On Fri, 7 Sep 2018, Andy Lutomirski wrote: > On Fri, Sep 7, 2018 at 5:04 PM, Linus Torvalds > <torva...@linux-foundation.org> wrote: > > Virtual mapping tricks may be cool, but in the end, not having to use > > them is better still, I think. > > > > If (and this is a *big* if) all the percpu data is within 2GB of the > entry text, then we could avoid this extra TLB reference by accessing > it directly instead of using an alias. > > I suppose the summary is that the retpoline-free trampoline variant is > even more complicated than the code I'm removing in this series, and > that it would be at best a teeny tiny win. Once all the Spectre dust > settles and we get fixed CPUs, we could consider re-optimizing this.
That's going to be after my retirement ...
