On Sun, Nov 5, 2017 at 6:33 AM, Ingo Molnar <mi...@kernel.org> wrote:
>
> Please note that this pull request is RFC due to the top commit:
>
> ec1e1b610917: objtool: Prevent GCC from merging annotate_unreachable(),
> take 2
>
> ... which is admittedly somewhat of an ad-hoc workaround for something the
> compiler should have done - if there's another solution we can try that.
So I'm certainly ok with that workaround since apparently "asm
volatile" doesn't do it.
That said, I think that if that asm needs to not be merged, it should
_also_ be marked as "volatile" - since that's the documented bit for
"not moved significantly". Of course, then because apparently that
isn't enough, the __COUNTER__ games are ok, but might really mention
an explicit comment in the code as to why they exist. Because right
now they look just odd and nonsensical.
Linus
