Re: [PATCH 01/62] kvm: Make pi_enable_wakeup_handler() easier to analyze

[Bart Van Assche]

On 2/26/26 12:13 PM, Marco Elver wrote:
> The goal of RELOC_HIDE is to make the optimizer be less aggressive.
> But the Thread Safety Analysis's alias analysis happens during
> semantic analysis and is completely detached from the optimizer, and
> we could potentially construct an expression that (a) lets Thread
> Safety Analysis figure out that __ptr is an alias to ptr, while (b)
> still hiding it from the optimizer. But I think we're sufficiently
> scared of breaking (b) that I'm not sure if this is feasible in a
> clean enough way that won't have other side-effects (e.g. worse
> codegen).

Does the thread-safety alias analyzer assume that function calls with
identical inputs produce identical outputs? If so, how about changing
RELOC_HIDE() from a macro into an inline function? Would that be
sufficient to make the thread-safety checker recognize identical
per_cpu() expressions as identical without affecting the behavior of the
optimizer?

Thanks,

Bart.