Re: [RFC PATCH] tools/memory-model: Remove (dep ; rfi) from ppo

From: Peter Zijlstra
Date: Wed Mar 06 2019 - 11:58:58 EST


On Thu, Mar 07, 2019 at 12:46:05AM +0900, Akira Yokosawa wrote:
> So, I'm looking at the macro RELOC_HIDE() defined in include/linux/compiler-gcc.h.

> Am I the only one who was not aware of this gcc-specific macro?

It's one I regularly see, but had forgotten about in this context.

However; you can also fix things by adding asm volatile ("":::"memory");
in places.

But that's not really the point; I would really rather have a cmdline
knob to fix things. That way we can compile the kernel with and without
and look for differences. -fno-unicorns or something :-)

While I understand some compiler people revel in UB and love to make
unicorns happen, I think in this case the produces result is utterly
insane.