On Mon, Dec 09, 2019 at 10:21:22PM +0530, Srikar Dronamraju wrote: > diff --git a/kernel/sched/core.c b/kernel/sched/core.c > index 44123b4d14e8..efd740aafa17 100644 > --- a/kernel/sched/core.c > +++ b/kernel/sched/core.c > @@ -2664,7 +2664,12 @@ try_to_wake_up(struct task_struct *p, unsigned int state, int wake_flags) > */ > int wake_up_process(struct task_struct *p) > { > - return try_to_wake_up(p, TASK_NORMAL, 0); > + int wake_flags = 0; > + > + if (is_per_cpu_kthread(p)) > + wake_flags = WF_KTHREAD; > + > + return try_to_wake_up(p, TASK_NORMAL, WF_KTHREAD); This is buggy. It always sets WF_KTHREAD, even for non-kernel processes. I think you meant: return try_to_wake_up(p, TASK_NORMAL, wake_flags); I suspect this bug invalidates the test results presented, too... -Dave. -- Dave Chinner david@xxxxxxxxxxxxx