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    SubjectRe: [BUG] msr-trace.h:42 suspicious rcu_dereference_check() usage!
    > And a popf can be much more expensive than any of these. You should
    > know, not all instructions are equal.
    >
    > Using perf, I've seen popf take up almst 30% of a function the size of
    > this.

    In any case it's a small fraction of the 600+ instructions which are currently
    executed for every enabled trace point.

    If ftrace was actually optimized code this would make some sense, but it
    clearly isn't ...

    -Andi

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