On Thu, Sep 28, 2017 at 06:03:57PM +0200, Sebastian Andrzej Siewior wrote: > On 2017-09-22 11:46:10 [-0700], Paul E. McKenney wrote: > > On Fri, Sep 22, 2017 at 05:28:05PM +0200, Sebastian Andrzej Siewior wrote: > > > On RT we can't invoke queue_delayed_work() within an atomic section > > > (which is provided by raw_spin_lock_irqsave()). > > > srcu_reschedule() invokes queue_delayed_work() outside of the > > > raw_spin_lock_irq_rcu_node() section so this should be fine here, too. > > > If the remaining callers of call_srcu() aren't atomic > > > (spin_lock_irqsave() is fine) then this should work on RT, too. > > > > Just to make sure I understand... The problem is not the _irqsave, > > but rather the raw_? > > exactly. The _irqsave is translated into a sleeping lock on RT and does > not matter. The raw_ ones stay as they are and queue_delayed_work() uses > sleeping locks itself and this is where things fall apart.
OK, internally I could get rid of raw_ at the expense of some code bloat, but in the call_srcu() case, the caller might well hold a raw_ lock. Thoughts? Thanx, Paul