Messages in this thread | | | Date | Mon, 20 Mar 2023 09:28:11 +0100 | From | Peter Zijlstra <> | Subject | Re: [PATCH] sched/core: Reduce cost of sched_move_task when config autogroup |
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On Sun, Mar 19, 2023 at 03:56:43PM +0800, wuchi wrote: > Some sched_move_task calls of autogroup is useless when the > task_struct->sched_task_group isn't changed because of task_group > of cpu_cgroup overlay task_group of autogroup. The overlay key codes > are as follows: > > sched_cgroup_fork->autogroup_task_group->task_wants_autogroup > sched_change_group->autogroup_task_group->autogroup_task_group > > sched_move_task eg: > task A belongs to cpu_cgroup0 and autogroup0, it will always to > cpu_cgroup0 when doing exit. So there is no need to do {de|en}queue. > The call graph is as follow. > > do_exit > sched_autogroup_exit_task > sched_move_task > dequeue_task > sched_change_group > A.sched_task_group = sched_get_task_group > enqueue_task > > So do some check before dequeue task in sched_move_task.
No immediate objection; but the $subject seems to suggest you did this for performance reasons, yet there are no performance results in this Changelog. How much does this save under what load?
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