On Mon, Aug 12, 2019 at 07:27:26PM -0700, Paul E. McKenney wrote: > On Mon, Aug 12, 2019 at 09:02:49PM -0400, Joel Fernandes wrote: > > On Mon, Aug 12, 2019 at 04:01:38PM -0700, Paul E. McKenney wrote: [ . . . ] > > Instead of checking dynticks_nmi_nesting == 2 in rcu_nmi_exit_common(), can > > we do the tick_dep_set_cpu(rdp->cpu, TICK_DEP_MASK_RCU) from > > rcu_nmi_enter_common() ? We could add this code there, under the "if > > (rcu_dynticks_curr_cpu_in_eqs())". > > It might well make sense to do this on entry, especially if doing so > might safe an instruction or two. It won't make the tick happen much > faster, given that interrupts are disabled throughout the handler. > > > I will test this patch tomorrow and let you know how it goes. > > No need, it dies horribly and quickly with rcutorture. Not exactly > a surprise. ;-) And also not a surprise, due to a laughably stupid mistake... Thanx, Paul