On Tue, May 27, 2025 at 08:11:58PM -0700, Mina Almasry wrote:
> On Tue, May 27, 2025 at 7:29 PM Byungchul Park <byungchul@xxxxxx> wrote:
> >
> > To eliminate the use of struct page in page pool, the page pool code
> > should use netmem descriptor and APIs instead.
> >
> > As part of the work, introduce netmem alloc APIs allowing the code to
> > use them rather than the existing APIs for struct page.
> >
> > Signed-off-by: Byungchul Park <byungchul@xxxxxx>
> > ---
> > include/net/netmem.h | 13 +++++++++++++
> > 1 file changed, 13 insertions(+)
> >
> > diff --git a/include/net/netmem.h b/include/net/netmem.h
> > index a721f9e060a2..37d0e0e002c2 100644
> > --- a/include/net/netmem.h
> > +++ b/include/net/netmem.h
> > @@ -177,6 +177,19 @@ static inline netmem_ref page_to_netmem(struct page *page)
> > return (__force netmem_ref)page;
> > }
> >
> > +static inline netmem_ref alloc_netmems_node(int nid, gfp_t gfp_mask,
> > + unsigned int order)
> > +{
> > + return page_to_netmem(alloc_pages_node(nid, gfp_mask, order));
> > +}
> > +
> > +static inline unsigned long alloc_netmems_bulk_node(gfp_t gfp, int nid,
> > + unsigned long nr_netmems, netmem_ref *netmem_array)
> > +{
> > + return alloc_pages_bulk_node(gfp, nid, nr_netmems,
> > + (struct page **)netmem_array);
> > +}
> > +
> > /**
> > * virt_to_netmem - convert virtual memory pointer to a netmem reference
> > * @data: host memory pointer to convert
>
> Code looks fine to me, but I'm not sure we want to export these
> helpers in include/net where they're available to the entire kernel
> and net stack. Can we put these helpers in net/core/page_pool.c or at
> least net/core/netmem_priv.h?
>
> Also maybe the helpers aren't needed anyway. AFAICT there is only 1
> call site in page_pool.c for each, so maybe we can implement this
> inline.
Ah. I recalled the reason why I added these APIs this way, that is, to
make the allocation method easier to be altered in the future. I will
move it to net/core/netmem_priv.h but keep it in the header anyway.
Byungchul
>
> --
> Thanks,
> Mina
