Re: Impact of CONFIG_PARAVIRT=y / mmap benchmark

From: Ingo Molnar
Date: Wed Mar 29 2017 - 14:06:17 EST



* Randy Dunlap <rdunlap@xxxxxxxxxxxxx> wrote:

> On 03/28/17 10:17, Radu Rendec wrote:
> > Hi,
> >
> > I'm trying to assess the performance impact of enabling PARAVIRT (and
> > XEN) in a custom kernel configuration. I came across a very old thread
> > (https://lkml.org/lkml/2009/5/13/449) on this topic and the conclusion
> > back then was that the performance impact was (arguably) around 1%.
> >
> > Does anyone still have a copy of Ingo Molnar's mmap-perf.c program (the
> > old link is broken)? Would it still be relevant to use it for measuring
> > performance in case of PARAVIRT?
> >
> > Last but not least, has anyone looked into PARAVIRT performance more
> > recently?
> >
> > Thank you!
> >
> > Best regards,
> > Radu Rendec
>
> I have mmap-perf.c that says:
> /* Copyright Ingo Molnar (c) 2006 */
>
> and no license info...
> Ingo?

It's GPL v2, like the kernel.

Thanks,

Ingo