Re: [PATCH] selftests: KVM: Handle compiler optimizations in ucall

[oliver . upton]

June 16, 2022 11:48 AM, "David Laight" <David.Laight@xxxxxxxxxx> wrote:
> No wonder I was confused.
> It's not surprising the compiler optimises it all away.
> 
> It doesn't seem right to be 'abusing' WRITE_ONCE() here.
> Just adding barrier() should be enough and much more descriptive.

I had the same thought, although I do not believe barrier() is sufficient
on its own. barrier_data() with a pointer to uc passed through
is required to keep clang from eliminating the dead store.

--
Thanks,
Oliver