[Qemu-devel] Re: [PATCH] Dynamic ticks

[Dan Kenigsberg]

Thank you (Luca and Thiemo) for your prompt review and comments!

On Tue, Aug 14, 2007 at 12:06:20AM +0100, Thiemo Seufer wrote:
> Luca Tettamanti wrote:
> [snip]
> > I've implemented some of my suggestions in the following patch - rebased
> > to kvm-userspace current git since it's easier to test (...ok, I'm lazy -
> > but you get the idea):
> > 
> > 
> > diff --git a/qemu/configure b/qemu/configure
> > index 365b7fb..38373db 100755
> > --- a/qemu/configure
> > +++ b/qemu/configure
> > @@ -262,6 +262,8 @@ for opt do
> >    ;;
> >    --enable-uname-release=*) uname_release="$optarg"
> >    ;;
> > +  --disable-dynamic-ticks) dynamic_ticks="no"
> > +  ;;
> 
> Is there a situation where the attempt to use dynticks is harmful?
> 

Well, I cannot really say when and how much, but rearming the timer
every shot has its price (especially when the guest is not idling).
I thought that even just uselessly checking use_dynamic_ticks in every
signal handler call would be frowned upon.

Maybe you are right, and for the sake of code and build simplisity I
should drop that ifdef altogether.

Thanks,

Dan.