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Subject: Re: [PATCH 5/9] jump label: Add
 register_jump_label_key/unregister_jump_label_key
From: Peter Zijlstra <peterz@infradead.org>
To: Steven Rostedt <rostedt@goodmis.org>
Cc: linux-kernel@vger.kernel.org, Ingo Molnar <mingo@elte.hu>,
        Andrew Morton <akpm@linux-foundation.org>,
        Frederic Weisbecker <fweisbec@gmail.com>,
        Jason Baron <jbaron@redhat.com>
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Date: Fri, 15 Oct 2010 23:13:35 +0200
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On Fri, 2010-10-15 at 17:09 -0400, Steven Rostedt wrote:
> On Fri, 2010-10-15 at 23:03 +0200, Peter Zijlstra wrote:
> 
> > Urgh, this sucks.. :-(
> > 
> > So now we have to actually track all JUMP_LABEL() sites and call
> > register muck on them.. even though we already track them through the
> > special data section.
> > 
> > Is there really no way around this?
> 
> I'll take a look to see if we can monkey with magic and automate it.

So the problem is something like:

core kernel:

 jump_label_enable()

module:

 JUMP_LABEL()

And then because we don't have a proper __jump_table section, the
jump_label_enable() won't properly work?

Why not let jump_label_enable() add a dummy entry with the enabled bit
and once you load the module merge the real entry into it.