On Fri, Jun 28, 2019 at 06:04:08PM +0200, Peter Zijlstra wrote: > On Fri, Jun 28, 2019 at 08:54:04AM -0700, Paul E. McKenney wrote: > > Thank you! Plus it looks like scheduler_ipi() takes an early exit if > > ->wake_list is empty, regardless of TIF_NEED_RESCHED, right? > > Yes, TIF_NEED_RESCHED is checked in the interrupt return path. OK, got it. So the following sequence would be a valid way to get the scheduler's attention on the current CPU shortly after interrupts are re-enabled, even if the current CPU is already holding some rq or pi locks, correct? set_tsk_need_resched(current); set_preempt_need_resched(); smp_send_reschedule(smp_processor_id()); Thanx, Paul