Messages in this thread | | | Subject | Re: [PATCH] sched/rt: fix SCHED_RR across cgroups | From | Peter Zijlstra <> | Date | Fri, 18 May 2012 10:56:35 +0200 |
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On Wed, 2012-05-16 at 21:34 -0700, Colin Cross wrote: > task_tick_rt has an optimization to only reschedule SCHED_RR tasks > if they were the only element on their rq. However, with cgroups > a SCHED_RR task could be the only element on its per-cgroup rq but > still be competing with other SCHED_RR tasks in its parent's > cgroup. In this case, the SCHED_RR task in the child cgroup would > never yield at the end of its timeslice. If the child cgroup > rt_runtime_us was the same as the parent cgroup rt_runtime_us, > the task in the parent cgroup would starve completely. > > Modify task_tick_rt to check that the task is the only task on its > rq, and that the each of the scheduling entities of its ancestors > is also the only entity on its rq. > > Signed-off-by: Colin Cross <ccross@android.com>
OK, fair enough.. one does wonder though, WTH is android doing with SCHED_RR?
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