On Mon, Sep 11, 2023 at 07:54:52PM -0400, Liam R. Howlett wrote: > Taking the mutex lock in kernel/irq/manage.c __setup_irq() is calling a > cond_resched(). > > >From what Michael said [1] in this thread, since something has already > set TIF_NEED_RESCHED, it will eventually enable interrupts on us. > > I've traced this to running call_rcu() in kernel/rcu/tiny.c and > is_idle_task(current) is true, which means rcu runs: > /* force scheduling for rcu_qs() */ > resched_cpu(0); > > the task is set idle in sched_init() -> init_idle() and never changed, > afaict. Should calling init_idle() be deferred until after interrupts are all set up?
