Messages in this thread | | | Date | Sat, 9 Aug 2014 09:05:10 -0700 | From | "Paul E. McKenney" <> | Subject | Re: [PATCH v3 tip/core/rcu 1/9] rcu: Add call_rcu_tasks() |
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On Sat, Aug 09, 2014 at 08:44:39AM -0400, Steven Rostedt wrote: > On Sat, 9 Aug 2014 08:15:14 +0200 > Peter Zijlstra <peterz@infradead.org> wrote: > > > > As for idle tasks, I'm not sure about those, I think that we should say > > NO to anything that would require waking idle CPUs, push the pain to > > ftrace/kprobes, we should _not_ be waking idle cpus. > > I agree, but I haven't had a chance to review the patch set (will > probably do that on Monday, just got back from vacation last week and > was inundated by other things).
Let me get v5 out first. I expect to have it out by end of Monday.
> Does the idle waking happen only when > there's something queued in the call_rcu_tasks()? It should definitely > not be waking all the time. That's just wrong. > > But if it only wakes when something is queued, it wouldn't be burdening > anything, unless it is needed.
Indeed, idle waking only happens when there is an RCU-tasks grace period in progress. No RCU-tasks grace period, no RCU-tasks idle waking.
Thanx, Paul
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