Re: [PATCH v5 3/4] mm/gup: allow FOLL_LONGTERM & FOLL_PCI_P2PDMA
From: Christoph Hellwig
Date: Wed Aug 14 2024 - 00:27:07 EST
On Tue, Aug 13, 2024 at 01:05:02PM -0300, Jason Gunthorpe wrote:
> > Where do we block driver unbind with an open resource?
>
> I keep seeing it in different subsystems, safe driver unbind is really
> hard. :\ eg I think VFIO has some waits in it
Well, waits for what? Usuaully an unbind has to wait for something,
but waiting for unbound references is always a bug. And I can't
think of any sensible subsystem doing this.