Re: [PATCH 00/22] add support for Clang LTO

Peter Zijlstra
2020-07-06T18:30:03Z

On Mon, Jul 06, 2020 at 09:26:33AM -0700, Paul E. McKenney wrote:

> And perhaps more constructively, we do need to prioritize address and data
> dependencies over control dependencies. For one thing, there are a lot
> more address/data dependencies in existing code than there are control
> dependencies, and (sadly, perhaps more importantly) there are a lot more
> people who are convinced that address/data dependencies are important.

If they do not consider their Linux OS running correctly :-)

> For another (admittedly more theoretical) thing, the OOTA scenarios
> stemming from control dependencies are a lot less annoying than those
> from address/data dependencies.
>
> And address/data dependencies are as far as I know vulnerable to things
> like conditional-move instructions that can cause problems for control
> dependencies.
>
> Nevertheless, yes, control dependencies also need attention.

Today I added one more \o/