Messages in this thread | | | Date | Fri, 27 Apr 2018 11:40:05 -0400 | From | Steven Rostedt <> | Subject | Re: [PATCH RFC] tracepoint: Introduce tracepoint callbacks executing with preempt on |
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On Fri, 27 Apr 2018 08:38:26 -0700 "Paul E. McKenney" <paulmck@linux.vnet.ibm.com> wrote:
> On Fri, Apr 27, 2018 at 10:47:47AM -0400, Steven Rostedt wrote: > > On Fri, 27 Apr 2018 10:26:29 -0400 (EDT) > > Mathieu Desnoyers <mathieu.desnoyers@efficios.com> wrote: > > > > > The general approach and the implementation look fine, except for > > > one small detail: I would be tempted to explicitly disable preemption > > > around the call to the tracepoint callback for the rcuidle variant, > > > unless we plan to audit every tracer right away to remove any assumption > > > that preemption is disabled in the callback implementation. > > > > I'm thinking that we do that audit. There shouldn't be many instances > > of it. I like the idea that a tracepoint callback gets called with > > preemption enabled. > > Are you really sure you want to increase your state space that much?
Why not? The code I have in callbacks already deals with all sorts of context - normal, softirq, irq, NMI, preemption disabled, irq disabled.
-- Steve
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