Re: [RFC PATCH 1/2] x86/ibpb: Skip IBPB when we switch back to same user process

[Peter Zijlstra]

On Thu, Jan 25, 2018 at 01:04:23PM -0800, Andy Lutomirski wrote:
> Can we please not rely on any of the active_mm shit?  That thing has
> really weird semantics and should just die.

I don't agree on the weird semantics. Its simply the last user mm.

I won't mind seeing it go as it would reduce the number of atomics on
the schedule path, but its really not terribly.