Re: [Qemu-devel] [PATCH v2 04/23] memory: merge adjacent segments of a single memory region

[Avi Kivity]

On 07/26/2011 02:51 PM, Paolo Bonzini wrote:
> On 07/26/2011 01:38 PM, Avi Kivity wrote:
> > > if (j != i) {
> > >
> > > > +        memmove(&view->ranges[i], &view->ranges[j],
> > > > +                (view->nr - j) * sizeof(view->ranges[j]));
> > > > +        view->nr -= j - i;
> > > > +    }
> > >
> > > }
> >
> > Seems to work both ways?
>
> Sure, but you're pointlessly memmove-ing memory over itself.  I'm not 
> sure how many segments a single memory region will usually have, but 
> it's better to be safe.

This will never be an issue in practice.  We expect to have few 
FlatRanges (O(100)), simplify() will be called very rarely (never during 
normal operations; a few dozen times during boot; a few during hotplug); 
everything is in L1 cache; and the cost will be dwarfed by any calls to 
kvm (if enabled).

--
error compiling committee.c: too many arguments to function