On Sat, 2010-10-09 at 16:20 -0700, Linus Torvalds wrote: > On Sat, Oct 9, 2010 at 2:15 PM, Steven Rostedt <rostedt@xxxxxxxxxxx> wrote: > > > > The difference here compared to all other user interfaces, is that this > > interface has the sole purpose of showing what is happening inside the > > kernel. > > Bogus and dishonest argument. > > Listen to yourself, and read this thread again. > > The thread was about doing some kind of open-source library to allow > non-open-source access to these events, and keeping backwards > compatibility in user space. In fact, that is what you yourself said. > > So you claimed it could be backwards-compatible. If that's the case, > then there is no excuse for not being so in the kernel. > > You can't have it both ways. Stop the f*cking waffling. Let me rephrase it then, and lets forget about the library. I was just brain storming ideas. I'm all for labeling specific trace points as "ABI", such that, these trace points have had sufficient thought and are not expected to change in the near future. But I'm against the idea that any tracepoint that has been shown to userspace can be considered stable. With or without libraries, I'm for two kinds of interfaces: One that is stable and has been thoroughly thought through, and one that is free for the maintainers to have an interface to let them see what is happening in the kernel, even on a production system, but be able to change them whenever they feel the need. That's the basis of my idea. A stable backward-compatible interface, and an interface that is unstable for developers. Whether we put the stable interface into a library (to keep the ugliness from developers, which you obviously do not like), or two, distinctly label the tracepoint as ABI, to let the developers and everyone else know what tracepoints an application can count on and what ones they should not. Thus my waffling is really wanting both, a stable ABI and an unstable one. I've been hesitant in the pass from doing the TRACE_EVENT_ABI() before, because Peter Zijlstra (who is currently MIA) has been strongly against it. -- Steve -- To unsubscribe from this list: send the line "unsubscribe linux-trace-users" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
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