Re: [PATCH v3 04/17] KVM: arm64: Add a heap allocator for the pKVM hyp

[Vincent Donnefort <vdonnefort@google.com>]

On Thu, Jul 23, 2026 at 02:19:00PM +0100, Fuad Tabba wrote:
> Hi Vincent,
> 
> On Mon, 20 Jul 2026 at 18:15, Vincent Donnefort <vdonnefort@google.com> wrote:
> 
> > +static unsigned long hyp_allocator_reclaimable(struct hyp_allocator *allocator)
> > +{
> > +       unsigned long reclaimable = 0;
> > +       struct chunk_hdr *chunk;
> > +
> > +       guard(hyp_spinlock)(&allocator->lock);
> > +
> > +       chunk = allocator->head;
> > +       while (chunk) {
> > +               reclaimable += hyp_allocator_chunk_reclaimable(allocator, chunk, NULL, NULL);
> > +               chunk = chunk_get_next(chunk);
> > +       }
> 
> Sashiko raised this, again, confusingly in a different patch.
> hyp_allocator_reclaimable() counts only the per-chunk reclaimable
> pages, but hyp_allocator_reclaim() drains allocator->mc first, so the
> memcache pages are reclaimable yet not counted here. When mc holds the
> only free pages and there are no reclaimable chunks, this returns 0,
> pkvm_shrinker_count() reports SHRINK_EMPTY, and scan() is never called
> to free them. Should you add allocator->mc.nr_pages to the total?

Yes of course, this should be added. We actually have it in the Android version.

> 
> Cheers,
> /fuad