> > On 08/17/2018 11:27 AM, Steve Muckle wrote: > > > When rt_mutex_setprio changes a task's scheduling class to RT, > > > we're seeing cases where the task's vruntime is not updated > > > correctly upon return to the fair class.
> > > Specifically, the following is being observed: > > > - task is deactivated while still in the fair class > > > - task is boosted to RT via rt_mutex_setprio, which changes > > > the task to RT and calls check_class_changed. > > > - check_class_changed leads to detach_task_cfs_rq, at which point > > > the vruntime_normalized check sees that the task's state is > > > TASK_WAKING, > > > which results in skipping the subtraction of the rq's min_vruntime > > > from the task's vruntime > > > - later, when the prio is deboosted and the task is moved back > > > to the fair class, the fair rq's min_vruntime is added to > > > the task's vruntime, even though it wasn't subtracted earlier. I'm thinking that is an incomplete scenario; where do we get to TASK_WAKING.
