Re: [Qemu-devel] [PATCH, RESEND] kvm: Fix dirty tracking with large kernel page size

[David Gibson]

On Wed, Apr 04, 2012 at 12:58:37PM +0200, Jan Kiszka wrote:
> On 2012-04-04 03:12, David Gibson wrote:
> >> Also, what's about coalesced MMIO? I see that the ring definition
> >> depends on [TARGET_]PAGE_SIZE. What page size does the power kernel use
> >> for it, and does it make a relevant difference for space?
> > 
> > Hr, so the HV variant of Power KVM doesn't do coalesced mmio.  The PR
> > variant does, but I don't know enough about it to easily answer that.
> > If there's a bug there, it hasn't bitten yet, so how about we fix that
> > another day.
> 
> Not really a smart approach, specifically now that we are aware of a
> potential problem here.

My point is that the fact that there may be another bug out there
should sure as hell not hold up putting this bug fix in.  The bugs may
have similar causes and solutions, but they're entirely different code
paths and the other fix will in no way replace or subsume this one.

-- 
David Gibson                    | I'll have my music baroque, and my code
david AT gibson.dropbear.id.au  | minimalist, thank you.  NOT _the_ _other_
                                | _way_ _around_!
http://www.ozlabs.org/~dgibson