Re: [RFC PATCH v2 12/26] KVM: arm64: Introduce a Hyp buddy page allocator

[Quentin Perret]

On Thursday 04 Feb 2021 at 18:24:05 (+0000), Will Deacon wrote:
> On Thu, Feb 04, 2021 at 06:19:36PM +0000, Quentin Perret wrote:
> > On Thursday 04 Feb 2021 at 14:31:08 (+0000), Will Deacon wrote:
> > > Just feels a bit backwards having __find_buddy() take an order parameter,
> > > yet then return a page of the wrong order! __hyp_extract_page() always
> > > passes the p->order as the order,
> > 
> > Gotcha, so maybe this is just a naming problem. __find_buddy() is simply
> > a helper to lookup/index the vmemmap, but it's perfectly possible that
> > the 'destination' page that is being indexed has already been allocated,
> > and split up multiple time (and so at a different order), etc ... And
> > that is the caller's job to decide.
> > 
> > How about __lookup_potential_buddy() ? Any suggestion?
> 
> Hey, my job here is to waffle incoherently and hope that you find bugs in
> your own code. Now you want me to _name_ something! Jeez...

Hey, that's my special -- I already got Marc to make a suggestion on v1
and it's been my favorite function name so far, so why not try again?

https://lore.kernel.org/kvmarm/d6a674a0e8e259161ab741d78924c756@xxxxxxxxxx/

> Ok, how about __find_buddy() does what it does today but doesn't take an
> order argument, whereas __find_buddy_of_order() takes the order argument
> and checks the page order before returning?

Sounds like a plan!

Cheers,
Quentin