Re: 4g/4g for 2.6.6

Ingo Molnar
2004-05-25T19:53:46Z

* Manfred Spraul <manfred@colorfullife.com> wrote:

> >also, the 4:4 overhead is really a hardware problem - and there are
> >x86-compatible CPUs (amd64) where the TLB flush problem has already been
> >solved: on amd64 the 4:4 feature has no noticeable overhead.
> >
> Do you have an idea why amd64 is better for 4g4g? Which benchmark did
> you use for testing?

i used an althlon64 CPU. amd64 is better because it has a hardware
feature that 'watches' for memory updates to cached TLBs, and it tags
the TLBs by cr3. So it can avoid having to flush those TLBs that didnt
actually change. So an amd64 CPU has in excess of 1000+ TLBs ...

Ingo