Re: [PATCH 01/13] jump label v9: notifier atomic call chain notrace

From: Frederic Weisbecker
Date: Wed Jun 09 2010 - 17:58:27 EST


On Wed, Jun 09, 2010 at 05:38:52PM -0400, Jason Baron wrote:
> From: Mathieu Desnoyers <mathieu.desnoyers@xxxxxxxxxx>
>
> In LTTng, being able to use the atomic notifier from cpu idle entry to
> ensure the tracer flush the last events in the current subbuffer
> requires the rcu read-side to be marked "notrace", otherwise it can end
> up calling back into lockdep and the tracer.
>
> Also apply to the the die notifier.
>
> Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@xxxxxxxxxx>
> Signed-off-by: Jason Baron <jbaron@xxxxxxxxxx>
> Reviewed-by: Masami Hiramatsu <mhiramat@xxxxxxxxxx>
> ---



I don't understand the purpose of this patch. The only notifier
I see that is used by jmp label is the module notifier, and I
don't see how it can do bad things if we don't use the notrace
version.

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