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

Peter Zijlstra
2020-07-01T15:05:21Z

On Wed, Jul 01, 2020 at 07:06:54AM -0700, Paul E. McKenney wrote:

> The current state in the C++ committee is that marking variables
> carrying dependencies is the way forward. This is of course not what
> the Linux kernel community does, but it should not be hard to have a
> -fall-variables-dependent or some such that causes all variables to be
> treated as if they were marked. Though I was hoping for only pointers.
> Are they -sure- that they -absolutely- need to carry dependencies
> through integers???

What's 'need'? :-)

I'm thinking __ktime_get_fast_ns() is better off with a dependent load
than it is with an extra smp_rmb().

Yes we can stick an smp_rmb() in there, but I don't like it. Like I
wrote earlier, if I wanted a control dependency, I'd have written one.