On Tue, May 31, 2016 at 02:33:45PM +0200, Vincent Guittot wrote: > The sched_avg of a task is not used anymore in copy_process with > yuyang's patchset. To be fully correct, we still have a > p->se.avg.last_update_time = 0 in cpu_cgroup_fork but this is just the > side effect of factoring cpu_group_fork and cpu_group_move in > sched_move_task and it will be overwritten by > init_entity_runnable_average before being used.
Yeah, but why? Why does init_entity_runnable_average() live in wake_up_new_task()? That doesn't seem to make sense. Also note that vruntime_normalized() (ab)uses !se->sum_exec_runtime to detect the new task state. > Now, cpu_cgroup_fork() only sets task group and cfs_rq of the forked task > > copy_process > sched_fork > ... > cgroup_post_fork > ss->fork() := cpu_cgroup_fork() which only set task group and > cfs_rq of the sched_entity of the task > > wake_up_new_task > init_entity_runnable_average > activate_task > enqueue_task > attach_task
