Messages in this thread | | | Date | Fri, 28 Feb 2014 17:05:53 -0500 | From | Steven Rostedt <> | Subject | Re: perf_fuzzer compiled for x32 causes reboot |
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On Fri, 28 Feb 2014 22:55:11 +0100 Peter Zijlstra <peterz@infradead.org> wrote:
> On Fri, Feb 28, 2014 at 01:51:50PM -0800, Paul E. McKenney wrote: > > On Fri, Feb 28, 2014 at 10:27:00PM +0100, Peter Zijlstra wrote: > > > On Fri, Feb 28, 2014 at 01:17:33PM -0800, Paul E. McKenney wrote: > > > > This code isn't running in idle context is it? If so, RCU will happily > > > > free out from under it. CONFIG_PROVE_RCU should detect this sort of thing, > > > > though. > > > > > > Well, interrupts/NMIs can happen when idle, but the interrupt/NMI > > > entry code deals with the idle state AFAIK. > > > > Yep, rcu_irq_enter() and rcu_nmi_enter() deal with that. More worried > > about this being code invoked from some energy-efficiency driver or > > another within the idle loop. > > Right, so any tracepoint can end up there; but I thought there was > already the rule that tracepoints needed RCU enabled.
There is and we have special tracepoint caller for those cases we want a tracepoint out of RCU scope. These will reactivate rcu in the tracepoint code.
trace_<tp_name>_rcuidle(...)
-- Steve
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