On Thu, Aug 07, 2014 at 03:53:26PM -0400, Steven Rostedt wrote: > On Thu, 7 Aug 2014 15:49:07 -0400 > Steven Rostedt <rost...@goodmis.org> wrote: > > > > Only voluntary calls to schedule() will be a quiescent state. Preempt > > doesn't count. And no, function callbacks to not call schedule(), > > function callbacks should be treated even stricter than interrupt > > handlers. They should never call schedule() directly or even take any > > locks. Heck, they should be stricter than NMIs for that matter. > > > > Hence, once something calls schedule() directly, we know that it is not > > on a trampoline, nor is it going to return to one. > > I should also be a bit clearer here. It's not just function callbacks, > but anything that adds a trampoline that can be called from any context > (like for kprobes). The point is, these trampolines that can execute > anywhere (including in NMIs), must have strict use cases. These are not > a notifier or other generic operation that normal RCU is fine for. > These are for really specific cases that require the call_rcu_task() to > free. > > call_rcu_task() should seldom be used. The only cases really are for > kprobes and function tracing, and perhaps other dynamic callers.
OK, you've got to start over and start at the beginning, because I'm really not understanding this.. What is a 'trampoline' and what are you going to use them for. -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
