Re: [PATCH net-next v6 3/5] page_pool: Allow drivers to hint on SKB recycling

[Tariq Toukan]

On 6/7/2021 7:38 AM, Ilias Apalodimas wrote:
> Hi Tariq,
>
> > > > > Yes the comment is there to prohibit people (mlx5 only actually) to add the
> > > > > recycling bit on their driver.  Because if they do it will *probably* work
> > > > > but they might get random corrupted packets which will be hard to debug.
> > > >
> > > > What's the complexity for getting it to work with split page model?
> > > > Since 1500 is the default MTU, requiring a page per packet means a lot
> > > > of wasted memory.
> > >
> > > We could create a new memory model, e.g. MEM_TYPE_PAGE_SPLIT, and
> > > restore the behavior present in the previous versions of this serie,
> > > which is, save xdp_mem_info in struct page.
> > > As this could slightly impact the performances, this can be added in a
> > > future change when the drivers which are doing it want to use this
> > > recycling api.
> >
> > page-split model doesn't only help reduce memory waste, but increase
> > cache-locality, especially for aggregated GRO SKBs.
> >
> > I'm looking forward to integrating the page-pool SKB recycling API into
> > mlx5e datapath. For this we need it to support the page-split model.
> >
> > Let's see what's missing and how we can help making this happen.
>
> Yes that's the final goal.  As I said I don't think adding the page split
> model will fundamentally change the current patchset.  So imho we should
> get this in first, make sure that everything is fine, and then add code for
> the mlx cards.

Sounds good