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    SubjectRe: [RFC] Unified Ring Buffer (Next Generation)
    > The plan here is to create a ring buffer that supports per-buffer instance
    > "flags" that specify what must be supported: e.g. either splice() or mmap(),
    > global vs per-cpu buffers, etc.

    And you plan to test all those flags in the hot path?

    > The new implementation I propose lessens the complexity level, presents clear
    > abstractions to deal with that complexity, and comes with a formal proof of
    > correctness, all of which I think is really very important to give a good level
    > of insurance that the ring buffer works as expected.

    Any simplifcation for the ftrace buffer would be a good thing IMHO.

    > > For debugging kernels etc. with tracing that's not that big an issue, but
    > > I think it's a problem for "non debugging" use. After all Linux
    > > still has the goal to be at least configurable as a low footprint operating
    > > system.
    > My implementation, at the moment, has 50% less lines of code and is 25% smaller
    > in object size than the current ring buffer.


    > But all in all, I think users needing _something_ to perform system-wide tracing
    > shout a lot louder than users who need to save a few bytes. So let's try to get
    > something good in first, while keeping an eye on the object size, and if it
    > happens to be too large for some users, then they can always implement a
    > slower and less efficient ring_buffer_tiny.c if they feel like it.

    They don't need to, they already have kfifo.

    > I totally agree with you. This is in good part why I spent a large part of 2009
    > writing papers explaining my ring buffer, doing Promela models and formal proofs
    > of correctness. I think after all that work, the abstractions I will use will be
    > much easier to grap by anyone willing to do a bit of reading.

    Writing papers is not a replacement for simple maintainable code.


    -- -- Speaking for myself only.

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