Messages in this thread | | | Date | Sun, 26 Apr 2009 13:27:17 +0200 | From | Ingo Molnar <> | Subject | Re: [PATCH RFC] v2 expedited "big hammer" RCU grace periods |
| |
* Paul E. McKenney <paulmck@linux.vnet.ibm.com> wrote:
> Second cut of "big hammer" expedited RCU grace periods, but only > for rcu_bh. This creates another softirq vector, so that entering > this softirq vector will have forced an rcu_bh quiescent state (as > noted by Dave Miller). Use smp_call_function() to invoke > raise_softirq() on all CPUs in order to cause this to happen. > Track the CPUs that have passed through a quiescent state (or gone > offline) with a cpumask.
hm, i'm still asking whether doing this would be simpler via a reschedule vector - which not only is an existing facility but also forces all RCU domains through a quiescent state - not just bh-RCU participants.
Triggering a new softirq is in no way simpler that doing an SMP cross-call - in fact softirqs are a finite resource so using some other facility would be preferred.
Am i missing something?
Ingo
| |