Re: [PATCH tip/core/rcu 10/20] rcu: Add functions to test for trivial grace periods

2017-01-16 Thread Paul E. McKenney
On Mon, Jan 16, 2017 at 12:01:29AM -0800, Josh Triplett wrote: > On Sat, Jan 14, 2017 at 01:13:11AM -0800, Paul E. McKenney wrote: > > Under some circumstances, RCU grace periods are zero cost. For > > RCU-preempt, this is the case during boot, and for RCU-bh and RCU-sched, > > this is the case

Re: [PATCH tip/core/rcu 10/20] rcu: Add functions to test for trivial grace periods

2017-01-16 Thread Paul E. McKenney
On Mon, Jan 16, 2017 at 12:01:29AM -0800, Josh Triplett wrote: > On Sat, Jan 14, 2017 at 01:13:11AM -0800, Paul E. McKenney wrote: > > Under some circumstances, RCU grace periods are zero cost. For > > RCU-preempt, this is the case during boot, and for RCU-bh and RCU-sched, > > this is the case

Re: [PATCH tip/core/rcu 10/20] rcu: Add functions to test for trivial grace periods

2017-01-16 Thread Josh Triplett
On Sat, Jan 14, 2017 at 01:13:11AM -0800, Paul E. McKenney wrote: > Under some circumstances, RCU grace periods are zero cost. For > RCU-preempt, this is the case during boot, and for RCU-bh and RCU-sched, > this is the case if there is only one CPU. This means that RCU users > might wish to

Re: [PATCH tip/core/rcu 10/20] rcu: Add functions to test for trivial grace periods

2017-01-16 Thread Josh Triplett
On Sat, Jan 14, 2017 at 01:13:11AM -0800, Paul E. McKenney wrote: > Under some circumstances, RCU grace periods are zero cost. For > RCU-preempt, this is the case during boot, and for RCU-bh and RCU-sched, > this is the case if there is only one CPU. This means that RCU users > might wish to

[PATCH tip/core/rcu 10/20] rcu: Add functions to test for trivial grace periods

2017-01-14 Thread Paul E. McKenney
Under some circumstances, RCU grace periods are zero cost. For RCU-preempt, this is the case during boot, and for RCU-bh and RCU-sched, this is the case if there is only one CPU. This means that RCU users might wish to dispense with grace-period-avoidance strategies when grace periods are zero

[PATCH tip/core/rcu 10/20] rcu: Add functions to test for trivial grace periods

2017-01-14 Thread Paul E. McKenney
Under some circumstances, RCU grace periods are zero cost. For RCU-preempt, this is the case during boot, and for RCU-bh and RCU-sched, this is the case if there is only one CPU. This means that RCU users might wish to dispense with grace-period-avoidance strategies when grace periods are zero