@ -12935,6 +12935,14 @@ static void task_change_group_fair(struct task_struct *p) #endif set_task_rq(p, task_cpu(p)); attach_task_cfs_rq(p); + + if (!cfs_bandwidth_used()) + return; + + if (task_needs_throttling(p)) + task_throttle_setup(p); + else + task_throttle_cancel(p); } void free_fair_sched_group(struct task_group *tg) -- 2.43.0
