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    SubjectRe: [for-next][PATCH 00/18] function_graph: Add separate depth counter to prevent trace corruption
    On Wed, 28 Nov 2018 15:39:31 -0500
    Joe Lawrence <joe.lawrence@redhat.com> wrote:

    > Hi Steve,
    >
    > With your ftrace/urgent branch linked above, if I try a quick
    > function_graph test like the following:
    >
    > SYSFS=/sys/kernel/debug/tracing
    >
    > echo 0 > "$SYSFS/tracing_on"
    > echo cmdline_proc_show > "$SYSFS/set_graph_function"
    > echo function_graph > "$SYSFS/current_tracer"
    > echo 1 > "$SYSFS/tracing_on"
    >
    > I see a bunch of scheduler interrupt functions in the trace/trace_pipe
    > without even invoking cmdline_proc_show().
    >
    > This tests works as expected with Linux 4.20-rc3 though:
    >
    > % cat /sys/kernel/debug/tracing/trace_pipe
    > 2) | cmdline_proc_show() {
    > 2) 0.320 us | seq_puts();
    > 2) 0.030 us | seq_putc();
    > 2) 1.352 us | }
    >
    > Operator error, or did the patchset break something?

    Nope, that does seem to be a bug :-/

    -- Steve

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