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

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

On Fri, 5 Jun 2009 05:01:25 pm Gerd Hoffmann wrote:
>    Hi,
>
> > I think you're missing the point of Rusty's benchmark.  I see his
> > exercise as "compare a kernel configured as a distro would vs a
> > custom-built kernel configured for the exact target environment".  In
> > that light, questions about the CONFIG options Rusty used should be based
> > on whether most distros would use them in their stock kernels as opposed
> > to how necessary they are.
>
> Well.  The test ran on a machine with so much memory that you need
> HIGHMEM to use it all.  I think it also was SMP.  So a custom kernel for
> *that* machine would certainly include SMP and HIGHMEM ...

I have a UP machine with 512M of RAM, but I wasn't going to take it out just 
to prove the point.  Hence I used my test machine with mem=880 maxcpus=1 to 
simulate it, but that's a distraction here.

> While it might be
> interesting by itself to see what the overhead of these config options
> is, it is IMHO quite pointless *in the context of this discussion*.

No, you completely missed the point.
Rusty.