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    SubjectRe: Potential Issue in Tracing Ring Buffer
    On Tue, 8 Dec 2020 11:37:13 -0800
    "J. Avila" <elavila@google.com> wrote:

    > Hello Steven,
    >
    > Thank you once again for all of your support. We saw that you also recently
    > merged a change[1] which adds some validation for the timestamps in
    > ring_buffer.c. Would you have any recommendations on how to add a more
    > lightweight check for time going "backwards" in the timestamps? The idea
    > is that we could use this quick test to detect the problem, then run a build
    > with your config to dig deeper.

    I'm looking at adding a user space kernel selftest to make sure the buffer
    never goes backwards[1] (note the code has changed since that posting). You
    can see the stand alone code here[2]. But requires downloading and
    installing libtraceevent[3] and libtracefs[4].

    -- Steve


    [1] https://lore.kernel.org/r/20201201160656.7cc6a5e8@gandalf.local.home
    [2] http://rostedt.org/code/test-ring-buffer/
    [3] https://git.kernel.org/pub/scm/libs/libtrace/libtraceevent.git/
    [4] https://git.kernel.org/pub/scm/libs/libtrace/libtracefs.git/

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