Messages in this thread | | | Subject | Re: Relicensing tracepoints and markers to Dual LGPL v2.1/GPL v2,headers to Dual BSD/GPL | From | Steven Rostedt <> | Date | Mon, 26 Oct 2009 09:29:52 -0400 |
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On Mon, 2009-10-26 at 09:17 -0400, Pierre-Marc Fournier wrote: > Ingo Molnar wrote: > > > > But i also disagree with it on a technical level: code duplication is > > _bad_. Why does the code have to be duplicated in user-space like that? > > I'd like Linux tracing code to be in the kernel repo. Why isnt this done > > properly, as part of the kernel project - to make sure it all stays in > > sync? > > > > If you mean that this code should solely be used inside the kernel, then > what you propose technically does not work. There is a very high cost to > accessing kernel code from userspace. This cost is simply unacceptable > for the kind of userspace tracing that is needed today.
I think that Ingo is thinking that the tracing is for the kernel, and is asking why the duplication needs to be done for tools tracing the kernel.
But what I think is trying to be done here is to use the same types of MACROS that we have in the kernel to do tracing in userspace. That a userspace program can add their own "TRACE_EVENT" and that the headers there will create a tracepoint for them the same way we currently do in the kernel.
Am I correct in my analysis?
-- Steve
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