On Fri, Dec 18, 2020 at 03:49:44PM -0500, Willem de Bruijn wrote:
> On Fri, Dec 18, 2020 at 3:23 PM Jonathan Lemon <jonathan.le...@gmail.com>
> wrote:
> >
> > From: Jonathan Lemon <b...@fb.com>
> >
> > This is set of cleanup patches for zerocopy which are intended
> > to allow a introduction of a different zerocopy implementation.
>
> Can you describe in more detail what exactly is lacking in the current
> zerocopy interface for this this different implementation? Or point to
> a github tree with the feature patches attached, perhaps.
I'll get the zctap features up into a github tree.
Essentially, I need different behavior from ubuf_info:
- no refcounts on RX packets (static ubuf)
- access to the skb on RX skb free (for page handling)
- no page pinning on TX/tx completion
- marking the skb data as inaccessible so skb_condense()
and skb_zeroocopy_clone() leave it alone.
> I think it's good to split into multiple smaller patchsets, starting
> with core stack support. But find it hard to understand which of these
> changes are truly needed to support a new use case.
Agree - kind of hard to see why this is done without a use case.
These patches are purely restructuring, and don't introduce any
new features.
> If anything, eating up the last 8 bits in skb_shared_info should be last
> resort.
I would like to add 2 more bits in the future, which is why I
moved them. Is there a compelling reason to leave the bits alone?
--
Jonathan
