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CP15 Barrier emulation performance?



Some of the reproducible builds armhf nodes are actually arm64 capable
machines, running an arm64 kernel build.  When haskell related packages
get built, I get a tremendous number of messages on to the console:

  "ghc" (13126) uses deprecated CP15 Barrier instruction at 0xefadd224

In the kernel's boot/config-*:

  CONFIG_CP15_BARRIER_EMULATION=y

Does this emulation take a considerable performance hit, as opposed to
running on armhf hardware/kernel, where the instruction doesn't appear
to be listed as deprecated?

Several of the arm64 machines with armhf userland machines seem to
perform very poorly... I was wondering if this might somehow be part of
the issue.


live well,
  vagrant

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