Re: [benchmark] 1% performance overhead of paravirt_ops on native kernels

[Rusty Russell <rusty@rustcorp.com.au>]

On Sat, 6 Jun 2009 12:24:43 am Linus Torvalds wrote:
> On Fri, 5 Jun 2009, Rusty Russell wrote:
> > Distributions don't ship UP kernels any more; this shows what that costs
> > if you're actually on a UP box.  If we really don't care, perhaps we
> > should make CONFIG_SMP=n an option under EMBEDDED for x86.  And we can
> > rip out the complex patching SMP patching stuff too.
>
> The complex SMP patching is what makes it _possible_ to not ship UP
> kernels any more.

"possible"?  You mean "acceptable".  Gray, not black and white.

1) Where's the line?
2) Where are we?  Does patching claw back 5% of the loss?  50%?  90%?

No point benchmarking on my (SMP) laptop for this one.  Gerd cc'd, maybe he 
has benchmarks from when he did the work originally?

Thanks,
Rusty.