On Mon, Sep 21, 2020 at 02:43:50PM +0200, Frederic Weisbecker wrote: > I have no idea what I'm doing but doing that looks necessary to me.
Now -there- is a commit log that inspires confidence!!! ;-) > Inspired-by: Paul E. McKenney <[email protected]> > Signed-off-by: Frederic Weisbecker <[email protected]> > Cc: Paul E. McKenney <[email protected]> > Cc: Josh Triplett <[email protected]> > Cc: Steven Rostedt <[email protected]> > Cc: Mathieu Desnoyers <[email protected]> > Cc: Lai Jiangshan <[email protected]> > Cc: Joel Fernandes <[email protected]> > --- > kernel/rcu/tree.c | 7 +++---- > 1 file changed, 3 insertions(+), 4 deletions(-) > > diff --git a/kernel/rcu/tree.c b/kernel/rcu/tree.c > index 928907e9ba94..8cef5ea8d1f0 100644 > --- a/kernel/rcu/tree.c > +++ b/kernel/rcu/tree.c > @@ -2619,7 +2619,6 @@ static __latent_entropy void rcu_core(void) > unsigned long flags; > struct rcu_data *rdp = raw_cpu_ptr(&rcu_data); > struct rcu_node *rnp = rdp->mynode; > - const bool offloaded = rcu_segcblist_is_offloaded(&rdp->cblist); > const bool do_batch = !rcu_segcblist_completely_offloaded(&rdp->cblist); > > if (cpu_is_offline(smp_processor_id())) > @@ -2640,11 +2639,11 @@ static __latent_entropy void rcu_core(void) > > /* No grace period and unregistered callbacks? */ > if (!rcu_gp_in_progress() && > - rcu_segcblist_is_enabled(&rdp->cblist) && !offloaded) { > - local_irq_save(flags); > + rcu_segcblist_is_enabled(&rdp->cblist) && do_batch) { > + rcu_nocb_lock_irqsave(rdp, flags); > if (!rcu_segcblist_restempty(&rdp->cblist, RCU_NEXT_READY_TAIL)) > rcu_accelerate_cbs_unlocked(rnp, rdp); It might also be that rcu_advance_cbs() is needed somewhere. I will need to look carefully to work out whether either of them need to be invoked at this particular point in the code. Thanx, Paul > - local_irq_restore(flags); > + rcu_nocb_unlock_irqrestore(rdp, flags); > } > > rcu_check_gp_start_stall(rnp, rdp, rcu_jiffies_till_stall_check()); > -- > 2.28.0 >
