On 03/16, Paul E. McKenney wrote: > > In the process of writing up the mechanical proof of correctness for the > dynticks/preemptable-RCU interface, I noticed misplaced memory barriers > in rcu_enter_nohz() and rcu_exit_nohz(). Can't comment this patch, there is no rcu_enter_nohz() in my rcupreempt.h ;) I'm not sure the code below is up to date, but what I have in arch/s390/kernel/time.c is: stop_hz_timer: cpu_set(cpu, nohz_cpu_mask); if (rcu_needs_cpu(cpu) || local_softirq_pending()) { cpu_clear(cpu, nohz_cpu_mask); return; } Don't we need smp_mb() after cpu_set() ? Oleg. -- To unsubscribe from this list: send the line "unsubscribe linux-rt-users" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html