Re: [Qemu-devel] [RFC] virtio: Report new guest memory statistics pertinent to memory ballooning

[Jamie Lokier]

Avi Kivity wrote:
> >             (qemu) info balloon
> >             balloon: actual=1024 MB
> >             balloon: pswapin=0 pages
> >             balloon: pswapout=0 pages
> >             balloon: panon=3928 KB
> >             balloon: pgmajfault=0
> >             balloon: pgminfault=247914
> >             balloon: memfree=987032 KB
> >             balloon: memtot=1020812 KB
> 
> It's important that these statistics be cross platform.  Can you (or 
> someone knowledgeable in Windows) verify that all of these are 
> meaningful there?  I'd expect it to be so with the possible exception of 
> panon.

pswapin, pswapout, pgmajfault and pgminfault are not meaningful even
on some Linux targets (those without MMU, and therefore no page
faults).  Yet even those could, perhaps, use virtio-balloon.

It's probably best to have a way to omit values that are not
meaningful to a guest, or otherwise indicate "not defined by the
current guest".

-- Jamie