On Mon, 24 Feb 2025 19:55:11 -0800 Boqun Feng <boqun.feng@xxxxxxxxx> wrote: > From: Ankur Arora <ankur.a.arora@xxxxxxxxxx> > > To reduce RCU noise for nohz_full configurations, osnoise depends > on cond_resched() providing quiescent states for PREEMPT_RCU=n > configurations. For PREEMPT_RCU=y configurations -- where > cond_resched() is a stub -- we do this by directly calling > rcu_momentary_eqs(). > > With (PREEMPT_LAZY=y, PREEMPT_DYNAMIC=n), however, we have a > configuration with (PREEMPTION=y, PREEMPT_RCU=n) where neither > of the above can help. > > Handle that by providing an explicit quiescent state here for all > configurations. > > As mentioned above this is not needed for non-stubbed cond_resched(), > but, providing a quiescent state here just pulls in one that a future > cond_resched() would provide, so doesn't cause any extra work for > this configuration. > > Cc: Paul E. McKenney <paulmck@xxxxxxxxxx> > Cc: Daniel Bristot de Oliveira <bristot@xxxxxxxxxx> > Cc: Steven Rostedt <rostedt@xxxxxxxxxxx> Acked-by: Steven Rostedt (Google) <rostedt@xxxxxxxxxxx> -- Steve > Suggested-by: Paul E. McKenney <paulmck@xxxxxxxxxx> > Acked-by: Daniel Bristot de Oliveira <bristot@xxxxxxxxxx> > Signed-off-by: Ankur Arora <ankur.a.arora@xxxxxxxxxx> > Reviewed-by: Frederic Weisbecker <frederic@xxxxxxxxxx> > Signed-off-by: Paul E. McKenney <paulmck@xxxxxxxxxx> > Signed-off-by: Boqun Feng <boqun.feng@xxxxxxxxx> > ---
