Re: [PATCH v8 10/10] mm: Renumber FOLL_PIN and FOLL_GET down

[David Howells]

Christoph Hellwig <hch@xxxxxxxxxxxxx> wrote:

> > > With the latest series we don't need PAGE_CLEANUP_PUT at all.
> > 
> > We will when it comes to skbuffs.
> 
> I'm a little doubtful of that.

skbuff fragments will be and will have to be a mixture of allocated pages that
need putting and pinned or non-ref'd and non-pinned zerocopy stuff.  I have
posted a patch that works for the limited amount of driverage that I use on my
test machine.

Think network filesystem messages where you have a mixture of protocol bits
generated by the kernel and data provided by direct I/O being sent by zerocopy
(libceph, for example).

David