Messages in this thread |  | | | Date | Tue, 24 Nov 2009 08:52:49 +0100 | | From | Ingo Molnar <> | | Subject | Re: [PATCH -tip v5 00/10] kprobes: Kprobes jump optimization support |
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* Frederic Weisbecker <fweisbec@gmail.com> wrote:
> On Tue, Nov 24, 2009 at 03:03:19AM +0100, Frederic Weisbecker wrote: > > On Mon, Nov 23, 2009 at 06:21:16PM -0500, Masami Hiramatsu wrote: > > > When the optimized-kprobe is hit before optimization, its handler > > > changes IP(instruction pointer) to copied code and exits. So, the > > > instructions which were copied to detour buffer are executed on the detour > > > buffer. > > > > > > > > Hm, why is it playing such hybrid game there? > > If I understand well, we have executed int 3, executed the > > handler and we jump back to the detour buffer? > > > > I got it, I think. We have instructions to patch. And the above turn > this area into dead code, safe to patch. > > But still, stop_machine() seem to make it not necessary anymore.
i think 'sending an IPI to all online CPUs' might be an adequate sequence to make sure patching effects have propagated. I.e. an smp_call_function() with a dummy function?
Ingo
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