On Mon, Dec 12, 2022 at 12:49:59PM +0100, Peter Zijlstra wrote: > On Tue, Nov 29, 2022 at 10:22:50PM -1000, Tejun Heo wrote: > > These will be used by a new sched_class. > > Uhhh.. wtf does a policy need __setscheduler_prio() for? Whether a task is on sched_ext or not is determined by a few factors - the chosen sched class of the task, whether the BPF scheduler is loaded and whether it's using scx_bpf_switch_all(). That selection logic is implemented in __setscheduler_prio(). When the BPF scheduler gets initialized and exited, the selection changes and sched_ext needs to walk the tasks reapplying the selection logic, so the export. This ties together with the sched_enq_and_set_task() that you replied to in another thread. Imma continue there. -- tejun
